Buildings.Fluid.Interfaces.Examples

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Buildings.Fluid.Interfaces.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.Fluid.Interfaces.

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

Package Content

Name	Description
ConservationEquation	Model that tests the conservation equation
HeaterCoolerPrescribed	Model that tests a heat exchanger model with reverse flow
HumidifierPrescribed
ReverseFlowHumidifier	Model that tests the reverse flow for a humidifier
ReverseFlowMassExchanger	Model that tests the reverse flow for a mass exchanger

Buildings.Fluid.Interfaces.Examples.ConservationEquation

Model that tests the conservation equation

Information

Model that tests the conservation equations that are used for the heat and mass balance.

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

Modelica definition

model ConservationEquation 
  "Model that tests the conservation equation"
extends Modelica.Icons.Example;
 package Medium = Buildings.Media.ConstantPropertyLiquidWater "Medium model";
  Buildings.Fluid.Interfaces.ConservationEquation dyn(redeclare package Medium
      = Medium, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
    nPorts=2,
    fluidVolume=0.01) "Dynamic conservation equation";

  Buildings.Fluid.Interfaces.StaticTwoPortConservationEquation ste(
    redeclare package Medium = Medium,
    m_flow_nominal=0.01,
    sensibleOnly=false,
    show_T=true) "Steady-state conservation equation";

  Modelica.Blocks.Sources.Constant mWat_flow(k=0) 
    "Water mass flow rate added to the control volume";
  Modelica.Blocks.Sources.TimeTable QSen_flow(startTime=0, table=[
                                0,-100;
                                900,-100;
                                900,0;
                                1800,0;
                                1800,100]) 
    "Sensible heat flow rate added to the control volume";
  Buildings.Fluid.Sources.Boundary_pT sin(
    nPorts=2,
    use_p_in=false,
    redeclare package Medium = Medium,
    p=101325,
    T=283.15);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res1(
    from_dp=true,
    redeclare package Medium = Medium,
    m_flow_nominal=0.01,
    dp_nominal=100) "Flow resistance";
  Buildings.Fluid.Sources.MassFlowSource_T bou(
    nPorts=2,
    redeclare package Medium = Medium,
    m_flow=0.01) "Boundary condition for mass flow rate";
  Buildings.Fluid.FixedResistances.FixedResistanceDpM res2(
    from_dp=true,
    redeclare package Medium = Medium,
    m_flow_nominal=0.01,
    dp_nominal=100) "Flow resistance";
  inner Modelica.Fluid.System system;
equation 
  connect(QSen_flow.y, dyn.Q_flow);
  connect(mWat_flow.y, dyn.mWat_flow);

  connect(bou.ports[1], dyn.ports[1]);
  connect(res1.port_b, sin.ports[1]);
  connect(QSen_flow.y, ste.Q_flow);
  connect(mWat_flow.y, ste.mWat_flow);
  connect(res2.port_b, sin.ports[2]);
  connect(ste.port_a, bou.ports[2]);
  connect(ste.port_b, res2.port_a);
  connect(dyn.ports[2], res1.port_a);
end ConservationEquation;

Buildings.Fluid.Interfaces.Examples.HeaterCoolerPrescribed

Model that tests a heat exchanger model with reverse flow

Information

Model that tests the basic class that is used for the heater models. It adds and removes heat for forward and reverse flow. The top and bottom models should give similar results, although the sign of the temperature difference over the components differ because of the reverse flow. The model uses assert statements that will be triggered if results that are expected to be close to each other differ by more than a prescribed threshold. All temperature sensors are configured as steady-state sensors to avoid differences in temperature due to the dynamic response of the sensor.

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

Modelica definition

model HeaterCoolerPrescribed 
  "Model that tests a heat exchanger model with reverse flow"
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.ConstantPropertyLiquidWater;

  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea1(
                                                         redeclare package
      Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
  Modelica.Blocks.Sources.Constant TDb(k=293.15) "Drybulb temperature";
  Buildings.Fluid.Sources.Boundary_pT sou_1(
    redeclare package Medium = Medium,
    use_T_in=true,
    nPorts=4,
    p(displayUnit="Pa") = 101735,
    T=293.15);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_11(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_12(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.Sources.Boundary_pT sin_1(                       redeclare 
      package Medium = Medium,
    use_p_in=true,
    T=288.15,
    nPorts=4);
    Modelica.Blocks.Sources.Constant POut(k=101325);
    Modelica.Blocks.Sources.Ramp u(
    height=2,
    duration=3600,
    offset=-1,
    startTime=0) "Control signal";
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea2(
                                                 redeclare package Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
  Modelica.Blocks.Math.Gain gain(k=-1);
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea3(
                                                         redeclare package
      Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_2(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_3(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea4(
                                                 redeclare package Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_4(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.MixingVolumes.MixingVolume mix1(
                                           redeclare package Medium = Medium, V=
       0.000001,
    nPorts=2,
    m_flow_nominal=0.5,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
  Buildings.Utilities.Diagnostics.AssertEquality ass1(               threShold=
        0.05, startTime=600);
  Buildings.Utilities.Diagnostics.AssertEquality ass2(               threShold=
        0.05, startTime=600);
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea5(
                                                         redeclare package
      Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_1(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_5(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea6(
                                                 redeclare package Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea7(
                                                         redeclare package
      Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_6(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_7(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed hea8(
                                                 redeclare package Medium =
        Medium, Q_flow_nominal=5000,
    m_flow_nominal=0.5,
    dp_nominal=200,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_8(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.MixingVolumes.MixingVolume mix2(
                                           redeclare package Medium = Medium, V=
       0.000001,
    nPorts=2,
    m_flow_nominal=0.5,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
  Buildings.Utilities.Diagnostics.AssertEquality ass9(
             threShold=0.05, startTime=600);
  Buildings.Utilities.Diagnostics.AssertEquality ass10(
             threShold=0.05, startTime=600);
  inner Modelica.Fluid.System system(m_flow_start=0, energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState);
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem2a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem2b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem1a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem1b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem3a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem3b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem4a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem4b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Utilities.Diagnostics.AssertEquality ass3(               threShold=
        0.05, startTime=600);
  Buildings.Utilities.Diagnostics.AssertEquality ass4(               threShold=
        0.05, startTime=600);
  Buildings.Utilities.Diagnostics.AssertEquality ass5(               threShold=
        0.05, startTime=600);
  Buildings.Utilities.Diagnostics.AssertEquality ass6(               threShold=
        0.05, startTime=600);
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem6b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem6a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem5b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem5a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Utilities.Diagnostics.AssertEquality ass7(               threShold=
        0.05, startTime=600);
  Buildings.Utilities.Diagnostics.AssertEquality ass8(               threShold=
        0.05, startTime=600);
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem8b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem8a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem7b(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      senTem7a(redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    tau=0) "Temperature sensor";
equation 
  connect(POut.y,sin_1. p_in);
  connect(TDb.y,sou_1. T_in);
  connect(u.y, hea1.u);
  connect(gain.y, hea2.u);
  connect(u.y, gain.u);
  connect(u.y, hea3.u);
  connect(gain.y, hea4.u);
  connect(u.y, hea6.u);
  connect(u.y, hea8.u);
  connect(gain.y, hea5.u);
  connect(gain.y, hea7.u);
  connect(sin_1.ports[1], res_12.port_a);
  connect(sin_1.ports[2], res_3.port_a);
  connect(sou_1.ports[1], res_11.port_a);
  connect(sou_1.ports[2], res_2.port_a);
  connect(sin_1.ports[3], res_1.port_a);
  connect(sin_1.ports[4], res_6.port_a);
  connect(sou_1.ports[3], res_5.port_a);
  connect(sou_1.ports[4], res_7.port_a);
  connect(mix1.ports[1], res_4.port_a);
  connect(mix2.ports[1], res_8.port_a);
  connect(senTem1a.T, ass1.u1);
  connect(senTem2a.T, ass1.u2);
  connect(senTem1b.T, ass2.u2);
  connect(senTem2b.T, ass2.u1);
  connect(senTem4a.T, ass4.u2);
  connect(senTem3a.T, ass4.u1);
  connect(senTem4b.T, ass3.u1);
  connect(senTem3b.T, ass3.u2);
  connect(senTem6a.T, ass6.u2);
  connect(senTem5a.T, ass6.u1);
  connect(senTem6b.T, ass5.u1);
  connect(senTem5b.T, ass5.u2);
  connect(senTem8a.T, ass8.u2);
  connect(senTem7a.T, ass8.u1);
  connect(senTem8b.T, ass7.u1);
  connect(senTem7b.T, ass7.u2);
  connect(senTem3a.T, ass10.u1);
  connect(senTem7a.T, ass10.u2);
  connect(senTem2b.T, ass9.u1);
  connect(senTem5b.T, ass9.u2);
  connect(res_12.port_b, senTem2a.port_a);
  connect(senTem2a.port_b, hea2.port_a);
  connect(hea2.port_b, senTem2b.port_a);
  connect(senTem2b.port_b, senTem1b.port_b);
  connect(hea1.port_b, senTem1b.port_a);
  connect(res_11.port_b, senTem1a.port_a);
  connect(senTem1a.port_b, hea1.port_a);
  connect(res_2.port_b, senTem3a.port_a);
  connect(senTem3a.port_b, hea3.port_a);
  connect(hea3.port_b, senTem3b.port_a);
  connect(senTem3b.port_b, mix1.ports[2]);
  connect(hea4.port_b, senTem4b.port_a);
  connect(res_3.port_b, senTem4a.port_a);
  connect(senTem4a.port_b, hea4.port_a);
  connect(senTem4b.port_b, res_4.port_b);
  connect(res_5.port_b, senTem6a.port_a);
  connect(senTem6a.port_b, hea6.port_a);
  connect(hea6.port_b, senTem6b.port_a);
  connect(senTem6b.port_b, senTem5b.port_b);
  connect(senTem5b.port_a, hea5.port_b);
  connect(hea5.port_a, senTem5a.port_b);
  connect(senTem5a.port_a, res_1.port_b);
  connect(res_7.port_b, senTem8a.port_a);
  connect(senTem8a.port_b, hea8.port_a);
  connect(hea8.port_b, senTem8b.port_a);
  connect(senTem8b.port_b, res_8.port_b);
  connect(mix2.ports[2], senTem7b.port_b);
  connect(senTem7b.port_a, hea7.port_b);
  connect(hea7.port_a, senTem7a.port_b);
  connect(senTem7a.port_a, res_6.port_b);
end HeaterCoolerPrescribed;

Buildings.Fluid.Interfaces.Examples.HumidifierPrescribed

Information

Model that tests the basic class that is used for the humidifier model. It adds and removes water for forward and reverse flow. The top and bottom models should give similar results, although the sign of the humidity difference over the components differ because of the reverse flow. The model uses assert statements that will be triggered if results that are expected to be close to each other differ by more than a prescribed threshold.

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

Parameters

Type Name Default Description

MassFlowRate mWat_flow_nominal 0.001 Nominal water mass flow rate [kg/s]

Type	Name	Default	Description
MassFlowRate	mWat_flow_nominal	0.001	Nominal water mass flow rate [kg/s]

Modelica definition

model HumidifierPrescribed
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.PerfectGases.MoistAirUnsaturated;
 parameter Modelica.SIunits.MassFlowRate mWat_flow_nominal = 0.001 
    "Nominal water mass flow rate";
  Humidifier hea1(redeclare package Medium =
        Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
  Modelica.Blocks.Sources.Constant TDb(k=293.15) "Drybulb temperature";
  Buildings.Fluid.Sources.Boundary_pT sou_1(
    redeclare package Medium = Medium,
    use_T_in=true,
    nPorts=4,
    p(displayUnit="Pa") = 101435,
    T=293.15);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_11(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_12(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.Sources.Boundary_pT sin_1(
    redeclare package Medium = Medium,
    use_p_in=true,
    T=288.15,
    nPorts=4);
    Modelica.Blocks.Sources.Constant POut(k=101325);
    Modelica.Blocks.Sources.Ramp u(
    duration=3600,
    startTime=0,
    height=1,
    offset=0) "Control signal";
  Humidifier hea2(
    redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
  Modelica.Blocks.Math.Gain gain(k=-1);
  Humidifier hea3(
    redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_2(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_3(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Humidifier hea4(
    redeclare package Medium = Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_4(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.MixingVolumes.MixingVolume mix1(
    redeclare package Medium = Medium,
    V=0.000001,
    nPorts=2,
    m_flow_nominal=0.5,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
  Buildings.Utilities.Diagnostics.AssertEquality ass1(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y1(y=hea2.staB.T);
  Modelica.Blocks.Sources.RealExpression y2(y=hea1.staB.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass2(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y3(y=hea2.staA.T);
  Modelica.Blocks.Sources.RealExpression y4(y=hea1.staA.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass3(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y5(y=hea4.staB.T);
  Modelica.Blocks.Sources.RealExpression y6(y=hea3.staB.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass4(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y7(y=hea4.staA.T);
  Modelica.Blocks.Sources.RealExpression y8(y=hea3.staA.T);
  Humidifier hea5(redeclare package Medium =
        Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_1(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_5(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Humidifier hea6(                               redeclare package Medium =
        Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
  Humidifier hea7(redeclare package Medium =
        Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_6(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_7(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Humidifier hea8(                               redeclare package Medium =
        Medium,
    m_flow_nominal=0.5,
    mWat_flow_nominal=mWat_flow_nominal,
    dp_nominal=50,
    show_T=true,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Heater and cooler";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res_8(
    redeclare package Medium = Medium,
    dp_nominal=5,
    m_flow_nominal=0.5);
  Buildings.Fluid.MixingVolumes.MixingVolume mix2(
                                           redeclare package Medium = Medium, V=
       0.000001,
    nPorts=2,
    m_flow_nominal=0.5,
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial);
  Buildings.Utilities.Diagnostics.AssertEquality ass5(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y9(y=hea6.staB.T);
  Modelica.Blocks.Sources.RealExpression y10(
                                            y=hea5.staB.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass6(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y11(
                                            y=hea6.staA.T);
  Modelica.Blocks.Sources.RealExpression y12(
                                            y=hea5.staA.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass7(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y13(
                                            y=hea8.staB.T);
  Modelica.Blocks.Sources.RealExpression y14(
                                            y=hea7.staB.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass8(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y15(
                                            y=hea8.staA.T);
  Modelica.Blocks.Sources.RealExpression y16(
                                            y=hea7.staA.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass9(
    startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y17(y=hea2.staB.T);
  Modelica.Blocks.Sources.RealExpression y18(y=hea5.staB.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass10(
     startTime=0.3,
    threShold=0.05);
  Modelica.Blocks.Sources.RealExpression y19(y=hea4.staA.T);
  Modelica.Blocks.Sources.RealExpression y20(y=hea7.staA.T);
  Buildings.Utilities.Diagnostics.AssertEquality ass11(
    threShold=1E-2,
    startTime=0.3);
  Modelica.Blocks.Sources.RealExpression y21(y=hea2.staB.X[1]);
  Modelica.Blocks.Sources.RealExpression y22(y=hea1.staB.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass12(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y23(
                                            y=hea2.staA.X[1]);
  Modelica.Blocks.Sources.RealExpression y24(
                                            y=hea1.staA.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass13(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y25(
                                            y=hea4.staB.X[1]);
  Modelica.Blocks.Sources.RealExpression y26(
                                            y=hea3.staB.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass14(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y27(
                                            y=hea4.staA.X[1]);
  Modelica.Blocks.Sources.RealExpression y28(
                                            y=hea3.staA.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass15(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y29(
                                            y=hea6.staB.X[1]);
  Modelica.Blocks.Sources.RealExpression y30(
                                            y=hea5.staB.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass16(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y31(
                                            y=hea6.staA.X[1]);
  Modelica.Blocks.Sources.RealExpression y32(
                                            y=hea5.staA.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass17(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y33(
                                            y=hea8.staB.X[1]);
  Modelica.Blocks.Sources.RealExpression y34(
                                            y=hea7.staB.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass18(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y35(
                                            y=hea8.staA.X[1]);
  Modelica.Blocks.Sources.RealExpression y36(
                                            y=hea7.staA.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass19(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y37(y=hea2.staB.X[1]);
  Modelica.Blocks.Sources.RealExpression y38(y=hea5.staB.X[1]);
  Buildings.Utilities.Diagnostics.AssertEquality ass20(threShold=1E-2, startTime=
        0.3);
  Modelica.Blocks.Sources.RealExpression y39(y=hea4.staA.X[1]);
  Modelica.Blocks.Sources.RealExpression y40(y=hea7.staA.X[1]);
  inner Modelica.Fluid.System system(energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState);
protected 
  model Humidifier 
    "Model for humidifier that adds a variable for the thermodynamic states at its ports"
    extends Buildings.Fluid.MassExchangers.HumidifierPrescribed;
   Medium.ThermodynamicState staA=
      Medium.setState_phX(port_a.p,
                          actualStream(port_a.h_outflow),
                          actualStream(port_a.Xi_outflow)) 
      "Thermodynamic state in port a";
   Medium.ThermodynamicState staB=
      Medium.setState_phX(port_b.p,
                          actualStream(port_b.h_outflow),
                          actualStream(port_b.Xi_outflow)) 
      "Thermodynamic state in port b";
  end Humidifier;
equation 
  connect(POut.y,sin_1. p_in);
  connect(TDb.y,sou_1. T_in);
  connect(res_11.port_b, hea1.port_a);
  connect(u.y, hea1.u);
  connect(gain.y, hea2.u);
  connect(u.y, gain.u);
  connect(res_12.port_b, hea2.port_a);
  connect(res_2.port_b, hea3.port_a);
  connect(u.y, hea3.u);
  connect(gain.y, hea4.u);
  connect(res_3.port_b, hea4.port_a);
  connect(hea4.port_b, res_4.port_b);
  connect(hea1.port_b, hea2.port_b);
  connect(y1.y, ass1.u1);
  connect(y2.y, ass1.u2);
  connect(y3.y, ass2.u1);
  connect(y4.y, ass2.u2);
  connect(y5.y, ass3.u1);
  connect(y6.y, ass3.u2);
  connect(y7.y, ass4.u1);
  connect(y8.y, ass4.u2);
  connect(res_1.port_b, hea5.port_a);
  connect(res_5.port_b, hea6.port_a);
  connect(res_6.port_b,hea7. port_a);
  connect(res_7.port_b,hea8. port_a);
  connect(hea8.port_b,res_8. port_b);
  connect(hea5.port_b,hea6. port_b);
  connect(y9.y,ass5. u1);
  connect(y10.y, ass5.u2);
  connect(y11.y, ass6.u1);
  connect(y12.y, ass6.u2);
  connect(y13.y, ass7.u1);
  connect(y14.y, ass7.u2);
  connect(y15.y, ass8.u1);
  connect(y16.y, ass8.u2);
  connect(y17.y,ass9. u1);
  connect(y18.y,ass9. u2);
  connect(y19.y, ass10.u1);
  connect(y20.y, ass10.u2);
  connect(u.y, hea6.u);
  connect(u.y, hea8.u);
  connect(gain.y, hea5.u);
  connect(gain.y, hea7.u);
  connect(y21.y, ass11.u1);
  connect(y22.y, ass11.u2);
  connect(y23.y, ass12.u1);
  connect(y24.y, ass12.u2);
  connect(y25.y, ass13.u1);
  connect(y26.y, ass13.u2);
  connect(y27.y, ass14.u1);
  connect(y28.y, ass14.u2);
  connect(y29.y, ass15.u1);
  connect(y30.y, ass15.u2);
  connect(y31.y, ass16.u1);
  connect(y32.y, ass16.u2);
  connect(y33.y, ass17.u1);
  connect(y34.y, ass17.u2);
  connect(y35.y, ass18.u1);
  connect(y36.y, ass18.u2);
  connect(y37.y, ass19.u1);
  connect(y38.y, ass19.u2);
  connect(y39.y, ass20.u1);
  connect(y40.y, ass20.u2);
  connect(sin_1.ports[1], res_12.port_a);
  connect(sin_1.ports[2], res_3.port_a);
  connect(sou_1.ports[1], res_11.port_a);
  connect(sou_1.ports[2], res_2.port_a);
  connect(sin_1.ports[3], res_1.port_a);
  connect(sin_1.ports[4], res_6.port_a);
  connect(sou_1.ports[3], res_5.port_a);
  connect(sou_1.ports[4], res_7.port_a);
  connect(hea3.port_b, mix1.ports[1]);
  connect(mix1.ports[2], res_4.port_a);
  connect(hea7.port_b, mix2.ports[1]);
  connect(mix2.ports[2], res_8.port_a);
end HumidifierPrescribed;

Buildings.Fluid.Interfaces.Examples.ReverseFlowHumidifier

Model that tests the reverse flow for a humidifier

Information

This model tests whether the results for a humidifer are identical for forward flow and reverse flow. If the results differ, then an assert is triggered.

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

Modelica definition

model ReverseFlowHumidifier 
  "Model that tests the reverse flow for a humidifier"
  extends Modelica.Icons.Example;
package Medium = Buildings.Media.PerfectGases.MoistAir;
  Buildings.Utilities.Diagnostics.AssertEquality assTem(threShold=0.01) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Utilities.Diagnostics.AssertEquality assEnt(threShold=0.5) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Utilities.Diagnostics.AssertEquality assMas(threShold=1E-5) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Fluid.MassExchangers.HumidifierPrescribed humBac(
    redeclare package Medium = Medium,
    dp_nominal=0,
    m_flow(start=1),
    m_flow_nominal=1,
    T=283.15,
    mWat_flow_nominal=0.1) "Humidifier with backward flow";
  Buildings.Fluid.MassExchangers.HumidifierPrescribed humFor(
    redeclare package Medium = Medium,
    dp_nominal=0,
    m_flow(start=1),
    m_flow_nominal=1,
    T=283.15,
    mWat_flow_nominal=0.1) "Humidifier with forward flow";
  Modelica.Blocks.Sources.Constant u2(k=0.01) "Control input";
  Modelica.Fluid.Sources.MassFlowSource_T source1(
    redeclare package Medium = Medium,
    use_m_flow_in=false,
    use_T_in=false,
    use_X_in=false,
    T(displayUnit="K") = 323.15,
    X={0.01,0.99},
    nPorts=1,
    m_flow=0.5) "Fluid source";
  Buildings.Fluid.Sources.FixedBoundary sink1(
    redeclare package Medium = Medium,
    nPorts=2) "Fluid sink";
  Sensors.SpecificEnthalpy senEnt1(redeclare package Medium = Medium) 
    "Specific enthalpy sensor";
  Sensors.Temperature senTem1(redeclare package Medium = Medium) 
    "Temperature sensor";
  Sensors.MassFraction senMas1(redeclare package Medium = Medium) 
    "Mass fraction sensor";
  Sensors.Temperature senTem2(redeclare package Medium = Medium) 
    "Temperature sensor";
  Sensors.SpecificEnthalpy senEnt2(redeclare package Medium = Medium) 
    "Specific enthalpy sensor";
  Sensors.MassFraction senMas2(redeclare package Medium = Medium) 
    "Mass fraction sensor";
  FixedResistances.FixedResistanceDpM res1(
    redeclare package Medium = Medium,
    m_flow_nominal=1,
    from_dp=true,
    linearized=false,
    dp_nominal=1000) "Fixed resistance";
  FixedResistances.FixedResistanceDpM res2(
    redeclare package Medium = Medium,
    m_flow_nominal=1,
    from_dp=true,
    linearized=false,
    dp_nominal=1000) "Fixed resistance";
  inner Modelica.Fluid.System system;
  Modelica.Fluid.Sources.MassFlowSource_T source2(
    redeclare package Medium = Medium,
    use_m_flow_in=false,
    use_T_in=false,
    use_X_in=false,
    T(displayUnit="K") = 323.15,
    X={0.01,0.99},
    nPorts=1,
    m_flow=0.5) "Fluid source";
equation 
  connect(u2.y, humFor.u);
  connect(u2.y, humBac.u);
  connect(humFor.port_b, senTem1.port);
  connect(humFor.port_b, senEnt1.port);
  connect(humFor.port_b, senMas1.port);
  connect(humBac.port_a, senTem2.port);
  connect(humBac.port_a, senEnt2.port);
  connect(humBac.port_a, senMas2.port);
  connect(humFor.port_b, res1.port_a);
  connect(res1.port_b, sink1.ports[1]);
  connect(humBac.port_a, res2.port_a);
  connect(res2.port_b, sink1.ports[2]);
  connect(senTem1.T, assTem.u1);
  connect(senEnt1.h_out, assEnt.u1);
  connect(senMas1.X, assMas.u1);
  connect(senTem2.T, assTem.u2);
  connect(senEnt2.h_out, assEnt.u2);
  connect(senMas2.X, assMas.u2);
  connect(humFor.port_a, source1.ports[1]);
  connect(source2.ports[1], humBac.port_b);
end ReverseFlowHumidifier;

Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger

Model that tests the reverse flow for a mass exchanger

Information

This model tests whether the results for a mass exchanger are identical for forward flow and reverse flow. If the results differ, then an assert is triggered.

Note that if the latent heat transfer effectiveness is non-zero, then the results will differ. The reason is that the maximum capacity stream is computed using the mass flow rates at port_a1 and port_a2. For reverse flow, they are not equal if moisture is added to the mass flow rate. Using an average mass flow rate in computing the heat and moisture transfer would lead to identical results, but it would introduce additional nonlinear equations that need to be solved. Therefore, the model uses the mass flow rates at port_a1 and port_a2.

Note: This problem fails to translate in Dymola 2012 due to an error in Dymola's support of stream connector. This bug will be corrected in future versions of Dymola.

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

Modelica definition

model ReverseFlowMassExchanger 
  "Model that tests the reverse flow for a mass exchanger"
  extends Modelica.Icons.Example;
package Medium = Buildings.Media.PerfectGases.MoistAir;
  Buildings.Utilities.Diagnostics.AssertEquality assTem(threShold=1E-8,
      startTime=0) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Utilities.Diagnostics.AssertEquality assEnt(threShold=1E-8,
      startTime=0) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Utilities.Diagnostics.AssertEquality assMas(threShold=1E-8,
      startTime=0) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Modelica.Fluid.Sources.MassFlowSource_T source2(
    m_flow=1,
    redeclare package Medium = Medium,
    use_m_flow_in=false,
    use_T_in=false,
    use_X_in=false,
    nPorts=1,
    T(displayUnit="degC") = 303.15,
    X={0.02,0.98});
  Buildings.Fluid.MassExchangers.ConstantEffectiveness masExcFor(
    redeclare package Medium1 = Medium,
    redeclare package Medium2 = Medium,
    m1_flow_nominal=1,
    m2_flow_nominal=1,
    dp1_nominal=0,
    dp2_nominal=0,
    epsL=0) "Mass exchanger with forward flow";
  Buildings.Fluid.MassExchangers.ConstantEffectiveness masExcRev(
    redeclare package Medium1 = Medium,
    redeclare package Medium2 = Medium,
    m1_flow_nominal=1,
    m2_flow_nominal=1,
    dp1_nominal=0,
    dp2_nominal=0,
    epsL=0) "Mass exchanger with reverse flow";
  Buildings.Fluid.Sources.FixedBoundary sink2(
     redeclare package Medium = Medium,
     nPorts=2) "Fluid sink";
  FixedResistances.FixedResistanceDpM res3(
    redeclare package Medium = Medium,
    m_flow_nominal=1,
    from_dp=true,
    linearized=false,
    dp_nominal=1000) "Fixed resistance";
  FixedResistances.FixedResistanceDpM res4(
    redeclare package Medium = Medium,
    m_flow_nominal=1,
    from_dp=true,
    linearized=false,
    dp_nominal=1000) "Fixed resistance";
  Sensors.SpecificEnthalpy senEnt3(redeclare package Medium = Medium);
  Sensors.Temperature senTem3(redeclare package Medium = Medium);
  Sensors.MassFraction senMas3(redeclare package Medium = Medium);
  Sensors.SpecificEnthalpy senEnt4(redeclare package Medium = Medium);
  Sensors.Temperature senTem4(redeclare package Medium = Medium);
  Sensors.MassFraction senMas4(redeclare package Medium = Medium);
  Buildings.Utilities.Diagnostics.AssertEquality assTem1(threShold=1E-8,
      startTime=0) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Utilities.Diagnostics.AssertEquality assEnt1(threShold=1E-8,
      startTime=0) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Buildings.Utilities.Diagnostics.AssertEquality assMas1(threShold=1E-8,
      startTime=0) 
    "Assert to test if the outputs of the forward flow and reverse flow model are identical";
  Modelica.Fluid.Sources.MassFlowSource_T source3(
    m_flow=1,
    redeclare package Medium = Medium,
    use_m_flow_in=false,
    use_T_in=false,
    use_X_in=false,
    X={0.01,0.99},
    nPorts=1,
    T(displayUnit="degC") = 293.15);
  Modelica.Fluid.Sources.MassFlowSource_T source4(
    m_flow=1,
    redeclare package Medium = Medium,
    use_m_flow_in=false,
    use_T_in=false,
    use_X_in=false,
    nPorts=1,
    T(displayUnit="degC") = 303.15,
    X={0.02,0.98});

  Modelica.Fluid.Sources.MassFlowSource_T source1(
    m_flow=1,
    redeclare package Medium = Medium,
    use_m_flow_in=false,
    use_T_in=false,
    use_X_in=false,
    X={0.01,0.99},
    nPorts=1,
    T(displayUnit="degC") = 293.15);
  Buildings.Fluid.Sources.FixedBoundary sink1(
    redeclare package Medium = Medium,
    nPorts=2) "Fluid sink";
  Sensors.SpecificEnthalpy senEnt1(redeclare package Medium = Medium);
  Sensors.Temperature senTem1(redeclare package Medium = Medium);
  Sensors.MassFraction senMas1(redeclare package Medium = Medium);
  Sensors.Temperature senTem2(redeclare package Medium = Medium);
  Sensors.SpecificEnthalpy senEnt2(redeclare package Medium = Medium);
  Sensors.MassFraction senMas2(redeclare package Medium = Medium);
  FixedResistances.FixedResistanceDpM res1(
    redeclare package Medium = Medium,
    m_flow_nominal=1,
    from_dp=true,
    linearized=false,
    dp_nominal=1000) "Fixed resistance";
  FixedResistances.FixedResistanceDpM res2(
    redeclare package Medium = Medium,
    m_flow_nominal=1,
    from_dp=true,
    linearized=false,
    dp_nominal=1000) "Fixed resistance";
  inner Modelica.Fluid.System system;
equation 

  connect(res1.port_b, sink1.ports[1]);
  connect(res2.port_b, sink1.ports[2]);
  connect(senTem1.T, assTem.u1);
  connect(senEnt1.h_out, assEnt.u1);
  connect(senMas1.X, assMas.u1);
  connect(senTem2.T, assTem.u2);
  connect(senEnt2.h_out, assEnt.u2);
  connect(senMas2.X, assMas.u2);
  connect(masExcFor.port_b1, res1.port_a);
  connect(masExcFor.port_a1, source1.ports[1]);
  connect(masExcRev.port_a1, res2.port_a);
  connect(source2.ports[1], masExcFor.port_a2);
  connect(masExcRev.port_a1, senTem2.port);
  connect(masExcRev.port_a1, senEnt2.port);
  connect(masExcRev.port_a1, senMas2.port);
  connect(masExcFor.port_b1, senTem1.port);
  connect(masExcFor.port_b1, senEnt1.port);
  connect(masExcFor.port_b1, senMas1.port);
  connect(masExcFor.port_b2, res3.port_a);
  connect(masExcRev.port_a2, res4.port_a);
  connect(res3.port_b, sink2.ports[1]);
  connect(res4.port_b, sink2.ports[2]);
  connect(senTem3.T, assTem1.u1);
  connect(senTem4.T, assTem1.u2);
  connect(senEnt3.h_out, assEnt1.u1);
  connect(senEnt4.h_out, assEnt1.u2);
  connect(senMas3.X, assMas1.u1);
  connect(senMas4.X, assMas1.u2);
  connect(masExcFor.port_b2, senTem3.port);
  connect(masExcFor.port_b2, senEnt3.port);
  connect(masExcFor.port_b2, senMas3.port);
  connect(masExcRev.port_a2, senTem4.port);
  connect(masExcRev.port_a2, senEnt4.port);
  connect(masExcRev.port_a2, senMas4.port);
  connect(source3.ports[1], masExcRev.port_b1);
  connect(source4.ports[1], masExcRev.port_b2);
end ReverseFlowMassExchanger;

Buildings.Fluid.Interfaces.Examples.HumidifierPrescribed.Humidifier

Model for humidifier that adds a variable for the thermodynamic states at its ports

Information

Extends from Buildings.Fluid.MassExchangers.HumidifierPrescribed (Ideal humidifier or dehumidifier with prescribed water mass flow rate addition or subtraction).

Parameters

Type Name Default Description

replaceable package Medium PartialCondensingGases Medium in the component

Boolean use_T_in false Get the temperature from the input connector

Temperature T 293.15 Temperature of water that is added to the fluid stream (used if use_T_in=false) [K]

MassFlowRate mWat_flow_nominal Water mass flow rate at u=1, positive for humidification [kg/s]

Nominal condition

MassFlowRate m_flow_nominal Nominal mass flow rate [kg/s]

Pressure dp_nominal Pressure [Pa]

Initialization

MassFlowRate m_flow.start 0 Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]

Pressure dp.start 0 Pressure difference between port_a and port_b [Pa]

Assumptions

Boolean allowFlowReversal system.allowFlowReversal = true to allow flow reversal, false restricts to design direction (port_a -> port_b)

Advanced

MassFlowRate m_flow_small 1E-4*abs(m_flow_nominal) Small mass flow rate for regularization of zero flow [kg/s]

Boolean homotopyInitialization true = true, use homotopy method

Diagnostics

Boolean show_T false = true, if actual temperature at port is computed

Flow resistance

Boolean from_dp false = true, use m_flow = f(dp) else dp = f(m_flow)

Boolean linearizeFlowResistance false = true, use linear relation between m_flow and dp for any flow rate

Real deltaM 0.1 Fraction of nominal flow rate where flow transitions to laminar

Dynamics

Nominal condition

Time tau 30 Time constant at nominal flow (if energyDynamics <> SteadyState) [s]

Equations

Dynamics energyDynamics Modelica.Fluid.Types.Dynamic... Formulation of energy balance

Dynamics massDynamics energyDynamics Formulation of mass balance

Initialization

AbsolutePressure p_start Medium.p_default Start value of pressure [Pa]

Temperature T_start Medium.T_default Start value of temperature [K]

MassFraction X_start[Medium.nX] Medium.X_default Start value of mass fractions m_i/m [kg/kg]

ExtraProperty C_start[Medium.nC] fill(0, Medium.nC) Start value of trace substances

Type	Name	Default	Description
replaceable package Medium	PartialCondensingGases	Medium in the component
Boolean	use_T_in	false	Get the temperature from the input connector
Temperature	T	293.15	Temperature of water that is added to the fluid stream (used if use_T_in=false) [K]
MassFlowRate	mWat_flow_nominal		Water mass flow rate at u=1, positive for humidification [kg/s]
Nominal condition
MassFlowRate	m_flow_nominal		Nominal mass flow rate [kg/s]
Pressure	dp_nominal		Pressure [Pa]
Initialization
MassFlowRate	m_flow.start	0	Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]
Pressure	dp.start	0	Pressure difference between port_a and port_b [Pa]
Assumptions
Boolean	allowFlowReversal	system.allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRate	m_flow_small	1E-4*abs(m_flow_nominal)	Small mass flow rate for regularization of zero flow [kg/s]
Boolean	homotopyInitialization	true	= true, use homotopy method
Diagnostics
Boolean	show_T	false	= true, if actual temperature at port is computed
Flow resistance
Boolean	from_dp	false	= true, use m_flow = f(dp) else dp = f(m_flow)
Boolean	linearizeFlowResistance	false	= true, use linear relation between m_flow and dp for any flow rate
Real	deltaM	0.1	Fraction of nominal flow rate where flow transitions to laminar
Dynamics
Nominal condition
Time	tau	30	Time constant at nominal flow (if energyDynamics <> SteadyState) [s]
Equations
Dynamics	energyDynamics	Modelica.Fluid.Types.Dynamic...	Formulation of energy balance
Dynamics	massDynamics	energyDynamics	Formulation of mass balance
Initialization
AbsolutePressure	p_start	Medium.p_default	Start value of pressure [Pa]
Temperature	T_start	Medium.T_default	Start value of temperature [K]
MassFraction	X_start[Medium.nX]	Medium.X_default	Start value of mass fractions m_i/m [kg/kg]
ExtraProperty	C_start[Medium.nC]	fill(0, Medium.nC)	Start value of trace substances

Connectors

Type Name Description

FluidPort_a port_a Fluid connector a (positive design flow direction is from port_a to port_b)

FluidPort_b port_b Fluid connector b (positive design flow direction is from port_a to port_b)

input RealInput T_in Temperature of water added to the fluid stream

input RealInput u Control input

Type	Name	Description
FluidPort_a	port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
FluidPort_b	port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
input RealInput	T_in	Temperature of water added to the fluid stream
input RealInput	u	Control input

Modelica definition

model Humidifier 
  "Model for humidifier that adds a variable for the thermodynamic states at its ports"
  extends Buildings.Fluid.MassExchangers.HumidifierPrescribed;
 Medium.ThermodynamicState staA=
    Medium.setState_phX(port_a.p,
                        actualStream(port_a.h_outflow),
                        actualStream(port_a.Xi_outflow)) 
    "Thermodynamic state in port a";
 Medium.ThermodynamicState staB=
    Medium.setState_phX(port_b.p,
                        actualStream(port_b.h_outflow),
                        actualStream(port_b.Xi_outflow)) 
    "Thermodynamic state in port b";
end Humidifier;

Automatically generated Thu Oct 24 15:10:19 2013.