Buildings.Media.Examples.BaseClasses
Package with base classes for Buildings.Media.Examples
Information
This package contains base classes that are used to construct the models in Buildings.Media.Examples.
Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).
Package Content
| Name | Description |
|---|---|
 FluidProperties
|
Model that tests the implementation of the fluid properties |
| PartialProperties
|
Partial model that contains common parameters of the fluid properties |
| TestTemperatureEnthalpyInversion
|
Model to check computation of h(T) and its inverse with a controlleable tolerance |
Buildings.Media.Examples.BaseClasses.FluidProperties
Model that tests the implementation of the fluid properties
Information
This example checks thermophysical properties of the medium.
Extends from PartialProperties (Partial model that contains common parameters of the fluid properties).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | ||
| Temperature | TMin | Minimum temperature for the simulation [K] | |
| Temperature | TMax | Maximum temperature for the simulation [K] | |
| Pressure | p | Medium.p_default | Pressure [Pa] |
| MassFraction | X[Medium.nX] | Medium.X_default | Mass fraction [1] |
Modelica definition
partial model FluidProperties
"Model that tests the implementation of the fluid properties"
extends PartialProperties;
Medium.ThermodynamicState state_phX "Medium state";
Medium.ThermodynamicState state_psX "Medium state";
Modelica.Media.Interfaces.Types.DerDensityByPressure ddpT
"Density derivative w.r.t. pressure";
Modelica.Media.Interfaces.Types.DerDensityByTemperature ddTp
"Density derivative w.r.t. temperature";
Modelica.SIunits.Density[Medium.nX] dddX
"Density derivative w.r.t. mass fraction";
equation
// Check setting the states
state_pTX = Medium.setState_pTX(p=p, T=T, X=X);
state_phX = Medium.setState_phX(p=p, h=h, X=X);
state_psX = Medium.setState_psX(p=p, s=s, X=X);
checkState(state_pTX, state_phX, "state_phX");
checkState(state_pTX, state_psX, "state_psX");
// Check the implementation of the functions
ddpT = Medium.density_derp_T(state_pTX);
ddTp = Medium.density_derT_p(state_pTX);
dddX = Medium.density_derX(state_pTX);
end FluidProperties;
Buildings.Media.Examples.BaseClasses.PartialProperties
Partial model that contains common parameters of the fluid properties
Information
This example checks thermophysical properties of the medium.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | Modelica.Media.Interfaces.Pa... | ||
| Temperature | TMin | Minimum temperature for the simulation [K] | |
| Temperature | TMax | Maximum temperature for the simulation [K] | |
| Pressure | p | Medium.p_default | Pressure [Pa] |
| MassFraction | X[Medium.nX] | Medium.X_default | Mass fraction [1] |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package Medium | ||
Modelica definition
partial model PartialProperties
"Partial model that contains common parameters of the fluid properties"
replaceable package Medium = Modelica.Media.Interfaces.PartialMedium;
parameter Modelica.SIunits.Temperature TMin
"Minimum temperature for the simulation";
parameter Modelica.SIunits.Temperature TMax
"Maximum temperature for the simulation";
parameter Modelica.SIunits.Pressure p = Medium.p_default "Pressure";
parameter Modelica.SIunits.MassFraction X[Medium.nX]=
Medium.X_default "Mass fraction";
Medium.Temperature T "Temperature";
Modelica.SIunits.Conversions.NonSIunits.Temperature_degC T_degC
"Celsius temperature";
Medium.ThermodynamicState state_pTX "Medium state";
Modelica.SIunits.Density d "Density";
Modelica.SIunits.DynamicViscosity eta "Dynamic viscosity";
Modelica.SIunits.SpecificEnthalpy h "Specific enthalpy";
Modelica.SIunits.SpecificInternalEnergy u "Specific internal energy";
Modelica.SIunits.SpecificEntropy s "Specific entropy";
Modelica.SIunits.SpecificEnergy g "Specific Gibbs energy";
Modelica.SIunits.SpecificEnergy f "Specific Helmholtz energy";
Modelica.SIunits.SpecificEnthalpy hIse "Isentropic enthalpy";
Modelica.Media.Interfaces.Types.IsobaricExpansionCoefficient beta
"Isobaric expansion coefficient";
Modelica.SIunits.IsothermalCompressibility kappa "Isothermal compressibility";
Modelica.SIunits.SpecificHeatCapacity cp "Specific heat capacity";
Modelica.SIunits.SpecificHeatCapacity cv "Specific heat capacity";
Modelica.SIunits.ThermalConductivity lambda "Thermal conductivity";
Modelica.SIunits.AbsolutePressure pMed "Pressure";
Medium.Temperature TMed "Temperature";
Modelica.SIunits.MolarMass MM "Mixture molar mass";
Medium.BaseProperties basPro "Medium base properties";
protected
constant Real conv(unit="1/s") = 1 "Conversion factor to satisfy unit check";
function checkState
extends Modelica.Icons.Function;
input Medium.ThermodynamicState state1 "Medium state";
input Medium.ThermodynamicState state2 "Medium state";
input String message "Message for error reporting";
algorithm
assert(abs(Medium.temperature(state1)-Medium.temperature(state2))
< 1e-8, "Error in temperature of " + message);
assert(abs(Medium.pressure(state1)-Medium.pressure(state2))
< 1e-8, "Error in pressure of " + message);
end checkState;
equation
// Compute temperatures that are used as input to the functions
T = TMin + conv*time * (TMax-TMin);
T_degC = Modelica.SIunits.Conversions.to_degC(T);
// Check the implementation of the functions
d = Medium.density(state_pTX);
eta = Medium.dynamicViscosity(state_pTX);
h = Medium.specificEnthalpy(state_pTX);
u = Medium.specificInternalEnergy(state_pTX);
s = Medium.specificEntropy(state_pTX);
g = Medium.specificGibbsEnergy(state_pTX);
f = Medium.specificHelmholtzEnergy(state_pTX);
hIse = Medium.isentropicEnthalpy(p, state_pTX);
beta = Medium.isobaricExpansionCoefficient(state_pTX);
kappa = Medium.isothermalCompressibility(state_pTX);
cp = Medium.specificHeatCapacityCp(state_pTX);
cv = Medium.specificHeatCapacityCv(state_pTX);
lambda = Medium.thermalConductivity(state_pTX);
pMed = Medium.pressure(state_pTX);
assert(abs(p-pMed) < 1e-8, "Error in pressure computation.");
TMed = Medium.temperature(state_pTX);
assert(abs(T-TMed) < 1e-8, "Error in temperature computation.");
MM = Medium.molarMass(state_pTX);
// Check the implementation of the base properties
assert(abs(h-basPro.h) < 1e-8, "Error in enthalpy computation in BaseProperties.");
assert(abs(u-basPro.u) < 1e-8, "Error in internal energy computation in BaseProperties.");
end PartialProperties;
Buildings.Media.Examples.BaseClasses.TestTemperatureEnthalpyInversion
Model to check computation of h(T) and its inverse with a controlleable tolerance
Information
This model computesh=f(T0) and
T=g(h). It then checks whether T=T0.
Hence, it checks whether the function T_phX is
implemented correctly.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | Modelica.Media.Interfaces.Pa... | ||
| Temperature | T0 | 273.15 + 20 | Temperature [K] |
| Real | tol | 1E-8 | Numerical tolerance |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package Medium | ||
Modelica definition
partial model TestTemperatureEnthalpyInversion
"Model to check computation of h(T) and its inverse with a controlleable tolerance"
replaceable package Medium =
Modelica.Media.Interfaces.PartialMedium;
parameter Modelica.SIunits.Temperature T0=273.15+20 "Temperature";
parameter Real tol = 1E-8 "Numerical tolerance";
Modelica.SIunits.Temperature T "Temperature";
Modelica.SIunits.SpecificEnthalpy h "Enthalpy";
Medium.MassFraction Xi[:] = Medium.reference_X "Mass fraction";
equation
h = Medium.specificEnthalpy_pTX(p=101325, T=T0, X=Xi);
T = Medium.temperature_phX(p=101325, h=h, X=Xi);
if (time>0.1) then
assert(abs(T-T0)<tol, "Error in implementation of functions.\n"
+ " T0 = " + String(T0) + "\n"
+ " T = " + String(T));
end if;
end TestTemperatureEnthalpyInversion;