I am trying to optimise is the performance of PRVs in a distribution network. Is the Darwin designer the best application to use for this in WaterGEMS? It appears as though I can only select pipes for my design group. Is there a way I can select the all the PRVs in the network as my design group and then apply the minimum and maximum desired pressures to be achieved at all junctions in the network?
Hello Emma,
Darwin Designer is used to help to design pipes in the model, including minimizing cost. This would not be the right tool. Darwin Calibrator is closer. It is used to help to calibrate the model based on field tests. Darwin Calibrator typically adjusts the roughness coefficient in order to do this. PRV settings and status can be used as a boundary override, but they are not themselves adjusted.
What kind of data do you have for the optimization? Is there field data, such as flow tests? Do the PRVs exist in the system already and are they not acting as expected?
Regards,
Scott
Hi Scott,
I do not have flow tests but I can should be able to access the SCADA system for the area. At the minute I just have the model of the distribution network and the ideal pressure parameters.
To cut a long story short there is an excessive number of PRVs in the network I am looking at and I'm hoping to use WaterGEMS to rationalise the number of PRVs needed in the network by optimising the output pressures of some and identifying those that are not needed and can be decommissioned.
Thanks
Emma
Darwin Designer will design pipe sizes based on design criteria, and Darwin Calibrator will adjust roughness, demand and pipe open/closed status based on observed data.
If you are wanting to optimize the PRV settings based on some pressure criteria, Designer and Calibrator will not work for this purpose, since they do not adjust PRV settings.
The best course of action here may be to use symbology (color coding for example) and other tools to help you in the process of selecting the PRV pressure setting and optimizing the number of PRVs. Some things to consider:
When my colleague Dr. Walski returns from the AWWA conference this week, he may be able to provide further advice for your particular situation.
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
The fact that you are using PRVs means that you are setting up pressures zones. The pressure zones will control where you put the PRVs and where to set them
For example, let's say the elevations in this area you are trying to serve vary from 600 to 700 ft. Therefore the setting for the PRVs serving that zone should be set to abut 800 ft and the PRVs feeding the zone should be located around elevation 700 ft.
Look at the contour lines of the area you are trying to serve and decide on the high and low pressures you want to achieve. Based on the elevation of your customers, you would like to give them at least a pressure head of around 60 ft at the highest elevation and no more than 200 ft at the lowest elevation.
A lot depends on whether you are working on a new system or an existing system. With a new system, you have a lot of flexibility while for an existing system, you have existing pressure zones and you need to decide if there is a better way to set them up.
Since you are working with an existing system, use the pressure manager tool and check the range of pressures and check the range of pressures and view the color coded zones. Having a lot of RVs is not a problem. Having poorly laid out pressure zones can be a problem. The key is to avoid excessive range of pressures (too big of a step in HGL between zones) or too many zones (too small of a step in HGL between zones).
Many thanks for your suggestions to resolve this issue.