Dear all
I am perfoming a steady state simulation dor an 8 klm pipeline with an inner diamter of 899 mm. The pump station contains 3 pumps (2 working+1 stand-by). The operating point of each pump is 500l/s and 26.8m.
After perfomring the system head curve analysis the following reuslts are generated:
The pump curve is a straight line and it is provided from the supplier.
My main issue is that the system is a straight line which is not similar to a typical system curve like the figure below:
Kindly ask you to give me your feed back.
Kind Regards
Hello Abderahmen,
In the System Head Curve tool, did you enter a sufficient "number of intervals" to capture the detail of the parabolic shape?
If that does not help, the following article from our Wiki has some advice on this subject, which may help explain what you see: System head curve generated in WaterGEMS, WaterCAD, or SewerCAD looks different from hand calculations?
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Thank you for your reply.
I increased the number of intervals but I still got the straight trend.
I read the article in the link you proided, but it doesn't apply to my case.
As i mentioned I am modelling an 8 klm pipeline with an inner diamter of 899 mm and I have one demand at the end junction of the pipeline.
Thank you
Are you saying that you have a closed system with no downstream storage? In that case the program cannot accurately determine the system head curve because it cannot vary the flow through it, since it must always meet the exact demand specified. If this is indeed the case, you may need to use Pressure Dependent demands so that the flow can vary. See: System head curves with no downstream storage
Well my system is composed of a resevoir +2 working pumps +8 klm pipeline+end junction with a demand of 1000 l/s.
See the article mentioned in my previous reply - if there is no storage on the downstream side of the pump, the system head curve cannot vary the flow, as it needs to be equal to the sum of the downstream demands.