Buildings.Fluid.HeatExchangers.BaseClasses.Examples

Information

This package contains examples for the use of models that can be found in Buildings.Fluid.HeatExchangers.BaseClasses.

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

Package Content

Name	Description
HexElement	Model that tests the basic element that is used to built heat exchanger models
Manifold	Test model for coil manifold
MassExchange	Test model for latent heat exchange
MassExchangeDummy	Test model for dummy model that is used to replace the latent heat exchange model in dry coils
EpsilonNTUZ	Test model for the functions epsilon_ntuZ and ntu_epsilonZ

Buildings.Fluid.HeatExchangers.BaseClasses.Examples.HexElement

Information

Modelica definition

model HexElement 
  "Model that tests the basic element that is used to built heat exchanger models"
  import Buildings;
  extends Modelica.Icons.Example;
 package Medium_W = Buildings.Media.ConstantPropertyLiquidWater;
 package Medium_A = Buildings.Media.PerfectGases.MoistAirUnsaturated;
  Buildings.Fluid.Sources.Boundary_pT sin_2(
    redeclare package Medium = Medium_A,
    use_p_in=true,
    use_T_in=true,
    T=288.15,
    nPorts=1);
    Modelica.Blocks.Sources.Ramp PIn(
    height=20,
    duration=300,
    startTime=300,
    offset=101325);
  Buildings.Fluid.Sources.Boundary_pT sou_2(
    redeclare package Medium = Medium_A,
    use_p_in=true,
    use_T_in=true,
    T=283.15,
    nPorts=1);
    Modelica.Blocks.Sources.Ramp TWat(
    startTime=1,
    height=4,
    duration=300,
    offset=303.15) "Water temperature";
  Modelica.Blocks.Sources.Constant TDb(k=278.15) "Drybulb temperature";
    Modelica.Blocks.Sources.Constant POut(k=101325);
  Buildings.Fluid.Sources.Boundary_pT sin_1(
   redeclare package Medium = Medium_W,
    use_p_in=true,
    T=288.15,
    nPorts=1);
  Buildings.Fluid.Sources.Boundary_pT sou_1(
    redeclare package Medium = Medium_W,
    use_T_in=true,
    nPorts=1,
    p=101340,
    T=293.15);
    Fluid.FixedResistances.FixedResistanceDpM res_22(
    m_flow_nominal=5,
    dp_nominal=5,
    redeclare package Medium = Medium_A);
    Fluid.FixedResistances.FixedResistanceDpM res_12(
    m_flow_nominal=5,
    dp_nominal=5,
    redeclare package Medium = Medium_W);
  Buildings.Fluid.HeatExchangers.BaseClasses.HexElement hex(
    redeclare Buildings.Fluid.MixingVolumes.MixingVolumeDryAir vol2,
    m1_flow_nominal=5,
    m2_flow_nominal=5,
    UA_nominal=9999,
    redeclare package Medium1 = Medium_W,
    redeclare package Medium2 = Medium_A,
    dp1_nominal=5,
    dp2_nominal=5);
  Modelica.Blocks.Sources.Constant TDb1(k=303.15) "Drybulb temperature";
    Fluid.FixedResistances.FixedResistanceDpM res_11(
    m_flow_nominal=5,
    dp_nominal=5,
    redeclare package Medium = Medium_W);
    Fluid.FixedResistances.FixedResistanceDpM res_21(
    m_flow_nominal=5,
    dp_nominal=5,
    redeclare package Medium = Medium_A);
  Modelica.Blocks.Sources.Constant hACon(k=10000) "Convective heat transfer";
  inner Modelica.Fluid.System system;
equation 
  connect(TDb.y, sou_1.T_in);
  connect(POut.y, sin_1.p_in);
  connect(PIn.y, sou_2.p_in);
  connect(TWat.y, sou_2.T_in);
  connect(POut.y, sin_2.p_in);
  connect(hex.port_b1, res_12.port_a);
  connect(res_22.port_a, hex.port_b2);
  connect(TDb1.y, sin_2.T_in);
  connect(res_11.port_b, hex.port_a1);
  connect(hex.port_a2, res_21.port_b);
  connect(hACon.y, hex.Gc_1);
  connect(hACon.y, hex.Gc_2);
  connect(sou_2.ports[1], res_21.port_a);
  connect(sin_1.ports[1], res_12.port_b);
  connect(sou_1.ports[1], res_11.port_a);
  connect(sin_2.ports[1], res_22.port_b);
end HexElement;

Buildings.Fluid.HeatExchangers.BaseClasses.Examples.Manifold

Information

Parameters

Type	Name	Default	Description
Integer	nPipPar	3	Number of parallel pipes
Integer	nPipSeg	4	Number of pipe segments

Modelica definition

model Manifold "Test model for coil manifold"
 package Medium = Buildings.Media.ConstantPropertyLiquidWater;
  extends Modelica.Icons.Example;
 parameter Integer nPipPar = 3 "Number of parallel pipes";
 parameter Integer nPipSeg = 4 "Number of pipe segments";
    Modelica.Blocks.Sources.Constant POut(k=101325);
  Buildings.Fluid.Sources.Boundary_pT sin_1(                       redeclare 
      package Medium = Medium,
    use_p_in=true,
    T=283.15,
    nPorts=2);
  Buildings.Fluid.Sources.Boundary_pT sou_1(
    redeclare package Medium = Medium,
    use_p_in=true,
    use_T_in=true,
    p=101335,
    T=293.15,
    nPorts=2);
    Fluid.FixedResistances.FixedResistanceDpM res_1(
    m_flow_nominal=5,
    redeclare package Medium = Medium,
    dp_nominal=10,
    use_dh=true,
    from_dp=false);
  Buildings.Fluid.Sensors.MassFlowRate[nPipPar] mfr_1(redeclare each package
      Medium = Medium);
  Modelica.Blocks.Sources.Ramp TDb(
    height=1,
    duration=1,
    offset=293.15);
  Modelica.Blocks.Sources.Ramp P(
    duration=1,
    height=40,
    offset=101305);
  Buildings.Fluid.HeatExchangers.BaseClasses.PipeManifoldFixedResistance
    pipFixRes_1(
    redeclare package Medium = Medium,
    nPipPar=nPipPar,
    m_flow_nominal=5,
    dp_nominal=10,
    linearized=false,
    mStart_flow_a=5);
  Buildings.Fluid.HeatExchangers.BaseClasses.PipeManifoldNoResistance
    pipNoRes_1(
      redeclare package Medium = Medium, nPipPar=nPipPar,
    mStart_flow_a=5);
    Fluid.FixedResistances.FixedResistanceDpM res_2(
    m_flow_nominal=5,
    redeclare package Medium = Medium,
    dp_nominal=10,
    use_dh=true,
    from_dp=false);
  Buildings.Fluid.Sensors.MassFlowRate[nPipPar, nPipSeg] mfr_2(redeclare each 
      package Medium =
               Medium);
  Buildings.Fluid.HeatExchangers.BaseClasses.DuctManifoldFixedResistance
    ducFixRes_2(
    redeclare package Medium = Medium,
    nPipPar=nPipPar,
    nPipSeg=nPipSeg,
    m_flow_nominal=5,
    dp_nominal=10,
    linearized=false,
    mStart_flow_a=5);
  Buildings.Fluid.HeatExchangers.BaseClasses.DuctManifoldNoResistance
    ducNoRes_2(
      redeclare package Medium = Medium,
      nPipPar=nPipPar,
      nPipSeg=nPipSeg,
    mStart_flow_a=5);
  Buildings.Fluid.HeatExchangers.BaseClasses.CoilHeader hea1(
      redeclare package Medium = Medium,
      nPipPar=nPipPar,
    mStart_flow_a=5) "Header for water-side heat exchanger register";
  Buildings.Fluid.HeatExchangers.BaseClasses.CoilHeader hea2(
      redeclare package Medium = Medium,
      nPipPar=nPipPar,
    mStart_flow_a=5) "Header for water-side heat exchanger register";
  inner Modelica.Fluid.System system;
equation 
  connect(POut.y, sin_1.p_in);
  connect(TDb.y, sou_1.T_in);
  connect(P.y, sou_1.p_in);
  connect(res_1.port_a, pipNoRes_1.port_a);
  connect(res_2.port_a,ducNoRes_2. port_a);
  connect(pipFixRes_1.port_b, hea1.port_a);
  connect(hea1.port_b, mfr_1.port_a);
  connect(mfr_1.port_b, hea2.port_a);
  connect(hea2.port_b, pipNoRes_1.port_b);
  connect(ducFixRes_2.port_b, mfr_2.port_a);
  connect(mfr_2.port_b, ducNoRes_2.port_b);
  connect(sou_1.ports[1], pipFixRes_1.port_a);
  connect(sou_1.ports[2], ducFixRes_2.port_a);
  connect(sin_1.ports[1], res_1.port_b);
  connect(sin_1.ports[2], res_2.port_b);
end Manifold;

Buildings.Fluid.HeatExchangers.BaseClasses.Examples.MassExchange

Information

Modelica definition

model MassExchange "Test model for latent heat exchange"
  extends Modelica.Icons.Example;
  package Medium = Buildings.Media.PerfectGases.MoistAir;
  Buildings.Fluid.HeatExchangers.BaseClasses.MassExchange masExc(redeclare 
      package Medium =
               Medium) "Model for mass exchange";
  Modelica.Blocks.Sources.Ramp TSur(
    duration=1,
    height=20,
    offset=273.15 + 5) "Surface temperature";
    Modelica.Blocks.Sources.Constant X_w(k=0.01) 
    "Humidity mass fraction in medium";
    Modelica.Blocks.Sources.Constant Gc(k=1) 
    "Sensible convective thermal conductance";
equation 
  connect(TSur.y, masExc.TSur);
  connect(Gc.y, masExc.Gc);
  connect(X_w.y, masExc.XInf);
end MassExchange;

Buildings.Fluid.HeatExchangers.BaseClasses.Examples.MassExchangeDummy

Information

Modelica definition

model MassExchangeDummy 
  "Test model for dummy model that is used to replace the latent heat exchange model in dry coils"
  import Buildings;
  extends Modelica.Icons.Example;
  package Medium = Buildings.Media.PerfectGases.MoistAir;
  Buildings.Fluid.HeatExchangers.BaseClasses.MassExchangeDummy
                                                          masExc 
    "Model for mass exchange";
  Modelica.Blocks.Sources.Ramp TSur(
    duration=1,
    height=20,
    offset=273.15 + 5) "Surface temperature";
    Modelica.Blocks.Sources.Constant X_w(k=0.01) 
    "Humidity mass fraction in medium";
    Modelica.Blocks.Sources.Constant Gc(k=1) 
    "Sensible convective thermal conductance";
equation 
  connect(TSur.y, masExc.TSur);
  connect(Gc.y, masExc.Gc);
  connect(X_w.y, masExc.XInf);
end MassExchangeDummy;

Buildings.Fluid.HeatExchangers.BaseClasses.Examples.EpsilonNTUZ

Information

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

Modelica definition

model EpsilonNTUZ 
  "Test model for the functions epsilon_ntuZ and ntu_epsilonZ"
  extends Modelica.Icons.Example;
  import f = Buildings.Fluid.Types.HeatExchangerFlowRegime;
  Real epsilon[5] "Heat exchanger effectiveness";
  Real eps[5] "Heat exchanger effectiveness";
  Real Z[5] "Ratio of capacity flow rates";
  Real ntu[5] "Number of transfer units";
  Real diff[5] "Difference in results";

equation 
  for conf in {f.ParallelFlow,
               f.CounterFlow,
               f.CrossFlowUnmixed,
               f.CrossFlowCMinMixedCMaxUnmixed,
               f.CrossFlowCMinUnmixedCMaxMixed} loop
     Z[conf]       = abs(cos(time));
     epsilon[conf] = 0.01 + 0.98*abs(sin(time)) * 1/(1+Z[conf]);
     ntu[conf]     = ntu_epsilonZ(epsilon[conf], Z[conf], conf);
     eps[conf]     = epsilon_ntuZ(ntu[conf],     Z[conf], conf);
     diff[conf]    = epsilon[conf] - eps[conf];
     assert(abs(diff[conf]) < 1E-10, "Check model implementation for bugs.");
  end for;
end EpsilonNTUZ;