Hi,
I am modelling a pumping system, with one pump on a ‘fixed head’ VSD controlling the pressure of a header pipe which distributes to six drains via orifice plates. I am trying to model a transient case where one of six isolation valves closes rapidly (using a TCV element). However during a transient run, when the valve closes, the pressure in the header rises, but the VSD does not respond to slow down the pump and maintain the target pressure in the header pipe.
Does the Hammer variable speed drive function during a transient? Do you have any suggestions as to how I could model this case (e.g. do I need to use a variable speed pump battery element, or do I need to manually enter a pump transient operation rule to match the closure of the valve)?
Also is there a way of setting a delay or deadband on the vsd during a transient?
Thank you
Hello Luke,
Hammer assumes that the pumps are controlled by an operating rule or, in the case of the "Shut down after time delay" transient pump type, a time value at which the pumps will stop operating.
You will need to setup the operating rule to model this transient event of valve closure.
The below article contains information about variable speed of pump in Hammer, which you may find useful.
http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/25660.modeling-a-pump-shut-down-transient-event
Regards,
Sushma Choure
Bentley Technical Suppport
Answer Verified By: Jesse Dringoli
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Answer Verified By: Sushma Choure