Your collection system flow will be the input to your model, and your total dynamic head will be determined from your static head plus the velocity head (based on your pipe diameter and flow from the pump). You will need to pick a family of pump curves (from your pump manufacturer) that will be roughly in the range of your TDH and flow from DWF. Then pick the impellar diameter that suits your flow and head requirements as well as physical constraints of your pump station site. Enter a few pump curves in the model and see which one performs the best (flow and head in the high efficiency range of the pump curve). This will be a trial and error approach. Getting the best representation of your system curve (optimum operating point on the curve: flow vs head) is more of an art than science.
Your pump operation will be determined by how these pumps will be turned on and off, how much surcharge can you allow in the upstream system, and whether they are duplex, triplex or bigger stations.
You can also consider variable frequency drive (vfd) pumps which will operate at a constant point by varying the speed of the pump. This will be modeled through real time control (RTC).
I hope this will provide you some guidance.
Rizwan Hamid, PE
rhamid@aqualyzeinc.com
www.aqualyzeinc.com
Linear Mode
