Buildings.Utilities.Psychrometrics.Examples

Collection of models that illustrate model use and test models

Information

This package contains examples for the use of models that can be found in Buildings.Utilities.Psychrometrics.

Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).

Package Content

Name Description
Buildings.Utilities.Psychrometrics.Examples.Density_pTX Density_pTX Model to test the density computation
Buildings.Utilities.Psychrometrics.Examples.DewPointTemperature DewPointTemperature Unit test for dew point temperature calculation
Buildings.Utilities.Psychrometrics.Examples.HumidityRatioPressure HumidityRatioPressure Unit test for humidity ratio model
Buildings.Utilities.Psychrometrics.Examples.MassFraction_pTphi MassFraction_pTphi Unit test for dew point temperature calculation
Buildings.Utilities.Psychrometrics.Examples.Phi_pTX Phi_pTX Model to test the relative humidity computation
Buildings.Utilities.Psychrometrics.Examples.SaturationPressure SaturationPressure Model to test the wet bulb temperature computation
Buildings.Utilities.Psychrometrics.Examples.SaturationPressureLiquid SaturationPressureLiquid Model to test the wet bulb temperature computation
Buildings.Utilities.Psychrometrics.Examples.SublimationPressureIce SublimationPressureIce Model to test the wet bulb temperature computation
Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi TWetBul_TDryBulPhi Model to test the wet bulb temperature computation
Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulXi TWetBul_TDryBulXi  
Buildings.Utilities.Psychrometrics.Examples.TotalAirDryAir TotalAirDryAir Unit test for conversion of humidity per total air and dry air mass

Buildings.Utilities.Psychrometrics.Examples.Density_pTX Buildings.Utilities.Psychrometrics.Examples.Density_pTX

Model to test the density computation

Buildings.Utilities.Psychrometrics.Examples.Density_pTX

Information

This examples is a unit test for the density computation.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model Density_pTX "Model to test the density computation" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Modelica.Blocks.Sources.Constant p(k=101325) "Pressure"; Modelica.Blocks.Sources.Ramp XDryBul( height=0.014, offset=0, duration=0.5) "Dry bulb water vapor mass fraction"; Buildings.Utilities.Psychrometrics.Density_pTX den "Density"; Modelica.Blocks.Sources.Ramp TDryBul( duration=0.5, startTime=0.5, height=-10, offset=303.15) "Dry bulb temperature"; equation connect(XDryBul.y, den.X_w); connect(den.p, p.y); connect(TDryBul.y, den.T); end Density_pTX;

Buildings.Utilities.Psychrometrics.Examples.DewPointTemperature Buildings.Utilities.Psychrometrics.Examples.DewPointTemperature

Unit test for dew point temperature calculation

Buildings.Utilities.Psychrometrics.Examples.DewPointTemperature

Information

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model DewPointTemperature "Unit test for dew point temperature calculation" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Buildings.Utilities.Psychrometrics.pW_TDewPoi watVapPre; Modelica.Blocks.Sources.Ramp XHum( duration=1, height=(0.01 - 0.1), offset=0.1) "Humidity concentration"; Buildings.Utilities.Psychrometrics.pW_X humRat( use_p_in=false); Buildings.Utilities.Psychrometrics.TDewPoi_pW TDewPoi; equation connect(XHum.y, humRat.X_w); connect(humRat.p_w, TDewPoi.p_w); connect(TDewPoi.T, watVapPre.T); end DewPointTemperature;

Buildings.Utilities.Psychrometrics.Examples.HumidityRatioPressure Buildings.Utilities.Psychrometrics.Examples.HumidityRatioPressure

Unit test for humidity ratio model

Buildings.Utilities.Psychrometrics.Examples.HumidityRatioPressure

Information

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model HumidityRatioPressure "Unit test for humidity ratio model" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Buildings.Utilities.Psychrometrics.pW_X vapPre( use_p_in=true) "Model for humidity ratio"; Modelica.Blocks.Sources.Ramp XHumDryAir( duration=1, height=(0.0133 - 0.2), offset=0.2) "Humidity concentration in [kg/kg dry air]"; Modelica.Blocks.Sources.Constant p(k=101325) "Pressure"; Buildings.Utilities.Psychrometrics.X_pW humRat( use_p_in=true); Diagnostics.AssertEquality assertEquality(threShold=1E-5) "Checks that model and its inverse implementation are correct"; ToTotalAir toTotalAir; equation connect(vapPre.p_w, humRat.p_w); connect(humRat.X_w, assertEquality.u1); connect(p.y, humRat.p_in); connect(p.y, vapPre.p_in); connect(XHumDryAir.y, toTotalAir.XiDry); connect(toTotalAir.XiTotalAir, vapPre.X_w); connect(toTotalAir.XiTotalAir, assertEquality.u2); end HumidityRatioPressure;

Buildings.Utilities.Psychrometrics.Examples.MassFraction_pTphi Buildings.Utilities.Psychrometrics.Examples.MassFraction_pTphi

Unit test for dew point temperature calculation

Buildings.Utilities.Psychrometrics.Examples.MassFraction_pTphi

Information

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model MassFraction_pTphi "Unit test for dew point temperature calculation" extends Modelica.Icons.Example; package Medium1 = Buildings.Media.Air "Medium model"; package Medium2 = Buildings.Media.Air "Medium model"; Modelica.Blocks.Sources.Ramp Phi( offset=0, duration=0.5, height=1) "Relative humidity"; Buildings.Utilities.Psychrometrics.X_pTphi masFra1 "Mass fraction computation"; Modelica.Blocks.Sources.Ramp T( height=10, offset=283.15, duration=0.5, startTime=0.5) "Temperature"; Modelica.Blocks.Sources.Constant P(k=101325) "Pressure"; Buildings.Utilities.Psychrometrics.X_pTphi masFra2(use_p_in=false) "Mass fraction computation"; equation connect(T.y, masFra1.T); connect(Phi.y, masFra1.phi); connect(T.y, masFra2.T); connect(Phi.y, masFra2.phi); connect(P.y, masFra1.p_in); end MassFraction_pTphi;

Buildings.Utilities.Psychrometrics.Examples.Phi_pTX Buildings.Utilities.Psychrometrics.Examples.Phi_pTX

Model to test the relative humidity computation

Buildings.Utilities.Psychrometrics.Examples.Phi_pTX

Information

This examples is a unit test for the relative humidity computation.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model Phi_pTX "Model to test the relative humidity computation" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Modelica.Blocks.Sources.Constant p(k=101325) "Pressure"; Modelica.Blocks.Sources.Ramp XDryBul( height=0.014, offset=0, duration=0.5) "Dry bulb water vapor mass fraction"; Buildings.Utilities.Psychrometrics.Phi_pTX phi "Relative humidity"; Modelica.Blocks.Sources.Ramp TDryBul( duration=0.5, startTime=0.5, height=-10, offset=303.15) "Dry bulb temperature"; equation connect(XDryBul.y, phi.X_w); connect(phi.p, p.y); connect(TDryBul.y, phi.T); end Phi_pTX;

Buildings.Utilities.Psychrometrics.Examples.SaturationPressure Buildings.Utilities.Psychrometrics.Examples.SaturationPressure

Model to test the wet bulb temperature computation

Buildings.Utilities.Psychrometrics.Examples.SaturationPressure

Information

This examples is a unit test for the saturation pressure computation.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model SaturationPressure "Model to test the wet bulb temperature computation" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Buildings.Utilities.Psychrometrics.SaturationPressure pSat "Saturation pressure"; Modelica.Blocks.Sources.Ramp T( height=373.15 - 190, duration=1, offset=190) "Temperature"; equation connect(T.y, pSat.TSat); end SaturationPressure;

Buildings.Utilities.Psychrometrics.Examples.SaturationPressureLiquid Buildings.Utilities.Psychrometrics.Examples.SaturationPressureLiquid

Model to test the wet bulb temperature computation

Buildings.Utilities.Psychrometrics.Examples.SaturationPressureLiquid

Information

This examples is a unit test for the saturation pressure computation of liquid water.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model SaturationPressureLiquid "Model to test the wet bulb temperature computation" extends Modelica.Icons.Example; Buildings.Utilities.Psychrometrics.SaturationPressureLiquid pSat "Saturation pressure"; Modelica.Blocks.Sources.Ramp T( height=100, duration=1, offset=273.15) "Temperature"; equation connect(T.y, pSat.TSat); end SaturationPressureLiquid;

Buildings.Utilities.Psychrometrics.Examples.SublimationPressureIce Buildings.Utilities.Psychrometrics.Examples.SublimationPressureIce

Model to test the wet bulb temperature computation

Buildings.Utilities.Psychrometrics.Examples.SublimationPressureIce

Information

This examples is a unit test for the sublimation pressure computation of ice.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model SublimationPressureIce "Model to test the wet bulb temperature computation" extends Modelica.Icons.Example; Buildings.Utilities.Psychrometrics.SublimationPressureIce pSat "Saturation pressure"; Modelica.Blocks.Sources.Ramp T( height=273.15 - 190, duration=1, offset=190) "Temperature"; equation connect(T.y, pSat.TSat); end SublimationPressureIce;

Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi

Model to test the wet bulb temperature computation

Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi

Information

This examples is a unit test for the wet bulb computation. The model on the top uses the accurate computation of the wet bulb temperature, whereas the model below uses the approximate computation of the wet bulb temperature.

The model contains an assert that validates the model based on a single operating point from Example 17.1 in Ananthanarayanan (2013).

References

Ananthanarayanan, P. N. Basic refrigeration and air conditioning. Tata McGraw-Hill Education, 2013.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model TWetBul_TDryBulPhi "Model to test the wet bulb temperature computation" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Buildings.Utilities.Psychrometrics.TWetBul_TDryBulPhi wetBulPhi( redeclare package Medium = Medium) "Model for wet bulb temperature"; Modelica.Blocks.Sources.Constant p(k=101325) "Pressure"; Modelica.Blocks.Sources.Ramp phi( duration=1, height=1, offset=0) "Relative humidity"; Modelica.Blocks.Sources.Constant TDryBul(k=273.15 + 29.4) "Dry bulb temperature"; Buildings.Utilities.Psychrometrics.TWetBul_TDryBulPhi wetBulPhiApp( redeclare package Medium = Medium, approximateWetBulb=true) "Model for wet bulb temperature"; Buildings.Utilities.Psychrometrics.TWetBul_TDryBulXi wetBulXi( redeclare package Medium = Medium) "Model for wet bulb temperature using Xi as an input, used to verify consistency with wetBulPhi"; Buildings.Utilities.Psychrometrics.X_pTphi x_pTphi "Computes mass fraction"; protected block Assertions extends Modelica.Blocks.Icons.Block; constant Modelica.SIunits.Temperature dT_max=0.1 "Maximum allowed deviation with reference result"; Modelica.Blocks.Interfaces.RealInput phi "Relative humidity"; Modelica.Blocks.Interfaces.RealInput wetBulPhi_TWetBul "Wet bulb temperature from wetBulPhi_phi"; Modelica.Blocks.Interfaces.RealInput wetBulXi_TWetBul "Wet bulb temperature from wetBulXi_phi"; equation // Validation of one data point based on example 17.1 in // Ananthanarayanan, P. N. Basic refrigeration and air conditioning. Tata McGraw-Hill Education, 2013. if abs(phi-0.48)<0.001 then assert(abs(wetBulPhi_TWetBul - 21.1-273.15) < dT_max, "Error in computation of wet bulb temperature, deviation with reference result is larger than " + String(dT_max) + " K since the wet bulb temperature equals " +String(wetBulPhi_TWetBul)); end if; assert(abs(wetBulPhi_TWetBul-wetBulXi_TWetBul)<1e-2, "Inconsistent implementation of wetBulPhi and wetBulXi."); end Assertions; Assertions assertions "Verifies that the results are correct"; equation connect(p.y, wetBulPhi.p); connect(TDryBul.y, wetBulPhi.TDryBul); connect(phi.y, wetBulPhi.phi); connect(p.y, wetBulPhiApp.p); connect(TDryBul.y, wetBulPhiApp.TDryBul); connect(phi.y, wetBulPhiApp.phi); connect(wetBulXi.TDryBul, TDryBul.y); connect(wetBulXi.p, p.y); connect(x_pTphi.p_in, p.y); connect(x_pTphi.T, TDryBul.y); connect(x_pTphi.phi, phi.y); connect(x_pTphi.X[1], wetBulXi.Xi[1]); connect(wetBulPhi.TWetBul, assertions.wetBulPhi_TWetBul); connect(wetBulXi.TWetBul, assertions.wetBulXi_TWetBul); connect(assertions.phi, phi.y); end TWetBul_TDryBulPhi;

Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulXi Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulXi


Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulXi

Information

This examples is a unit test for the wet bulb computation. The model on the top uses the accurate computation of the wet bulb temperature, whereas the model below uses the approximate computation of the wet bulb temperature.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model TWetBul_TDryBulXi extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Modelica.Blocks.Sources.Ramp TDryBul( height=10, duration=1, offset=273.15 + 30) "Dry bulb temperature"; Buildings.Utilities.Psychrometrics.TWetBul_TDryBulXi wetBul( redeclare package Medium = Medium) "Model for wet bulb temperature"; Modelica.Blocks.Sources.Constant p(k=101325) "Pressure"; Modelica.Blocks.Sources.Ramp XHum( duration=1, height=(0.0133 - 0.0175), offset=0.0175) "Humidity concentration"; Buildings.Utilities.Psychrometrics.TWetBul_TDryBulXi wetBulApp(redeclare package Medium = Medium, approximateWetBulb=true) "Model for wet bulb temperature"; equation connect(p.y, wetBul.p); connect(XHum.y, wetBul.Xi[1]); connect(TDryBul.y, wetBul.TDryBul); connect(p.y, wetBulApp.p); connect(XHum.y, wetBulApp.Xi[1]); connect(TDryBul.y, wetBulApp.TDryBul); end TWetBul_TDryBulXi;

Buildings.Utilities.Psychrometrics.Examples.TotalAirDryAir Buildings.Utilities.Psychrometrics.Examples.TotalAirDryAir

Unit test for conversion of humidity per total air and dry air mass

Buildings.Utilities.Psychrometrics.Examples.TotalAirDryAir

Information

Extends from Modelica.Icons.Example (Icon for runnable examples).

Modelica definition

model TotalAirDryAir "Unit test for conversion of humidity per total air and dry air mass" extends Modelica.Icons.Example; package Medium = Buildings.Media.Air "Medium model"; Modelica.Blocks.Sources.Ramp XHum( duration=1, height=(0.01 - 0.1), offset=0.1) "Humidity concentration"; ToTotalAir toTotalAir; ToDryAir toDryAir; Diagnostics.AssertEquality assertEquality(threShold=1E-5) "Checks that model and its inverse implementation are correct"; equation connect(toTotalAir.XiDry, XHum.y); connect(toTotalAir.XiTotalAir, toDryAir.XiTotalAir); connect(toDryAir.XiDry, assertEquality.u1); connect(assertEquality.u2, XHum.y); end TotalAirDryAir;

Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi.Assertions Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi.Assertions


Buildings.Utilities.Psychrometrics.Examples.TWetBul_TDryBulPhi.Assertions

Information

Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).

Connectors

TypeNameDescription
input RealInputphiRelative humidity
input RealInputwetBulPhi_TWetBulWet bulb temperature from wetBulPhi_phi
input RealInputwetBulXi_TWetBulWet bulb temperature from wetBulXi_phi

Modelica definition

block Assertions extends Modelica.Blocks.Icons.Block; constant Modelica.SIunits.Temperature dT_max=0.1 "Maximum allowed deviation with reference result"; Modelica.Blocks.Interfaces.RealInput phi "Relative humidity"; Modelica.Blocks.Interfaces.RealInput wetBulPhi_TWetBul "Wet bulb temperature from wetBulPhi_phi"; Modelica.Blocks.Interfaces.RealInput wetBulXi_TWetBul "Wet bulb temperature from wetBulXi_phi"; equation // Validation of one data point based on example 17.1 in // Ananthanarayanan, P. N. Basic refrigeration and air conditioning. Tata McGraw-Hill Education, 2013. if abs(phi-0.48)<0.001 then assert(abs(wetBulPhi_TWetBul - 21.1-273.15) < dT_max, "Error in computation of wet bulb temperature, deviation with reference result is larger than " + String(dT_max) + " K since the wet bulb temperature equals " +String(wetBulPhi_TWetBul)); end if; assert(abs(wetBulPhi_TWetBul-wetBulXi_TWetBul)<1e-2, "Inconsistent implementation of wetBulPhi and wetBulXi."); end Assertions;