Hi there.
I come from the pumping industry in Australia and trialing the use of SewerCAD at the moment, we use steady-state modeling via excel sheets and also some of the other modeling tools available in the market.
I have gone through the exercises available on Youtube and also from your learn server, where it doesn't actually represent a real-life problem, the pump curves are not just available for a project as you show, and in most cases, for a model it is the responsibility of the designer to choose the pump/s with the help of suppliers, for this, the designer is expected to provide a duty point ie. flow and required head.
please see attached for a simplified real-life problem where we are required to work the pump duty point so we can select a pump. We can do this in various other ways as I have mentioned above and what I want to please know is how to tackle this from SewerCAD. How would you model a system to work out the pump's duty point without placing the pump?
PDF
explanation of the scenario:
we have a wet well and the pump sets are submersible centrifugal sewer pumps.
the incoming gravity pipework is 225mm Ductile Iron pipework, ID is 240mm. The peak incoming flow is 12L/s, and our requirement is the match this flow via the pump selection. ie. the pump flow rate has to be min 12L/s. The levels are provided in the model and based on this flow rate we have selected the forced main as 125mm PE100 PN16 (ID is 102mm)
In some of the other modeling tools, we can place the pump as a fixed flow pump and when we run the model it would develop the required duty point.
while searching about this topic, I had come across this: https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/16879/estimating-a-pump-curve-for-a-model but not too sure if this works or not.
your help in this regard is appreciated and believe this will help many.
Cheers,
Imran
Thanks Gary. I agree. WaterCAD (WaterGEMS) . It has more tools than SewerCAD for things like system head curves, combination pump curves and energy costing. You just need to separate out the portion of the system from the wet well to the final discharge point.
For the benefit of other forum viewers, you can use WaterCad to do exactly what you describe above.
I have used WaterCad to successfully design many sanitary pumping stations. It's a great tool and easy to use. Once you have a library of pump curves it's almost a trivial exercise to see which pump works the best for a given configuration.
WaterCad is also useful for designing and modeling manifolded wastewater pumping stations (which are essentially vastly simplified water distribution systems).
Thank you Yashodhan for your time and effort to clarify this issue, this is what I like about Bentley, a fantastic team to respond to whenever you needed the most.
Hi Imran,
I checked your model but it doesn't have any pump curve defined. If your intention was to determine the pump curve see the following steps I followed. I have sent you the modified model via private message.
1. Using the information from the earlier article you went through (Estimating Pump Curve) I setup the model in such a way that I could estimate the head required. See the scenario "Without Pump" in the shared model. With the difference in HGL at J-1 and J-2 being 13.68 m and flow required as 10 L/s (as per your minimum required) I could setup Test Pump Curve-1.
2. I ran this model with pump in scenario "With Pump @13.68 m head / 10 L/s". In this scenario I checked the System Head Curve as per the article shared by Tom. The system head curve gave me value of head as approximately 18.75 m and flow of 5.2 L/s (which is what is actually calculated).
3. With these values I setup Test Pump Curve-2 and ran the scenario "With Pump@ 16.75 m head / 5.2 L/s".
You can refine the pump curve like this iteratively. What the system head curve shows are the required values. In your case, you require 10 L/s as flow due to scouring requirement, so you can change the pump curves accordingly.
I have leveraged the Scenarios and Alternatives functionality in our products here.
Also, since you are new to SewerCAD, I would also recommend you go through the below article which points to various learning resources;
Learning Resource Guide for New Users of SewerCAD
Let me know if this helps.
Regards,
Yashodhan Joshi
Answer Verified By: Imran Saheer
Hi Yashodhan,
thanks for your response, please see below.
Hope I have packaged it correctly.
Cheers.
TestPSsystemhead.stswpkg.zip