.Buildings.DHC.Loads.Steam.BaseClasses.ValveSelfActing

Information

This is the model of self-acting control valve that automatically adjusts the diameter of valve orifice to reduce the unregulated inlet pressure to a constant, reduced outlet pressure.

Implementation

To simplify the complex relationships of the valve opening (y_actual), mass flow rate (m_flow), and change in pressure (dp) for compressible medium (such as steam), this model is implemented using an ideal source Buildings.Fluid.Movers.BaseClasses.IdealSource, that allows the pressure drop to be prescribed independently of mass flow rate.

The model maintains dp based on the user specified downstream pressure value (pb_nominal), except for instances where the upstream pressure falls below pb_nominal. In these instances, the valve exibits no pressure drop (dpSet = 0) and asserts a warning. This model assumes that dp across the valve is independent of m_flow. This generally leads to a simplier set of equations.

References

Kathryn Hinkelman, Saranya Anbarasu, Michael Wetter, Antoine Gautier, Wangda Zuo. 2022. “A Fast and Accurate Modeling Approach for Water and Steam Thermodynamics with Practical Applications in District Heating System Simulation,” Energy, 254(A), pp. 124227. 10.1016/j.energy.2022.124227

Kathryn Hinkelman, Saranya Anbarasu, Michael Wetter, Antoine Gautier, Baptiste Ravache, Wangda Zuo 2022. “Towards Open-Source Modelica Models For Steam-Based District Heating Systems.” Proc. of the 1st International Workshop On Open Source Modelling And Simulation Of Energy Systems (OSMSES 2022), Aachen, German, April 4-5, 2022. 10.1109/OSMSES54027.2022.9769121

Revisions

• September 15, 2023, by Kathryn Hinkelman:
  Added publication references.
• March 2, 2022 by Saranya Anbarasu:
  First implementation.