Hi Bentley Systems,
I am modelling a water distribution network using WaterGEMs connect edition update 1.
I am trying to simulate an EPS model by assigning demand patterns. Study area has a large number of domestic customers and some commercial customers as well.
However, a strange demand pattern was observed in the area because most of the customers of the study area have domestic storage tanks in their houses due to the uncertainty of the supply. Those tanks get started to fill during the high pressure time in night. Hence the actual consumption pattern is not reflected through the observed pattern.
1. How can I model this situation?
2. Is there a method to incorporate the customer tanks to the model? (Assuming a common volume or a level)
Harsha
Hello Harsha,
You may need to consider how the upstream hydraulics would behave in the real system. Is there a single pump station at the source, that would need to add enough head to fill these individual tanks?
If you replace the tanks with junctions or customer elements (and neglect the fill/drain of the tanks), the hydraulic results may not correctly simulate how the pump(s) lifted the water to those tanks. Meaning, you might end up with a hydraulic grade at the demand nodes that is less than the elevation of the tank, indicating that the pressure would actually be higher in the real system due to the pump lifting the water to the tank elevation.
If the pumps that fill these tanks are private pumps, and not a pump at the water source, then replacing them with junctions or customer elements may be OK, but you may want to consider the points raised here: Modeling private customer pump stations
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Dear Sushma and Jesse,
Whilst thanking you for the prompt reply I would like to elaborate further my problem as below.
1. I want to model an existing water distribution network, which is totally fed through gravity. The main source is a large reservoir located in a high elevation. And there are several boundary connections with adjacent networks, where the inflows could be measured using flow meters.
2.Pump operations are not involved in anywhere in the system.
3. During high peak times some areas do not get water in sufficient pressure. Because of that, customers maintain domestic storage tanks in their premises. Those tanks also get filled through water distribution network through gravity, without any pumping. Stored water is being consumed mostly during network low pressure situations. Tank filling normally happens during night time when the system pressure is high.
4.I have installed flow meters with data loggers and recorded a certain demand pattern. But I suppose the observed demand pattern is not the actual demand pattern of consumption due to the above situation.
5.Modelling customer elements is not practically possible due to lack of individual customer data. I assigned customer pack demands (polygon area-wise demand) using load builder to each node.
Hope you can understand this scenario.
a) Is there any possibility to model this situation?
b) Is there a possibility to adjust my nodal demands or demand multipliers in order to model this situation?
Thank you,