late night testing on home bru hydro
z
(http://www.windbluepower.com/) with the new stater. Been drinking a few
single malts with my buddies so this is some out west type
experimentation late night: CAUTION LOW VOLTATGE!! i'm gonna paint that
on my power shack .. anyway
I reworked the shaft support using my nifty new Frelon sleeve bearing
from www.mcmaster.com (holy crap they have a LOT of cool stuff.. beware
shopping on that site, you'll end up buying a lot of stuff)
ALUMINUM-BACKED FRELON SLEEVE BEARING, FLANGED, FOR 1/2"
SHAFT DIA, 3/4" OD, 3/4" LENGTH
Eventually I got the alternator setup right with the bearing and its all
together.. I slog out through the freaking mud and drop it into the
olive barrel and open up the valves.. she spins.. good.. no vibration
I put the multi-meter on it and its hitting 28 volts!! a bit of
adjustment and I get her up to 31 volts.. now we're cooking with gas
So rather than hooking directly to the battery bank, I disconnected the
solar panels and routed it through the solar voltage controller.. its got
an ammeter and a little LED that lights up when you are charging.
and hit the switch .. Yup! thats the ticket.. The LED is lit so i'm doing
somethjing and the alternator came under serious load -- dropped about
1/2 the free RPM and started charging.
The solar controller shows i'm doing about 4 amps on the hydro alone ..
which isn't like super amazing but the way it's been raining i can run
that bitch 24/7.
the reading via multi-meter on the alternator reads 13.4 volts but I
can't tell if thats what the battery is or if its what the alternator is
making under load
I have a couple of high VDC blocking diodes i'll plumb in tomorrow so the
electricity only goes one way. Should get more accurate readings with
those in play ..
but aye.. its doing the business!!
So kudos to wind blue power from Kansas.. they did by me right
and cheers for all the advice from here
and thanks to hammes beer (land of the sky blue waters) and Laphroaig of
Islay, and the Langlois Locals who helped so much-- gonna run the bitch
all night and see what lives in the morning. The xantrex c35 charge
controller in diversion mode shows my bats at 12.9 at the moment..
they're charging !!! For so long water was my nemisis.. now its my
friend har har har
till then sleep well fellas
-zachary
z
like you guys were saying.. pure mechanical resistance seems less in this
setup -- maybe the new bearing is helping -- so it'd be worth experimenting
some more .. need to spin that thing FASTER!!
Tony Wesley
> but aye.. its doing the business!!
Great! I've been lurking, reading your adventures. This is really
cool stuff.
Bob F
"z" <z...@yada.yada.com> wrote in message
news:Xns9A79F127CEA...@216.196.97.131...
> So the alternator came in today from Wind Blue Power
> (http://www.windbluepower.com/) with the new stater. Been drinking a few
> single malts with my buddies so this is some out west type
> experimentation late night: CAUTION LOW VOLTATGE!! i'm gonna paint that
> on my power shack .. anyway
>
> I reworked the shaft support using my nifty new Frelon sleeve bearing
> from www.mcmaster.com (holy crap they have a LOT of cool stuff.. beware
> shopping on that site, you'll end up buying a lot of stuff)
>
> ALUMINUM-BACKED FRELON SLEEVE BEARING, FLANGED, FOR 1/2"
> SHAFT DIA, 3/4" OD, 3/4" LENGTH
>
> Eventually I got the alternator setup right with the bearing and its all
> together.. I slog out through the freaking mud and drop it into the
> olive barrel and open up the valves.. she spins.. good.. no vibration
>
> I put the multi-meter on it and its hitting 28 volts!! a bit of
> adjustment and I get her up to 31 volts.. now we're cooking with gas
>
> So rather than hooking directly to the battery bank, I disconnected the
> solar panels and routed it through the solar voltage controller.. its got
> an ammeter and a little LED that lights up when you are charging.
>
> and hit the switch .. Yup! thats the ticket.. The LED is lit so i'm doing
> somethjing and the alternator came under serious load -- dropped about
> 1/2 the free RPM and started charging.
>
> The solar controller shows i'm doing about 4 amps on the hydro alone ..
> which isn't like super amazing but the way it's been raining i can run
> that bitch 24/7.
The solar controller could be limiting the current if it thinks the battery is
charged. Testing with an ammeter between the battery and the alternater would be
a better test to determine your actual maximum current capability.
>
> the reading via multi-meter on the alternator reads 13.4 volts but I
> can't tell if thats what the battery is or if its what the alternator is
> making under load
Or more likely, both of the above. The battery limits the voltage at any given
charge current.
>
> I have a couple of high VDC blocking diodes i'll plumb in tomorrow so the
> electricity only goes one way. Should get more accurate readings with
> those in play ..
If you are using the DC output from the alternator, I don't see why these would
be needed. There are already diodes in the alternator.
>
> but aye.. its doing the business!!
>
> So kudos to wind blue power from Kansas.. they did by me right
>
> and cheers for all the advice from here
>
> and thanks to hammes beer (land of the sky blue waters) and Laphroaig of
> Islay, and the Langlois Locals who helped so much-- gonna run the bitch
> all night and see what lives in the morning. The xantrex c35 charge
> controller in diversion mode shows my bats at 12.9 at the moment..
> they're charging !!! For so long water was my nemisis.. now its my
> friend har har har
>
>
> till then sleep well fellas
It sounds like you are operating in the right speed range for the alternator
now. Increasing the water jet speed will give you some increase in power output.
Certainly optimizing for the minimum of pressure losses before the nozzles will
help. It may be that doubling the number of nozzles would be the next step to
increase the output current. as that could double the torque you have to
overcome the load which slows down the generator.
Congratulations on a successful project, and thanks for sharing it here.
Ulysses
> (http://www.windbluepower.com/) with the new stater. Been drinking a few
> single malts with my buddies so this is some out west type
> experimentation late night: CAUTION LOW VOLTATGE!! i'm gonna paint that
> on my power shack .. anyway
>
> I reworked the shaft support using my nifty new Frelon sleeve bearing
> from www.mcmaster.com (holy crap they have a LOT of cool stuff.. beware
> shopping on that site, you'll end up buying a lot of stuff)
>
> ALUMINUM-BACKED FRELON SLEEVE BEARING, FLANGED, FOR 1/2"
> SHAFT DIA, 3/4" OD, 3/4" LENGTH
>
> Eventually I got the alternator setup right with the bearing and its all
> together.. I slog out through the freaking mud and drop it into the
> olive barrel and open up the valves.. she spins.. good.. no vibration
>
> I put the multi-meter on it and its hitting 28 volts!! a bit of
> adjustment and I get her up to 31 volts.. now we're cooking with gas
>
> So rather than hooking directly to the battery bank, I disconnected the
> solar panels and routed it through the solar voltage controller.. its got
> an ammeter and a little LED that lights up when you are charging.
>
> and hit the switch .. Yup! thats the ticket.. The LED is lit so i'm doing
> somethjing and the alternator came under serious load -- dropped about
> 1/2 the free RPM and started charging.
>
> The solar controller shows i'm doing about 4 amps on the hydro alone ..
> which isn't like super amazing but the way it's been raining i can run
> that bitch 24/7.
4 amps 24/7 is pretty damn good.
>
z
news:S66dnTAeWJ_eF2ba...@comcast.com:
They aren't really needed, but I like the idea of sending the electricity
one way only -- so when I have the volt meter on the generator i'm not
reading battery voltage when its not spinning kind of thing.
Plus I have a couple of high amp diodes anyway so i'm gonna put those in
whenever i get some time off of work.
>>
>> but aye.. its doing the business!!
>>
>> So kudos to wind blue power from Kansas.. they did by me right
>>
>> and cheers for all the advice from here
>>
>> and thanks to hammes beer (land of the sky blue waters) and Laphroaig
>> of Islay, and the Langlois Locals who helped so much-- gonna run the
>> bitch all night and see what lives in the morning. The xantrex c35
>> charge controller in diversion mode shows my bats at 12.9 at the
>> moment.. they're charging !!! For so long water was my nemisis.. now
>> its my friend har har har
>>
>>
>> till then sleep well fellas
>
> It sounds like you are operating in the right speed range for the
> alternator now. Increasing the water jet speed will give you some
> increase in power output. Certainly optimizing for the minimum of
> pressure losses before the nozzles will help. It may be that doubling
> the number of nozzles would be the next step to increase the output
> current. as that could double the torque you have to overcome the load
> which slows down the generator.
>
> Congratulations on a successful project, and thanks for sharing it
> here.
cheers. Yeah I got a bunch of new nozzils i'm going to play with. Right
now since spring is coming i'm working on getting more water into the
feeding pond. Thats the next step -- to extend the run time as late into
summer as possible.
She's been spinning for a few days and no major failures yet!
>
>
>
z
news:lEOKj.6171$ED4....@fe105.usenetserver.com:
Heh as usual i'm a bit over in my estimation. Once the rain stopped I
couldn't run it 24/7 -- things are finally starting to dry out around
here as spring/summer hits, so now i'm working on getting more water into
the feeder pond.
Couple of streams near by i'm tapping .. just need to build some intakes
and run some lines and I should be able to run the thing into early
summer I hope.
Need to pay my freaking taxes first before spending more dosh on poly
pipe. Today i'm going up to scout a good intake spot on this one small
creek that should feed the pond well into july.
I hadn't spend a whole lot of energy feeding the pond since it overflows
most of the winter and wanted to prove to myself the hydro part of things
would work before investing in more damn pipe and hauling a bunch of
stuff through some steep assed rough country -- now i'm highly motivated
though ;)
take it easy
-z
Bob F
>>> I have a couple of high VDC blocking diodes i'll plumb in tomorrow so
>>> the electricity only goes one way. Should get more accurate readings
>>> with those in play ..
>>
>> If you are using the DC output from the alternator, I don't see why
>> these would be needed. There are already diodes in the alternator.
>>
>
> They aren't really needed, but I like the idea of sending the electricity
> one way only -- so when I have the volt meter on the generator i'm not
> reading battery voltage when its not spinning kind of thing.
>
> Plus I have a couple of high amp diodes anyway so i'm gonna put those in
> whenever i get some time off of work.
The voltage you read will still be limited by the battery as long as it is
connected. The diodes you add will reduce the voltage available from the
alternator by a few tenths of a volt, depending on the type of diode, which will
reduce the current to the battery. I would again recommend that you skip this
step. It really has no real advantage, and some disadvantages.
Ulysses
If I could have gotten 1 amp from my half-ass wind generator experiment I'd
probably be working on improving it right now. I've not given up (not in my
nature--or yours either it seems) and I don't think I'll ever be able to
charge my 48 volt battery bank here but 12 volts might be possible. If not
12 then 6 volts. Some AAs maybe?
>
> Couple of streams near by i'm tapping .. just need to build some intakes
> and run some lines and I should be able to run the thing into early
> summer I hope.
>
> Need to pay my freaking taxes first before spending more dosh on poly
> pipe. Today i'm going up to scout a good intake spot on this one small
> creek that should feed the pond well into july.
>
> I hadn't spend a whole lot of energy feeding the pond since it overflows
> most of the winter and wanted to prove to myself the hydro part of things
> would work before investing in more damn pipe and hauling a bunch of
> stuff through some steep assed rough country -- now i'm highly motivated
> though ;)
I dug 300 feet of trenches through what felt like solid granite with a pick
last summer (had to take a break when it got over 115 F) because it seemed
too steep for a trencher but now I have a gravity-feed water system and it's
great and all that digging was worthwhile.
It sounds like your efforts will pay off. I wish I had more wind or water
or something. My creek flows only about 4-5 gallons/minute over my
waterfall and that's during years when we had a decent amount of rain.
Besides that they are kinda touchy around here about people messing with
creeks. Maybe I should put a little hydro turbine in my water pipe and make
electricity whenever someone flushes the toilet.
>
> take it easy
>
> -z
z
news:c0vLj.11699$Mf4....@fe085.usenetserver.com:
You know somebody just gave me a dead eu1000 -- I wonder if the smaller
generator might make higher voltage at the same RPM??
Get this, the guy fell a tree on it when he was out logging and had heard
I worked on the hondas .. its pretty messed up I doubt it'll run again :)
For one thing he left it in the rain for about 4 months after that-- the
carb was completely destroyed.. and most of the plastic case was smashed,
but it has compression. It might run.. eventually ;)
>
>>
>> Couple of streams near by i'm tapping .. just need to build some
>> intakes and run some lines and I should be able to run the thing into
>> early summer I hope.
>>
>> Need to pay my freaking taxes first before spending more dosh on poly
>> pipe. Today i'm going up to scout a good intake spot on this one
>> small creek that should feed the pond well into july.
>>
>> I hadn't spend a whole lot of energy feeding the pond since it
>> overflows most of the winter and wanted to prove to myself the hydro
>> part of things would work before investing in more damn pipe and
>> hauling a bunch of stuff through some steep assed rough country --
>> now i'm highly motivated though ;)
>
> I dug 300 feet of trenches through what felt like solid granite with a
> pick last summer (had to take a break when it got over 115 F) because
> it seemed too steep for a trencher but now I have a gravity-feed water
> system and it's great and all that digging was worthwhile.
there is something to be said about working hard for water. Unlike most
of the so called civilized world where they just turn a tap and like
magic water flows out into a glass. My water system is gravity too.
>
> It sounds like your efforts will pay off. I wish I had more wind or
> water or something. My creek flows only about 4-5 gallons/minute over
> my waterfall and that's during years when we had a decent amount of
> rain. Besides that they are kinda touchy around here about people
> messing with creeks. Maybe I should put a little hydro turbine in my
> water pipe and make electricity whenever someone flushes the toilet.
Yeah.. the turbine in the urinal idea might work good too .. get that
thing spinning when you piss!!
Luckily i own the land where the stream goes and above that are timber
company lands and they won't care if I tap the stream a bit on their
turf. I get along with those guys just fine.
There isn't anybody else around for miles so nobody bugs me too much
about this stuff :)
Now i'm heading up to brush out a trail and pick a spot to tap -- and
chase any bears out!!
bea...@gmail.com
But, how many feet of head are you working with?
On Apr 11, 8:06 am, z <z...@yada.yada.com> wrote:
> "Ulysses" <eatmys...@spamola.com/> wrote innews:c0vLj.11699$Mf4....@fe085.usenetserver.com:
>
>
>
>
>
> > "z" <z...@yada.yada.com> wrote in message
> >news:Xns9A7C7371ED2...@216.196.97.131...
> >> "Ulysses" <eatmys...@spamola.com/> wrote in
> >>news:lEOKj.6171$ED4....@fe105.usenetserver.com:
>
> >> > "z" <z...@yada.yada.com> wrote in message
> >> >news:Xns9A79F127CEA...@216.196.97.131...
> >> >> So the alternator came in today from Wind Blue Power
> >> >> (http://www.windbluepower.com/) with the new stater. Been
> >> >> drinking a few single malts with my buddies so this is some out
> >> >> west type experimentation late night: CAUTION LOW VOLTATGE!! i'm
> >> >> gonna paint that on my power shack .. anyway
>
> >> >> I reworked the shaft support using my nifty new Frelon sleeve
> >> >> bearing fromwww.mcmaster.com(holy crap they have a LOT of cool
Charles
> The diodes you add will reduce the voltage available
> from the alternator by a few tenths of a volt, depending on the type
> of diode, which will reduce the current to the battery.
0.7 volts for silicon (likely), 0.2 volts for germanium (rare). That's for a
single diode. To get the high voltage rating they may be stacking up several
diodes in series inside the package. Look up the part number on the World
Wide Web and take a look at the data sheet.
--
Chuck
Ulysses
The eu2000 alternator puts out around 240 volts 3-phase but I don't know at
what RPM. I suspect the eu1000 would be similar. I got 30 volts by
sticking a 30" fan blade on mine in about 30 mph wind but, like I said, no
current that I could read. I rewired mine from Star to Delta and I'm
playing around with getting the voltage DOWN. It puts out 155 VDC at
regular engine speed (3600 rpm) which is a bit too high for charging my
batteries and with a small engine (4 HP or so) it would bog down if I turn
down the engine speed to where the voltage was within my range (120-130 or
so). Of course then it loses power and the output drops considerably. I
tried running from a bigger engine (10 HP) and got it down to about 120 VDC
and it was charging my batteries at about 1000 watts going through a charge
controller. It seems to have overcome the bogging down. Yesterday I tried
gearing it down and got about 75 VDC at a higher engine speed but have not
tried it out yet. It looks promising though. If this doesn't work then I
will have to rewind all the coils for a lower voltage. I almost understand
enough about alternators to do this.
Did that guy ever get his government grant?
>
> Luckily i own the land where the stream goes and above that are timber
> company lands and they won't care if I tap the stream a bit on their
> turf. I get along with those guys just fine.
>
> There isn't anybody else around for miles so nobody bugs me too much
> about this stuff :)
I had a RAM pump in my creek for a short time. Someone threatened to call
the authorities. My creek is near the road but on my property. But in
California it does not make it MY creek. It is, however, MY water. But, if
I want to use MY water I have to file some forms saying how much water I'm
going to use etc. And then the Water Quality Management Whatever will have
to come out and make sure my apparatus is not going to pollute the water.
Then the Department of Fish and Game will have to make sure it's not
disrupting any frogs. Then I'll have to hire a biologist to do an
Environmental Impact Study to make sure the kangaroo rats will not be
inconvenienced.
Right now (I just barely made it before they passed a bunch of new laws)
they have it where it's almost impossible to build a new house out here.
And it will cost a fortune for all the studies and permits etc. But you can
bet in 30 years the hills will be coverered with tract houses.
>
> Now i'm heading up to brush out a trail and pick a spot to tap -- and
> chase any bears out!!
Maybe if you give 'em some snacks (or beer?) they'll help you clear the
brush.
Ulysses
I suspect you already know all of this, but just in case....
Car alternators with voltage regulators generally charge at around 13.5
volts but that is too low for charging a deep cycle battery. Ideally you
would want to achieve your ABSORB voltage of somewhere around 14.5-15.0
volts (this number may vary by manufacturer) and hold it there for a while
until your specific gravity indicates a full charge (1.280 or so) on all of
the cells. It might take some monitoring at first to find out how long that
"for a while" is. But since your charging source is going to be fairly
consistant then that time probably will be too. Once this is accomplished
you would either go into FLOAT mode (reduced voltage: 13.5 or so) or divert
the power to another load. You said you have your charge controller running
in diversion mode so I'm not clear on what you are doing. Since you have
the Xantrex charge controller all this should be easy to set up. Once every
month or month-and-a-half you should equalize for perhaps an hour at an
increased voltage (15.5 maybe). From what I've been reading lately cronic
undercharging and sulfated batteries are an epidemic. It's best to get the
specific numbers from your battery manufacturer.
> I have a couple of high VDC blocking diodes i'll plumb in tomorrow so the
> electricity only goes one way. Should get more accurate readings with
> those in play ..
>
> but aye.. its doing the business!!
>
> So kudos to wind blue power from Kansas.. they did by me right
>
> and cheers for all the advice from here
>
> and thanks to hammes beer (land of the sky blue waters) and Laphroaig of
> Islay, and the Langlois Locals who helped so much-- gonna run the bitch
> all night and see what lives in the morning. The xantrex c35 charge
> controller in diversion mode shows my bats at 12.9 at the moment..
> they're charging !!! For so long water was my nemisis.. now its my
> friend har har har
This has kinda been nagging at me: what is the condition of the battery (%
charged) when you are starting out? If it's already near full then you
might not get a very high amperage reading.
z
news:pjvMj.127$MT2...@fe111.usenetserver.com:
Yeah .. this is one reason why I'm probably going to plumb in the diode.
I think I'm reading the battery voltage at the alternator rather than the
altnerator itself.
Like today I've been running it for about 12 hours and the xantrex charge
controller set in diverter mode has been reading slowly higher voltages
all day creeping up. Now i'm at 14.4 volts with three LED blinks, which
means the batteries are nearly charged (it goes to 5 blinks and then goes
into float mode). So at 3 blinks i'm only minus .75 Vdc from the max
before it floats and starts diverting.
I think if I plumb the diode i'll get a reading from only the altnerator
.. but as you might imagine i'm semi-cluess about this magical
electricity stuff.
In any case, I've been working on the feeder intake to the pond -- ended
up having to go another 400 feet up the damn hill to find a good spot to
take water from a stream.
But with the flow i'm getting, it looks like I could swap over to that
source during the winter some times and gain another 100 foot of head, so
thats been the trick. Need to buld some more infrastructure to make that
happen but thats the plan for next winter.
Now my pond is filling faster than I can drain it, but it has been
raining like a mofo and SNOWING .. which is pretty strange for us this
time of year. It should keep me going well into early summer with the
extra water. Pretty happy with it.. no bears yet.
So I've been too paranoid to leave it running over night. This is the
first serious long term test and I want to get the batteries fully
charged and see if my diverter load works out right.
we'll see.
take it easy
-z
Bob F
The only difference the diode will make is that the voltage you read will be 1
diode voltage drop higher than the battery - .2V-.7V - probably nearer the high
end. You will drop the voltage available to the battery by the same amount,
resulting in less charging current.
Just try wiring the diode in temporarily and test it, if you need to verify
this.
Ulysses
"Bob F" <bobn...@gmail.com> wrote in message
news:LpGdnVnP6P4bAo3V...@comcast.com...
z, I'm now wondering what the diodes are for. With a PMA there should be no
drain on the batteries when it's not turning because there's no voltage
regulator or field coils. With my Honda eu2000 alternator connected to a
digital multi-meter it reads 0.00 amps when it's not turning. Does the
alternator have AC output and you are using the diodes to rectify, or for
blocking? At least now I understand what you mean by "diversion mode."
Meanwhile I managed to get a reading of over 1 amp with my "wind generator"
made from the eu2000. That's a screaming 12.5 watts! I made a seven foot
diameter 3-blade propeller and I'm getting higher voltage readings (with
less wind) with my 30" fan blade. I think my half-ass propeller is actually
slowing it down. It looks like something inbetween the two might get me a
couple of amps in 20-25 mph wind. It's time to start carving some real
blades I think.
It will be interesting to see how much power I get in 60 mph winds next
fall. We regularly get winds from 80-100 mph in the fall/winter so it's
going to need to be rather sturdy.
Ulysses
> "Ulysses" <eatm...@spamola.com/> wrote in
> news:pjvMj.127$MT2...@fe111.usenetserver.com:
>
> >
> > "z" <z...@yada.yada.com> wrote in message
> > news:Xns9A79F127CEA...@216.196.97.131...
> >> So the alternator came in today from Wind Blue Power
> >> (http://www.windbluepower.com/) with the new stater.
I probably shouldn't even be telling you this, but here goes: I've been
talking with a guy in Costa Rica (on a forum) who has an "ancient" generator
head installed as a hydro generator in a small reservoir. What is different
from everything else I've read about micro-hydros is that it's a 110 volt AC
generator, apparently 60 Hz. So, instead of using it to charge batteries
directly he's seeing if it's possible to connect it directly to the AC Input
of his Xantrex inverter and use it just like one would use a
gasoline-powered generator. It might be a little less effecient but it sure
simplifies things. He didn't know what the specs were on the generator (I
think he inherited it with the land) so I don't know if it's a 3600 or 1800
rpm unit. But he said it's consistant enough to run a TV or washing
machine. His reservoir gradually fills up during the day which gives him
enough water to power his hydro for about four hours when he opens the
valve.
I hope to hear the results soon. He didn't have any batteries yet to try
it out on.
z
news:wU2Qj.28181$wL5....@fe101.usenetserver.com:
OK yeah. Screw the diode. Well I hit full charge and my 12 volt heater
started heating !!! So the diversion part seems to be working like
advertised
So I know that part of the system is working. This is pretty sweet
because the plan is to put the heater in my green house (next to the
power shed) in the hopes that it'll keep the hard frost out during the
winter .. if I can keep from draining down the batteries too much
Kind of looking for another charge controller to handle the input voltage
rather than hooking direct to the battery. I have the remote display in
my house which only gives you the battery voltage and charge state when
in diversion mode. If I had another c40 on the input side the display
would show watts produced and load current.
But actually it does flash the watts (just noticed) when it diverts ..
looks like I'm diverting 142 watts -- which isn't really that hot. So
finally I can give a rating on the ol home bru -- 142 watts. I'd guess
that pretty accurate since thats the extra power above what the
controller thinks the batteries need for the float charge.
Now i'm thinking about upgrading to a 3 inch pipe.. that'll make the
thing scream! Pipe is hellishly expensive at the moment so it'll be a
while.
> Meanwhile I managed to get a reading of over 1 amp with my "wind
> generator" made from the eu2000. That's a screaming 12.5 watts! I
> made a seven foot diameter 3-blade propeller and I'm getting higher
> voltage readings (with less wind) with my 30" fan blade. I think my
> half-ass propeller is actually slowing it down. It looks like
> something inbetween the two might get me a couple of amps in 20-25 mph
> wind. It's time to start carving some real blades I think.
Thats awsome ! If you get a chance grab a few pics. I'd love to have a
look at your work. I have this dead eu2000 like I said -- be neat to do
something with it. My Ma lives near the ocean so she gets all kinds of
wind. Be neat to rig her up something -- i'm too far up in the mountains
in kind of a sheltered area so the wind isn't really a resource I can
tap.
>
> It will be interesting to see how much power I get in 60 mph winds
> next fall. We regularly get winds from 80-100 mph in the fall/winter
> so it's going to need to be rather sturdy.
Yeah .. thats the thing. We hit 130 mph this winter -- be a hell of a
turbine that could last through that.
Can you take it down pretty easy? Like if you get a storm warning?
take it easy
-z
Bob F
> thing scream! Pipe is hellishly expensive at the moment so it'll be a
> while.
Measure the water pressure near the outlet end of your current pipe, both when
the generator is running, and when it is not(water flow off). If the pressure
difference is small, then a bigger pipe from the water supply would not make
much difference. A simple "T" with a pressure gauge before you split off to the
nozzles should give you this measurement.
z
I actually have a gauge and the fittings for it, but i'm kind of using
the system so much that I don't want to break the siphon and have to
reprime etc.
Once summer gets here i'll be able to do some more plumbing and find out
more. For one thing its freaking cold and wet .. not the time to be
outside screwing with water.. I don't have a valve above where I need to
put the gauge so its going to be kind of a pain in the ass. When its 85
outside and i'm not running it all the time i'll get some more data :)
I also found some 1 inch nozzles (rather than 3/4) so I might go from 1-
1/2 inch to directly into 1 inch rather than stepping down from 1-1/2 to
1 inch and then 3/4th , but this is all just tuning -- I'm just blown
away that this thing is actually working. Once again thanks all you guys
for the advice.
Sometime last night my coupler grub screw rattled out so my stupid wheel
was spinning without turning the alternator. Have to get some lock tight
or something. That was annoying as hell getting up in the morning and
seeing no charge going into the batteries for who knows how long.
cheers
-z
Ulysses
> >
> > z, I'm now wondering what the diodes are for. With a PMA there should
> > be no drain on the batteries when it's not turning because there's no
> > voltage regulator or field coils. With my Honda eu2000 alternator
> > connected to a digital multi-meter it reads 0.00 amps when it's not
> > turning. Does the alternator have AC output and you are using the
> > diodes to rectify, or for blocking? At least now I understand what
> > you mean by "diversion mode."
> >
>
> OK yeah. Screw the diode. Well I hit full charge and my 12 volt heater
> started heating !!! So the diversion part seems to be working like
> advertised
>
> So I know that part of the system is working. This is pretty sweet
> because the plan is to put the heater in my green house (next to the
> power shed) in the hopes that it'll keep the hard frost out during the
> winter .. if I can keep from draining down the batteries too much
Right now I dream of need a charge controller some day for my "wind
generator." A diversion load for me right now would be like expecting to
win the lottery.
>
> Kind of looking for another charge controller to handle the input voltage
> rather than hooking direct to the battery. I have the remote display in
> my house which only gives you the battery voltage and charge state when
> in diversion mode. If I had another c40 on the input side the display
> would show watts produced and load current.
I'm not quite sure I follow how you have it wired. On my OutBack system
there is a shunt on the negative side and everything is wired through it so
everything reads on my battery meter.
>
> But actually it does flash the watts (just noticed) when it diverts ..
> looks like I'm diverting 142 watts -- which isn't really that hot. So
> finally I can give a rating on the ol home bru -- 142 watts. I'd guess
> that pretty accurate since thats the extra power above what the
> controller thinks the batteries need for the float charge.
>
> Now i'm thinking about upgrading to a 3 inch pipe.. that'll make the
> thing scream! Pipe is hellishly expensive at the moment so it'll be a
> while.
I suspect that increasing the volume of water is going to make a big
difference. 3 inch sounds pretty huge though. I guess you need to find a
balance between how much power you can get and how much water flow is
available. In any case if you are charging a 12 volt battery bank then 10
amps is significant.
>
>
> > Meanwhile I managed to get a reading of over 1 amp with my "wind
> > generator" made from the eu2000. That's a screaming 12.5 watts! I
> > made a seven foot diameter 3-blade propeller and I'm getting higher
> > voltage readings (with less wind) with my 30" fan blade. I think my
> > half-ass propeller is actually slowing it down. It looks like
> > something inbetween the two might get me a couple of amps in 20-25 mph
> > wind. It's time to start carving some real blades I think.
>
> Thats awsome ! If you get a chance grab a few pics. I'd love to have a
> look at your work. I have this dead eu2000 like I said -- be neat to do
> something with it. My Ma lives near the ocean so she gets all kinds of
> wind. Be neat to rig her up something -- i'm too far up in the mountains
> in kind of a sheltered area so the wind isn't really a resource I can
> tap.
I used to be good a making web sites but I seem to stink at it now. I'll
see what I can do. It's not much to look at right now.
>
I won't know how much power the eu2000 alternator is capable of producing
until I get some "real" wind but I did get 2.2 amps during a gust yesterday.
That brings us up to about 30 watts. I either get not enough or too much
wind here. From what I've read most wind generators are designed to turn
away from the wind at around 60 mph (I think) and that's about what the
Santa Ana Winds do here, for starters. I had it connected to a 4 HP engine
for a while and I was getting about 2300 watts from it.
I'm beginning to hear about more worn out eu2000s so finding new life for
them is inevitable. They have too good of a PMA in there to let it just sit
there doing nothing. I've also considered doing the bicycle thing. I have
managed to get about 8 amps at 12 volts just turning it by hand. This also
tells me my fan and propeller designs need a lot of work. I just stuck some
stuff on it to see if I would be worth the trouble and it looks like if I
put the thing on top of my hill I might get some usuable amps, at least some
times. I just took inventory and I have about 140' of three conductor
direct burial wire so naturally I'm going to move it to a better location.
It's just kinda tough climbing up the hill whenever the winds starts blowing
to see how it's doing. Right now my goal (perhaps just a fantasy) is to
power my garage so I want to try to keep it close enough to do that. I
already have a 440 Ah 12 volt battery bank and some 12 volt inverters. If I
could only find an air compressor that would run from my 1500 watt
inverter.... I figure sooner or later I'm going to have to buy a DC motor
for my belt-driven compressor. I have a compressor my father-in-law made
from a 120 volt DC motor which he made a power supply for (this I SHOULD
take pictures of--it's great) but it will only run from my 48 volt battery
bank sometimes.
> >
> > It will be interesting to see how much power I get in 60 mph winds
> > next fall. We regularly get winds from 80-100 mph in the fall/winter
> > so it's going to need to be rather sturdy.
>
> Yeah .. thats the thing. We hit 130 mph this winter -- be a hell of a
> turbine that could last through that.
That sounds like hurricane speeds. We don't really ever get hurricanes here
in South California but we think nothing of 100 mph. We don't even board up
our windows for that. For us natives "if it'll blow down you don't put it
up."
>
> Can you take it down pretty easy? Like if you get a storm warning?
Right now it's all experimental so I can take it down in about five seconds.
But then I'd never know how many amps it would put out in high winds ;-) I
can also connect it to my battery charger contraption in about thirty
minutes if my other Delco alternator should fail.
>
>
> take it easy
>
> -z
Eric Sears
wrote:
>
>Right now I dream of need a charge controller some day for my "wind
>generator." A diversion load for me right now would be like expecting to
>win the lottery.
>
>I'm not quite sure I follow how you have it wired. On my OutBack system
>there is a shunt on the negative side and everything is wired through it so
>everything reads on my battery meter.
>
Just a couple of questions and comments (I haven't been reading this
thread very throughly lately).
I assume from your comments that you have some sort of controller? and
that you also have some kind of wind gen? (homemade?). Do you also
have hydro input, or maybe solar?
The comment is that many charge controllers can be used for diversion.
My preferred way to divert is to put all input direct to the battery
(unless you are using an MX60 or other MPPT), and use the
regulator/controller to switch a relay, which turns on a diversion
load (often run from the OUTPUT of the inverter). Its much easier to
switch "grid-voltage" (and to find suitable loads), than to switch low
voltage, high currents. Its true that this sometimes defeats the
clever charging curves etc, or the controller.
An alternative is just to add a simple homemade switching circuit to
do this diversion when the voltage on the battery gets higher than you
would like.
This could mean that your solar (if you have it) does exactly the what
it does now, but if your wind gen pushes the voltage up (eg 14.2v),
then the "dump" load switches on until the voltage drops to say 13.6v
Some charge controllers can be used in this way- to switch a relay,
instead of controlling the current into the battery.
I have set up my MX60 to do something similar, so that even if I added
some uncontrolled panels (because I've got too many for the MX60 to
handle at 12v), it would still shunt any excess power, via a relay, to
my hot water tank.
Regards
Eric Sears.
Ulysses
"Eric Sears" <pho...@025379386.for.email.address> wrote in message
news:481431e4...@news.clear.net.nz...
> On Sat, 26 Apr 2008 11:00:47 -0700, "Ulysses" <eatm...@spamola.com/>
> wrote:
>
>
> >
> >Right now I dream of need a charge controller some day for my "wind
> >generator." A diversion load for me right now would be like expecting to
> >win the lottery.
>
> >
> >I'm not quite sure I follow how you have it wired. On my OutBack system
> >there is a shunt on the negative side and everything is wired through it
so
> >everything reads on my battery meter.
> >
> Just a couple of questions and comments (I haven't been reading this
> thread very throughly lately).
> I assume from your comments that you have some sort of controller? and
> that you also have some kind of wind gen? (homemade?). Do you also
> have hydro input, or maybe solar?
That's the trouble with Usenet and such--you would have to go back and find
everything I've written in the last year to know the whole story.
"z" had written that he had his Xantrex charge controller in "diversion
mode" so I was not sure what he meant. I have an MX60 so I think the
terminology from each manufacturer might be a little different even though
the effect is the same. Apparently what z meant was that he has it set up
so it would divert the charging from the batteries to another load, just as
you described.
At this moment in my life I am charging my 48 volt battery bank with a Delco
alternator driven by a 4 HP Honda engine. I have the AUX on my VFX3648 OB
inverter set so that it will activate a relay and shut off my battery
charging gizmo if the battery voltage exceeds about .6 volts. I'm doing my
charging more or less manually but I am able to adjust the engine speed so
that it will reach my ABSORB voltage and pretty much stay there, within
about .2 or .3 volts. This is all pretty good and is way more effecient
than using a generator connected to AC In on my OB inverters but it would be
great if I could figure out a way to have it reach ABSORB voltage, stay
there for a preset amount of time, and THEN shut it off. So far, from what
I understand, Gen Start will activate a normally closed relay and keep it
energized for the duration of the charging cycle and then shut off the
generator (charger) after a preset time. This is OK but I'd rather not have
a relay energized all the time mainly because I think it would be less
reliable. There is also the danger of the relay being closed, shorting the
ignition to ground, because the voltage is above the preset limits or the
relay got stuck. This might make starting the engine a bit difficult. If
you know of another way to do it I'd love to hear it.
So far I have no solar panels and my "wind generator" is a toy that I'm
playing with. Electricity is now $4 per gallon so I need to do something
very soon! I'm considering making methane, woodgas, and anything else that
might run a small engine or turbine. I don't have enough water in my creek
to do the hydro thing. Hopefully someday I'll have to use my Diversion
setting. ;-)
The resources I have available are plenty of sunlight (Southern California),
lots of Oak trees, tons of greasewood, and lots of dirt. I don't (yet) have
any livestock to provide raw material for methane but I do have some
garbage. I figure I need about $5000 worth of solar panels to do any good
and money is not a current resouce. I have a potato clock that has been
running from dirt for 1 1/2 years (same dirt--just a sec, I gotta water the
clock) and I did get an LED to light from a series of dirt cells but I would
need a lot of copper and zinc to make any sizeable cells, but it appears to
be a possibility.
Eric Sears
wrote:
OK - well without completely understanding it (because I don't know
the inverter you describe), since I have an MX-60 I might suggest the
following:
Set the MX-60 so that it has the absorb time that you want and then
goes into float.
Now go the the AUX menu on the MX-60 and set the output to come on
when the MX-60 is in float. Connect a 12v relay to the AUX output, and
use the contacts to short the gen - to turn it off. Because the gen is
now off, the MX-60 will soon drop out of float mode (or there is a
setting to make sure it will - when it drops a couple of volts in your
case). The relay will then switch off. This would mean that the relay
used to turn off the generator only stays on for a relatively short
time.
I do something similar to divert extra solar power to the hot water
cylinder - except I don't use the "float" mode - I use one of the
other modes (battery disconnect).
>
>So far I have no solar panels and my "wind generator" is a toy that I'm
>playing with. Electricity is now $4 per gallon so I need to do something
>very soon! I'm considering making methane, woodgas, and anything else that
>might run a small engine or turbine. I don't have enough water in my creek
>to do the hydro thing. Hopefully someday I'll have to use my Diversion
>setting. ;-)
Yes, understood. I have a holiday home in the mountains where I run
hydro year-round. Sadly the stream about 80m from my place here in the
city is in a park! I've tried to think of ways of hiding a generator
in the stream ;} !!! I've also thought of running a methane digester
on the 1/4 acre we have here - you probably don't need a great deal of
animal manure. My solar panels I imported from USA (to NZ). They were
just US$2.40 per watt when I bought them 3 years ago. Good value.
What about a solar trough collector? Fixed position (non tracking),
boiling water at relatively low temp to run a homemade turbine?
You would be surprised what happens when you direct a jet of steam at
an impulse-type turbine, and attach it to a generator. But don't blow
yourself up!
>
>The resources I have available are plenty of sunlight (Southern California),
>lots of Oak trees, tons of greasewood, and lots of dirt. I don't (yet) have
>any livestock to provide raw material for methane but I do have some
>garbage. I figure I need about $5000 worth of solar panels to do any good
>and money is not a current resouce. I have a potato clock that has been
>running from dirt for 1 1/2 years (same dirt--just a sec, I gotta water the
>clock) and I did get an LED to light from a series of dirt cells but I would
>need a lot of copper and zinc to make any sizeable cells, but it appears to
>be a possibility.
Have a look for broken solar cells (not panels) on the net. I imported
cells at US$1 per watt some years ago. A friend used them to make 8 X
50watt solar panels to run his house. He soldered them (carefully!!)
and sandwiched them between two sheets of glass with RTV. They worked
well and as far as I know are still working.
Best wishes
Eric Sears.
Ulysses
"Eric Sears" <pho...@025379386.for.email.address> wrote in message
> On Sun, 27 Apr 2008 10:41:44 -0700, "Ulysses" <eatm...@spamola.com/>
> wrote:
> OK - well without completely understanding it (because I don't know
> the inverter you describe), since I have an MX-60 I might suggest the
> following:
> Set the MX-60 so that it has the absorb time that you want and then
> goes into float.
> Now go the the AUX menu on the MX-60 and set the output to come on
> when the MX-60 is in float. Connect a 12v relay to the AUX output, and
> use the contacts to short the gen - to turn it off. Because the gen is
> now off, the MX-60 will soon drop out of float mode (or there is a
> setting to make sure it will - when it drops a couple of volts in your
> case). The relay will then switch off. This would mean that the relay
> used to turn off the generator only stays on for a relatively short
> time.
I thought I'd thoroughly read the MX60 manual but I missed that feature!
Thanks! I'll give that a try.
> Yes, understood. I have a holiday home in the mountains where I run
> hydro year-round. Sadly the stream about 80m from my place here in the
> city is in a park! I've tried to think of ways of hiding a generator
> in the stream ;} !!! I've also thought of running a methane digester
> on the 1/4 acre we have here - you probably don't need a great deal of
> animal manure. My solar panels I imported from USA (to NZ). They were
> just US$2.40 per watt when I bought them 3 years ago. Good value.
> What about a solar trough collector? Fixed position (non tracking),
> boiling water at relatively low temp to run a homemade turbine?
> You would be surprised what happens when you direct a jet of steam at
> an impulse-type turbine, and attach it to a generator. But don't blow
> yourself up!
I read something about this many years ago but what I saw looked like
sombody's idea of what might work if somebody else figured it out for them.
Well, I've been thinking about it for years and I guess I'm not the one to
do it ;-) Meanwhile, I read some stuff about "solar power" and was a bit
surprised to find that this is rather old technology (at least 150 years
old) and that solar-heated steam was generating electricity before very many
people even had electricity. I don't remember exactly what made me decide
to not go out and start building one right away so I need to go back and
read it all again. If you have any links showing how to do a small-scale
solar steam turbine please share them. I also looked at steam engines but
was unable to determine what it was they were selling. I got the impresson
that they were small toys but some were rated to be able to produce hundreds
or thousands of watts. In any case blowing myself up seems to be a very
likely scenerio with either methane, woodgas, or steam. But like I always
say, what's the fun in being a mad scientist if you don't get to blow
something up once-in-a-while? As for the solar trough I could not see how
to continually add more water without reducing the temperature of the water
inside the boiler. Maybe it's like alternators. I didn't understand them
and then suddenly I do. At least enough to get them to do what I want.
I looked at some individual solar cells at www.bgmicro.com but it was still
going to cost some serious moola to build enough panels. I've not seen any
broken cells for sale that might be repairable. I'll look. In addition,
the more I read about people's solar systems the more doubt I have as to
their viability. I get the impression that many people don't really have
enough solar panels to fully charge their batteries on a regular basis and
they are ending up with some really expensive sulfated battery banks. I
don't see why this is unless they are just not doing it right but it makes
me pause....
Ken Maltby
"Ulysses" <eatm...@spamola.com/> wrote in message
news:2iIRj.21848$2c3....@fe097.usenetserver.com...
>
> "Eric Sears" <pho...@025379386.for.email.address> wrote in message
> news:4816e0bd...@news.clear.net.nz...
>
>> What about a solar trough collector? Fixed position (non tracking),
>> boiling water at relatively low temp to run a homemade turbine?
>> You would be surprised what happens when you direct a jet of steam at
>> an impulse-type turbine, and attach it to a generator. But don't blow
>> yourself up!
>
Impulse versus Expansion. The impulse approach might be of interest
to "z" with his impeller. The power available from the expansion of a
compressed gas/steam is a lot easier to exploit. (You should be able to
modify an internal combustion engine, piston or rotary; to run on the
expansion of steam instead of the expansion of the burning fuel gas.)
> I read something about this many years ago but what I saw looked like
> sombody's idea of what might work if somebody else figured it out for
> them.
> Well, I've been thinking about it for years and I guess I'm not the one to
> do it ;-) Meanwhile, I read some stuff about "solar power" and was a bit
> surprised to find that this is rather old technology (at least 150 years
> old) and that solar-heated steam was generating electricity before very
> many
> people even had electricity. I don't remember exactly what made me decide
> to not go out and start building one right away so I need to go back and
> read it all again. If you have any links showing how to do a small-scale
> solar steam turbine please share them. I also looked at steam engines but
> was unable to determine what it was they were selling. I got the
> impresson
> that they were small toys but some were rated to be able to produce
> hundreds
> or thousands of watts. In any case blowing myself up seems to be a very
> likely scenerio with either methane, woodgas, or steam. But like I always
> say, what's the fun in being a mad scientist if you don't get to blow
> something up once-in-a-while? As for the solar trough I could not see how
> to continually add more water without reducing the temperature of the
> water
> inside the boiler. Maybe it's like alternators. I didn't understand them
> and then suddenly I do. At least enough to get them to do what I want.
>
The amount of water that needs to be injected, to replace that used as
steam, is probably less than you are assuming. The output power of a
steam engine is usually calculated with the power used by the injector
pump factored in. (Sorta like the sizing of a car's engine includes the
power needed for the water pump, alternator, ect...) Many steam setups
include a steam condenser to reclaim the water that is reinjected. In any
case the boiler's heat requirements are designed to overcome any loss
from the injected water.
The trough can be sized to produce very high temp, high enough to
use a higher temp working fluid than water. You would run that through
a homemade flash boiler/ heat exchanger. The steam would then go to
an IC engine where: the intake port/valve would be disabled (made
permanently closed) and modified to open a timed steam pulse, from the
steam pipe that replaced the spark plug. The spent steam that is coming
out the "exhaust" would go through a simple condenser (maybe a truck
radiator) and the water from that feed a pump to the flash boiler.
Luck;
Ken
Eric Sears
wrote:
>
>I read something about this many years ago but what I saw looked like
>sombody's idea of what might work if somebody else figured it out for them.
>Well, I've been thinking about it for years and I guess I'm not the one to
>do it ;-) Meanwhile, I read some stuff about "solar power" and was a bit
>surprised to find that this is rather old technology (at least 150 years
>old) and that solar-heated steam was generating electricity before very many
>people even had electricity. I don't remember exactly what made me decide
>to not go out and start building one right away so I need to go back and
>read it all again. If you have any links showing how to do a small-scale
>solar steam turbine please share them.
Well I don't have any links - but if you do a google search on "solar
trough collectors" you should find something. Try putting in the word
"homemade" in your search as well.
I have a book from the 1970's by Farrington Daniels called "Direct use
of the Sun's energy" - or something similar. It has photos of
collectors built nearly 40 years ago.
Basically they have a cross section that is parabolic (though a
semi-circle will usually be close enough) with a steel pipe (ie very
strong) running down the centre at the point of focus - usually
painted black - or with a black absorption coating. Generally such a
pipe will not reach temperatures high enough to cause an explosion -
but will boil the water in it. A small orifice admits water at one end
(under some pressure), and the steam drives a small engine or turbine
at the other. Actually I think they used something other than water in
the pipes, with a lower boiling point.
Just for fun I once made a toy steam turbine - using a golden syrup
tin with water in it and a small hole punched in the lid. A small
tinplate wheel stood on the lid where the jet of steam hit it - really
whizzed around. If the pressure in the tin got too great it just
popped off the lid - though I never had that happen. I guess the
pressure was only a few psi.
Now just imagine something stronger scaled up, with a steam jet of 6
to 10 mm, instead of 1mm. Not very efficient, I know, but could be
cheap to make. I would use something like a pelton wheel or turgo
wheel.
Alternatively a small "toy" steam engine might be much more efficient
and produce maybe 200 - 300 watts - but would probably require higher
pressure steam.
>
>I looked at some individual solar cells at www.bgmicro.com but it was still
>going to cost some serious moola to build enough panels. I've not seen any
>broken cells for sale that might be repairable. I'll look. In addition,
>the more I read about people's solar systems the more doubt I have as to
>their viability. I get the impression that many people don't really have
>enough solar panels to fully charge their batteries on a regular basis and
>they are ending up with some really expensive sulfated battery banks. I
>don't see why this is unless they are just not doing it right but it makes
>me pause....
I don't exactly remember, but I think I bought my cells from "The
Solar Cell Company" (very original name !!).
The broken cells were just individual pieces, You don't have to repair
them - just solder them together. They came in lots of 36 cells which
had all been tested for output - and wired together they made a 50w
panel.
You are right that maintaining batteries in a charged state so that
they do not sulphate is important. However, there are many good
systems around that do this adequately. I have about 750 watts of
panels on my roof which run the things I want to run, but I watch the
state of my batteries carefully. (PS - I don't have expensive
batteries - I have a set of used forklift batteries which do an
adequate job).
Best wishes
Eric Sears.
>
>
>
>
Morris Dovey
> On Tue, 29 Apr 2008 09:47:58 -0700, "Ulysses" <eatm...@spamola.com/>
> wrote:
>
>> I read something about this many years ago but what I saw looked like
>> sombody's idea of what might work if somebody else figured it out for them.
>> Well, I've been thinking about it for years and I guess I'm not the one to
>> do it ;-) Meanwhile, I read some stuff about "solar power" and was a bit
>> surprised to find that this is rather old technology (at least 150 years
>> old) and that solar-heated steam was generating electricity before very many
>> people even had electricity. I don't remember exactly what made me decide
>> to not go out and start building one right away so I need to go back and
>> read it all again. If you have any links showing how to do a small-scale
>> solar steam turbine please share them.
>
> Well I don't have any links - but if you do a google search on "solar
> trough collectors" you should find something. Try putting in the word
> "homemade" in your search as well.
I have a web page at http://www.iedu.com/DeSoto/Stirling/Heat.html
showing construction of a relatively inexpensive parabolic trough collector.
You might consider a Stirling, rather than steam, engine. The Stirling
is generally safer (operates at lower temperature and pressure) and
works on air instead of water...
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/
z
news:34KQj.35525$ye3....@fe119.usenetserver.com:
>
> "z" <z...@yada.yada.com> wrote in message
> news:Xns9A8A75D78F1...@216.196.97.131...
>> >
>> > z, I'm now wondering what the diodes are for. With a PMA there
>> > should be no drain on the batteries when it's not turning because
>> > there's no voltage regulator or field coils. With my Honda eu2000
>> > alternator connected to a digital multi-meter it reads 0.00 amps
>> > when it's not turning. Does the alternator have AC output and you
>> > are using the diodes to rectify, or for blocking? At least now I
>> > understand what you mean by "diversion mode."
>> >
>>
>> OK yeah. Screw the diode. Well I hit full charge and my 12 volt
>> heater started heating !!! So the diversion part seems to be working
>> like advertised
>>
>> So I know that part of the system is working. This is pretty sweet
>> because the plan is to put the heater in my green house (next to the
>> power shed) in the hopes that it'll keep the hard frost out during
>> the winter .. if I can keep from draining down the batteries too much
>
> Right now I dream of need a charge controller some day for my "wind
> generator." A diversion load for me right now would be like expecting
> to win the lottery.
Heh yeah. I swear it was like the lottary when my diversion actually
kicked in.. I had charged those suckers to the point where no more power
would go in.
I'm still blown away that it actually works.
>
>>
>> Kind of looking for another charge controller to handle the input
>> voltage rather than hooking direct to the battery. I have the remote
>> display in my house which only gives you the battery voltage and
>> charge state when in diversion mode. If I had another c40 on the
>> input side the display would show watts produced and load current.
>
> I'm not quite sure I follow how you have it wired. On my OutBack
> system there is a shunt on the negative side and everything is wired
> through it so everything reads on my battery meter.
LIke Eric says I have the alternator hooked directly into the pos and neg
of the battery bank, and the controller is hooked to the bank as well
with the diversion load hooked to the controller. The controller
monitors the voltage of the batteries and then shunts the juice to the DC
heater.
This is great, but all the fancy functions that come with the xantrex
controller aren't in use since the incoming charge isn't sent through it
.. so it can't tell you the watts produced or give a meaningful usage of
amp/hours.
But it does give you the watts it sends to the diversion load, so when
the bank is fully charged the screen gives you the dump load. So thats
the number I figure is being produced by the hydro -- the amount of power
that is getting shunted away from the bank is 142 watts.
Its cool though because it keeps the load on the alternator constant, so
you don't just spin like a mofo when the batteries are charged + I get
some heat for the greenhouse.
>
>>
>> But actually it does flash the watts (just noticed) when it diverts
>> .. looks like I'm diverting 142 watts -- which isn't really that hot.
>> So finally I can give a rating on the ol home bru -- 142 watts. I'd
>> guess that pretty accurate since thats the extra power above what the
>> controller thinks the batteries need for the float charge.
>>
>> Now i'm thinking about upgrading to a 3 inch pipe.. that'll make the
>> thing scream! Pipe is hellishly expensive at the moment so it'll be
>> a while.
>
> I suspect that increasing the volume of water is going to make a big
> difference. 3 inch sounds pretty huge though. I guess you need to
> find a balance between how much power you can get and how much water
> flow is available. In any case if you are charging a 12 volt battery
> bank then 10 amps is significant.
Yeah -- just judging from the water thats available I could increase the
pipe size.. if I could afford it. freaking pipe is expensive man. The
system has been running for about a week non-stop and the pond is still
overflowing so no reason I couldn't increase the volume at some point.
>
>>
>>
>> > Meanwhile I managed to get a reading of over 1 amp with my "wind
>> > generator" made from the eu2000. That's a screaming 12.5 watts! I
>> > made a seven foot diameter 3-blade propeller and I'm getting higher
>> > voltage readings (with less wind) with my 30" fan blade. I think
>> > my half-ass propeller is actually slowing it down. It looks like
>> > something inbetween the two might get me a couple of amps in 20-25
>> > mph wind. It's time to start carving some real blades I think.
>>
>> Thats awsome ! If you get a chance grab a few pics. I'd love to
>> have a look at your work. I have this dead eu2000 like I said -- be
>> neat to do something with it. My Ma lives near the ocean so she gets
>> all kinds of wind. Be neat to rig her up something -- i'm too far up
>> in the mountains in kind of a sheltered area so the wind isn't really
>> a resource I can tap.
>
> I used to be good a making web sites but I seem to stink at it now.
> I'll see what I can do. It's not much to look at right now.
>
>>
>
> I won't know how much power the eu2000 alternator is capable of
> producing until I get some "real" wind but I did get 2.2 amps during a
> gust yesterday. That brings us up to about 30 watts. I either get not
> enough or too much wind here. From what I've read most wind
> generators are designed to turn away from the wind at around 60 mph (I
> think) and that's about what the Santa Ana Winds do here, for
> starters. I had it connected to a 4 HP engine for a while and I was
> getting about 2300 watts from it.
The wind thing seems a lot more complicated than the hydro thing.. i mean
you've got the aerodynamics and the structure needs to be a lot more
sound than the simple hydro thing with a pelton wheel. Freaking thing
might break and cut yer head off!!
>
> I'm beginning to hear about more worn out eu2000s so finding new life
> for them is inevitable. They have too good of a PMA in there to let
> it just sit there doing nothing. I've also considered doing the
> bicycle thing. I have managed to get about 8 amps at 12 volts just
> turning it by hand. This also tells me my fan and propeller designs
> need a lot of work. I just stuck some stuff on it to see if I would
> be worth the trouble and it looks like if I put the thing on top of my
> hill I might get some usuable amps, at least some times. I just took
> inventory and I have about 140' of three conductor direct burial wire
> so naturally I'm going to move it to a better location. It's just
> kinda tough climbing up the hill whenever the winds starts blowing to
> see how it's doing.
I know the feeling. My new water intake is a serious hike. So far its
good but will need a lot of work before the winter. But hell.. exercise
man.. can't kill ya huh?
Right now my goal (perhaps just a fantasy) is to
> power my garage so I want to try to keep it close enough to do that.
> I already have a 440 Ah 12 volt battery bank and some 12 volt
> inverters. If I could only find an air compressor that would run from
> my 1500 watt inverter.... I figure sooner or later I'm going to have
> to buy a DC motor for my belt-driven compressor. I have a compressor
> my father-in-law made from a 120 volt DC motor which he made a power
> supply for (this I SHOULD take pictures of--it's great) but it will
> only run from my 48 volt battery bank sometimes.
Heh what about building a turbine that just ran the compressor directly
and screw the electricty? If you had a big enough tank you could slowly
increase the air pressure in the tank as the wind blew .. like an air
battery. Just (somehow heh) get the crank to turn on the compressor and
build a reserve
Probably not uber practical .. just a thought
>
>
>> >
>> > It will be interesting to see how much power I get in 60 mph winds
>> > next fall. We regularly get winds from 80-100 mph in the
>> > fall/winter so it's going to need to be rather sturdy.
>>
>> Yeah .. thats the thing. We hit 130 mph this winter -- be a hell of
>> a turbine that could last through that.
>
> That sounds like hurricane speeds. We don't really ever get
> hurricanes here in South California but we think nothing of 100 mph.
> We don't even board up our windows for that. For us natives "if it'll
> blow down you don't put it up."
>
This winter was a pretty nasty one .. oregon got hit hard -- you might
have seen it on the news. When I was a kid they had a wind farm on
wiskey run that was pretty cool, but one of the big pacific storms took
them out.
>>
>> Can you take it down pretty easy? Like if you get a storm warning?
>
> Right now it's all experimental so I can take it down in about five
> seconds. But then I'd never know how many amps it would put out in
> high winds ;-) I can also connect it to my battery charger
> contraption in about thirty minutes if my other Delco alternator
> should fail.
Yeah.. thats the key. I've learned (kinda) over the years to really
think out things like how easy is it to take apart etc.. I'm quite sure
my hydro setup isn't nearly as efficient as it could be, but man .. i can
pull the whole wheel and alternator asembly out in about 2 mins to work
on it.
Not so much on the water.. wish i'd spent a few bucks more on valves heh
So those boys at windblue power weren't kidding when they said the
alternator needed some time to break itself in. Since i've been running
24-7 the voltage produced has increased from 31 to around 34 free
spinning.. that and the shaft and bearing are getting used to being spun.
Been able to run my house off it for probably 8-10 hours a day before
turning off the power and letting the batteries recharge. I haven't hit
the low point on the batteries yet .. like now they are reading 12.4
volts which is OK i suspect. But I don't have much going.. just a dish
network DVR + LCD monitor, laptop and a couple of CF lights ..
Had to only use the laptop though.. the big computer eats up the juice
fast -- i have some huge monitors.. those are the suckers. Need to save
some dosh and get some LCDs .. like a 22 inch LCD wide screen takes about
30 watts.. I can do that.
anyway, look forward to your experimentations with the eu's .. i finally
got the parts list so i'll try to scan that soon and post it. Turns out
those part numbers for the oil splasher was right.. well they look right.
I have one to rebuild so i'll know for sure here in a while.
-z
z
news:hU2Rj.34571$OV4....@fe127.usenetserver.com:
Hey Ulysses have you looked into buying individual solar cells and
building your own pannels? A while back I scored a bunch of various
cells and thats the next thing I plan on doing -- given the water will
run out soon.
Man its a pain to get the soldering right.. so touchy but if you have
skills you can build solar pannels for a lot less. I'm just getting
started on my home bru solar setup -- I have enough cells to make a few
25 watt pannels. I could make one big one, but the fecking soldering
long strings of them together has been a bitch. I figure i'll make a lot
of smaller ones I can manage.
Also I scored a bunch of 12x16 1/8th thick inch aluminum sheets so that
limits the size of each pannel -- read how you can make a non-conductive
backing and put plexiglass on them and seal them up.
For the do it yerself type this seems like the way to go if you are handy
with a soldering iron. I had to practice a bunch on broken cells before
I felt comfortable doing the big cells and I still kind of suck, but you
can make your own pannels for a fraction of the price once you get good
at it. If you can score the cells at a good price.
-zachary
Ulysses
"z" <z...@yada.yada> wrote in message
news:Xns9A8FCB409...@216.196.97.131...
It HAS to work--many of us are counting on you.
I've actually made a little progress with my eu2000 wind generator--for a
brief moment it read 2.5 amps. I reduced the diameter of my plywood fan
blade (can't really call it a propeller). This seems to work better. I
went back and re-read Hugh Piggot's wind generator manual and he said, with
his design, you should expect to get about 4 volts turning the rotor by hand
at about 1 rpm. I'm getting about 8 volts so I'm not sure if that is good
or bad. I've been studying plans for an aerodynamic propeller and now I
just have to decide how big to make it. If the new propeller doesn't do the
trick then I'll have to rewind the stator with more turns of smaller wire.
Once I do that there will be no going back to connecting it to the original
inverter unit so I want to be sure....
>
>
> >
> >>
Ulysses
"z" <z...@yada.yada> wrote in message
I've been soldering since I was about 12 (that's a long time) so I'll
probably get the hang of it right away. Yea, I just looked at broken and
individual cells yesterday after Eric Sears suggested it. www.bgmicro.com
has some individual cells but so far I have not found any place where I can
get them for $2/watt. I thought about making one (for starters) with an
open voltage of about 70 Voc and run it through my OutBack MX60 charge
controller. It has MPPT. I have access to lots of plexiglas and glass and
aluminum framing materials so building the enclosures and mounts etc will
not be a problem. I suspect the type of rosin or flux in the solder is very
important. The wrong kind might short out the cells and eat them up.
Ulysses
"Eric Sears" <pho...@025379386.for.email.address> wrote in message
That reminds me--when I was about 5 years old I had a little toy boat that
was steam powered. It used a birthday cake candle to heat the water.
I looked some more for solar-powered steam generators and found some more of
those "this might work if you figure it out" designs. I found one design
that somebody did for a Phd thesis and it looks like it would require all
the facilities of NASA to build and apparently consumes more power than it
produces.
I had an idea after reading about the old European designs from the
1800s--instead of trying to build one parabolic reflector and tracking the
sun a series of smaller reflectors might work but the angle would have to be
adjusted every couple of weeks or so (just guessing) but this would
accomplish about the same thing as the trough design which probably would
not have to be adjusted for the position of the sun. But the parabolics
might get it hotter.
I'll keep searching. I had an idea that a pressure relief valve could be
positioned so that when the pressure is high enough to start running the
turbine or engine it could open the valve automatically....
Ulysses
"Ken Maltby" <kma...@sbcglobal.net> wrote in message
news:Fs6dnY2Hl8MOHIrV...@giganews.com...
Considering how many engines were powered by steam 100 years ago it sure
seems like this information should be easy to find. Right now I know just
about nothing about steam engines so I need to start from scratch. The
existing steam engines that I've found so far were either little toys or
huge industrial things.
I have a truck radiator on hand (I knew there was *some* reason I didn't
throw it away ;-) ) and might have a suitable IC engine that could be
converted. I just need to learn all about how it works. I guess the first
step would be to make some steam. Naturally it's cloudy and cold today so a
backup heating system immediately comes to mind.
Ecnerwal
"Ulysses" <eatm...@spamola.com/> wrote:
> has some individual cells but so far I have not found any place where I can
> get them for $2/watt. I thought about making one (for starters) with an
> open voltage of about 70 Voc and run it through my OutBack MX60 charge
> controller. It has MPPT. I have access to lots of plexiglas and glass and
> aluminum framing materials so building the enclosures and mounts etc will
> not be a problem. I suspect the type of rosin or flux in the solder is very
> important. The wrong kind might short out the cells and eat them up.
Then again, you could drop $4.12 per watt for a fully built, warranteed,
albeit somewhat sneered at for being amorphous panel that fits perfectly
with the MX60 input specs, with no extra costs of backing, covering,
etc. $247.05 + shipping each for 60 watt panels. Crystalline will cost
you a bit more per watt, and don't come in the convenient-for-MPPT high
voltage per single panel. Given a lack of ultra cheap raw cells, the
economics are a bit silly for building them yourself.
--
Cats, coffee, chocolate...vices to live by
Neon John
> I have access to lots of plexiglas and glass and
>aluminum framing materials so building the enclosures and mounts etc will
>not be a problem. I suspect the type of rosin or flux in the solder is very
>important. The wrong kind might short out the cells and eat them up.
You definitely don't want to use plex in this application. It'll solarize
(turn dark) and craze in a very short time in direct sunlight. UV-resistant
Lexan (sign face material) is good, as is glass.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Hell is truth seen too late. -Hobbs
Ulysses
"Ecnerwal" <Lawren...@SOuthernVERmont.NyET> wrote in message
news:LawrenceSMITH-B45...@news.verizon.net...
That's how it was beginning to look.
Ulysses
"Neon John" <n...@never.com> wrote in message
news:2fkh14pdl32val6db...@4ax.com...
> On Wed, 30 Apr 2008 08:48:13 -0700, "Ulysses" <eatm...@spamola.com/>
wrote:
>
> > I have access to lots of plexiglas and glass and
> >aluminum framing materials so building the enclosures and mounts etc will
> >not be a problem. I suspect the type of rosin or flux in the solder is
very
> >important. The wrong kind might short out the cells and eat them up.
>
> You definitely don't want to use plex in this application. It'll solarize
> (turn dark) and craze in a very short time in direct sunlight.
UV-resistant
> Lexan (sign face material) is good, as is glass.
>
> John
Thanks NJ. I have some sheets of acrylic (same as plexiglas) that have been
out in the sun and they became brittle and crazed. And they said it had a
life expectancy of 500,000 years. I have some UV plex but I've read that
the UV protection deteriotes after a number of years.
Lexan sounds good (if I should decide to *make* a panel). I worry about
glass that large because we get a lot of little "tornados" here that throw
stuff around. In the midwest they probably call what we have "whirlwinds"
but to me anything that throws my patio furniture thirty feet is a tornado
;-)
Ulysses
"Morris Dovey" <mrd...@iedu.com> wrote in message
news:48178b7c$0$33221$815e...@news.qwest.net...
> Eric Sears wrote:
> > On Tue, 29 Apr 2008 09:47:58 -0700, "Ulysses" <eatm...@spamola.com/>
> > wrote:
>
> > Well I don't have any links - but if you do a google search on "solar
> > trough collectors" you should find something. Try putting in the word
> > "homemade" in your search as well.
>
I have not yet found the "how I did it" links but at least I've found some
stuff. One interesting point was that according to Wikipedia 86% of the
worlds electricity is produced with steam power, mostly turbines. So how
come I can't go to Home Depot and buy a steam-powered generator?
Morris Dovey
> I have not yet found the "how I did it" links but at least I've found some
> stuff. One interesting point was that according to Wikipedia 86% of the
> worlds electricity is produced with steam power, mostly turbines. So how
> come I can't go to Home Depot and buy a steam-powered generator?
The generator obviously isn't the problem - but steam engines pose
liability issues that I'd guess most vendors would prefer to avoid.
You probably noticed that even on a web page showing "how I did it," I
was careful to post a difficult-to-miss warning of the danger posed just
by the collector. Seven hundred plus degree temperatures (not to mention
live steam) are /dangerous/.
What I'd really like to see are good off-the-shelf 1/2, 1, 2, and 5 hp
_rotary_ Stirling engines. They'd be a lot safer than steam, and would
encourage DIY'ers to develop practical alternative energy solutions.
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
Neon John
>I have not yet found the "how I did it" links but at least I've found some
>stuff. One interesting point was that according to Wikipedia 86% of the
>worlds electricity is produced with steam power, mostly turbines. So how
>come I can't go to Home Depot and buy a steam-powered generator?
The controls and training necessary to make one that is efficient (high
temperature and pressure) and safe are a bit beyond what Home Depot offers.
You can buy package systems but they're a bit expensive. Steam doesn't scale
down well. I think that around 4,000 HP is the smallest pelton wheel turbine
I've seen that was efficient enough to be the primary consumer of the steam
source. Smaller turbines certainly exist - emergency boiler feed pumps, fire
pumps and the like but they don't have to be particularly efficient, as
they're relatively tiny parasitic loads on the steam supply system.
To get even remotely close to the efficiency of an IC engine, particularly a
combined heat and electricity setup, you'd need very high pressure and
temperature (in the range of 1200 psi and 600 deg) with multiple stages of
feedwater and steam reheat.
For example, a typical pressurized water reactor that runs approx those
pressure and temperature can be tickled up to nearly 35% efficiency. That
involves 5 or 6 stages of feedwater reheat (and corresponding stage bleeds
from the turbine) and one stage of steam reheat between the HP and LP
turbines.
Very high pressure and temperature and supercritical fuel boilers do a bit
better but none break the 50% mark. Only the combined cycle gas turbine
plants manage to break 50% by combining the gas turbine with a steam cycle.
For something that you could reasonably run fairly safely, say 150 psi, you'd
probably be doing good to achieve 20% efficiency. There was a huge amount of
work done on engines in that pressure range, as it encompasses both
locomotives and medium pressure industrial piston engines. No amount of work
can break through the basic thermodynamic barrier erected by the low delta-T
across the engine.
I have several books on early steam power, both e- and dead tree. Google
books is a good place to look for ebooks. So is
alt.binaries.e-books.technical if you have a binary Usenet feed. Lindsay
books is an excellent place to buy dead tree versions of steam books.
http://www.lindsaybks.com/ His inventory varies but he periodically has a
number of excellent reprints for steam topics.
Unless your fuel is free and you have a lot of time to dedicate to running the
thing, I wouldn't spend too much time on steam. It's a lot of work running a
steam plant and it's very very easy to blow yourself up. That's why many
states require a steam engineer's license to operate any boiler over a trivial
size. It varies by state but typically either 15psi or 1,000,000 btu input or
a combination.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
If we aren't supposed to eat animals, why are they made with meat?
Neon John
>Thanks NJ. I have some sheets of acrylic (same as plexiglas) that have been
>out in the sun and they became brittle and crazed. And they said it had a
>life expectancy of 500,000 years. I have some UV plex but I've read that
>the UV protection deteriotes after a number of years.
>
>Lexan sounds good (if I should decide to *make* a panel). I worry about
>glass that large because we get a lot of little "tornados" here that throw
>stuff around. In the midwest they probably call what we have "whirlwinds"
>but to me anything that throws my patio furniture thirty feet is a tornado
GE (and probably others) makes a laminated Lexan that has the UV resistant
coating laminated over the Lexan. GE guarantees a 20 year life when exposed
to direct sun (sign faces and glazing). It's a very popular sign face
material because it's almost vandal-proof.
If you're near a place that heat-treats glass then you might could go with
tempered glass. My ex is a stained glass artist and I had quite a number of
custom-shaped pieces tempered. The process is quite inexpensive. Per the
instructions of the tempering shop, I always sent two pieces, in case the
first one shattered during cooling. Tempered glass would certainly resist the
kind of debris you're talking about. If a patio chair happened to hit it :-),
it simply shatters into zillions of small round dull pieces that are easily
swept up.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Democracy is three wolves and one sheep voting on what to have for supper.
Ulysses
> Ulysses wrote:
>
> > I have not yet found the "how I did it" links but at least I've found
some
> > stuff. One interesting point was that according to Wikipedia 86% of the
> > worlds electricity is produced with steam power, mostly turbines. So
how
> > come I can't go to Home Depot and buy a steam-powered generator?
>
> The generator obviously isn't the problem - but steam engines pose
> liability issues that I'd guess most vendors would prefer to avoid.
>
> You probably noticed that even on a web page showing "how I did it," I
> was careful to post a difficult-to-miss warning of the danger posed just
> by the collector. Seven hundred plus degree temperatures (not to mention
> live steam) are /dangerous/.
While busy searching for many things under many headings I somehow missed
visiting your web site. I'm headed there now.
>
> What I'd really like to see are good off-the-shelf 1/2, 1, 2, and 5 hp
> _rotary_ Stirling engines. They'd be a lot safer than steam, and would
> encourage DIY'ers to develop practical alternative energy solutions.
I'm beginning to think that at least one reasonable way to produce a little
electricity would be the ol' bicycle-powered alternator. If you want to
watch TV, start peddeling.
I think it's time for me to find out what a Stirling engine is. I keep
seeing mention of them here but somehow it never seemed to apply to anything
I was doing.
Ulysses
Well, what got me started was the idea of using some kind of parabolic dish
or solar trough to make the steam. If water would work then that's almost
free. I read that it's being done on a large scale but I've not yet seen a
simplified DIY version. Things like smog pumps and air drills have been
suggested as possible turbines and the drawbacks have also been pointed out.
I'm looking at Morris Dovey's site now but have not yet gotten to what he
did with the steam. 724 degrees F is pretty serious. Perhaps putting a
rotiserie on there instead of a steam pipe...
I've not given up yet on using the eu2000 PMA for a wind generator. At this
point it looks like my attempts will be mainly for future posterity. The
only place I have enough wind is on top of my hill and I just don't think I
really have enough wind here to make a wind generator worthwhile. But I
have to find out what it can and can't do. After I make some decent blades
and get some sustained 30 mph winds I expect to know if the stator needs to
be rewound with smaller wire. The Hugh Piggot home brew wind generators put
out about 170 watts (I think) in those kinds of winds (I think) so if I can
get it to read 8 amps at 14 volts then it might be worth doing. So far I've
only read 2.5 amps at 13 volts so that's a long ways to go.
Ulysses
Ahh, stained glass and neon lights. Makes a pretty picture in my head.
I buy a lot of glass and mirror so I'll ask about tempered glass from my
suppliers. Thanks.
Ulysses
the
> thing, I wouldn't spend too much time on steam. It's a lot of work
running a
> steam plant and it's very very easy to blow yourself up. That's why many
> states require a steam engineer's license to operate any boiler over a
trivial
> size. It varies by state but typically either 15psi or 1,000,000 btu
input or
> a combination.
Speaking of "blowing yourself up" I wonder what ever happened to "don" and
his woodgas generator. I hope he's OK. I'm planning on making one very
soon so I wanted to see how his was going before I started.
z
>
> "Ulysses" <eatm...@spamola.com/> wrote in message
> news:2iIRj.21848$2c3....@fe097.usenetserver.com...
>>
>> "Eric Sears" <pho...@025379386.for.email.address> wrote in message
>> news:4816e0bd...@news.clear.net.nz...
>
>>
>>> What about a solar trough collector? Fixed position (non tracking),
>>> boiling water at relatively low temp to run a homemade turbine?
>>> You would be surprised what happens when you direct a jet of steam
>>> at an impulse-type turbine, and attach it to a generator. But don't
>>> blow yourself up!
>>
>
> Impulse versus Expansion. The impulse approach might be of interest
> to "z" with his impeller. The power available from the expansion of a
> compressed gas/steam is a lot easier to exploit. (You should be able
> to modify an internal combustion engine, piston or rotary; to run on
> the expansion of steam instead of the expansion of the burning fuel
> gas.)
>
heh probably should switch from plastic turbine to metal or something
before shooting steam at it huh?
Morris Dovey
> I'm looking at Morris Dovey's site now but have not yet gotten to what he
> did with the steam. 724 degrees F is pretty serious. Perhaps putting a
> rotiserie on there instead of a steam pipe...
Morris is making every effort to avoid steam. The original plan was to
feed the air heated in the focal tube directly to a heat exchanger
inside the hot head of a fluidyne (liquid piston Stirling cycle engine)
- but we've decided to use flat panel collectors instead after
discovering that 700+F is a tad warm for our PVC prototypes, and we
reason that a flat panel collector will work better in marginal weather
conditions.
We're also only peripherally interested in producing electricity. We're
focusing our efforts on solving fundamental food and shelter problems -
and it's questionable whether light bulbs are even available in our
targeted "market" areas.
Neon John
>Ahh, stained glass and neon lights. Makes a pretty picture in my head.
yep, her stained glass work is what got me interested in making neon. She
made a piece in silhouette of a cat sitting in a window. We both
independently but almost simultaneously exclaimed that the piece would look
superb with a little neon. So I sez, "OK, I'll learn how to do it." 10 years
later and here we are :-)
>
>I buy a lot of glass and mirror so I'll ask about tempered glass from my
>suppliers. Thanks.
Be sure to ask if he has a conduit for having custom pieces tempered and what
the dimensional limitations are. Tempering involves sending the piece through
a lehr on a wire belt where it is heated almost to the softening point. Then
a blast of cold air chills one side, locking in huge compressive stresses.
Breaking tempered glass involves applying a force that exceeds both the
compressive stresses (huge) and the tensile strength of the glass. Or
slightly nicking it, creating a stress riser :-) The size limitation is the
throat width of the lehr.
I once started to cut a pattern on our diamond band saw from a plate of clear
glass. I hadn't noticed that it was tempered. The saw bit in maybe a
millimeter before the whole plate just vaporized in my hand with a loud POP.
Followed by a long "Awwwwwwwww sh*t". :-)
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
There is room for all of God's creatures.... Right next to the mashed potatoes.
Vaughn Simon
>
> 724 degrees F is pretty serious.
Damn right! Just as a single point of comparison, the steam temperature from
the naval nuclear reactors I once operated was hundreds of degrees less.
Vaughn
Morris Dovey
I was mulling over the comparison with naval reactors when it (finally!)
dawned on me that the tube at the trough's focus could actually /be/ the
hot head of a Stirling engine (fluidyne or other type).
Assuming a cold side temperature of 70F (perhaps as low as 55F if water
cooled), this should provide a considerable improvement in hot/cold side
temperature differential.
The new questions are: What might I use as a working fluid for a
fluidyne with that high a hot-side temperature, and do I need to plan on
using something other than air as the working gas?
Hmm. Time to go fire up the software model with new temperature
parameters...
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
daestrom
"Vaughn Simon" <vaughnsimo...@att.FAKE.net> wrote in message
news:SjqSj.147690$D_3....@bgtnsc05-news.ops.worldnet.att.net...
Yeah, but those are like almost all nuclear plants and run saturated steam
systems.
A good coal plant will use superheaters to get hotter than 724, even at
modest pressures. And newer 'super-critical' plantscan beat that as well
('super-critical' refers to being hotter/higher pressure than the critical
point of water 705F/3208psi)
But as Morris found out on his own, those high temperatures require some
rather exotic materials to contain it. Can't use simple carbon-steel and
certainly not copper/bronze or PVC :-)
Since the only 'fuel cost' for these setups is the capital invested in the
collectors, you can go hi-tech collector (expensive) with a smallish
collection area and get hi efficiency, or lo-tech (cheap) with a largish
collection area and only get mediocre efficiency. Never done the
calculations, but this sort of thing seems like a 'sweet spot' could be
found in between.
daestrom
daestrom
> Vaughn Simon wrote:
>> "Ulysses" <eatm...@spamola.com/> wrote in message
>> news:VvmSj.198$aj...@fe093.usenetserver.com...
>
>>> 724 degrees F is pretty serious.
>>
>> Damn right! Just as a single point of comparison, the steam
>> temperature from the naval nuclear reactors I once operated was hundreds
>> of degrees less.
>
> I was mulling over the comparison with naval reactors when it (finally!)
> dawned on me that the tube at the trough's focus could actually /be/ the
> hot head of a Stirling engine (fluidyne or other type).
>
> Assuming a cold side temperature of 70F (perhaps as low as 55F if water
> cooled), this should provide a considerable improvement in hot/cold side
> temperature differential.
>
> The new questions are: What might I use as a working fluid for a fluidyne
> with that high a hot-side temperature, and do I need to plan on using
> something other than air as the working gas?
>
Well, when you consider that water or water/anti-freeze would have to be
seriously pressurized to avoid steam if you wanted to use it as just the
'primary' coolant to carry heat to the actual engine, that would probably be
ruled out. Some oil/organic compounds could be used, but many tend to break
down with high temperatures leaving a gooey, tarry mess.
But you mentioned putting the working fluid right through the collector.
That might be tricking with a long-trough. You can't go too narrow with the
tube due to increased friction, so a long trough collector pipe would
increase the volume of the 'hot side' quite a bit. Just means you need a
'cold side' that is similar in size (well, actually smaller by the ratio of
temperatures). And the 'displacement' of the liquid in the fluidyne would
have to move an 'appreciable amount' of the gas from hot to cold, so with a
large hot and cold, you need a large 'displacement' (either really long
stroke, very wide bore, or combination).
You don't need any sort of phase change for the working fluid (unlike
Rankine cycle), so I should think any gas that behaves close to the ideal
gas law at these temperatures / pressures would suffice. The only reason to
not use air would be if the high-temperature oxygen causes some corrosion
problem. Material selection for the piping and such would seem to be key.
daestrom
Neon John
<daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>You don't need any sort of phase change for the working fluid (unlike
>Rankine cycle), so I should think any gas that behaves close to the ideal
>gas law at these temperatures / pressures would suffice. The only reason to
>not use air would be if the high-temperature oxygen causes some corrosion
>problem. Material selection for the piping and such would seem to be key.
I'd start out using a high BP liquid instead of gas. Something such as the
heat transfer oils that are ubiquitous in the petrochem industry. Good for
several hundred degrees at essentially atmospheric pressure, higher with
modest (less than 100psi) pressure.
Though I haven't done the calcs, I suspect that the upper limit will be set by
re-radiation off the back side (ironically, the side pointing toward the sun)
of the absorber, assuming no fancy infrared optics or insulation is deployed.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Why the US is losing its competitivve edge:"It used to be that the USA was pretty good at
producing stuff teenaged boys could lose a finger or two playing with."-James Niccol
Ken Maltby
http://www.smokstak.com/forum/showthread.php?t=40695
http://www.dangerouslaboratories.org/genboiler.html
http://www.tinypower.com/electric.htm (a solar powered
flash boiler set up could address many of the issues raised,
but not all of them.)
http://www.powells.com/psection/Energy.html
More fuel for the fire.
Luck;
Ken
Morris Dovey
> Well, when you consider that water or water/anti-freeze would have to be
> seriously pressurized to avoid steam if you wanted to use it as just the
> 'primary' coolant to carry heat to the actual engine, that would
> probably be ruled out. Some oil/organic compounds could be used, but
> many tend to break down with high temperatures leaving a gooey, tarry mess.
The original approach was to use the trough only to heat air that flowed
(by natural convection) into the heat exchanger inside the hot head of
the fluidyne. Since the body of the fluidyne was constructed of PVC
(which doesn't seem to tolerate temperatures much above 165F) we had a
bit of a problem with overheating...
> But you mentioned putting the working fluid right through the collector.
> That might be tricking with a long-trough. You can't go too narrow with
> the tube due to increased friction, so a long trough collector pipe
> would increase the volume of the 'hot side' quite a bit. Just means you
> need a 'cold side' that is similar in size (well, actually smaller by
> the ratio of temperatures). And the 'displacement' of the liquid in the
> fluidyne would have to move an 'appreciable amount' of the gas from hot
> to cold, so with a large hot and cold, you need a large 'displacement'
> (either really long stroke, very wide bore, or combination).
On this engine, I think I can keep the inside of the hot head dry - but
there will be at least one gas/fluid interface to deal with.
At the moment, I'm thinking of a single 8' hot head tube at the focus.
The air in this tube will expand into the cold head. I'm thinking that
the cold head can be a couple of 8' lengths of baseboard radiator
fintube located under/behind the trough. At least part of the cold head
will need to be fluid filled (by the fluid displacer) to provide an
expansion/contraction "arena" in which the displacer can move.
Both hot cold heads will need to be connected to a fluid reservoir, to
which the open "tuning" tube also connects. The open end of the tuning
tube is where I plan to extract the power.
> You don't need any sort of phase change for the working fluid (unlike
> Rankine cycle), so I should think any gas that behaves close to the
> ideal gas law at these temperatures / pressures would suffice. The only
> reason to not use air would be if the high-temperature oxygen causes
> some corrosion problem. Material selection for the piping and such
> would seem to be key.
Understood. I think I'd like a fluid that remains liquid (without
boiling) in the 40F - 800F range. I was actually more worried about a
diesel-type ignition with air as the working gas, but I'm not sure
that's a real problem.
Material selection looks like iron pipe for the hot head, copper
fintubes for the cold head, steel for the reservoir, and iron pipe again
for the tuning tube / power connection.
Bruce Richmond
Might want to use multiple base board tubes in parallel to give the
same cross section as the rest of the tubing. Not sure how hot things
will be at the cold head but you may need to take that into
consideration if you are using soder joints.
> Both hot cold heads will need to be connected to a fluid reservoir, to
> which the open "tuning" tube also connects. The open end of the tuning
> tube is where I plan to extract the power.
>
> > You don't need any sort of phase change for the working fluid (unlike
> > Rankine cycle), so I should think any gas that behaves close to the
> > ideal gas law at these temperatures / pressures would suffice. The only
> > reason to not use air would be if the high-temperature oxygen causes
> > some corrosion problem. Material selection for the piping and such
> > would seem to be key.
>
> Understood. I think I'd like a fluid that remains liquid (without
> boiling) in the 40F - 800F range. I was actually more worried about a
> diesel-type ignition with air as the working gas, but I'm not sure
> that's a real problem.
For a working fluid you might want to consider brake fluid. It is
designed to deal with high temps. Since you seem to be getting away
from the "found anywhere" concept I will again suggest helium. It's
not that hard to get and would improve efficiency. And since you will
be dealing with materials that could withstand a fair amount of
pressure you may want to consider some way of closing the system so
you can run higher pressure.
> Material selection looks like iron pipe for the hot head, copper
> fintubes for the cold head, steel for the reservoir, and iron pipe again
> for the tuning tube / power connection.
Copper might be better for the hot head. It will have no problem with
the temperture and conducts heat better. Adding fins inside and
outside of the tube would give it more surface area for heat
transfer.
Bruce
Jeff
> Vaughn Simon wrote:
>> "Ulysses" <eatm...@spamola.com/> wrote in message
>> news:VvmSj.198$aj...@fe093.usenetserver.com...
>
>>> 724 degrees F is pretty serious.
>>
>> Damn right! Just as a single point of comparison, the steam
>> temperature from the naval nuclear reactors I once operated was
>> hundreds of degrees less.
>
> I was mulling over the comparison with naval reactors when it (finally!)
> dawned on me that the tube at the trough's focus could actually /be/ the
> hot head of a Stirling engine (fluidyne or other type).
Then, you've considered acoustic stirlings?
>
While I was googling for some background info for you, I ran across this:
http://www.youtube.com/watch?v=TWbMTk1rQ0g
Jeff
Morris Dovey
> Might want to use multiple base board tubes in parallel to give the
> same cross section as the rest of the tubing. Not sure how hot
> things will be at the cold head but you may need to take that into
> consideration if you are using soder joints.
We did a design walk-through this afternoon, and agreed to start out
with a single 8' run of fin tube for the cold head. There won't be any
solder joints anywhere - joins will either be threaded, welded, or brazed.
> For a working fluid you might want to consider brake fluid. It is
> designed to deal with high temps. Since you seem to be getting away
> from the "found anywhere" concept I will again suggest helium. It's
> not that hard to get and would improve efficiency. And since you
> will be dealing with materials that could withstand a fair amount of
> pressure you may want to consider some way of closing the system so
> you can run higher pressure.
Hmm - brake fluid would never have entered my mind. We're going to start
out with water, and I made a note (to myself) so as to not forget this
option if we have problems with water. Thanks - it's always good a Good
Thing to have a "Plan 'B'" :-)
>> Material selection looks like iron pipe for the hot head, copper
>> fintubes for the cold head, steel for the reservoir, and iron pipe
>> again for the tuning tube / power connection.
>
> Copper might be better for the hot head. It will have no problem
> with the temperture and conducts heat better. Adding fins inside and
> outside of the tube would give it more surface area for heat
> transfer.
We talked about this and decided to start out with the iron pipe we
already have - but will switch to copper if we need to. I suspect that
the /second/ unit we build will have a copper hot head even if the iron
works satisfactorily.
We also talked about adding a "clip on" semicircular reflective shield
to the sun side of the hot head to reduce radiation losses. That, also,
will probably come later.
The hot head will be 3/4"ID x 8' iron pipe. The regenerator tube will be
3/4"ID x 18" iron pipe. The cold head will be 3/4"ID x 8' copper fin
tube, and both hot and cold heads will connect to an (initially
water-filled) expansion chamber. Some of the calculations went like this:
The volume of the hot head is 42.412 cu in (0.184 gal) and when the air
inside is heated from 70F to 700F, it will expand (assuming constant
presure) to 424.12 cu in (1.836 gal).
The difference between the expanded and unexpanded air volumes (1.836
gal - 0.184 gal = 1.652 gal) is the volume we'd like to see the engine
pump with each cycle. Our PVC engine has run fairly consistently in the
1 to 1.5 Hz range. If this engine runs at a (convenient for calculation)
1 Hz, then it should pump 1.652 gal/sec, 99.12 gal/min, and 5947.2 gal/hour.
We already know that won't happen, because the cold head temperature
won't return to 70F for each cycle. Still, even if the cold head
temperature averages somewhere around 300F, it should still pump at a
reasonable speed. If the temperature seems unreasonably high we'll adopt
your suggestion to add a parallel 8' run of fin tube to the cold head -
but I'm hoping that isn't necessary.
Morris Dovey
>> I was mulling over the comparison with naval reactors when it
>> (finally!) dawned on me that the tube at the trough's focus could
>> actually /be/ the hot head of a Stirling engine (fluidyne or other type).
>
> Then, you've considered acoustic stirlings?
>>
> While I was googling for some background info for you, I ran across this:
>
> http://www.youtube.com/watch?v=TWbMTk1rQ0g
That's neat! I've been nudged several times to look at the acoustic
Stirlings, but I haven't seen anything yet that encouraged me to attempt
scaling one up into the multi-horsepower range - and all of the
non-fluidyne Stirlings require shop capabilities that I don't have and
can't afford.
Morris Dovey
> I'd start out using a high BP liquid instead of gas. Something such
> as the heat transfer oils that are ubiquitous in the petrochem
> industry. Good for several hundred degrees at essentially
> atmospheric pressure, higher with modest (less than 100psi) pressure.
The fluidyne needs both a liquid and a gas. We're planning to start off
with water and air because of cost and availability. With 700F air from
the hot head, we'll probably make a bit of steam.
> Though I haven't done the calcs, I suspect that the upper limit will
> be set by re-radiation off the back side (ironically, the side
> pointing toward the sun) of the absorber, assuming no fancy infrared
> optics or insulation is deployed.
We gave this a bit of thought and decided to try a bare focal tube for
our initial design. If the engine runs at all (and we think it will)
then we'll probably try a "half-pipe" reflector on the back side to see
if that'll make any difference in performance.
I'm guessing that our most significant limitation will be the amount of
heat we can shed at the cold head without spending more than strikes us
as reasonable.
Bruce Richmond
You need to be working with absolute temps. Add 460 to your F temps.
So (700+460)/(70+460)=1160/530=2.19 as opposed to the 10 you got using
F degrees.
Morris Dovey
> You need to be working with absolute temps. Add 460 to your F temps.
>
> So (700+460)/(70+460)=1160/530=2.19 as opposed to the 10 you got using
> F degrees.
Yes! Thank you! Methinks my brain gears are missing a few teeth - you've
made me really glad I posted before we started welding.
Actually, the lesser ratio makes construction noticeably easier (and
less expensive <g>)
Thanks again.
Bruce Richmond
> Bruce Richmond wrote:
> > Might want to use multiple base board tubes in parallel to give the
> > same cross section as the rest of the tubing. Not sure how hot
> > things will be at the cold head but you may need to take that into
> > consideration if you are using soder joints.
>
> We did a design walk-through this afternoon, and agreed to start out
> with a single 8' run of fin tube for the cold head. There won't be any
> solder joints anywhere - joins will either be threaded, welded, or brazed.
Whatever the method try to make the transitions as smooth as
possible. Any turbulance or other resistance to flow will reduce the
net output as they must be overcome when the fluid moves back and
forth.
> > For a working fluid you might want to consider brake fluid. It is
> > designed to deal with high temps. Since you seem to be getting away
> > from the "found anywhere" concept I will again suggest helium. It's
> > not that hard to get and would improve efficiency. And since you
> > will be dealing with materials that could withstand a fair amount of
> > pressure you may want to consider some way of closing the system so
> > you can run higher pressure.
>
> Hmm - brake fluid would never have entered my mind. We're going to start
> out with water, and I made a note (to myself) so as to not forget this
> option if we have problems with water. Thanks - it's always good a Good
> Thing to have a "Plan 'B'" :-)
>
> >> Material selection looks like iron pipe for the hot head, copper
> >> fintubes for the cold head, steel for the reservoir, and iron pipe
> >> again for the tuning tube / power connection.
By "reservoir" I assume you mean the bottom tube and parts of the
vertical tubes that are constantly filled with liquid. How about the
regenerator or top tube?
> > Copper might be better for the hot head. It will have no problem
> > with the temperture and conducts heat better. Adding fins inside and
> > outside of the tube would give it more surface area for heat
> > transfer.
>
> We talked about this and decided to start out with the iron pipe we
> already have - but will switch to copper if we need to. I suspect that
> the /second/ unit we build will have a copper hot head even if the iron
> works satisfactorily.
>
> We also talked about adding a "clip on" semicircular reflective shield
> to the sun side of the hot head to reduce radiation losses. That, also,
> will probably come later.
>
> The hot head will be 3/4"ID x 8' iron pipe. The regenerator tube will be
> 3/4"ID x 18" iron pipe. The cold head will be 3/4"ID x 8' copper fin
> tube, and both hot and cold heads will connect to an (initially
> water-filled) expansion chamber. Some of the calculations went like this:
The flow resistance of 3/4" pipe will be much greater than the 3" PVC
you were using. I know larger pipe gets expensive quick but you might
try a second system with 1" pipe for comparison. My previous
suggestion to use multiple baseboard pipes on the cold head was to
match the cross sectional area of the larger pipe I had assumed you
would be using for the hot head.
> The volume of the hot head is 42.412 cu in (0.184 gal) and when the air
> inside is heated from 70F to 700F, it will expand (assuming constant
> presure) to 424.12 cu in (1.836 gal).
>
> The difference between the expanded and unexpanded air volumes (1.836
> gal - 0.184 gal = 1.652 gal) is the volume we'd like to see the engine
> pump with each cycle. Our PVC engine has run fairly consistently in the
> 1 to 1.5 Hz range. If this engine runs at a (convenient for calculation)
> 1 Hz, then it should pump 1.652 gal/sec, 99.12 gal/min, and 5947.2 gal/hour.
>
> We already know that won't happen, because the cold head temperature
> won't return to 70F for each cycle. Still, even if the cold head
> temperature averages somewhere around 300F, it should still pump at a
> reasonable speed. If the temperature seems unreasonably high we'll adopt
> your suggestion to add a parallel 8' run of fin tube to the cold head -
> but I'm hoping that isn't necessary.
You seem to be under the impression that you can use the full stroke
of the moving fluid to pump with. I am quite certain you will find
there is much less power to be had. Going back to the analogy of a
pendulum, there is energy to be had as it swings down to vertical.
But if you take that energy there is none left to carry it up the
remainder of the swing. The clock works adds just a bit of energy to
each stroke to make up for the energy lost to friction. Use that
energy to power something else and it will stop swinging.
The energy added on each stroke is the movement seen in the cold
head. Without it the motion in the hot head will quickly die. You
can take some of that energy and have a reduced amplitude in the hot
head, but some of the added energy must go to replacing the energy
lost in the movement of the fluid.
As a quick calculation, your reflector has an area of 2 meters ^ 2.
That means it gathers about 2 KW of power. At most the efficiency of
the system can be (1160-530)/1160=54%. I would be very surprised if
you could obtain half of the theoretical efficiency. That would put
the max output at about 500 watts. That's really not too bad when you
look at what a 300 watt low temp Stirling engine looks like.
http://www.nmri.go.jp/eng/khirata/stirling/kiriki/yama1/300pfrm.html
or a 1 KW
http://www.nmri.go.jp/eng/khirata/stirling/kiriki/yama2/index.html
Bruce
Morris Dovey
> By "reservoir" I assume you mean the bottom tube and parts of the
> vertical tubes that are constantly filled with liquid. How about the
> regenerator or top tube?
The regenerator will be 3/4" iron pipe filled with 1/8" copper tubes.
It'll be wrapped with fiberglass and the whole enclosed in a length of
scrap aluminum tubing.
> The flow resistance of 3/4" pipe will be much greater than the 3" PVC
> you were using. I know larger pipe gets expensive quick but you might
> try a second system with 1" pipe for comparison. My previous
> suggestion to use multiple baseboard pipes on the cold head was to
> match the cross sectional area of the larger pipe I had assumed you
> would be using for the hot head.
Understood (the PVC engine is 4" PVC pipe, BTW). It's an affordability
issue - we'd use larger diameter and copper if we could (we're able to
use fintube only because I intercepted two pieces on their way to the
local landfill).
I wish I know enough to accurately predetermine the behavior with tubing
material and ID as independent variables.
> You seem to be under the impression that you can use the full stroke
> of the moving fluid to pump with. I am quite certain you will find
> there is much less power to be had. Going back to the analogy of a
> pendulum, there is energy to be had as it swings down to vertical.
> But if you take that energy there is none left to carry it up the
> remainder of the swing. The clock works adds just a bit of energy to
> each stroke to make up for the energy lost to friction. Use that
> energy to power something else and it will stop swinging.
Hell, I'm not even under the impression that I can make it work at all
on the first (second, third,..) attempt. :-)
We did find that the PVC version seemed to do better when it had a load
to work against. We're still not sure if that's a basic characteristic
of the device or if adding load doesn't in some way correct a deficient
design...
> The energy added on each stroke is the movement seen in the cold
> head. Without it the motion in the hot head will quickly die. You
> can take some of that energy and have a reduced amplitude in the hot
> head, but some of the added energy must go to replacing the energy
> lost in the movement of the fluid.
I think I'll need some quiet time to digest this - I had been thinking
that the energy added at each stroke was the heat absorbed at the hot head.
> As a quick calculation, your reflector has an area of 2 meters ^ 2.
> That means it gathers about 2 KW of power. At most the efficiency of
> the system can be (1160-530)/1160=54%. I would be very surprised if
> you could obtain half of the theoretical efficiency. That would put
> the max output at about 500 watts. That's really not too bad when you
> look at what a 300 watt low temp Stirling engine looks like.
I think we'd consider 27% efficiency to be incredible success, worthy of
a major Iowa celebration (as in: "Barkeep, brew and corn dogs for
everyone!")
A 500W output with less than US$250 worth of materials (retail) from an
engine whose only moving parts were air and water seems to me an
acceptable outcome. Even a 300W output wouldn't be too shabby.
If we see a 300W output, of course, that'd just mean that we'd have to
see how close we could come to the theoretical - that's just human nature...
> http://www.nmri.go.jp/eng/khirata/stirling/kiriki/yama1/300pfrm.html
>
> or a 1 KW
>
> http://www.nmri.go.jp/eng/khirata/stirling/kiriki/yama2/index.html
These guys obviously have much deeper pockets than I - but I think we're
not all trying to solve the same problems...
The questions of the day (this day only - tomorrow's will be different)
are whether it can be used to pump brine out of a rice field, and
whether it can pump water to/through a water purification system - and
how many can be stowed in a C-130 cargo bay and whether knocked-down
kits can survive a parachute drop and be deployed in under an hour by an
average person with no training.
Bruce Richmond
wrote:
> "Morris Dovey" <mrdo...@iedu.com> wrote in message
>
> news:481a757a$0$87075$815e...@news.qwest.net...
>
>
>
>
>
> > Vaughn Simon wrote:
Just noticed this. On the examples built so far the hot and cold
pipes were the same diameter. Making the cold pipe smaller will
increase the movement of the fluid in that pipe for a given
displacement volume. That would translate into a higher velocity with
more momentum. This would definitely be a means of tuning the
system. With previous designs the hot and cold pipes were not all
that different in terms of absolute temperture. With this new set-up
the hot tube will be about twice the temperture of the cold tube.
Might need to take that into account when sizing the tubing.
> And the 'displacement' of the liquid in the fluidyne would
> have to move an 'appreciable amount' of the gas from hot to cold, so with a
> large hot and cold, you need a large 'displacement' (either really long
> stroke, very wide bore, or combination).
>
> You don't need any sort of phase change for the working fluid (unlike
> Rankine cycle), so I should think any gas that behaves close to the ideal
> gas law at these temperatures / pressures would suffice. The only reason to
> not use air would be if the high-temperature oxygen causes some corrosion
> problem. Material selection for the piping and such would seem to be key.
>
> daestrom
The lower molecular weight of helium allows it to change temperture
quicker which increases the efficiency of the engine. Hydrogen would
work even better but is more difficult and dangerous to work with.
>
>
> > Hmm. Time to go fire up the software model with new temperature
> > parameters...
>
> > --
> > Morris Dovey
> > DeSoto Solar
> > DeSoto, Iowa USA
> >http://www.iedu.com/DeSoto/Stirling/Heat.html- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
Bruce Richmond
Heat energy flows through a heat engine and in the process some of it
is converted to mechanical energy. The large movement seen in the hot
tube and the open tube is mostly due to harmonic pressure fluctuations
in the air trapped in the loop. It is roughly equivelent to the
displacer piston in a mechanical Sterling engine. Its motion does not
produce the power, it just pushes the air to where it needs to be for
the heating and cooling cycles. The power, both for moving the
displacer and for net output, is produced by the power piston, which
is much smaller than the displacer. The cold tube is roughly
equivelent to the power piston. If you put a valve in it so that you
can block it you would see that the large motions in the other tubes
will quickly stop when you block flow in the cold tube.
> > As a quick calculation, your reflector has an area of 2 meters ^ 2.
> > That means it gathers about 2 KW of power. At most the efficiency of
> > the system can be (1160-530)/1160=54%. I would be very surprised if
> > you could obtain half of the theoretical efficiency. That would put
> > the max output at about 500 watts. That's really not too bad when you
> > look at what a 300 watt low temp Stirling engine looks like.
>
> I think we'd consider 27% efficiency to be incredible success, worthy of
> a major Iowa celebration (as in: "Barkeep, brew and corn dogs for
> everyone!")
Notice I said I would be surprised if you got that. It may be
possible though with enough tweaking.
> A 500W output with less than US$250 worth of materials (retail) from an
> engine whose only moving parts were air and water seems to me an
> acceptable outcome. Even a 300W output wouldn't be too shabby.
>
> If we see a 300W output, of course, that'd just mean that we'd have to
> see how close we could come to the theoretical - that's just human nature...
of course :)
> >http://www.nmri.go.jp/eng/khirata/stirling/kiriki/yama1/300pfrm.html
>
> > or a 1 KW
>
> >http://www.nmri.go.jp/eng/khirata/stirling/kiriki/yama2/index.html
>
> These guys obviously have much deeper pockets than I - but I think we're
> not all trying to solve the same problems...
>
> The questions of the day (this day only - tomorrow's will be different)
> are whether it can be used to pump brine out of a rice field, and
> whether it can pump water to/through a water purification system - and
> how many can be stowed in a C-130 cargo bay and whether knocked-down
> kits can survive a parachute drop and be deployed in under an hour by an
> average person with no training.
How much elevation change to pump the brine out?
Bruce
Morris Dovey
> How much elevation change to pump the brine out?
AFAICT from looking at the news videos, only about 2-3 feet.
Morris Dovey
>> But you mentioned putting the working fluid right through the
>> collector. That might be tricking with a long-trough. You can't go
>> too narrow with the tube due to increased friction, so a long
>> trough collector pipe would increase the volume of the 'hot side'
>> quite a bit. Just means you need a 'cold side' that is similar in
>> size (well, actually smaller by the ratio of temperatures).
>
> Just noticed this. On the examples built so far the hot and cold
> pipes were the same diameter. Making the cold pipe smaller will
> increase the movement of the fluid in that pipe for a given
> displacement volume. That would translate into a higher velocity
> with more momentum. This would definitely be a means of tuning the
> system. With previous designs the hot and cold pipes were not all
> that different in terms of absolute temperture. With this new set-up
> the hot tube will be about twice the temperture of the cold tube.
> Might need to take that into account when sizing the tubing.
So far, the experimental models have all used a single size tube
throughout - save for the regenerator tube. I think it'll be a good idea
to tinker with the diameters of the various elements. The single-size
approach doesn't seem to be a bad starting point.
>> And the 'displacement' of the liquid in the fluidyne would have to
>> move an 'appreciable amount' of the gas from hot to cold, so with a
>> large hot and cold, you need a large 'displacement' (either really
>> long stroke, very wide bore, or combination).
Yesterday I wrote a program to calculate "displacer" dimensions based on
hot head dimensions and best guesses at hot and cold side temperatures.
This time I remembered to add an f2k(t) function to calculate the
expansion ratio in K instead of degrees Fahrenheit. :-)
> The lower molecular weight of helium allows it to change temperture
> quicker which increases the efficiency of the engine. Hydrogen would
> work even better but is more difficult and dangerous to work with.
You're right - but plain old air is going to have to do the job for this
engine. The H/He options will await an application in a more controlled
environment with trained personnel.
Bruce Richmond
One simple inexpensive thing you could try to improve the efficiency
would be to apply stove black to the hot pipe. I realize it will be
"black pipe", but such pipe is often not painted at all or has glossy
paint. Flat black paint may work as well, but paint can also act as
an insulator. In theory I believe the stove black would also help the
cold pipe radiate heat, but I don't recall ever seing it used on
baseboard heating elements.
Bruce
Bruce Richmond
> Bruce Richmond wrote:
> > On May 20, 11:55 am, Morris Dovey <mrdo...@iedu.com> wrote:
> >> The questions of the day (this day only - tomorrow's will be different)
> >> are whether it can be used to pump brine out of a rice field, and
> > How much elevation change to pump the brine out?
>
> AFAICT from looking at the news videos, only about 2-3 feet.
>
To get a better feel of what we are looking at I did some quick
calculations.
A gallon of water weighs about 8 lbs.
Lifting it 2 feet would take 16 ft. lbs. of work.
300 Watts = .4 hp = 220 ft. lbs. per second.
220/16=13.75 gal./sec
A 3/4" ID pipe has a cross sectional area of .44 sq in.
There are 231 cubic inches per gallon.
13.75 X 231 = 3176 cubic inches.
That would fill 3176/.44=7218.75 inches or 601.6 feet of pipe.
So the water would have to be flowing through the pipe at 600 ft/sec
or a bit over 400 mph to pump 13.75 gal/sec.
If the water is going up and down 8 ft during the cycle it would have
to make 75 cycles per second.
If the cycle is working at 1.5 hz then the water would have to be
going up and down 400 feet during the cycle.
A 4" pipe has a cross sectional area of 12.57 sq in or 28.6 times that
of the 3/4" pipe. That would reduce the velocity to about 21 ft/sec
for 13.75 gal/sec.
If we have the water in a 4" pipe going through a 7 ft cycle at 1.5 hz
it would lift 6.875 gal/sec the 2 feet and use 150 Watts, neglecting
losses.
But then like I said before, we can't expect to use the full stroke of
the fluid to pump without killing the cycle.
Let's say we can only use about 5% of the full travel for pumping.
That would mean about 1/3 gal per sec or 20 gal/min or 1200 gal/hr.
Might not sound as impressive as the 6000 gal/hr you estimated
earlier, but it would be a lot less work than lifting a 5 gal bucket 4
times a minute.
That is using 4" pipe. Seems the 3/4" would be too restrictive.
Making the whole thing out of 4" metal pipe would be expensive. How
about cutting the reflector into four 2 ft lengths for 4 pumps. Use a
2 ft section of thin wall 4" copper pipe with some sort of insulator
between it and pvc pipe for most of the pump. A single 8' section of
baseboard pipe could be cut into four 2 ft sections to be used in
parallel for the cold head.
Another possibility would be to mount 4" pvc a bit off from the focal
point so it would give say a 2" wide band of 200 F deg heat rather
than a 3/8" wide band of 700 F deg heat.
Just some things to think about.
Bruce
Morris Dovey
<snipped a lot of good thought>
Let's shift our thinking just a little bit. I'm hoping that that "little
bit" makes for much improved operation.
The plan is to move only air (no fluid, or as little fluid as possible)
in the 3/4" pipe because there'd be just too much resistance to flow.
An absolute maximum of the fluid flow will take place in 4" pipe, for
/exactly/ the reasons you put forth.
I know that the 3/4" ID is restrictive, even for air, but the
temperature within the hot head will have some kind of inverse
relationship to the hot head ID (IOW, the larger the volume, the lower
the temperature, and vice versa). I also understand that the greater the
temperature differential between the hot head and the cold head, the
greater the possible engine efficiency. The only practical way I have to
maximize that differential is by maximizing the hot head temperature.
So what I want to do is to find that balance point where I have the
highest hot head temperature /and/ the least airflow losses. I'm certain
that both can't be maximized simultaneously, so I'm going to be working
to find the best trade-off I can make using off-the-shelf supplies from
my local hardware/building store.
AFAICT so far, the engine's frequency is directly related to the height
to which the working fluid is displaced. That's counter-intuitive to me,
because I expected some kind of mass relationship, but I can cope. <g>
If that's true, then (up to a point) I can make the engine run faster by
shortening the vertical displacement of the working fluid. The speed
limit for the engine now under construction (I think) will be imposed by
the restricted airflow in the hothead/regenerator/cold head path - and,
as per usual, I'll need to play with the height of the fluid in the
tuning tube to attempt to approach some reasonable degree of resonance
between the Carnot cycle and the working fluid's natural (simple
harmonic?) frequency.
Your help is always much appreciated (I've been in over my head from the
very beginning).
Morris Dovey
> That is using 4" pipe. Seems the 3/4" would be too restrictive.
>
> Making the whole thing out of 4" metal pipe would be expensive. How
> about cutting the reflector into four 2 ft lengths for 4 pumps. Use a
> 2 ft section of thin wall 4" copper pipe with some sort of insulator
> between it and pvc pipe for most of the pump. A single 8' section of
> baseboard pipe could be cut into four 2 ft sections to be used in
> parallel for the cold head.
>
> Another possibility would be to mount 4" pvc a bit off from the focal
> point so it would give say a 2" wide band of 200 F deg heat rather
> than a 3/8" wide band of 700 F deg heat.
>
> Just some things to think about.
Hmm - thinking...
How about if I use 1.5" copper for the hot head and rotate my mirror
material so that the collector is 8' wide and 4' long? That should boost
the temperature right up there and simultaneously shorten hot and cold
heads by 50%.
It shouldn't produce temperatures much hotter than 1400F...
Bruce Richmond
> Bruce Richmond wrote:
>
> <snipped a lot of good thought>
>
> Let's shift our thinking just a little bit. I'm hoping that that "little
> bit" makes for much improved operation.
>
> The plan is to move only air (no fluid, or as little fluid as possible)
> in the 3/4" pipe because there'd be just too much resistance to flow.
>
> An absolute maximum of the fluid flow will take place in 4" pipe, for
> /exactly/ the reasons you put forth.
>
> I know that the 3/4" ID is restrictive, even for air, but the
> temperature within the hot head will have some kind of inverse
> relationship to the hot head ID (IOW, the larger the volume, the lower
> the temperature, and vice versa).
While the relationship does exist you still have to work within
certain limits. A gasoline engine gives more power for a given size
if you increase the compression ratio, but you can't just raise it as
high as you would like to. On pump gasoline it is difficult to avoid
detonation at ratios higher than 12:1. You also get more power by
increasing the frequency of the cycle, or in the gasoline engine the
rpm. But again if you try to go too far with this the engine will
break. I suspect that to use all the power of your 8' reflector you
will need to use large diameter pipe. To use smaller pipe would mean
increasing either the stroke length or frequency of the cycle, either
one of which can present problems. The idea of using small pipe for
the air and large pipe for the fluid seems reasonable.
> I also understand that the greater the
> temperature differential between the hot head and the cold head, the
> greater the possible engine efficiency. The only practical way I have to
> maximize that differential is by maximizing the hot head temperature.
I'm starting to think getting this to work using 724F on the hot side
is going to cost more than it's worth. Raising the hot side temp
increases efficiency but the smaller pipe decreases it. I also have
doubts about the actual temp of the air in the hot pipe. If the 724F
only applies to a 3/8" stripe down one side of the pipe, that heat
will spread around the pipe and average out the temp. I suspect the
average temp in the hot head will end up little if any higher than it
would if the light was focused on a stripe the full width of the pipe.
By adding the half pipe reflector you had mentioned before you could
even make the stripe wider than the pipe and let the half pipe
redirect it at the other side of the pipe. That might get the
localized temp back down to where PVC could take it. Might still want
to use copper for the hot head due to its better heat transfer
properties, but with the lower temp it could be directly connected to
PVC.
BTW, have you ever taken temp readings of the air and water at the hot
and cold heads?
> So what I want to do is to find that balance point where I have the
> highest hot head temperature /and/ the least airflow losses. I'm certain
> that both can't be maximized simultaneously, so I'm going to be working
> to find the best trade-off I can make using off-the-shelf supplies from
> my local hardware/building store.
>
> AFAICT so far, the engine's frequency is directly related to the height
> to which the working fluid is displaced. That's counter-intuitive to me,
> because I expected some kind of mass relationship, but I can cope. <g>
Think of the pendulum where the longer it is the bigger the swing and
the lower the frequency. How much weight is at the end doesn't make
much difference, just how far it is from the pivot point.
> If that's true, then (up to a point) I can make the engine run faster by
> shortening the vertical displacement of the working fluid. The speed
> limit for the engine now under construction (I think) will be imposed by
> the restricted airflow in the hothead/regenerator/cold head path - and,
> as per usual, I'll need to play with the height of the fluid in the
> tuning tube to attempt to approach some reasonable degree of resonance
> between the Carnot cycle and the working fluid's natural (simple
> harmonic?) frequency.
Putting a load on the engine should shorten the displacement. The
energy applied to the load would otherwise have gone into displacing
the fluid further. Using smaller pipe for the air chamber should
decrease the displacement and increase the frequency. Think of the
air chamber as a spring. As the displacement reduces its volume the
pressure goes up. Reduce the air chamber volume and the pressure will
rise quicker, reversing the motion of the fluid. Think of it as a
shorter, stiffer spring. You may find that going to 3/4" pipe for
most of the air chamber makes for too stiff a spring. If that is the
case I'm quite sure you will be able to use PVC for the air pipe to
the cold side of the regenerator. If I'm correct there should be a
considerable temp drop across the regenerator.
I got thinking about the heat flow through the water. It contributes
nothing to the power since the power is derived from the expansion and
contraction of the gas. So anything that would slow the transfer of
heat through the water pipe would improve efficiency. That is
basically what the regenerator does in the air pipe. Adding a
regenerator to the water pipe would have the same effect as having a
longer pipe without the increase in actual mass moving back and
forth. Wrapping the hot end of the water pipe in fiberglass would
also help.
While the water pipe regenerator will improve efficiency it may not be
worth the added expense. At this point it looks like the reflector
can put out more heat than the engine can handle. The money might be
better spent going to the next size bigger on the PVC pipe.
> Your help is always much appreciated (I've been in over my head from the
> very beginning).
I'm afraid it's the blind leading the blind here. I know some
thermodynamics and physics in general, but I never heard of a fluidyne
engine before reading your web page. Considering how much info can be
found on them it seems you are at the leading edge of the
technology :)
Bruce
Bruce Richmond
> Bruce Richmond wrote:
> > That is using 4" pipe. Seems the 3/4" would be too restrictive.
>
> > Making the whole thing out of 4" metal pipe would be expensive. How
> > about cutting the reflector into four 2 ft lengths for 4 pumps. Use a
> > 2 ft section of thin wall 4" copper pipe with some sort of insulator
> > between it and pvc pipe for most of the pump. A single 8' section of
> > baseboard pipe could be cut into four 2 ft sections to be used in
> > parallel for the cold head.
>
> > Another possibility would be to mount 4" pvc a bit off from the focal
> > point so it would give say a 2" wide band of 200 F deg heat rather
> > than a 3/8" wide band of 700 F deg heat.
>
> > Just some things to think about.
>
> Hmm - thinking...
>
> How about if I use 1.5" copper for the hot head and rotate my mirror
> material so that the collector is 8' wide and 4' long? That should boost
> the temperature right up there and simultaneously shorten hot and cold
> heads by 50%.
Should be better than 3/4" pipe I think. Shorter head should also go
better with the shorter displacement/higher frequency idea.
> It shouldn't produce temperatures much hotter than 1400F...
May want to try just half of your standard reflectors first.
Morris Dovey
> On May 23, 3:47 am, Morris Dovey <mrdo...@iedu.com> wrote:
>> I know that the 3/4" ID is restrictive, even for air, but the
>> temperature within the hot head will have some kind of inverse
>> relationship to the hot head ID (IOW, the larger the volume, the
>> lower the temperature, and vice versa).
>
> While the relationship does exist you still have to work within
> certain limits. A gasoline engine gives more power for a given size
> if you increase the compression ratio, but you can't just raise it as
> high as you would like to. On pump gasoline it is difficult to avoid
> detonation at ratios higher than 12:1. You also get more power by
> increasing the frequency of the cycle, or in the gasoline engine the
> rpm. But again if you try to go too far with this the engine will
> break. I suspect that to use all the power of your 8' reflector you
> will need to use large diameter pipe. To use smaller pipe would mean
> increasing either the stroke length or frequency of the cycle, either
> one of which can present problems. The idea of using small pipe for
> the air and large pipe for the fluid seems reasonable.
Yes to the limits - I just don't know where they are. I expect I need to
work my way through a whole range of tubing size combinations to find
where the trade-offs are. I think I'd rather go through all of that than
try to guess at the optimal point and lock onto the first combination
that worked.
>> I also understand that the greater the temperature differential
>> between the hot head and the cold head, the greater the possible
>> engine efficiency. The only practical way I have to maximize that
>> differential is by maximizing the hot head temperature.
>
> I'm starting to think getting this to work using 724F on the hot side
> is going to cost more than it's worth. Raising the hot side temp
> increases efficiency but the smaller pipe decreases it. I also have
> doubts about the actual temp of the air in the hot pipe. If the 724F
> only applies to a 3/8" stripe down one side of the pipe, that heat
> will spread around the pipe and average out the temp. I suspect the
> average temp in the hot head will end up little if any higher than it
> would if the light was focused on a stripe the full width of the
> pipe.
>
> By adding the half pipe reflector you had mentioned before you could
> even make the stripe wider than the pipe and let the half pipe
> redirect it at the other side of the pipe. That might get the
> localized temp back down to where PVC could take it. Might still
> want to use copper for the hot head due to its better heat transfer
> properties, but with the lower temp it could be directly connected to
> PVC.
It doesn't make much sense to even consider PVC with a concentrator. The
PVC loses integrity above 165F - and at the temperatures produced by the
concentrator, we can't even use solder to hold things together.
> BTW, have you ever taken temp readings of the air and water at the
> hot and cold heads?
No - the best we can do is take temperature readings of the tubes from
the outside.
>> AFAICT so far, the engine's frequency is directly related to the
>> height to which the working fluid is displaced. That's
>> counter-intuitive to me, because I expected some kind of mass
>> relationship, but I can cope. <g>
>
> Think of the pendulum where the longer it is the bigger the swing and
> the lower the frequency. How much weight is at the end doesn't make
> much difference, just how far it is from the pivot point.
Ok. Then if the mass of the water isn't a consideration, and if the
water functions only as a displacer, I should be working to reduce the
amount of water toward the minimum required to work as a displacer.
>> If that's true, then (up to a point) I can make the engine run
>> faster by shortening the vertical displacement of the working
>> fluid. The speed limit for the engine now under construction (I
>> think) will be imposed by the restricted airflow in the
>> hothead/regenerator/cold head path - and, as per usual, I'll need
>> to play with the height of the fluid in the tuning tube to attempt
>> to approach some reasonable degree of resonance between the Carnot
>> cycle and the working fluid's natural (simple harmonic?)
>> frequency.
>
> Putting a load on the engine should shorten the displacement. The
> energy applied to the load would otherwise have gone into displacing
> the fluid further. Using smaller pipe for the air chamber should
> decrease the displacement and increase the frequency.
Right. The displacement is reduced because the volume being expanded is
less. With the reduced volume, I'm hoping for more rapid heating and
/faster/ expansion - which should, indeed, increase the frequency.
> Think of the air chamber as a spring. As the displacement reduces
> its volume the pressure goes up. Reduce the air chamber volume and
> the pressure will rise quicker, reversing the motion of the fluid.
Now at least /I/ am on shakier ground. My reading is that this expansion
in a Stirling's hot head is isobaric - meaning that it takes place at
constant pressure. The classic Carnot pressure/volume plot shows a
relatively slow pressure drop during the expansion and a large, sudden
drop at the end of the expansion. Similarly I see the contraction phase
described as isobaric - during the time that the volume is contracting,
there's a relatively slow pressure increase with a large, sudden jump in
pressure at the end of the contraction.
I'm having difficulty making that match up with the picture you're
presenting - what am I missing?
> Think of it as a shorter, stiffer spring. You may find that going to
> 3/4" pipe for most of the air chamber makes for too stiff a spring.
> If that is the case I'm quite sure you will be able to use PVC for
> the air pipe to the cold side of the regenerator. If I'm correct
> there should be a considerable temp drop across the regenerator.
A large temperature drop across the regenerator is desirable, no? It
would mean that heat is being well-conserved between cycles.
> I got thinking about the heat flow through the water. It contributes
> nothing to the power since the power is derived from the expansion
> and contraction of the gas. So anything that would slow the transfer
> of heat through the water pipe would improve efficiency.
Yuppers. I've even given some thought to putting a small free-floating
piston at the air-water interface to reduce that transfer. It's on my
list of "things to try".
> That is basically what the regenerator does in the air pipe. Adding
> a regenerator to the water pipe would have the same effect as having
> a longer pipe without the increase in actual mass moving back and
> forth. Wrapping the hot end of the water pipe in fiberglass would
> also help.
I don't think that's the case. At the regenerator I want to capture heat
during the expansion phase to be released during the contraction phase.
At the hot head-displacer interface I want to inhibit heat transfer
across that interface at all times.
My regenerator is built as a bundle of small tubes within the outer tube
to have a maximum of surface area for grabbing heat from the air during
expansion and giving it back during contraction.
I'm a bit antsy about the regenerator inhibiting airflow, but recognize
the benefits. This is another Stirling trade-off point to be resolved.
However, I'm /really/ sure that I don't want to interpose a flow
restriction of any kind in the fluid flow.
> While the water pipe regenerator will improve efficiency it may not
> be worth the added expense. At this point it looks like the
> reflector can put out more heat than the engine can handle. The
> money might be better spent going to the next size bigger on the PVC
> pipe.
As I mentioned before PVC isn't an issue in this all-metal engine. More
heat than the engine can handle means (I think) overheating to the point
where it blows all its fluid out the tuning tube... :-(
>> Your help is always much appreciated (I've been in over my head
>> from the very beginning).
>
> I'm afraid it's the blind leading the blind here. I know some
> thermodynamics and physics in general, but I never heard of a
> fluidyne engine before reading your web page. Considering how much
> info can be found on them it seems you are at the leading edge of the
> technology :)
Fluidynes have been around for a while, and aren't new with me. You can
find a fair number of videos of 'em running on YouTube. What's
surprising is that fluidynes, and Stirling cycle engines in general,
have been so little commercialized other than as toys.
Bruce Richmond
> Bruce Richmond wrote:
> > On May 23, 3:47 am, Morris Dovey <mrdo...@iedu.com> wrote:
> >> I know that the 3/4" ID is restrictive, even for air, but the
> >> temperature within the hot head will have some kind of inverse
> >> relationship to the hot head ID (IOW, the larger the volume, the
> >> lower the temperature, and vice versa).
>
> > While the relationship does exist you still have to work within
> > certain limits. A gasoline engine gives more power for a given size
> > if you increase the compression ratio, but you can't just raise it as
> > high as you would like to. On pump gasoline it is difficult to avoid
> > detonation at ratios higher than 12:1. You also get more power by
> > increasing the frequency of the cycle, or in the gasoline engine the
> > rpm. But again if you try to go too far with this the engine will
> > break. I suspect that to use all the power of your 8' reflector you
> > will need to use large diameter pipe. To use smaller pipe would mean
> > increasing either the stroke length or frequency of the cycle, either
> > one of which can present problems. The idea of using small pipe for
> > the air and large pipe for the fluid seems reasonable.
>
> Yes to the limits - I just don't know where they are. I expect I need to
> work my way through a whole range of tubing size combinations to find
> where the trade-offs are. I think I'd rather go through all of that than
> try to guess at the optimal point and lock onto the first combination
> that worked.
>
I certainly didn't mean to dictate a particular size, just trying to
go in the right general direction from the start.
>
>
>
> >> I also understand that the greater the temperature differential
> >> between the hot head and the cold head, the greater the possible
> >> engine efficiency. The only practical way I have to maximize that
> >> differential is by maximizing the hot head temperature.
>
> > I'm starting to think getting this to work using 724F on the hot side
> > is going to cost more than it's worth. Raising the hot side temp
> > increases efficiency but the smaller pipe decreases it. I also have
> > doubts about the actual temp of the air in the hot pipe. If the 724F
> > only applies to a 3/8" stripe down one side of the pipe, that heat
> > will spread around the pipe and average out the temp. I suspect the
> > average temp in the hot head will end up little if any higher than it
> > would if the light was focused on a stripe the full width of the
> > pipe.
>
> > By adding the half pipe reflector you had mentioned before you could
> > even make the stripe wider than the pipe and let the half pipe
> > redirect it at the other side of the pipe. That might get the
> > localized temp back down to where PVC could take it. Might still
> > want to use copper for the hot head due to its better heat transfer
> > properties, but with the lower temp it could be directly connected to
> > PVC.
>
> It doesn't make much sense to even consider PVC with a concentrator. The
> PVC loses integrity above 165F - and at the temperatures produced by the
> concentrator, we can't even use solder to hold things together.
The 724 degrees is when the 4' wide panel concentrates the light into
a 3/8" wide beam. If it is only concentrated into a 4" wide beam it
will be at a much lower temp. Concentrate it into a 6" wide beam and
it will be an even lower temp. At some point the temp will be low
enough to work with PVC. It may not be as efficient as could be done
with metal, but on a per dollar basis it could be a winner.
> > BTW, have you ever taken temp readings of the air and water at the
> > hot and cold heads?
>
> No - the best we can do is take temperature readings of the tubes from
> the outside.
>
Shouldn't be that hard to mount thermometers at either head. Might
not be able to get real time variations ,but it should be good enough.
> >> AFAICT so far, the engine's frequency is directly related to the
> >> height to which the working fluid is displaced. That's
> >> counter-intuitive to me, because I expected some kind of mass
> >> relationship, but I can cope. <g>
>
> > Think of the pendulum where the longer it is the bigger the swing and
> > the lower the frequency. How much weight is at the end doesn't make
> > much difference, just how far it is from the pivot point.
>
> Ok. Then if the mass of the water isn't a consideration, and if the
> water functions only as a displacer, I should be working to reduce the
> amount of water toward the minimum required to work as a displacer.
Water is cheap. I wouldn't worry too much about reducing how much is
used.
The way I am seeing it, starting with the water at the high point in
the open tube, the water flows back from the open tube to the hot tube
raising the level there. At the "T" where the hot tube goes up there
is less resistance to the water going straight across than making the
turn to go up the cold tube. With the water rising in the hot tube
and little change in the cold tube the trapped air is being
compressed. With air being forced from the hot side to the cold side
it cools reducing its volume and the rise in pressure. The
regenerator helps here, quickly cooling a large volume of air while
heating the metal in the regenerator. With enough cooling it will
aproach a constant pressure. Eventually the air in the cold tube is
near the temp of the tube itself ruducing heat flow and contraction.
But the momentum of the water flowing in the lower pipe continues to
compress the trapped air. As the pressure rises it slows the flow in
the hot tube and increases the flow up the cold tube. With the water
at its highest point in the hot tube it has given up its momentum to
compress the air, and the compressed air, along with gravity, will now
start the water flowing back down the hot tube. The momentum of the
water floing up the cold tube will give an extra little shove to get
the water flowing back down the cold tube. When the momentum of the
water floing up the cold tube runs out it too will start flowing
down. The fact that the air is flowing into the hot tube and being
heated means the pressure drop from the fluid level dropping in the
hot tube will be less than it would be without the heat being added.
Add enough heat and the pressure will aproach constant despite the
falling water in the hot tube. As the water rises in the open tube it
will add to the resistance of the water flowing into that tube,
eventually stopping the flow and starting the cycle over again.
> > Think of it as a shorter, stiffer spring. You may find that going to
> > 3/4" pipe for most of the air chamber makes for too stiff a spring.
> > If that is the case I'm quite sure you will be able to use PVC for
> > the air pipe to the cold side of the regenerator. If I'm correct
> > there should be a considerable temp drop across the regenerator.
>
> A large temperature drop across the regenerator is desirable, no? It
> would mean that heat is being well-conserved between cycles.
Yes, the drop is desireable. There is however an optimal drop. It is
not just a "the more the better" thing.
> > I got thinking about the heat flow through the water. It contributes
> > nothing to the power since the power is derived from the expansion
> > and contraction of the gas. So anything that would slow the transfer
> > of heat through the water pipe would improve efficiency.
>
> Yuppers. I've even given some thought to putting a small free-floating
> piston at the air-water interface to reduce that transfer. It's on my
> list of "things to try".
I was thinking about adding a piston to reduce splashing as the
frequency increased. Using it to also block heat transfer would be a
good idea.
> > That is basically what the regenerator does in the air pipe. Adding
> > a regenerator to the water pipe would have the same effect as having
> > a longer pipe without the increase in actual mass moving back and
> > forth. Wrapping the hot end of the water pipe in fiberglass would
> > also help.
>
> I don't think that's the case. At the regenerator I want to capture heat
> during the expansion phase to be released during the contraction phase.
> At the hot head-displacer interface I want to inhibit heat transfer
> across that interface at all times.
You want the heat to flow through the air pipe where some of it can be
converted to mechanical energy. Heat that flows through the water is
just wasted. The fiberglass around the hot end of the water pipe will
prevent heat loss to the air around the pipe. The hotter the water in
that end of the pipe the more it resists additional heat flowing into
it. At the cold end we want the water as cool as possible to help
cool the air. Leaving that end of the pipe unwrapped lets the pipe
shed some heat before it gets to the air/water interface.
> My regenerator is built as a bundle of small tubes within the outer tube
> to have a maximum of surface area for grabbing heat from the air during
> expansion and giving it back during contraction.
>
> I'm a bit antsy about the regenerator inhibiting airflow, but recognize
> the benefits. This is another Stirling trade-off point to be resolved.
Just make the regenerator(s) a bit larger in diameter to reduce the
flow restriction through them.
> However, I'm /really/ sure that I don't want to interpose a flow
> restriction of any kind in the fluid flow.
>
> > While the water pipe regenerator will improve efficiency it may not
> > be worth the added expense. At this point it looks like the
> > reflector can put out more heat than the engine can handle. The
> > money might be better spent going to the next size bigger on the PVC
> > pipe.
>
> As I mentioned before PVC isn't an issue in this all-metal engine. More
> heat than the engine can handle means (I think) overheating to the point
> where it blows all its fluid out the tuning tube... :-(
Or the water starts splashing uncontrolably at high frequency, or the
stroke becomes so long that it eats up too much energy in flow
resistance.
> >> Your help is always much appreciated (I've been in over my head
> >> from the very beginning).
>
> > I'm afraid it's the blind leading the blind here. I know some
> > thermodynamics and physics in general, but I never heard of a
> > fluidyne engine before reading your web page. Considering how much
> > info can be found on them it seems you are at the leading edge of the
> > technology :)
>
> Fluidynes have been around for a while, and aren't new with me. You can
> find a fair number of videos of 'em running on YouTube. What's
> surprising is that fluidynes, and Stirling cycle engines in general,
> have been so little commercialized other than as toys.
Yes, it does seem strange.
Bruce
Morris Dovey
> On May 24, 10:56 pm, Morris Dovey <mrdo...@iedu.com> wrote:
>> Ok. Then if the mass of the water isn't a consideration, and if the
>> water functions only as a displacer, I should be working to reduce
>> the amount of water toward the minimum required to work as a
>> displacer.
>
> Water is cheap. I wouldn't worry too much about reducing how much is
> used.
I think water /isn't/ cheap here. The more of it there is, the greater
overhead it presents. I'll talk a bit about this below, but in the
meantime think about a mechanical Stirling engine built with Un
(unobtanium, which has no mass) pistons, connecting rods, and crankshaft...
<snip Carnot cycle description>
That was my original perspective. It was changed by (for lack or a
better term) communing with the 4" PVC engine...
The engine actually starts out at rest, with everything at ambient
temperature and at least close to atmospheric pressure.
As heat is added to the hot head, the air volume in the hot head expands
- and the hot and cold head "pistons" are depressed equally, and the
output (tuning) piston is raised - a fairly predictable behavior, all in
all.
The big clue is the behavior of the engine when the hot head has been
heated to (again for lack of a better term) its maximum temperature - a
temperature that it seems to not want to exceed.
At that point (/exactly/ at that point) the balance is lost. The hot
head is stuck at that high temperature, but the cold head is bleeding
heat as fast as it can - and the air within it begins contracting.
At that point I see a very small motion, a slight twitch, in the cold
piston, but hear a rushing in the regenerator tube as replacement hot
air is drawn from the hot head.
The first few oscillations tend to be quite small, but build to full
scale in fewer than a dozen cycles - I think more as a result of the
regenerator plumbing coming up to temperature than anything else.
Everything I've seen seems to indicate that the water is a "necessary
evil" - necessary because a displacer is necessary, but evil because it
contributes no energy while presenting an energy "overhead".
The water's mass, if and only if the pendulum's period exactly matches
the period of the Carnot cycle, resembles a flywheel - but if there's
any mismatch at all, the water's inertia will work /against/ the
production of mechanical energy by the Carnot cycle - without delivering
the benefits a flywheel provides to a rotary engine...
...and no matter what, the water presents a power-robbing friction load.
<about the regenerator>
> Yes, the drop is desireable. There is however an optimal drop. It
> is not just a "the more the better" thing.
I had to think about that before I could nod in agreement, but yes - if
the regenerator could magically grab /all/ of the heat, the engine
couldn't run. Trying to engineer an optimal regenerator will probably
require a lot of experimentation, a lot of serious data acquisition, and
enough curve-fitting to keep a computer busy for a while. It probably
won't get done in my lifetime. :-(
> You want the heat to flow through the air pipe where some of it can
> be converted to mechanical energy. Heat that flows through the water
> is just wasted. The fiberglass around the hot end of the water pipe
> will prevent heat loss to the air around the pipe. The hotter the
> water in that end of the pipe the more it resists additional heat
> flowing into it. At the cold end we want the water as cool as
> possible to help cool the air. Leaving that end of the pipe
> unwrapped lets the pipe shed some heat before it gets to the
> air/water interface.
I think we want to keep the water as cool as possible by minimizing the
air-to-water heat transfer on both sides.
On the PVC engine, which has metal heads (and which locates the heat
exchanger /inside/ the hot head), both the hot head and the regenerator
tube are completely wrapped in fiberglass insulation.
>> My regenerator is built as a bundle of small tubes within the outer
>> tube to have a maximum of surface area for grabbing heat from the
>> air during expansion and giving it back during contraction.
>>
>> I'm a bit antsy about the regenerator inhibiting airflow, but
>> recognize the benefits. This is another Stirling trade-off point to
>> be resolved.
>
> Just make the regenerator(s) a bit larger in diameter to reduce the
> flow restriction through them.
Another trade-off. Every time there's a diameter change some power is
lost. I suspect there's a diameter transition geometry that minimizes
the power loss, but I doubt that I can go there with the tools (or
budget) at hand. I would guess that a general regenerator solution might
make a terrific thesis project for some ambitious student <nudge, nudge>.
Bruce Richmond
> Bruce Richmond wrote:
> > On May 24, 10:56 pm, Morris Dovey <mrdo...@iedu.com> wrote:
> >> Ok. Then if the mass of the water isn't a consideration, and if the
> >> water functions only as a displacer, I should be working to reduce
> >> the amount of water toward the minimum required to work as a
> >> displacer.
>
> > Water is cheap. I wouldn't worry too much about reducing how much is
> > used.
>
> I think water /isn't/ cheap here. The more of it there is, the greater
> overhead it presents. I'll talk a bit about this below, but in the
> meantime think about a mechanical Stirling engine built with Un
> (unobtanium, which has no mass) pistons, connecting rods, and crankshaft...
The mass of the pistons, connecting rods, and crankshaft make little
difference in how much power an engine produces at a steady speed.
The heavier parts add a bit of friction but other than that they do
not take any more energy to keep moving at a constant speed. If the
engine needs to accelerate, as in a race car, then the heavier
pistons, connecting rods, and crankshaft act much like a bigger
flywheel.
Thank you for this description of the start up. I've got to build one
of these things :) What have you been using as heat sources up to
now?
> Everything I've seen seems to indicate that the water is a "necessary
> evil" - necessary because a displacer is necessary, but evil because it
> contributes no energy while presenting an energy "overhead".
>
> The water's mass, if and only if the pendulum's period exactly matches
> the period of the Carnot cycle, resembles a flywheel - but if there's
> any mismatch at all, the water's inertia will work /against/ the
> production of mechanical energy by the Carnot cycle - without delivering
> the benefits a flywheel provides to a rotary engine...
>
> ...and no matter what, the water presents a power-robbing friction load.
Agreed on the friction load.
Best set up I can think of at the moment would be to have large radius
bends in the hot and open pipes so they almost form a U, with the cold
pipe rising from a T fitting in the middle. The water could be kept
down to where it is just above the bottom of the U at the lowest point
in the cycle. If you use a piston over the water it will have to stay
in the straight pipe above the curve. The cold pipe water has less
variation in height so the water would be further up in that tube,
about the mid point of the cycle in the hot tube. Cold tube diameter
and air chamber volume can be used to adjust the frequency. For
experimental purposes you might want to put in a section of pipe like
a slide trumbone. After the needed volume is established it can be
made with fewer curves and no slide.
> <about the regenerator>
>
> > Yes, the drop is desireable. There is however an optimal drop. It
> > is not just a "the more the better" thing.
>
> I had to think about that before I could nod in agreement, but yes - if
> the regenerator could magically grab /all/ of the heat, the engine
> couldn't run. Trying to engineer an optimal regenerator will probably
> require a lot of experimentation, a lot of serious data acquisition, and
> enough curve-fitting to keep a computer busy for a while. It probably
> won't get done in my lifetime. :-(
I think you should be able to get close with a few tries.
> > You want the heat to flow through the air pipe where some of it can
> > be converted to mechanical energy. Heat that flows through the water
> > is just wasted. The fiberglass around the hot end of the water pipe
> > will prevent heat loss to the air around the pipe. The hotter the
> > water in that end of the pipe the more it resists additional heat
> > flowing into it. At the cold end we want the water as cool as
> > possible to help cool the air. Leaving that end of the pipe
> > unwrapped lets the pipe shed some heat before it gets to the
> > air/water interface.
>
> I think we want to keep the water as cool as possible by minimizing the
> air-to-water heat transfer on both sides.
Not sure how you would do that other than the floating piston.
> On the PVC engine, which has metal heads (and which locates the heat
> exchanger /inside/ the hot head), both the hot head and the regenerator
> tube are completely wrapped in fiberglass insulation.
>
> >> My regenerator is built as a bundle of small tubes within the outer
> >> tube to have a maximum of surface area for grabbing heat from the
> >> air during expansion and giving it back during contraction.
>
> >> I'm a bit antsy about the regenerator inhibiting airflow, but
> >> recognize the benefits. This is another Stirling trade-off point to
> >> be resolved.
>
> > Just make the regenerator(s) a bit larger in diameter to reduce the
> > flow restriction through them.
>
> Another trade-off. Every time there's a diameter change some power is
> lost. I suspect there's a diameter transition geometry that minimizes
> the power loss, but I doubt that I can go there with the tools (or
> budget) at hand. I would guess that a general regenerator solution might
> make a terrific thesis project for some ambitious student <nudge, nudge>.
Hope that's not directed at me. I graduated in the class of '71.
Cone shaped nozzles will reduce turbulance when making a diameter
change. Might be able to find off the shelf reducers that smooth the
transitions a bit.
Bruce
Morris Dovey
> On May 25, 10:54 am, Morris Dovey <mrdo...@iedu.com> wrote:
> Thank you for this description of the start up. I've got to build
> one of these things :) What have you been using as heat sources up
> to now?
Remember that the only version built and tested so far have been a
couple of low-temperature engines. Just about anything hot: Heat gun,
hair dryer, propane torch, oxy-acetylene torch, water heater elements,
toaster-oven heat elements, a bearing-heater element, and (I almost
forgot <g>) the sun.
>> Trying to engineer an optimal regenerator will probably require a
>> lot of experimentation, a lot of serious data acquisition, and
>> enough curve-fitting to keep a computer busy for a while.
>
> I think you should be able to get close with a few tries.
I think I could optimize a single regenerator with 6 or 8 tries, but to
arrive at a general solution that allowed a designer to calculate a
solution for a new engine with a high degree of confidence won't be
quite so easy.
>> I think we want to keep the water as cool as possible by minimizing
>> the air-to-water heat transfer on both sides.
>
> Not sure how you would do that other than the floating piston.
I think that there might be a balance point between minimal interface
surface area and length of the stroke.
>> I would guess that a general regenerator solution might make a
>> terrific thesis project for some ambitious student <nudge, nudge>.
>
> Hope that's not directed at me. I graduated in the class of '71.
Nope, I was thinking about even younger folks - current students who
have access good labs, mentors, and (perhaps) collaborators close at hand.
> Cone shaped nozzles will reduce turbulance when making a diameter
> change. Might be able to find off the shelf reducers that smooth the
> transitions a bit.
I'd wager that the optimal solution will more resemble an asymetrical
ogee shape - but I wouldn't be willing to wager /much/. :-)
Ulysses
"Ken Maltby" <kma...@sbcglobal.net> wrote in message
news:Fs6dnY2Hl8MOHIrV...@giganews.com...> news:2iIRj.21848$2c3....@fe097.usenetserver.com...
> >
> > "Eric Sears" <pho...@025379386.for.email.address> wrote in message
> > news:4816e0bd...@news.clear.net.nz...
>
> >
> >> What about a solar trough collector? Fixed position (non tracking),
> >> boiling water at relatively low temp to run a homemade turbine?
> >> You would be surprised what happens when you direct a jet of steam at
> >> an impulse-type turbine, and attach it to a generator. But don't blow
> >> yourself up!
> >
>
> Impulse versus Expansion. The impulse approach might be of interest
> to "z" with his impeller. The power available from the expansion of a
> compressed gas/steam is a lot easier to exploit. (You should be able to
> modify an internal combustion engine, piston or rotary; to run on the
> expansion of steam instead of the expansion of the burning fuel gas.)
>
> > I read something about this many years ago but what I saw looked like
> > sombody's idea of what might work if somebody else figured it out for
> > them.
> > Well, I've been thinking about it for years and I guess I'm not the one
to
> > do it ;-) Meanwhile, I read some stuff about "solar power" and was a
bit
> > surprised to find that this is rather old technology (at least 150 years
> > old) and that solar-heated steam was generating electricity before very
> > many
> > people even had electricity. I don't remember exactly what made me
decide
> > to not go out and start building one right away so I need to go back and
> > read it all again. If you have any links showing how to do a
small-scale
> > solar steam turbine please share them. I also looked at steam engines
but
> > was unable to determine what it was they were selling. I got the
> > impresson
> > that they were small toys but some were rated to be able to produce
> > hundreds
> > or thousands of watts. In any case blowing myself up seems to be a very
> > likely scenerio with either methane, woodgas, or steam. But like I
always
> > say, what's the fun in being a mad scientist if you don't get to blow
> > something up once-in-a-while? As for the solar trough I could not see
how
> > to continually add more water without reducing the temperature of the
> > water
> > inside the boiler. Maybe it's like alternators. I didn't understand
them
> > and then suddenly I do. At least enough to get them to do what I want.
> >
>
> The amount of water that needs to be injected, to replace that used as
> steam, is probably less than you are assuming. The output power of a
> steam engine is usually calculated with the power used by the injector
> pump factored in. (Sorta like the sizing of a car's engine includes the
> power needed for the water pump, alternator, ect...) Many steam setups
> include a steam condenser to reclaim the water that is reinjected. In any
> case the boiler's heat requirements are designed to overcome any loss
> from the injected water.
>
> The trough can be sized to produce very high temp, high enough to
> use a higher temp working fluid than water. You would run that through
> a homemade flash boiler/ heat exchanger. The steam would then go to
> an IC engine where: the intake port/valve would be disabled (made
> permanently closed) and modified to open a timed steam pulse, from the
> steam pipe that replaced the spark plug. The spent steam that is coming
> out the "exhaust" would go through a simple condenser (maybe a truck
> radiator) and the water from that feed a pump to the flash boiler.
>
>
> Luck;
> Ken
>
>
Probably time to start a new thread, but then we might have to repeat
ourselves ;-)
From everything I've been reading the solar furnace/steam/steam engine or
turbine idea seems like a very good solution to my energy needs. I get
about 340 sunny days a year. Or pretty close to that anyway.
I like the idea of a fixed trough rather than a tracker if the trough idea
can produce enough heat for enough hours per day. When reading about the
early ones built in the 1800's my thought was to have a series of parabolic
dishes heating a tube of water (or other fluid) instead of a trough. Morris
Dovey reports getting well over 700 F with his trough design but I've been
reading numbers like 1200-1600 degrees F with the multiple flat mirrors
design so I'm not sure if 700 degrees is enough. I was thinking that the
parabolic dishes would only need to be adjusted periodically up and down as
the sun moves seasonally but the heat might be uneven. I am not dismissing
the tracker concept but I generally like to keep things as simple as
possible.
After many hours of searching I managed to learn that the "boiler" or
whatever it is called is sometimes made from the heat exchanger from an old
refrigerator etc or the heater core from a car. I've never seen a heater
core that measures 19" X 19". Must be a really big car.
I have not found any complete instructions yet for someone like me who
basically knows nothing but can do things if given enough information. So
far I have deduced that the basic elements are:
A dish or trough to focus the sun's energy
A heat exchanger/boiler to heat the water
A check valve
A steam engine or turbine (so far I've only found designs that use engines)
One source said the water pressure needs to be 90 psi so a pump would also
be required.
Ken, I hope you are reading this: what do you mean by a "timed steam pulse?"
Is it timed via the crankshaft in the IC engine opening and closing the
exhaust valve or some other way? Could the intake be used and just keep the
intake valve operational and plug the spark plug hole? I read that (I
think) Charles Curnutt used a modified air compressor for his steam engine.
I play around with one last night using compressed air to try to get it to
turn but the one I have uses two simple valves at the top to let the air in
and they are closed at top dead center. It moved but appears to need timed
valves to keep it going. I think I read somewhere that someone made a 1
1/2 HP steam engine from a compressor head and was getting over 6000 watts
of power. That one eludes me. How can you get 6000 watts from 1 1/2 HP?
Anyone know where I can find specific instructions on how to modify a
compressor or IC engine? Meanwhile I will keep playing around with them and
see what I can get them to do.
I have read the old articles on Mother Earth News but much of the
information seems to be missing, either the "sidebars" and illustrations are
not there or my old laptop with dialup just can't download everything. So
far I found four articles and I thought there were only three. Maybe there
are five. Someone directed me to www.phoenixnavigation.com but I could not
find specific instructions there either. I could not find the Mother Earth
News articles anywhere else but I'm a pretty lousy Googler. Charles
Curnutt's design preceeds the internet and he does not seem to have a web
site. So, if anyone knows where I can find complete step-by-step
instructions please tell me.
Ken Maltby
Tracking the sun can be very easy for a trough system. The sun travels
in an arc, with the arc's hight above the horizion changing seasonally.
The sun's position on the arc goes from one end of the arc in the morning
to the oppisite end of the arc in the evening. So the basic angle that the
trough leans back at, might be changed every three months, (if you were
trying for every possible bit of concentration of the sun's rays) or just
set
at an angle based on your latitude. All that's needed to track the sun's
daily movement along the arc is to tilt the trough, or more to the point the
trough's reflector, keeping the same focal point.
Water boils at 212F, you get a low superheated (Dry) steam
starting at around 450F. (At normal operating pressures.)
Assuming you have enough of it to handle the mass of water
you wish to heat, 700F is plenty. (1200-1600F is fine for
melting alluminum, though.)
>
> After many hours of searching I managed to learn that the "boiler" or
> whatever it is called is sometimes made from the heat exchanger from an
> old
> refrigerator etc or the heater core from a car. I've never seen a heater
> core that measures 19" X 19". Must be a really big car.
>
A steam "boiler" with a pressure vessel, can get you in both
legal and safety problems. A flash boiler can be made to fail
safe, but there is still the potential legal issue. (If you live
within some city limits, and there are any paid Code Compliance
Officers, kooks, or not so friendly neighbors about, you could
have real problems.)
I can't picture what a "heat exchanger from an old refrigerator"
would be, but I'm using a heater core as part of the water cooling
setup for this system that I'm typing on. It's mostly soldered copper,
so the design of the Boiler would be critical. Maybe there are some
welded together ones available?
> I have not found any complete instructions yet for someone like me who
> basically knows nothing but can do things if given enough information. So
> far I have deduced that the basic elements are:
>
> A dish or trough to focus the sun's energy
> A heat exchanger/boiler to heat the water
> A check valve
> A steam engine or turbine (so far I've only found designs that use
> engines)
>
> One source said the water pressure needs to be 90 psi so a pump would also
> be required.
>
> Ken, I hope you are reading this: what do you mean by a "timed steam
> pulse?"
> Is it timed via the crankshaft in the IC engine opening and closing the
> exhaust valve or some other way?
Details depend on a number of factors, IC engines come in several flavors,
2 Stroke, 4 Stroke, Rotary, gas, diesel; but the part that extracts the
power
of the expanding gas generated from igniting the fuel gas, is stolen
directly
from how steam power works. (Even gas turbine and Jet engines can
trace the part that extracts the power from the expanding gas, back to
the steam turbine.) In piston engines, the pressure from the expanding
gas, or the steam, pushes the piston down a cylinder and turning a crank
shaft. Intake and Exauhst valving is timed and used to accomplish a
number of things for the IC engine, that aren't needed for steam power.
IC engines need to compress an air fuel mixture to create an explosive
charge, not so for steam, and adding steam pressure during an IC
compression stroke would be counter productive.
The steam is at pressure to start, as the pressure is generated
externally
(it should be possible to create a pulse, say from a flash boiler, to match
an engine's requirements but I can't think of any practical way to do it.)
The "timed steam pulse" I mentioned would be drawn from a
pressurized reserve. It would be like using an air cleaner nozzle from an
air compressor, there is a little extra pulse of air when you first open the
valve. For the conversion of an IC engine, you want a pulse of the right
length of time to pressurize the cylinder and move the piston.
The timing need not, and won't, match that of the original valve timing
for
the IC engine. For instance you could change both the exhaust and intake
timing so that both valves were open during most of the compression cycle
(you would probably close one or both for a short part of the cycle to act
as
a shock absorber for the piston). Not needing a compression cycle should
make the engine a little more effective, probably even with the engine
having
to drive the feed water pump for the boiler.
Could the intake be used and just keep the
> intake valve operational and plug the spark plug hole?
As a lazy tinkerer, a threaded hole entering directly where
the initial expansion of the fuel gas was designed to occur,
is pretty hard to pass up. I guess you could use the intake
valve, if the intake manifold can take the pressure (it was
made to handle a fuel air mixture at relatively low pressure,
or you made your own.) and the timing adjusted of course.
> I read that (I
> think) Charles Curnutt used a modified air compressor for his steam
> engine.
> I play around with one last night using compressed air to try to get it to
> turn but the one I have uses two simple valves at the top to let the air
> in
> and they are closed at top dead center. It moved but appears to need
> timed
> valves to keep it going. I think I read somewhere that someone made a 1
> 1/2 HP steam engine from a compressor head and was getting over 6000 watts
> of power. That one eludes me. How can you get 6000 watts from 1 1/2 HP?
> Anyone know where I can find specific instructions on how to modify a
> compressor or IC engine? Meanwhile I will keep playing around with them
> and
> see what I can get them to do.
>
The simpler air compressor may actually be a better choice for
conversion to a steam motor. The fact that you would be trying
to reverse a process that involves the compression of the gas,
makes me wonder if there wouldn't be other complications, though.
Maybe that was 6000 watts from a 1 1/2 HP DC electric motor?
> I have read the old articles on Mother Earth News but much of the
> information seems to be missing, either the "sidebars" and illustrations
> are
> not there or my old laptop with dialup just can't download everything. So
> far I found four articles and I thought there were only three. Maybe
> there
> are five. Someone directed me to www.phoenixnavigation.com but I could
> not
> find specific instructions there either. I could not find the Mother
> Earth
> News articles anywhere else but I'm a pretty lousy Googler. Charles
> Curnutt's design preceeds the internet and he does not seem to have a web
> site. So, if anyone knows where I can find complete step-by-step
> instructions please tell me.
>
>
Luck;
Ken
P.S. I just bought a "smog pump" and will modify it to see if
will function as; first an air motor then as steam motor.
daestrom
>
<snip>
Valve timing on reciprocating steam engines evolved into quite a science in
its own right. A good place to learn a lot about it is railroad steam
locomotives. The duration of the 'pulse' is varied based on the amount of
load/speed wanted. With light loads the pulse is very short and the
expansion of the steam in the cylinder drops the pressure down to
atmospheric. With heavy loads, a longer/larger pulse and the steam pressure
in the cylinder is still quite high when the exhaust valve opens.
This is what creates that 'chuff-chuff' sound of the old steam locomotives
when working hard. The steam 'blasts' its way out the exhaust valve and up
the smoke stack. When operating like this the engine develops a lot of
tractive effort (i.e. 'pull') but it is not very efficient at all. A lot of
energy goes out the exhaust port.
Locomotive steam engines had two primary controls. The 'throttle' is a
simple valve that controls the flow of steam from the boiler towards the
cylinders. The reverser (also known as the 'Johnson-bar') controls some
linkages in the valve train that would control how far the inlet valve
opened and how long it remained open. Operating the two together to get the
power you want and without wasting a lot of steam was an art that railroad
engineers learned on-the-job. Generally, once running, you want to get the
throttle open as far as possible and cut back on the reverser for as short a
valve opening as possible to limit speed. The cylinder gets a very short
'pulse' of highest pressure/energy steam and that steam is allowed to expand
as much as possible before the exhaust opens. This reduces throttle losses
and conserves water.
I don't think you could use the intake valve to admit steam because the
steam pressure in the manifold would push the valve open all the time. So
on the 'exhaust' stroke when the cylinder is open to atmosphere through the
exhaust valve, you'd be blowing steam past the inlet valve straight to the
exhaust. And that's a bad thing. The idea to use inlet and exhaust both as
'outlet' valves and use the spark plug hole for some form of 'steam
injector' might work better. If you can come up with a sort of 'pop'
injector that you can control the steam injection would be great.
daestrom
Ulysses
I live outside the city limits but we have Code Enforcement and unfriendly
(at least one, anyway) neighbors. Most of my neighbors would think a wind
turbine or solar furnace would be great, but it only takes one... They even
have two black, unmarked helicoptors that fly around looking for stuff.
Probaby mostly drugs, but even so....
So, is it illegal to make steam or what? Or is it just illegal to made
steam above a certain temperature? I was thinking I could build a solar
furnace a put a rubber chicken at the top on a rotiserie as a decoy.
>
> I can't picture what a "heat exchanger from an old refrigerator"
> would be, but I'm using a heater core as part of the water cooling
> setup for this system that I'm typing on. It's mostly soldered copper,
> so the design of the Boiler would be critical. Maybe there are some
> welded together ones available?
I'm having trouble picturing much of what I've been reading and very little
luck finding any detailed photographs. This stuff was big 30 years ago but
seems to have wandered to the wayside. If the design by Charles Curnutt
worked as well as Mother Earth said it did then it seems like many people
would have them in their back yards and somebody would be commercially
producing them. Maybe they blow up. It sounded too good to be true.
Time to read about steam engines. This sounds pretty complicated. I was
also wondering about blowby past the piston rings. It seems like a lot of
water could get into the crankcase.
I've been looking at the Air Cutter at Harbor Freight that spins at 18,000
rpm and costs only $7. I suspect that once 700 degree steam is put into it
it will be a waste of $7. The thing about Harbor Freight stuff is that a
lot of it is very good quality and comparable to tools that cost many times
as much. But some of their stuff is cheap crap.
The turbine idea does seem much simpler.
>
>
drydem
> "Ken Maltby" <kmal...@sbcglobal.net> wrote in message
It's not the steam but operating any superheated furnance/engine
that's going to require a license in most jurisdiction. Typicall this
is
to insure safe operations - since steam engines/turbines have a
long history of blowing up when they are improperly operated or
poorly maintained. For example, a methane generator
- which operates by creating super heated gas from burning methane
- has electronics that automatically monitors its operational
temperature 24-hours/day every day of the year to presumedly to
automatically halt operations if a critical temperature is reached.
When the operating temperature goes above a certain level - a
facility engineer must be there to review the system safety. In
general the engineer needs to inspect for metal, defective sensors,
and engine integrity.
Morris Dovey
> Morris Dovey reports getting well over 700 F with his trough design
> but I've been reading numbers like 1200-1600 degrees F with the
> multiple flat mirrors design so I'm not sure if 700 degrees is
> enough.
I got the 724F temperature with a less than 4' wide trough. If I bend my
4x8 mirror the other way (to make a trough 4' long and a bit less than
8' wide) I think I'd roughly double that temperature to something like
1448F.
Neon John
>I live outside the city limits but we have Code Enforcement and unfriendly
>(at least one, anyway) neighbors. Most of my neighbors would think a wind
>turbine or solar furnace would be great, but it only takes one...
So burn 'em out. No, I'm not joking.
>So, is it illegal to make steam or what? Or is it just illegal to made
>steam above a certain temperature? I was thinking I could build a solar
>furnace a put a rubber chicken at the top on a rotiserie as a decoy.
Depends on the state. Some, like Ga regulate on BTU input. Others regulated
on pressure. In any event, if there has ever been a better instance for
"better to beg fogginess than permission", this is it.
>> The timing need not, and won't, match that of the original valve timing
>> for
>> the IC engine. For instance you could change both the exhaust and intake
>> timing so that both valves were open during most of the compression cycle
>> (you would probably close one or both for a short part of the cycle to act
>> as
>> a shock absorber for the piston). Not needing a compression cycle should
>> make the engine a little more effective, probably even with the engine
>> having
>> to drive the feed water pump for the boiler.
>
>Time to read about steam engines. This sounds pretty complicated. I was
>also wondering about blowby past the piston rings. It seems like a lot of
>water could get into the crankcase.
As you probably already know, real steam engines have sliding gland seals on
the pusher rod that connects to the con rod. In college, I watched the head
of the MechE department try to turn a Harley engine into a steam engine. It
mostly failed. His (successful) solution for lubrication was to mist some
steam cylinder oil into the incoming steam. The exhaust steam passed through
the crankcase, like a 2-stroke in reverse, to lube the lower end bearings.
Though wasteful, messy and smelly, that part worked.
For a closed loop steam system, my solution to the problem would probably be a
synthetic oil suitable for the temperature involved, allowed to circulate
freely in the system.
>> P.S. I just bought a "smog pump" and will modify it to see if
>> will function as; first an air motor then as steam motor.
I've never gotten one to run as an air motor so I doubt it would work on
steam. Too much volume involved, the vane geometry is all wrong for sealing
and the carbon vanes are quite weak and incapable of withstanding much
pressure.
I love smog pumps for what they are - low pressure, high volume pumps. I have
three running in parallel supplying 2 psi air to my neon shop burners. At 5
psi they start getting very unhappy, howling, spitting carbon dust and getting
very hot.
>
>I've been looking at the Air Cutter at Harbor Freight that spins at 18,000
>rpm and costs only $7. I suspect that once 700 degree steam is put into it
>it will be a waste of $7. The thing about Harbor Freight stuff is that a
>lot of it is very good quality and comparable to tools that cost many times
>as much. But some of their stuff is cheap crap.
You can try it but I doubt that it'll work very well. If you can work out the
lube problem, a hydraulic motor will probably be more suitable.
Incidentally, low pressure steam with enough superheat to reach 700 degrees is
simply a waste. Any superheat over that necessary to keep the steam dry at
the inlet of the engine is wasted at these low pressures. If there is enough
heat available to generate that kind of superheat then making a higher volume
of barely superheated steam will be much more satisfactory. Just inject more
water.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
You have a magnetic personality... That must be why all your mental floppies are blank.
Neon John
wrote:
>It's not the steam but operating any superheated furnance/engine
>that's going to require a license in most jurisdiction.
Superheating has absolutely nothing to do with it, at least not in any state
I've worked in. Licensing is governed by heat input or pressure or both.
Georgia requires a boiler license at 1,000,000 BTU input. That's why most
large restaurants in Georgia have 2 or more 900,000 BTU water heaters. This
is for HOT WATER and not even steam. I ran into that when upgrading some
friend's restaurant water system.
In other states, it's anything above 15psi. This is designed to exempt home
heating boilers. Other states (I believe that PA is in this group) regulate
on both pressure and BTU input.
"Superheating" is a big sexy sounding word but all it means is that the steam
is a dry gas that is hotter than its vapor pressure would indicate. As far as
safety goes, I'm much more concerned about very wet steam or steam/water
mixes. Dry steam simply leaks like any other gas and if a vessel explodes, it
is a simple gas expansion explosion. The water in wet steam, water/steam mix
or high pressure heated water flashes when depressurized, creating much more
overpressure and releases much more energy. Anyone who's ever been in the
(far) vicinity of a high pressure boiler feedwater blowout knows exactly what
I mean. Anyone in the near vicinity is no longer here to tell us about it.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Hell is truth seen too late. -Hobbs
Ken Maltby
"Neon John" <n...@never.com> wrote in message
news:9tc34416q0qk9rr2j...@4ax.com...
> On Sat, 31 May 2008 10:29:49 -0700, "Ulysses" <eatm...@spamola.com/>
> wrote:
>
>>Time to read about steam engines. This sounds pretty complicated. I was
>>also wondering about blowby past the piston rings. It seems like a lot of
>>water could get into the crankcase.
>
> As you probably already know, real steam engines have sliding gland seals
> on
> the pusher rod that connects to the con rod. In college, I watched the
> head
> of the MechE department try to turn a Harley engine into a steam engine.
> It
> mostly failed. His (successful) solution for lubrication was to mist some
> steam cylinder oil into the incoming steam. The exhaust steam passed
> through
> the crankcase, like a 2-stroke in reverse, to lube the lower end bearings.
> Though wasteful, messy and smelly, that part worked.
>
> For a closed loop steam system, my solution to the problem would probably
> be a
> synthetic oil suitable for the temperature involved, allowed to circulate
> freely in the system.
>
For the most part I think you would want to consider a change
in the lubrication system, as part of such a conversion. Perhaps
a system with oil pumped to the critical bearings and not relying
on the splash from a sump. This does make the aircompressor
conversion look better though. It's a good thing we are talking
about devices to power a relatively small generator. As it is, I
would want to start with a pretty substantial heavy duty
aircompressor.
>
>>> P.S. I just bought a "smog pump" and will modify it to see if
>>> will function as; first an air motor then as steam motor.
>
> I've never gotten one to run as an air motor so I doubt it would work on
> steam. Too much volume involved, the vane geometry is all wrong for
> sealing
> and the carbon vanes are quite weak and incapable of withstanding much
> pressure.
>
I'll continue playing with it, but my first impression certianly
bears that out.
> I love smog pumps for what they are - low pressure, high volume pumps. I
> have
> three running in parallel supplying 2 psi air to my neon shop burners. At
> 5
> psi they start getting very unhappy, howling, spitting carbon dust and
> getting
> very hot.
>
Hmm... low pressure, high volume; I wonder what effect that
approach might have with my little crucible furnace that I built
to melt aluminum for green sand casting. I used a little hair
dryer, the kind that feeds a bag placed on the head. I had it
feed into the furnace through a 1 1/4" PVC ball valve and
normally melted aluminum with it less than half way open.
Of course, at some point I had to see what it could do, so
I opened it up all the way and opened up the gas a little more
as well, the result was a big chunk of the cast iron pot I was
melting the aluminum in, itself melted into a puddle on the
bottom of the furnace.
>>
>>I've been looking at the Air Cutter at Harbor Freight that spins at 18,000
>>rpm and costs only $7. I suspect that once 700 degree steam is put into
>>it
>>it will be a waste of $7. The thing about Harbor Freight stuff is that a
>>lot of it is very good quality and comparable to tools that cost many
>>times
>>as much. But some of their stuff is cheap crap.
>
> You can try it but I doubt that it'll work very well. If you can work out
> the
> lube problem, a hydraulic motor will probably be more suitable.
>
I was thinking of using a hydraulic motor/pump to circulate hot oil,
(Dowtherm A, or Crisco I'm not sure yet) through a solar trough
collector of Mr. Dovey's design (if I can find his offer again). I was
thinking I might have to can the pump to limit leaking and allow me
to cool the end of the can that would have the mag drive interface.
> Incidentally, low pressure steam with enough superheat to reach 700
> degrees is
> simply a waste. Any superheat over that necessary to keep the steam dry
> at
> the inlet of the engine is wasted at these low pressures. If there is
> enough
> heat available to generate that kind of superheat then making a higher
> volume
> of barely superheated steam will be much more satisfactory. Just inject
> more
> water.
>
Right, and the 250C/480F range is pushing the working limits
of seals and components that are readily available; so that is what
I would be shooting for. The references to 700F and above
were to what can be obtained from the solar collector designs
that were discussed.
Luck;
Ken
Balanced View
It's like anything else, nobody wants to be first. There is a copy
making solar dishes located here:
Neon John
wrote:
>> I love smog pumps for what they are - low pressure, high volume pumps. I
>> have
>> three running in parallel supplying 2 psi air to my neon shop burners. At
>> 5
>> psi they start getting very unhappy, howling, spitting carbon dust and
>> getting
>> very hot.
>>
>
> Hmm... low pressure, high volume; I wonder what effect that
>approach might have with my little crucible furnace that I built
>to melt aluminum for green sand casting. I used a little hair
>dryer, the kind that feeds a bag placed on the head. I had it
>feed into the furnace through a 1 1/4" PVC ball valve and
>normally melted aluminum with it less than half way open.
>Of course, at some point I had to see what it could do, so
>I opened it up all the way and opened up the gas a little more
>as well, the result was a big chunk of the cast iron pot I was
>melting the aluminum in, itself melted into a puddle on the
>bottom of the furnace.
>
Smog pumps would work but they're quite noisy and inefficient. They were
simply the only thing I could get my hands on that would generate 2 psi (what
glass fire venturi mixers are designed for) at high volume at the time and
within my budget. Most of the input energy goes into heat and noise. It
takes a fully loaded 1hp motor to drive these pumps.
Probably the best thing for the kind of pressure and volume you want is a
regenerative blower. These are capable of up to about 5 psi, depending on
design and the number of stages, and very high volumes. Here's one that is
more than suitable for your foundry. I use a similar but smaller one for my
glass furnace that gets even hotter than aluminum smelting.
http://www.surpluscenter.com/item.asp?UID=2008053123454331&item=16-1084&catname=electric
As long as you maintain the mufflers (long structures on the inlet and
outlet), they are extremely quiet and quite efficient. Here's my page showing
the internal construction and explaining how they work
http://www.neon-john.com/Neon/Misc/Regen_blower/Regen_home.htm
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Beware the lollipop of mediocrity. Lick once and you suck forever.
Ulysses
I've been looking at (as opposed to studying as *studying would indicate
some sort of comprehension) diagrams of steam engines and I can sorta grasp
it in my mind but putting it into a practical application seems like it
would be very complicated mechanically. Hopefully it will *sink in*
eventually, as things usually do, given enough time.
>
> For a closed loop steam system, my solution to the problem would probably
be a
> synthetic oil suitable for the temperature involved, allowed to circulate
> freely in the system.
>
>
> >> P.S. I just bought a "smog pump" and will modify it to see if
> >> will function as; first an air motor then as steam motor.
>
> I've never gotten one to run as an air motor so I doubt it would work on
> steam. Too much volume involved, the vane geometry is all wrong for
sealing
> and the carbon vanes are quite weak and incapable of withstanding much
> pressure.
>
> I love smog pumps for what they are - low pressure, high volume pumps. I
have
> three running in parallel supplying 2 psi air to my neon shop burners. At
5
> psi they start getting very unhappy, howling, spitting carbon dust and
getting
> very hot.
>
This is the second time I've seen smog pumps mentioned in this context
recently and I suspect the other time was from Ken too ;-). I'm trying to
find out how they work and now it does not sound very promising.
> >
> >I've been looking at the Air Cutter at Harbor Freight that spins at
18,000
> >rpm and costs only $7. I suspect that once 700 degree steam is put into
it
> >it will be a waste of $7. The thing about Harbor Freight stuff is that a
> >lot of it is very good quality and comparable to tools that cost many
times
> >as much. But some of their stuff is cheap crap.
>
> You can try it but I doubt that it'll work very well. If you can work out
the
> lube problem, a hydraulic motor will probably be more suitable.
Hmmm, time to look up hydraulic motors....
>
> Incidentally, low pressure steam with enough superheat to reach 700
degrees is
> simply a waste. Any superheat over that necessary to keep the steam dry
at
> the inlet of the engine is wasted at these low pressures. If there is
enough
> heat available to generate that kind of superheat then making a higher
volume
> of barely superheated steam will be much more satisfactory. Just inject
more
> water.
This seems to be where the general design runs into problems--making steam
to generate electricity and then using the electricity to operate a water
pump to make steam to generate electricity. One article I read recently had
so much consumption I'm not sure if it had a net positive. One idea that is
floating around in the dark corners of my mind is to simply have an elevated
tank (higher than the steam pipe) along with a check valve. Would the
escaping steam create enough of a vacuum to pull the water into the pipe?
About what temperature do you suppose "barely superheated steam" would be
at?
Ulysses
"Balanced View" <Ni...@nill.net> wrote in message
news:g1sq8a$u1q$4...@aioe.org...
> >> P.S. I just bought a "smog pump" and will modify it to see if
> >> will function as; first an air motor then as steam motor.
> >>
> >
> > I've been looking at the Air Cutter at Harbor Freight that spins at
18,000
> > rpm and costs only $7. I suspect that once 700 degree steam is put into
it
> > it will be a waste of $7. The thing about Harbor Freight stuff is that
a
> > lot of it is very good quality and comparable to tools that cost many
times
> > as much. But some of their stuff is cheap crap.
> >
> > The turbine idea does seem much simpler.
> >
> >
>
> It's like anything else, nobody wants to be first. There is a copy
> making solar dishes located here:
>
I don't mind being first, but I sure don't want to spend months or years
figuring out what someone else already spent months or years figuring out.
Thanks for the link.
> http://www.acrosolarlasers.com/
Ulysses
wrote:
>
>
> >I live outside the city limits but we have Code Enforcement and
unfriendly
> >(at least one, anyway) neighbors. Most of my neighbors would think a
wind
> >turbine or solar furnace would be great, but it only takes one...
>
> So burn 'em out. No, I'm not joking.
I'm not sure who it is yet.
Other than the materials that it's made of (and lubrication problems) what
is the problem with running an air motor from steam? I've been reading
about steam pressures in the 80-100 psi range and that's about what most air
tools run at (well, a little higher). Is there less mass in steam than in
air? I would think there would be more. Do the air tools simply melt
before you find out what it can do? My thought was that an air tool that
has enough torque to cut through steel at 18,000 rpm would probably have
enough torque to drive an alternator if geared down 6:1. At that ratio I
would expect at least 1500 watts. All that is assuming enough pressure to
drive it, of course.
Ulysses
"Morris Dovey" <mrd...@iedu.com> wrote in message
news:48419376$0$87064$815e...@news.qwest.net...
> Ulysses wrote:
>
> > Morris Dovey reports getting well over 700 F with his trough design
> > but I've been reading numbers like 1200-1600 degrees F with the
> > multiple flat mirrors design so I'm not sure if 700 degrees is
> > enough.
>
> I got the 724F temperature with a less than 4' wide trough. If I bend my
> 4x8 mirror the other way (to make a trough 4' long and a bit less than
> 8' wide) I think I'd roughly double that temperature to something like
> 1448F.
So, if I understand this correctly, you would still have the same amount of
surface area on the trough but would be concentrating the heat onto half the
area of pipe?
If we settled on the ideal temperature for this project yet I missed it but
it's looking like 700 degrees is probably more than is needed so that part
seems to be getting simpler.
It's also looking like nobody is making and selling micro steam turbines
because of Code regulations. It is becomming more clear why you are using
the heat engine. Can it turn an alternator?
Anonymouse
>> A steam "boiler" with a pressure vessel, can get you in both
>> legal and safety problems. A flash boiler can be made to fail
>> safe, but there is still the potential legal issue. (If you live
>> within some city limits, and there are any paid Code Compliance
>> Officers, kooks, or not so friendly neighbors about, you could
>> have real problems.)
> So, is it illegal to make steam or what? Or is it just illegal to made
> steam above a certain temperature?
Mythbusters blowing up hot water heaters:
http://www.youtube.com/watch?v=pu3FwgIHsQA
Technique for dialup users:
Open the above link in a new window, click pause, go do something else
for 2 - 5 hours, Return and watch vid.
Morris Dovey
> "Morris Dovey" <mrd...@iedu.com> wrote in message
>> I got the 724F temperature with a less than 4' wide trough. If I bend my
>> 4x8 mirror the other way (to make a trough 4' long and a bit less than
>> 8' wide) I think I'd roughly double that temperature to something like
>> 1448F.
>
> So, if I understand this correctly, you would still have the same amount of
> surface area on the trough but would be concentrating the heat onto half the
> area of pipe?
Close, but for a parabolic trough I think temperature would be better
related to the /width/ of the trough (and perhaps the width of the
"bright line" onto which the solar energy was focused if the target
surface isn't exactly at the focus).
The energy reflected to the target will be proportional to the capture
area of the reflecting trough (I'm covering my backside here because I
don't think perfect reflectors exist).
The energy captured will be less than the energy reflected due to
reflection, conduction/convection, and re-radiation. Because these
losses are higher with greater temperature differentials, I'd expect
that the energy collection would be less efficient.
The interesting problem is to find the best trade-off between the
efficiency of the energy /collection/ and the temperature-related
efficiency of the process that /uses/ the energy. I hadn't grasped any
of this until someone pointed me at Carnot's findings on Wikipedia.
> If we settled on the ideal temperature for this project yet I missed it but
> it's looking like 700 degrees is probably more than is needed so that part
> seems to be getting simpler.
Actually, you need to know more than that - you do want to determine the
best temperature, but you also need to know how much energy input is
needed at that temperature. I'm not sure physicists define temperature,
but I think of it as energy /density/ (amount of energy per unit mass).
> It's also looking like nobody is making and selling micro steam turbines
> because of Code regulations. It is becomming more clear why you are using
> the heat engine. Can it turn an alternator?
I suspect that steam engines probably won't strike most folks as
appropriate in a consumer context ("real" men not only don't eat quiche,
they don't read directions) and the litigation exposure would probably
discourage nearly all would-be manufacturers/importers.
A rotary Stirling can indeed turn an alternator. The fluidynes I'm
working with would probably work best with a linear (push-pull) alternator.
Duane C. Johnson
> "Ken Maltby" <kma...@sbcglobal.net> wrote:
> > I like the idea of a fixed trough rather than a tracker
> > if the trough idea
>>>can produce enough heat for enough hours per day. When
>>>reading about the early ones built in the 1800's my
>>>thought was to have a series of parabolic dishes
>>>heating a tube of water (or other fluid) instead of a
>>>trough. Morris Dovey reports getting well over 700 F
>>>with his trough design but I've been reading numbers
>>>like 1200-1600 degrees F with the multiple flat mirrors
>>>design so I'm not sure if 700 degrees is enough.
>>>I was thinking that the parabolic dishes would only
>>>need to be adjusted periodically up and down,
>>>(DEClination), as the sun moves seasonally but the
>>>heat might be uneven. I am not dismissing the tracker
>>>concept but I generally like to keep things as simple
>>>as possible.
But a dish does require tracking on at least one axis.
>>Tracking the sun can be very easy for a trough system.
>>The sun travels in an arc, with the arc's height above
>>the horizon changing seasonally. The sun's position
>>on the arc goes from one end of the arc in the morning
>>to the opposite end of the arc in the evening. So the
>>basic angle that the trough leans back at, might be
>>changed every three months,
If you have a trough design that only needs DEClination
adjustment every 3 months the concentration ratio is
pretty low and would not be a good choice for producing
steam.
>>(if you were trying for every possible bit of
>>concentration of the sun's rays) or just set at an
>>angle based on your latitude. All that's needed to
>>track the sun's daily movement along the arc is to tilt
>>the trough, or more to the point the trough's reflector,
>>keeping the same focal point.
I would not use an E-W, East-West, axis trough for
producing steam. While the tracking sounds easier there are
major compromises to the simple "No-Tracker" trough idea.
1. There are geometric errors to the no-track method.
These errors cause the image to miss the receiver
line at the extremes of the day. I.e. output is
useful only in the middle of the day.
2. The power output varies throughout the day due to
Cosine law errors when the sun is not normal to the
trough. These errors can be fixed with active tracking.
I would use a N-S, North-South, or even better a Polar
axis oriented trough. Yes, these require active tracking.
However, there are major benefits if active tracking is
included in the trough design.
1. The trough can be designed with higher concentration
factors. High concentration makes the receiver
smaller and generally more efficient.
2. The power output from the trough will remain
essentially constant throughout the day.
3. More efficiency promotes smaller size and lower cost.
The lower cost probably justifies the added $35us for
the tracker.
>>Water boils at 212F, you get a low superheated (Dry)
>>steam starting at around 450F. (At normal operating
>>pressures.) Assuming you have enough of it to handle
>>the mass of water you wish to heat, 700F is plenty.
>>(1200-1600F is fine for melting aluminum, though.)
>>>After many hours of searching I managed to learn that
>>>the "boiler" or whatever it is called is sometimes made
>>>from the heat exchanger from an old refrigerator etc or
>>>the heater core from a car. I've never seen a heater
>>>core that measures 19" X 19". Must be a really big car.
Bad idea, the convection losses from the heater core fins
would be excessive. A flat surface is better than an finned
one.
>>A steam "boiler" with a pressure vessel, can get you in
>>both legal and safety problems. A flash boiler can be
>>made to fail safe, but there is still the potential legal
>>issue. (If you live within some city limits, and there
>>are any paid Code Compliance Officers, kooks, or not so
>>friendly neighbors about, you could have real problems.)
> So, is it illegal to make steam or what? Or is it
> just illegal to made steam above a certain temperature?
> I was thinking I could build a solar furnace a put a
> rubber chicken at the top on a rotisserie as a decoy.
The rule of thumb is if the pressurized volume is greater
than 1 quart you will need a boiler license. You need to
check with local laws though. The flash tube boiler designs
help here as the pressurized volume is much lower than a
conventional boiler.
>>I can't picture what a "heat exchanger from an
>>old refrigerator" would be, but I'm using a heater
>>core as part of the water cooling setup for the
>>system that I'm typing on. It's mostly soldered
>>copper, so the design of the Boiler would be
>>critical. Maybe there are some welded together
>>ones available?
I don't get the "refrigerator" reference either. Solar
concentrator receivers should NOT have external fins.
They generally should have smooth external surfaces.
Check out this receiver:
http://www.redrok.com/electron.htm#vdish1
Made from cast aluminum cans and worked well.
> I'm having trouble picturing much of what I've been
> reading and very little luck finding any detailed
> photographs. This stuff was big 30 years ago but
> seems to have wandered to the wayside. If the design
> by Charles Curnutt worked as well as Mother Earth
> said it did then it seems like many people would have
> them in their back yards and somebody would be
> commercially producing them. Maybe they blow up.
> It sounded too good to be true.
Or this:
http://www.redrok.com/main.htm#teton
>>>I have not found any complete instructions yet for
>>>someone like me who basically knows nothing but can
>>>do things if given enough information.
Use an obsolete C-band satellite dish. These things are
readily available and much of the hardware is already
there.
>>The simpler air compressor may actually be a better
>>choice for conversion to a steam motor. The fact that
>>you would be trying to reverse a process that involves
>>the compression of the gas, makes me wonder if there
>>wouldn't be other complications, though.
Or look to the scroll compressors. These work as
expanders with only minor modifications. See:
http://www.redrok.com/engine.htm#scroll
Duane
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Duane C. Johnson
> "Ken Maltby" <kma...@sbcglobal.net> wrote:
> > I like the idea of a fixed trough rather than a tracker
> > if the trough idea
>>>can produce enough heat for enough hours per day. When
>>>reading about the early ones built in the 1800's my
>>>thought was to have a series of parabolic dishes
>>>heating a tube of water (or other fluid) instead of a
>>>trough. Morris Dovey reports getting well over 700 F
>>>with his trough design but I've been reading numbers
>>>like 1200-1600 degrees F with the multiple flat mirrors
>>>design so I'm not sure if 700 degrees is enough.
>>>I was thinking that the parabolic dishes would only
>>>need to be adjusted periodically up and down,
>>>(DEClination), as the sun moves seasonally but the
>>>heat might be uneven. I am not dismissing the tracker
>>>concept but I generally like to keep things as simple
>>>as possible.
But a dish does require tracking on at least one axis.
>>Tracking the sun can be very easy for a trough system.
>>The sun travels in an arc, with the arc's height above
>>the horizon changing seasonally. The sun's position
>>on the arc goes from one end of the arc in the morning
>>to the opposite end of the arc in the evening. So the
>>basic angle that the trough leans back at, might be
>>changed every three months,
If you have a trough design that only needs DEClination
adjustment every 3 months the concentration ratio is
pretty low and would not be a good choice for producing
steam.
>>(if you were trying for every possible bit of
>>concentration of the sun's rays) or just set at an
>>angle based on your latitude. All that's needed to
>>track the sun's daily movement along the arc is to tilt
>>the trough, or more to the point the trough's reflector,
>>keeping the same focal point.
I would not use an E-W, East-West, axis trough for
producing steam. While the tracking sounds easier there are
major compromises to the simple "No-Tracker" trough idea.
1. There are geometric errors to the no-track method.
These errors cause the image to miss the receiver
line at the extremes of the day. I.e. output is
useful only in the middle of the day.
2. The power output varies throughout the day due to
Cosine law errors when the sun is not normal to the
trough. These errors can be fixed with active tracking.
I would use a N-S, North-South, or even better a Polar
axis oriented trough. Yes, these require active tracking.
However, there are major benefits if active tracking is
included in the trough design.
1. The trough can be designed with higher concentration
factors. High concentration makes the receiver
smaller and generally more efficient.
2. The power output from the trough will remain
essentially constant throughout the day.
3. More efficiency promotes smaller size and lower cost.
The lower cost probably justifies the added $35us for
the tracker.
>>Water boils at 212F, you get a low superheated (Dry)
>>steam starting at around 450F. (At normal operating
>>pressures.) Assuming you have enough of it to handle
>>the mass of water you wish to heat, 700F is plenty.
>>(1200-1600F is fine for melting aluminum, though.)
>>>After many hours of searching I managed to learn that
>>>the "boiler" or whatever it is called is sometimes made
>>>from the heat exchanger from an old refrigerator etc or
>>>the heater core from a car. I've never seen a heater
>>>core that measures 19" X 19". Must be a really big car.
Bad idea, the convection losses from the heater core fins
would be excessive. A flat surface is better than an finned
one.
>>A steam "boiler" with a pressure vessel, can get you in
>>both legal and safety problems. A flash boiler can be
>>made to fail safe, but there is still the potential legal
>>issue. (If you live within some city limits, and there
>>are any paid Code Compliance Officers, kooks, or not so
>>friendly neighbors about, you could have real problems.)
> So, is it illegal to make steam or what? Or is it
> just illegal to made steam above a certain temperature?
> I was thinking I could build a solar furnace a put a
> rubber chicken at the top on a rotisserie as a decoy.
The rule of thumb is if the pressurized volume is greater
than 1 quart you will need a boiler license. You need to
check with local laws though. The flash tube boiler designs
help here as the pressurized volume is much lower than a
conventional boiler.
>>I can't picture what a "heat exchanger from an
>>old refrigerator" would be, but I'm using a heater
>>core as part of the water cooling setup for the
>>system that I'm typing on. It's mostly soldered
>>copper, so the design of the Boiler would be
>>critical. Maybe there are some welded together
>>ones available?
I don't get the "refrigerator" reference either. Solar
concentrator receivers should NOT have external fins.
They generally should have smooth external surfaces.
Check out this receiver:
http://www.redrok.com/electron.htm#vdish1
Made from cast aluminum cans and worked well.
> I'm having trouble picturing much of what I've been
> reading and very little luck finding any detailed
> photographs. This stuff was big 30 years ago but
> seems to have wandered to the wayside. If the design
> by Charles Curnutt worked as well as Mother Earth
> said it did then it seems like many people would have
> them in their back yards and somebody would be
> commercially producing them. Maybe they blow up.
> It sounded too good to be true.
Or this:
http://www.redrok.com/main.htm#teton
>>>I have not found any complete instructions yet for
>>>someone like me who basically knows nothing but can
>>>do things if given enough information.
Use an obsolete C-band satellite dish. These things are
readily available and much of the hardware is already
there.
>>The simpler air compressor may actually be a better
>>choice for conversion to a steam motor. The fact that
>>you would be trying to reverse a process that involves
>>the compression of the gas, makes me wonder if there
>>wouldn't be other complications, though.
Or look to the scroll compressors. These work as