OpenFlows | Water Infrastructure Forum - Hydropneumatic tank in WaterGEMS Connerct Edition
BMPCreated with Sketch.BMPZIPCreated with Sketch.ZIPXLSCreated with Sketch.XLSTXTCreated with Sketch.TXTPPTCreated with Sketch.PPTPNGCreated with Sketch.PNGPDFCreated with Sketch.PDFJPGCreated with Sketch.JPGGIFCreated with Sketch.GIFDOCCreated with Sketch.DOC Error Created with Sketch.
Question

Hydropneumatic tank in WaterGEMS Connerct Edition

BCL
by
Bentley Communities Legacy Member
Expert

Good Day Everyone,

May I ask your help, I'm simulating a model that will cater the existing scenario that works with a hydropneumatic tank. The operational scheme is a submersible pump fills the pressure tank, then feeds to the system.

Data: 

Note these are the only data I have. 

-1265 gal - tank capacity  (1.56m - diameter, 2.5m height)

- NGL -20m, Pumping water level - 180ft

- SP8-15 pump  and 0.15MLD Demand

My questions are,

- First,  can I simulate this using WaterGEMS Connect Edition? If yes, will I ratio the 1265 tank with 70% Liquid : 30 % Gas?

- What does it mean of Liquid Volume(Inital)? Can I assumed that the initial volume is 50% of the 70% capacity?   

- In physical properties, the volume indicated there is the total volume of the tank?

- Tank model calculation: what do you recommend? Constant Area Approach? or Gas Law Model? 

- If Constant area - HGL On and Off - the on/off of the pump regarding to the 2.5 height? I mean if I allocate that 2.45 in HGL Off the pump will be off? and viser versa? 

- If Gas Law Model, will I indicate other inputs from my data or just the default  Variables like Atm pressure head, ratio of loss and Gas law exponent and run the system?

Can I ask some advice or other suggestions to consider for this scenario? Thank You!

God Bless and Best Regards,

Marco
Upvotes (0)
2114 Views
Accepted Solution
See this answer in context

Hello Marco,

  • You can model this scenario using WaterGEMS Connect Edition, for that you need to understand first how hydropneumatic tanks are handles in WaterGEMS, which is explained in the below mentioned link. 

communities.bentley.com/.../17625.how-are-surge-tanks-and-hydropneumatic-tanks-used-in-watergems-and-watercad-models

  • Liquid Volume(Inital) is volume of the liquid in the tank in initial conditions, corresponding to the initial HGL. So the initial gas volume would be difference between total volume of tank and the liquid volume ( Initial ), when "treat as junction" is set to "false".
  • The volume (tank) is the total volume of the hydropneumatic tank. 
  • Gas Law model method is more accurate compared to the constant area approach method.  The constant area approximation selection exposes the "Volume (effective)," "HGL on," and "HGL off" fields. The gas law selection exposes the "Atmospheric pressure" field. These fields are primarily there to support the WaterCAD and WaterGEMS products, which can directly open a HAMMER model. Detailed information on differences between these two methods is provided in the below mentioned wiki. 

communities.bentley.com/.../3104.modeling-reference-hydropneumatic-tanks 

  • In constant area approximation method, the HGL on & off values are basically which will turn the pump on & off, you may want to define controls for this. 
  • When using the gas law model method, you need to define all the required values for this method, an example model of hydropneumatic tank is provided in the first wiki on "how surge tanks and ahydropenumatic tanks are used in WaterGEMS".
Helpful (1)
replies (0)