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modelicadymola

Usage for ExternalMedia in Dymola

I am a student who is researching about HVAC. I'm modelling a heat pump system and I got some problem.

As I was going to get the fluid property by ExternalMedia, I got some error.

The source code is below:

model Pentane_hs
package wf
  extends ExternalMedia.Media.CoolPropMedium(
    mediumName = "Pentane",
    substanceNames = {"n-Pentane"},
    inputChoice=ExternalMedia.Common.InputChoice.hs);
end wf;
  wf.BaseProperties fluid "Properties of the two-phase fluid";
  Modelica.SIunits.SpecificEnthalpy h;
  Modelica.SIunits.Pressure p;
  Modelica.SIunits.SpecificEntropy s;
  Modelica.SIunits.DerDensityByEnthalpy drdh
    "Derivative of average density by enthalpy";
  Modelica.SIunits.DerDensityByPressure drdp
    "Derivative of average density by pressure";
equation 
  //p = 1E5;
  h = 0 + time*1E6;
  s = 1500;  //600 + time*2000;
  fluid.p = p;
  fluid.s = s;
  fluid.h = h;
  drdp = wf.density_derp_h(fluid.state);
  drdh = wf.density_derh_p(fluid.state);
end Pentane_hs;

This is the error I get:

enter image description here

I'm using Dymola 2023x.

I tried to import the library but it failed.

I want to get the property by pressure and temperature.

Solution

  • The solution of Marco works, but it limits you to use libraries that are also using MSL 3.2.3 instead of MSL 4.0.0. You can convert the ExternalMedia to MSL 4.0.0. Dymola should ask you if you want to do that when you load the ExternalMedia library. With the inbuilt conversion scripts most of the library is converted automatically and you should be able to test your model.