Buildings.Media.Water
Package with model for liquid water with constant density
Information
This medium package models liquid water.
The mass density is computed using a constant value of 995.586 kg/s. For a medium model in which the density is a function of temperature, use Buildings.Media.Specialized.Water.TemperatureDependentDensity which may have considerably higher computing time.
For the specific heat capacities at constant pressure and at constant volume, a constant value of 4184 J/(kg K), which corresponds to 20°C is used. The figure below shows the relative error of the specific heat capacity that is introduced by this simplification.
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. Water is modeled as an incompressible liquid. There are no phase changes.
Extends from Modelica.Media.Water.ConstantPropertyLiquidWater (Water: Simple liquid water medium (incompressible, constant data)), Modelica.Icons.Package (Icon for standard packages).
Package Content
Name | Description |
---|---|
BaseProperties | Base properties |
enthalpyOfLiquid | Return the specific enthalpy of liquid |
Inherited | |
simpleWaterConstants | |
cp_const | Constant specific heat capacity at constant pressure |
cv_const | Constant specific heat capacity at constant volume |
d_const | Constant density |
eta_const | Constant dynamic viscosity |
lambda_const | Constant thermal conductivity |
a_const | Constant velocity of sound |
T_min | Minimum temperature valid for medium model |
T_max | Maximum temperature valid for medium model |
T0=reference_T | Zero enthalpy temperature |
MM_const | Molar mass |
fluidConstants | 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 | Enumeration type for independent variables |
mediumName="unusablePartialMedium" | 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, 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=false | = true if medium contains the equation X = reference_X |
reference_p=101325 | Reference pressure of Medium: default 1 atmosphere |
reference_T=298.15 | Reference temperature of Medium: default 25 deg Celsius |
reference_X=fill(1/nX, nX) | Default mass fractions of medium |
p_default=101325 | Default value for pressure of medium (for initialization) |
T_default=Modelica.SIunits.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) |
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 |
Buildings.Media.Water.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
.
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
Buildings.Media.Water.enthalpyOfLiquid
Return the specific enthalpy of liquid
Information
Enthalpy of the water.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Type | Name | Default | Description |
---|---|---|---|
Temperature | T | Temperature [K] |
Outputs
Type | Name | Description |
---|---|---|
SpecificEnthalpy | h | Specific enthalpy [J/kg] |
Modelica definition
Buildings.Media.Water.BaseProperties.InputAbsolutePressure
Pressure as input signal connector
Modelica definition
Buildings.Media.Water.BaseProperties.InputMassFraction
Mass fraction as input signal connector
Modelica definition
Buildings.Media.Water.BaseProperties.InputSpecificEnthalpy
Specific enthalpy as input signal connector