modelDistribution2Pipe_R

Model of a two-pipe distribution network with hydraulic diameter of main line pipes calculated from pressure drop per length

Extends from Buildings.DHC.Networks.BaseClasses.PartialDistribution2Pipe.

Information

This is a model of a two-pipe distribution network using a connection model with pipes in the main lines whose hydraulic diameters are calculated at initialization based on the pressure drop per pipe length at nominal flow rate Buildings.DHC.Networks.Connections.Connection2Pipe_R. The same pipe model is also used at the end of the distribution line (after the last connection) only on the supply side.

Modeling considerations

Note that dhDis needs to be vectorized, even if the same value is computed for each array element in case of a one-pipe network. This is because the pipe diameter is computed at initialization by the model Buildings.DHC.Networks.Pipes.PipeAutosize which is instantiated for each connection. So the initialization system of equations would be overdetermined if using a parameter binding with a scalar variable.

Parameters

TypeNameDefaultDescription
Realdp_length_nominal250Pressure drop per pipe length at nominal flow rate
Modelica.Units.SI.Length[nCon]lDisLength of the distribution pipe before each connection (supply only, not counting return line)
Modelica.Units.SI.LengthlEndLength of the end of the distribution line (supply only, not counting return line)
Modelica.Units.SI.Length[nCon]dhDisHydraulic diameter of the distribution pipe before each connection
Modelica.Units.SI.Length[nCon]dhDisRetHydraulic diameter of the distribution pipe before each connection
Modelica.Units.SI.LengthdhEndHydraulic diameter of the end of the distribution line

Revisions

  • March 15, 2024, by David Blum:
    Renamed. This is for issue 3712.
  • December 20, 2023, by Ettore Zanetti:
    This is for issue 3431.
  • February 23, 2021, by Antoine Gautier:
    First implementation.