Hi
I have a system as shown in the image, in the node J-3 I have a demand of 10 L / s and as you can see I get higher flows than the exit of the tubes of the reservoirs, I understand that it is due to its hydraulic gradient with respect to First reservoir that has a higher piezometric dimension.It asks me is, is there any way to restrict that only a flow of capacity of the 3 catchments passes, ie (R-1 = 5 L / s, R-2 = 3 L / s, R- 3 = 2 L / s TOTAL = 10 L / s), do you have any valves at P-1, P-4 or P-5?Very grateful for your answers and suggestions.
The answer depends on whether you want to restrict the flows in the model or in the real system.
If you want to simulate that mix of flows in the model, simply add a flow control valve (FCV) each outlet pipe.
In the real system, you need to think about how you will accomplish those flows. Flow control valves require some kind of programmable logic controller with a motor activated valve and preferably connection to a SCADA System to communicate to the control room and the other valves.
Then there is the question of how you will adjust settings when the downstream demand changes from 10 L/s because no system ever runs at a constant demand.
The other thing that will occur is that the reservoir level will change over time and how do you want the valves to respond to that.
As you have your system set up now, the hydraulic grade at reservoir R-1 is so high that it will meet demand and the rest of the water will flow up into the other reservoirs.
A lot depends on the pressures that you will need at the customers (J-3). It looks as if you can reduce the size of the pipes and get the pressure down to something along the lines of 50 m using a pressure reducing valve out of each reservoir. A PRV would require no power and you can adjust them seasonally as needed to get the flow distribution you need.
Answer Verified By: Vanfa
Why in the FCV the hydraulic gradient is reduced to 3773.54, this causes my J-1 node to come out negative pressure, is there any solution or explanation about it?I believe that the hydraulic gradient from the reservoir should be gradual until the node J-1
Best Regards
I can't tell without seeing the model, but I suspect that the other tanks are at a low elevation such that the HGL they control is below the ground.
This article has some information and explanation regarding headloss through dynamic valves like FCVs:
Why do I see such a large headloss through my FCV, PSV or PRV?
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.