pilot loop hydraulic modelling with EPANET

[Sahini s r]

Hi All,

I'm working on EPANET and I have to model a pilot loop . the re circulation  tank is at a height of 0.75m and a capacity of 45lt which is connected to a pilot loop of 12.5m length and 50 mm diameter and at an elevation of 0.45m.there is a centrifugal pump giving a Q of 15 LPM . when i put these in the EPANET Im not getting a flow of 15LPM .
I think there is some problem with pump curve ( which is flow versus head , flow being 15LPM and head is 1m) or the input / elevations.since Im new to these modelling. Kindly help with this.
Thank you in advance.

[Patrick Moore]

I suspect the issue is that there are no demands in the model given this situation and it's the demands that drive the flow solution equations based on continuity and mass balances.  Try replacing your pump with positive and negative demands of 15 LPM with positive on the suction side and negative on the discharge side and the pump being set to "CLOSED".  The difference in head between the suction and discharge heads is the head required of the pump at 15 LPM flow.  This head difference will may change depending on the level of water in the tank, but since the suction and discharge are governed by the same tank HGL I suspect the only difference will be headloss in the recirculation pipe. I suspect you might want to verify the pump head is ok?

Also make sure you have assigned roughness coefficients for all pipes.

Pat Moore

[Sahini s r]

Hi Patrick,

   Thanks it worked and also can you suggest me some basics of hydraulics that I must and should learn to understand this software, next Ill be working on Real water distribution networks where there is intermittent water supply, How do I work with intermittent supply with EPANET and pressure driven analysis by this software.

Thanks and Regards