Setting Heating/Cooling Times

[proinsia...@ucdconnect.ie]

Hello,

I am using a model based on the example Building Thermal 4 Zones 1D and am trying to make it replicate the heating and cooling of my building. However, the building that I am investigating only runs from 07:00 to 19:00. Is there a way to set up then model so it only supplies heating/cooling between these times?  

Any help/ideas welcome. 

Thanks

[a.inderfurt...@gmail.com]

Hallo,

yes, there is. Instead of connecting a constant value (Modelica.Blocks.Sources.Constant) as heating and cooling threshold (TSetHeatingZone..., TSetCoolingZone...) connect a Modelica.Blocks.Sources.CombiTimeTable for both thresholds for each zone. In the time table you can give a daily schedule (or weekly, or whatever) in seconds and set the extrapolation to repeat periodically.

To achieve no cooling set the threshold to some unreasonable high value like +100°C and for no heating set a really low value like -100°C.

Now your building is only heated and cooled during your operation hours.

Hope that helps,

Alex

[proinsia...@ucdconnect.ie]

Hello Alex,

Thanks for your reply.

When I try to connect the CombiTimeTable to the heating/cooling set point on the building I get the error "Impossible connection. The connection to a connector with connector sizing parameter must have literal size." So I then tried to connect the table in between the inputs for heating/cooling set points so that I would get the 'make a connection' pop up.

I used this to connect the tables but when I go to simulate I get the errors attached.

I also trying to connect internals gains to my model and getting similar problems.  

In my combiTable I have the heating setpoints in the first column after time followed by the cooling set points.

Many thanks,

Proinsias

[proinsia...@ucdconnect.ie]

Forgot to attached the screenshots.

[a.inderfurt...@gmail.com]

The code snippet looks fine and it should work like that.

You could try a TimeTable instead of the CombiTimeTable and see if that works. It should.

Apart from that you can send your code so I can check the model.

[proinsia...@ucdconnect.ie]

Hello Alex,

I tried using the Timetables and this resulted in a different problem (attached).

I have attached the model if you dont mind having a look.

Thanks for all the help,

Proinsias

[a.inderfurt...@gmail.com]

First thing I noticed is that your temperatures in the tables are given in Celsius, they need to be in Kelvin. Because the tables have a Real output Dymola assumes the temps are in Kelvin.

Second would be to start the time tables at 0 seconds, so you have value defined at the beginning of the simulation.

It seems that the resulting errors are connected to your Office zone. I'm not sure what is causing the error. The easiest way to find out is to start with the 4 zone example and gradually extend it. Important would be to always simulate the model after each change. Then we know exactly which model change causes an error and can deal with it while being sure that everything else works.

[proinsia...@ucdconnect.ie]

Hi Alex,

Got it working perfectly. Thanks for all of the help.