Hi, Working with SewerGEMs, GVF-Convex solver. I need your assistance in setting up a VSP or VFD with the below on and off (elevations) controls. I want to use the fixed head VSP type and use my control node as the Wetwell. probably with a target HGL at midway of the lead pump. I have read around quite a bit about the VSP battery and does not seem to get me to where I need to be. Can the experts help me on this?? All my pump curves for the 4 pumps are set up already. Anybody??
The concept of a fixed head is fundamentally inconsistent with the idea of pumps coming on at different levels. Either you have a fixed head or you have pumps that come on at different heads.
For this complicated of a case, you could either set a level that you will maintain and use the VSPB or you could set up individual pumps each with several control statements along the lines of
IF(Level > x and Level < y) THEN Pump setting = 0.z
Good. So, if I decide to use option one which is the using the VSPB, what will be the optimum control level I need to use to accomodate all 4 pump settings? As you can see 4 pumps OFF and ON settings spanning from -8.35 and -0.35. It appears I would not be able to associate additional levels with the VSPB. Correct??
VSPB attempts to maintain a constant wet well level and will automatically turn pumps on and off to do so. It turns on an additional pump as soon as the current pumps can no longer keep up with inflow.
Ok. I am trying to set up the VSPB. What is the difference between Battery Pump Definition and a Constant Speed pump definition??
No difference, except that the one you select for the VSPB represents the pump definition of all the pumps in the battery whereas the one selected in the regular pump node represents that single pump. However, VSPBs and regular VSPs in parallel assume the pump definitions are the same, so you'd need to use the same pump definition anyways if you had multiple regular pump nodes in parallel, set as VSPs.
The pump curve should represent full speed. The program automatically adjusts the speed (and scales the pump curve) during the simulation to maintain a fixed level in the wetwell (match the inflow) when the wetwell is selected as the target node.
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.