Buildings.Media.Antifreeze.PropyleneGlycolWater
Package with model for propylene glycol - water with constant properties
Information
This medium package models propylene glycol - water mixtures.
The mass density, specific heat capacity, thermal conductivity and viscosity are assumed constant and evaluated at a set temperature and mass fraction of propylene glycol within the mixture. The dependence of the four properties are shown on the figure below.
The accuracy of the thermophysical properties is dependent on the temperature variations encountered during simulations. The figure below shows the relative error of the the four properties over a 10 °C range around the temperature used to evaluate the constant properties. The maximum errors are 0.8 % for mass density, 1.5 % for specific heat capacity, 3.2 % for thermal conductivity and 250 % for dynamic viscosity.
The figure below shows the relative error of the the four properties over a 20 °C range around the temperature used to evaluate the constant proepties. The maximum errors are 1.6 % for mass density, 3.0 % for specific heat capacity, 6.2 % for thermal conductivity and 950 % for dynamic viscosity.
The enthalpy is computed using the convention that h=0 if T=0 °C.
Limitations
Density, specific heat capacity, thermal conductivity and viscosity are constant. The propylene glycol/water mixture is modeled as an incompressible liquid. There are no phase changes. The medium is limited to temperatures below 100 °C and mass fractions below 0.60. As is the case for Buildings.Media.Water, this medium package should not be used if the simulation relies on the dynamic viscosity.
Typical use and important parameters
The temperature and mass fraction must be specified for the evaluation of the constant thermophysical properties. A typical use of the package is (e.g. for a temperature of 20 °C and a mass fraction of 0.40):
Medium = Buildings.Media.Antifreeze.PropyleneGlycolWater(property_T=293.15, X_a=0.40)
Extends from Modelica.Media.Interfaces.PartialSimpleMedium (Medium model with linear dependency of u, h from temperature. All other quantities, especially density, are constant.).
Package Content
| Name | Description |
|---|---|
| property_T | Temperature for evaluation of constant fluid properties |
| X_a | Mass fraction of propylene glycol in water |
 BaseProperties
|
Base properties |
| X_a_min=0. | Minimum allowed mass fraction of propylene glycol in water |
| X_a_max=0.6 | Maximum allowed mass fraction of propylene glycol in water |
| simplePropyleneGlycolWaterConstants | |
| proCoe | Coefficients for evaluation of thermo-physical properties |
 density_TX_a
|
Evaluate density of antifreeze-water mixture |
| dynamicViscosity_TX_a
|
Evaluate dynamic viscosity of antifreeze-water mixture |
| fusionTemperature_TX_a
|
Evaluate temperature of fusion of antifreeze-water mixture |
| polynomialProperty
|
Evaluates thermophysical property from 2-variable polynomial |
| specificHeatCapacityCp_TX_a
|
Evaluate specific heat capacity of antifreeze-water mixture |
| thermalConductivity_TX_a
|
Evaluate thermal conductivity of antifreeze-water mixture |
| Inherited | |
| cp_const=specificHeatCapacityCp_TX_a(T=property_T, X_a=X_a) | Constant specific heat capacity at constant pressure |
| cv_const=cp_const | Constant specific heat capacity at constant volume |
| d_const=density_TX_a(T=property_T, X_a=X_a) | Constant density |
| eta_const=dynamicViscosity_TX_a(T=property_T, X_a=X_a) | Constant dynamic viscosity |
| lambda_const=thermalConductivity_TX_a(T=property_T, X_a=X_a) | Constant thermal conductivity |
| a_const=1484 | Constant velocity of sound |
| T_min=fusionTemperature_TX_a(T=property_T, X_a=X_a) | Minimum temperature valid for medium model |
| T_max=Modelica.Units.Conversions.from_degC(100) | Maximum temperature valid for medium model |
| T0=273.15 | Zero enthalpy temperature |
| MM_const=(X_a/simplePropyleneGlycolWaterConstants[1].molarMass + (1 - X_a)/0.018015268)^(-1) | Molar mass |
| fluidConstants=simplePropyleneGlycolWaterConstants | Fluid constants |
 ThermodynamicState
|
Thermodynamic state |
| setState_pTX
|
Return thermodynamic state from p, T, and X or Xi |
| setState_phX
|
Return thermodynamic state from p, h, and X or Xi |
| setState_psX
|
Return thermodynamic state from p, s, and X or Xi |
| setState_dTX
|
Return thermodynamic state from d, T, and X or Xi |
| setSmoothState
|
Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b |
| dynamicViscosity
|
Return dynamic viscosity |
| thermalConductivity
|
Return thermal conductivity |
| pressure
|
Return pressure |
| temperature
|
Return temperature |
| density
|
Return density |
| specificEnthalpy
|
Return specific enthalpy |
| specificHeatCapacityCp
|
Return specific heat capacity at constant pressure |
| specificHeatCapacityCv
|
Return specific heat capacity at constant volume |
| isentropicExponent
|
Return isentropic exponent |
| velocityOfSound
|
Return velocity of sound |
| specificEnthalpy_pTX
|
Return specific enthalpy from p, T, and X or Xi |
| temperature_phX
|
Return temperature from p, h, and X or Xi |
| density_phX
|
Return density from p, h, and X or Xi |
 specificInternalEnergy
|
Return specific internal energy |
| specificEntropy
|
Return specific entropy |
| specificGibbsEnergy
|
Return specific Gibbs energy |
| specificHelmholtzEnergy
|
Return specific Helmholtz energy |
| isentropicEnthalpy
|
Return isentropic enthalpy |
| isobaricExpansionCoefficient
|
Returns overall the isobaric expansion coefficient beta |
| isothermalCompressibility
|
Returns overall the isothermal compressibility factor |
| density_derp_T
|
Returns the partial derivative of density with respect to pressure at constant temperature |
| density_derT_p
|
Returns the partial derivative of density with respect to temperature at constant pressure |
| density_derX
|
Returns the partial derivative of density with respect to mass fractions at constant pressure and temperature |
| molarMass
|
Return the molar mass of the medium |
| setState_pT
|
Return thermodynamic state from p and T |
| setState_ph
|
Return thermodynamic state from p and h |
| setState_ps
|
Return thermodynamic state from p and s |
| setState_dT
|
Return thermodynamic state from d and T |
| density_ph
|
Return density from p and h |
| temperature_ph
|
Return temperature from p and h |
| pressure_dT
|
Return pressure from d and T |
| specificEnthalpy_dT
|
Return specific enthalpy from d and T |
| specificEnthalpy_ps
|
Return specific enthalpy from p and s |
| temperature_ps
|
Return temperature from p and s |
| density_ps
|
Return density from p and s |
| specificEnthalpy_pT
|
Return specific enthalpy from p and T |
| density_pT
|
Return density from p and T |
| ThermoStates=Modelica.Media.Interfaces.Choices.IndependentVariables.pT | Enumeration type for independent variables |
| mediumName="PropyleneGlycolWater(X_a = " + String(X_a) + ", property_T = " + String(property_T) + ")" | Name of the medium |
| substanceNames={mediumName} | Names of the mixture substances. Set substanceNames={mediumName} if only one substance. |
| extraPropertiesNames=fill("", 0) | Names of the additional (extra) transported properties. Set extraPropertiesNames=fill("",0) if unused |
| singleState=true | = true, if u and d are not a function of pressure |
| reducedX=true | = true if medium contains the equation sum(X) = 1.0; set reducedX=true if only one substance (see docu for details) |
| fixedX=true | = true if medium contains the equation X = reference_X |
| reference_p=300000 | Reference pressure of Medium: default 1 atmosphere |
| reference_T=273.15 | Reference temperature of Medium: default 25 deg Celsius |
| reference_X={1} | Default mass fractions of medium |
| p_default=300000 | Default value for pressure of medium (for initialization) |
| T_default=Modelica.Units.Conversions.from_degC(20) | Default value for temperature of medium (for initialization) |
| h_default=specificEnthalpy_pTX(p_default, T_default, X_default) | Default value for specific enthalpy of medium (for initialization) |
| X_default=reference_X | Default value for mass fractions of medium (for initialization) |
| C_default=fill(0, nC) | Default value for trace substances of medium (for initialization) |
| nS=size(substanceNames, 1) | Number of substances |
| nX=nS | Number of mass fractions |
| nXi=if fixedX then 0 else if reducedX then nS - 1 else nS | Number of structurally independent mass fractions (see docu for details) |
| nC=size(extraPropertiesNames, 1) | Number of extra (outside of standard mass-balance) transported properties |
| C_nominal=1.0e-6*ones(nC) | Default for the nominal values for the extra properties |
| FluidConstants
|
Critical, triple, molecular and other standard data of fluid |
| prandtlNumber
|
Return the Prandtl number |
| heatCapacity_cp
|
Alias for deprecated name |
| heatCapacity_cv
|
Alias for deprecated name |
| beta
|
Alias for isobaricExpansionCoefficient for user convenience |
| kappa
|
Alias of isothermalCompressibility for user convenience |
| density_derp_h
|
Return density derivative w.r.t. pressure at const specific enthalpy |
| density_derh_p
|
Return density derivative w.r.t. specific enthalpy at constant pressure |
| specificEntropy_pTX
|
Return specific enthalpy from p, T, and X or Xi |
| density_pTX
|
Return density from p, T, and X or Xi |
| temperature_psX
|
Return temperature from p,s, and X or Xi |
| density_psX
|
Return density from p, s, and X or Xi |
| specificEnthalpy_psX
|
Return specific enthalpy from p, s, and X or Xi |
| MassFlowRate
|
Type for mass flow rate with medium specific attributes |
| AbsolutePressure
|
Type for absolute pressure with medium specific attributes |
| Density
|
Type for density with medium specific attributes |
| DynamicViscosity
|
Type for dynamic viscosity with medium specific attributes |
| EnthalpyFlowRate
|
Type for enthalpy flow rate with medium specific attributes |
| MassFraction
|
Type for mass fraction with medium specific attributes |
| MoleFraction
|
Type for mole fraction with medium specific attributes |
| MolarMass
|
Type for molar mass with medium specific attributes |
| MolarVolume
|
Type for molar volume with medium specific attributes |
| IsentropicExponent
|
Type for isentropic exponent with medium specific attributes |
| SpecificEnergy
|
Type for specific energy with medium specific attributes |
| SpecificInternalEnergy
|
Type for specific internal energy with medium specific attributes |
| SpecificEnthalpy
|
Type for specific enthalpy with medium specific attributes |
| SpecificEntropy
|
Type for specific entropy with medium specific attributes |
| SpecificHeatCapacity
|
Type for specific heat capacity with medium specific attributes |
| SurfaceTension
|
Type for surface tension with medium specific attributes |
| Temperature
|
Type for temperature with medium specific attributes |
| ThermalConductivity
|
Type for thermal conductivity with medium specific attributes |
| PrandtlNumber
|
Type for Prandtl number with medium specific attributes |
| VelocityOfSound
|
Type for velocity of sound with medium specific attributes |
| ExtraProperty
|
Type for unspecified, mass-specific property transported by flow |
| CumulativeExtraProperty
|
Type for conserved integral of unspecified, mass specific property |
| ExtraPropertyFlowRate
|
Type for flow rate of unspecified, mass-specific property |
| IsobaricExpansionCoefficient
|
Type for isobaric expansion coefficient with medium specific attributes |
| DipoleMoment
|
Type for dipole moment with medium specific attributes |
| DerDensityByPressure
|
Type for partial derivative of density with respect to pressure with medium specific attributes |
| DerDensityByEnthalpy
|
Type for partial derivative of density with respect to enthalpy with medium specific attributes |
| DerEnthalpyByPressure
|
Type for partial derivative of enthalpy with respect to pressure with medium specific attributes |
| DerDensityByTemperature
|
Type for partial derivative of density with respect to temperature with medium specific attributes |
| DerTemperatureByPressure
|
Type for partial derivative of temperature with respect to pressure with medium specific attributes |
| SaturationProperties
|
Saturation properties of two phase medium |
| FluidLimits
|
Validity limits for fluid model |
| FixedPhase
|
Phase of the fluid: 1 for 1-phase, 2 for two-phase, 0 for not known, e.g., interactive use |
 Basic
|
The most basic version of a record used in several degrees of detail |
| IdealGas
|
The ideal gas version of a record used in several degrees of detail |
| TwoPhase
|
The two phase fluid version of a record used in several degrees of detail |
Types and constants
constant Modelica.Units.SI.Temperature property_T "Temperature for evaluation of constant fluid properties";
constant Modelica.Units.SI.MassFraction X_a "Mass fraction of propylene glycol in water";
constant Modelica.Units.SI.MassFraction X_a_min=0. "Minimum allowed mass fraction of propylene glycol in water";
constant Modelica.Units.SI.MassFraction X_a_max=0.6 "Maximum allowed mass fraction of propylene glycol in water";
constant Modelica.Media.Interfaces.Types.Basic.FluidConstants[1] simplePropyleneGlycolWaterConstants( each chemicalFormula="C3H8O2", each structureFormula="CH3CH(OH)CH2OH", each casRegistryNumber="57-55-6", each iupacName="1,2-Propylene glycol", each molarMass=0.07609);
constant Buildings.Media.Antifreeze.BaseClasses.PropertyCoefficients proCoe( X_a_ref=0.307031, T_ref=Modelica.Units.Conversions.from_degC(32.7083), nX_a=6, nT={4,4,4,3,2,1}, nTot=18, a_d={1.018e3,-5.406e-1,-2.666e-3,1.347e-5,7.604e-1,-9.450e-3,5.541e-5,-1.343e-7, -2.498e-3,2.700e-5,-4.018e-7,3.376e-9,-1.550e-4,2.829e-6,-7.175e-9,-1.131e-6, -2.221e-8,2.342e-8}, a_eta={6.837e-1,-3.045e-2,2.525e-4,-1.399e-6,3.328e-2,-3.984e-4,4.332e-6,-1.860e-8, 5.453e-5,-8.600e-8,-1.593e-8,-4.465e-11,-3.900e-6,1.054e-7,-1.589e-9,-1.587e-8, 4.475e-10,3.564e-9}, a_Tf={-1.325e1,-3.820e-5,7.865e-7,-1.733e-9,-6.631e-1,6.774e-6,-6.242e-8,-7.819e-10, -1.094e-2,5.332e-8,-4.169e-9,3.288e-11,-2.283e-4,-1.131e-8,1.918e-10,-3.409e-6, 8.035e-11,1.465e-8}, a_cp={3.882e3,2.699e0,-1.659e-3,-1.032e-5,-1.304e1,5.070e-2,-4.752e-5, 1.522e-6,-1.598e-1,9.534e-5,1.167e-5,-4.870e-8,3.539e-4,3.102e-5,-2.950e-7, 5.000e-5,-7.135e-7,-4.959e-7}, a_lambda={4.513e-1,7.955e-4,3.482e-8,-5.966e-9,-4.795e-3,-1.678e-5,8.941e-8, 1.493e-10,2.076e-5,1.563e-7,-4.615e-9,9.897e-12,-9.083e-8,-2.518e-9, 6.543e-11,-5.952e-10,-3.605e-11,2.104e-11}) "Coefficients for evaluation of thermo-physical properties";
Buildings.Media.Antifreeze.PropyleneGlycolWater.BaseProperties
Base properties
Information
This base properties model is identical to
Modelica.Media.Water.ConstantPropertyLiquidWater,
except that the equation
u = cv_const*(T - reference_T)
has been replaced by u=h because
cp_const=cv_const.
Also, the model checks if the mass fraction of the mixture is within the
allowed limits.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Advanced | |||
| Boolean | preferredMediumStates | false | = true if StateSelect.prefer shall be used for the independent property variables of the medium |
Modelica definition
redeclare model BaseProperties "Base properties"
Temperature T(stateSelect=
if preferredMediumStates then StateSelect.prefer else StateSelect.default)
"Temperature of medium";
InputAbsolutePressure p "Absolute pressure of medium";
InputMassFraction[nXi] Xi=fill(0, 0)
"Structurally independent mass fractions";
InputSpecificEnthalpy h "Specific enthalpy of medium";
Modelica.Units.SI.SpecificInternalEnergy u
"Specific internal energy of medium";
Modelica.Units.SI.Density d=d_const "Density of medium";
Modelica.Units.SI.MassFraction[nX] X={1}
"Mass fractions (= (component mass)/total mass m_i/m)";
final Modelica.Units.SI.SpecificHeatCapacity R_s=0
"Gas constant (of mixture if applicable)";
final Modelica.Units.SI.MolarMass MM=MM_const
"Molar mass (of mixture or single fluid)";
ThermodynamicState state
"Thermodynamic state record for optional functions";
parameter Boolean preferredMediumStates=false
"= true if StateSelect.prefer shall be used for the independent property variables of the medium";
final parameter Boolean standardOrderComponents=true
"If true, and reducedX = true, the last element of X will be computed from the other ones";
Modelica.Units.NonSI.Temperature_degC T_degC=
Modelica.Units.Conversions.to_degC(T) "Temperature of medium in [degC]";
Modelica.Units.NonSI.Pressure_bar p_bar=Modelica.Units.Conversions.to_bar(p)
"Absolute pressure of medium in [bar]";
// Local connector definition, used for equation balancing check
connector InputAbsolutePressure = input Modelica.Units.SI.AbsolutePressure
"Pressure as input signal connector";
connector InputSpecificEnthalpy = input Modelica.Units.SI.SpecificEnthalpy
"Specific enthalpy as input signal connector";
connector InputMassFraction = input Modelica.Units.SI.MassFraction
"Mass fraction as input signal connector";
equation
assert(T >= T_min, "
In " + getInstanceName() + ": Temperature T exceeded its minimum allowed value of " + String(T_min-273.15)
+ " degC (" + String(T_min) + " Kelvin)
as required from medium model \""
+ mediumName + "\".");
assert(T <= T_max, "
In " + getInstanceName() + ": Temperature T exceeded its maximum allowed value of " + String(T_max-273.15)
+ " degC (" + String(T_max) + " Kelvin)
as required from medium model \""
+ mediumName + "\".");
assert(X_a >= X_a_min, "
In " + getInstanceName() + ": Mass fraction x_a exceeded its minimum allowed value of " + String(X_a_min) + "
as required from medium model \""
+ mediumName + "\".");
assert(X_a <= X_a_max, "
In " + getInstanceName() + ": Mass fraction x_a exceeded its maximum allowed value of " + String(X_a_max) + "
as required from medium model \""
+ mediumName + "\".");
h = cp_const*(T-reference_T);
u = h;
state.T = T;
state.p = p;
end BaseProperties;
Buildings.Media.Antifreeze.PropyleneGlycolWater.density_TX_a
Evaluate density of antifreeze-water mixture
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | T | Temperature of antifreeze-water mixture [K] | |
| MassFraction | X_a | Mass fraction of antifreeze [1] |
Outputs
| Type | Name | Description |
|---|---|---|
| Density | d | Density of antifreeze-water mixture [kg/m3] |
Modelica definition
replaceable function density_TX_a
"Evaluate density of antifreeze-water mixture"
extends Modelica.Icons.Function;
input Modelica.Units.SI.Temperature T
"Temperature of antifreeze-water mixture";
input Modelica.Units.SI.MassFraction X_a "Mass fraction of antifreeze";
output Modelica.Units.SI.Density d "Density of antifreeze-water mixture";
algorithm
d :=polynomialProperty(
X_a,
T,
proCoe.a_d);
end density_TX_a;
Buildings.Media.Antifreeze.PropyleneGlycolWater.dynamicViscosity_TX_a
Evaluate dynamic viscosity of antifreeze-water mixture
Information
Dynamic viscosity of antifreeze-water mixture at specified mass fraction and temperature, based on Melinder (2010).
References
Melinder, Åke. 2010. Properties of Secondary Working Fluids (Secondary Refrigerants or Coolants, Heat Transfer Fluids) for Indirect Systems. Paris: IIR/IIF.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | T | Temperature of antifreeze-water mixture [K] | |
| MassFraction | X_a | Mass fraction of antifreeze [1] |
Outputs
| Type | Name | Description |
|---|---|---|
| DynamicViscosity | eta | Dynamic Viscosity of antifreeze-water mixture [Pa.s] |
Modelica definition
replaceable function dynamicViscosity_TX_a
"Evaluate dynamic viscosity of antifreeze-water mixture"
extends Modelica.Icons.Function;
input Modelica.Units.SI.Temperature T
"Temperature of antifreeze-water mixture";
input Modelica.Units.SI.MassFraction X_a "Mass fraction of antifreeze";
output Modelica.Units.SI.DynamicViscosity eta
"Dynamic Viscosity of antifreeze-water mixture";
algorithm
eta :=1e-3*exp(polynomialProperty(
X_a,
T,
proCoe.a_eta));
end dynamicViscosity_TX_a;
Buildings.Media.Antifreeze.PropyleneGlycolWater.fusionTemperature_TX_a
Evaluate temperature of fusion of antifreeze-water mixture
Information
Fusion temperature of antifreeze-water mixture at specified mass fraction and temperature, based on Melinder (2010).
References
Melinder, Åke. 2010. Properties of Secondary Working Fluids (Secondary Refrigerants or Coolants, Heat Transfer Fluids) for Indirect Systems. Paris: IIR/IIF.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | T | Temperature of antifreeze-water mixture [K] | |
| MassFraction | X_a | Mass fraction of antifreeze [1] |
Outputs
| Type | Name | Description |
|---|---|---|
| Temperature | Tf | Temperature of fusion of antifreeze-water mixture [K] |
Modelica definition
replaceable function fusionTemperature_TX_a
"Evaluate temperature of fusion of antifreeze-water mixture"
extends Modelica.Icons.Function;
input Modelica.Units.SI.Temperature T
"Temperature of antifreeze-water mixture";
input Modelica.Units.SI.MassFraction X_a "Mass fraction of antifreeze";
output Modelica.Units.SI.Temperature Tf
"Temperature of fusion of antifreeze-water mixture";
algorithm
Tf :=Modelica.Units.Conversions.from_degC(polynomialProperty(
X_a,
T,
proCoe.a_Tf));
end fusionTemperature_TX_a;
Buildings.Media.Antifreeze.PropyleneGlycolWater.polynomialProperty
Evaluates thermophysical property from 2-variable polynomial
Information
Evaluates a thermophysical property of a mixture, based on correlations proposed by Melinder (2010).
The polynomial has the form
f = a1 (x-xm)0(y-ym)0 + a2 (x-xm)0(y-ym)1 + ... + any[1] (x-xm)0(y-ym)ny[1]-1 + ... + any[1])+1 (x-xm)1(y-ym)0 + ... + any[1]+ny[2] (x-xm)1(y-ym)ny[2]-1 + ...
References
Melinder, Åke. 2010. Properties of Secondary Working Fluids (Secondary Refrigerants or Coolants, Heat Transfer Fluids) for Indirect Systems. Paris: IIR/IIF.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | x | First independent variable | |
| Real | y | Second independent variable | |
| Real | a[sum(proCoe.nT)] | Polynomial coefficients |
Outputs
| Type | Name | Description |
|---|---|---|
| Real | f | Value of thermophysical property |
Modelica definition
replaceable function polynomialProperty
"Evaluates thermophysical property from 2-variable polynomial"
extends Modelica.Icons.Function;
input Real x "First independent variable";
input Real y "Second independent variable";
input Real a[sum(proCoe.nT)] "Polynomial coefficients";
output Real f "Value of thermophysical property";
protected
Real dx;
Real dy;
Integer n;
algorithm
dx := 100*(x - proCoe.X_a_ref);
dy := y - proCoe.T_ref;
f := 0;
n := 0;
for i in 0:proCoe.nX_a - 1 loop
for j in 0:proCoe.nT[i+1] - 1 loop
n := n + 1;
f := f + a[n]*dx^i*dy^j;
end for;
end for;
end polynomialProperty;
Buildings.Media.Antifreeze.PropyleneGlycolWater.specificHeatCapacityCp_TX_a
Evaluate specific heat capacity of antifreeze-water mixture
Information
Specific heat capacity of antifreeze-water mixture at specified mass fraction and temperature, based on Melinder (2010).
References
Melinder, Åke. 2010. Properties of Secondary Working Fluids (Secondary Refrigerants or Coolants, Heat Transfer Fluids) for Indirect Systems. Paris: IIR/IIF.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | T | Temperature of antifreeze-water mixture [K] | |
| MassFraction | X_a | Mass fraction of antifreeze [1] |
Outputs
| Type | Name | Description |
|---|---|---|
| SpecificHeatCapacity | cp | Specific heat capacity of antifreeze-water mixture [J/(kg.K)] |
Modelica definition
replaceable function specificHeatCapacityCp_TX_a
"Evaluate specific heat capacity of antifreeze-water mixture"
extends Modelica.Icons.Function;
input Modelica.Units.SI.Temperature T
"Temperature of antifreeze-water mixture";
input Modelica.Units.SI.MassFraction X_a "Mass fraction of antifreeze";
output Modelica.Units.SI.SpecificHeatCapacity cp
"Specific heat capacity of antifreeze-water mixture";
algorithm
cp :=polynomialProperty(
X_a,
T,
proCoe.a_cp);
end specificHeatCapacityCp_TX_a;
Buildings.Media.Antifreeze.PropyleneGlycolWater.thermalConductivity_TX_a
Evaluate thermal conductivity of antifreeze-water mixture
Information
Thermal conductivity of antifreeze-water mixture at specified mass fraction and temperature, based on Melinder (2010).
References
Melinder, Åke. 2010. Properties of Secondary Working Fluids (Secondary Refrigerants or Coolants, Heat Transfer Fluids) for Indirect Systems. Paris: IIR/IIF.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | T | Temperature of antifreeze-water mixture [K] | |
| MassFraction | X_a | Mass fraction of antifreeze [1] |
Outputs
| Type | Name | Description |
|---|---|---|
| ThermalConductivity | lambda | Thermal conductivity of antifreeze-water mixture [W/(m.K)] |
Modelica definition
replaceable function thermalConductivity_TX_a
"Evaluate thermal conductivity of antifreeze-water mixture"
extends Modelica.Icons.Function;
input Modelica.Units.SI.Temperature T
"Temperature of antifreeze-water mixture";
input Modelica.Units.SI.MassFraction X_a "Mass fraction of antifreeze";
output Modelica.Units.SI.ThermalConductivity lambda
"Thermal conductivity of antifreeze-water mixture";
algorithm
lambda :=polynomialProperty(
X_a,
T,
proCoe.a_lambda);
end thermalConductivity_TX_a;
Buildings.Media.Antifreeze.PropyleneGlycolWater.BaseProperties.InputAbsolutePressure
Pressure as input signal connector
Modelica definition
connector InputAbsolutePressure = input Modelica.Units.SI.AbsolutePressure
"Pressure as input signal connector";
Buildings.Media.Antifreeze.PropyleneGlycolWater.BaseProperties.InputMassFraction
Mass fraction as input signal connector
Modelica definition
connector InputMassFraction = input Modelica.Units.SI.MassFraction
"Mass fraction as input signal connector";
Buildings.Media.Antifreeze.PropyleneGlycolWater.BaseProperties.InputSpecificEnthalpy
Specific enthalpy as input signal connector
Modelica definition
connector InputSpecificEnthalpy = input Modelica.Units.SI.SpecificEnthalpy
"Specific enthalpy as input signal connector";