How can I use a pressure reducing valve in the hydraulic model controlling the pressure at a control node? In water supply systems, we often automate valves to communicate with a critical point, instead of controlling the outlet pressure (pressure to, ppstream). But in WateGEMS only the pumps have this function. How do I keep a pressure fixed on a junction with a PRV? Considering that I have several scenarios with different demands, so using patterns is not a way.
Eduardo Fernandes said:This article is exactly what I'm talking about. However, it explains the problem but does not explain a solution.
The article proposes a possible workaround to address this situation and explains why it may not be practical to have this in a real system.
Eduardo Fernandes said:The only part that leads to a solution is this part: "you can develop a relationship between demand in the zone and TCV setting". I understand that there is no solution for what happens on the operation. It talks about a PLC but doesn't show how I represent this in the model.Can I only do this with a "trick" using TCV?
The article is based on advice that our Dr. Tom Walski provided, to help another user a few years ago, here: Modelling active control for PRV
I have updated the article with some more details based on what I believe Dr. Walski was suggesting, plus the other idea I had posted in the above thread. Please also see these papers which Dr. Walski worked on:
The conclusion in these papers is that a conventional PRV is good enough in most cases, while remote control costs more and is subject to instability.
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Hi, Larry. Thank you for the reply.This article is exactly what I'm talking about. However, it explains the problem but does not explain a solution.The only part that leads to a solution is this part: "you can develop a relationship between demand in the zone and TCV setting". I understand that there is no solution for what happens on the operation. It talks about a PLC but doesn't show how I represent this in the model.Can I only do this with a "trick" using TCV?In my model I have 72 PRV that operates like this in field. I don't think that send it to you will finds a way. I can built a hypothetical model as a test, when diferents demand in results in the same pressure in a specific node.
Hi Eduardo,
I found this Wiki article which I believe speaks to the issue you are having - Modeling PRV / PSV controlled by pressure at remote location in the model
Please see if it answers your question but if not, we might need to get a copy of your model for analyis.
Thank-you,Larry Abla