Buildings.Fluid.FixedResistances.Examples

Information

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

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

Package Content

Name	Description
FixedResistance
FixedResistancesExplicit	Test of multiple resistances in series
FixedResistancesParallel
FixedResistancesSeries	Test of multiple resistances in series
SplitterFixedResistanceDpM
Pipe	Test of a pipe with multiple segments

Buildings.Fluid.FixedResistances.Examples.FixedResistance

Information

Modelica definition

model FixedResistance
  import Buildings;
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.ConstantPropertyLiquidWater;
    Modelica.Blocks.Sources.Constant PAtm(k=101325);
    Modelica.Blocks.Sources.Ramp P(
      duration=1,
    height=20,
    offset=101315);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res1(
    redeclare package Medium = Medium,
    from_dp=true,
    m_flow_nominal=5,
    dp_nominal=10);
  Buildings.Fluid.Sources.Boundary_pT sou1(          redeclare package Medium
      = Medium,
    use_p_in=true,
    T=293.15,
    nPorts=3);
  Buildings.Fluid.Sources.Boundary_pT sin1(          redeclare package Medium
      = Medium, T=283.15,
    use_p_in=true,
    nPorts=3);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res2(
    redeclare package Medium = Medium,
    from_dp=true,
    m_flow_nominal=5,
    dp_nominal=10,
    use_dh=true);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res3(
    redeclare package Medium = Medium,
    from_dp=true,
    m_flow_nominal=5,
    dp_nominal=10,
    use_dh=true);
  FixedResistances.LosslessPipe pipCon(redeclare package Medium = Medium,
      m_flow_nominal=5) "Lossless pipe connection";
  Buildings.Fluid.Sensors.MassFlowRate masFlo2(redeclare package Medium = Medium) 
    "Mass flow rate sensor";
  Buildings.Fluid.Sensors.MassFlowRate masFlo3(redeclare package Medium = Medium) 
    "Mass flow rate sensor";
  Buildings.Utilities.Diagnostics.AssertEquality assEqu(threShold=1E-4, message=
        "Inputs differ, check that lossless pipe is correctly implemented.") 
    "Assert equality of the two mass flow rates";
  inner Modelica.Fluid.System system;
equation 
  connect(res2.port_b, masFlo2.port_a);
  connect(res3.port_b, masFlo3.port_a);
  connect(masFlo3.port_b, pipCon.port_a);
  connect(P.y, sou1.p_in);
  connect(sou1.ports[1], res1.port_a);
  connect(sin1.ports[1], res1.port_b);
  connect(masFlo3.m_flow, assEqu.u1);
  connect(masFlo2.m_flow, assEqu.u2);
  connect(PAtm.y, sin1.p_in);
  connect(sou1.ports[2], res2.port_a);
  connect(sou1.ports[3], res3.port_a);
  connect(sin1.ports[2], masFlo2.port_b);
  connect(sin1.ports[3], pipCon.port_b);
end FixedResistance;

Buildings.Fluid.FixedResistances.Examples.FixedResistancesExplicit

Information

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

Modelica definition

model FixedResistancesExplicit 
  "Test of multiple resistances in series"
  import Buildings;
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.IdealGases.SimpleAir;
  Buildings.Fluid.Sources.Boundary_ph sou(
   redeclare package Medium = Medium,
    nPorts=1,
    p(displayUnit="Pa") = 101335,
    use_p_in=true);
  Buildings.Fluid.Sources.Boundary_ph sin(
    redeclare package Medium = Medium,
    nPorts=1,
    use_p_in=false,
    p=101325);

    Buildings.Fluid.FixedResistances.FixedResistanceDpM res(
    redeclare package Medium = Medium,
    from_dp = false,
    m_flow_nominal=2,
    dp_nominal=5);
  inner Modelica.Fluid.System system(p_ambient=101325);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res1(
    redeclare package Medium = Medium,
    from_dp = false,
    m_flow_nominal=2,
    dp_nominal=5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res2(
    redeclare package Medium = Medium,
    m_flow_nominal=2,
    dp_nominal=5,
    from_dp=true);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res3(
    redeclare package Medium = Medium,
    m_flow_nominal=2,
    dp_nominal=5,
    from_dp=true);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res4(
    redeclare package Medium = Medium,
    from_dp = false,
    m_flow_nominal=2,
    dp_nominal=5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res5(
    redeclare package Medium = Medium,
    from_dp = false,
    m_flow_nominal=2,
    dp_nominal=5);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res6(
    redeclare package Medium = Medium,
    m_flow_nominal=2,
    dp_nominal=5,
    from_dp=true);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res7(
    redeclare package Medium = Medium,
    m_flow_nominal=2,
    dp_nominal=5,
    from_dp=true);
  Buildings.Fluid.Sources.MassFlowSource_h bou(
    redeclare package Medium = Medium,
    m_flow=1,
    nPorts=1);
  Buildings.Fluid.Sources.MassFlowSource_h bou1(
    redeclare package Medium = Medium,
    m_flow=1,
    nPorts=1);
  Buildings.Fluid.Sources.Boundary_pT sin1(            redeclare package Medium
      =        Medium, T=273.15 + 10,
    nPorts=2,
    use_p_in=false,
    p=101325);
  Buildings.Fluid.Sources.Boundary_ph sin2(            redeclare package Medium
      =        Medium,
    nPorts=1,
    use_p_in=false,
    p=101325);
  Buildings.Fluid.Sources.Boundary_ph sou1(            redeclare package Medium
      =        Medium,
    nPorts=1,
    p(displayUnit="Pa") = 101335,
    use_p_in=true);
    Modelica.Blocks.Sources.Ramp P(
      duration=1,
    height=20,
    offset=101315);
  Buildings.Fluid.Sensors.MassFlowRate senMasFlo(redeclare package Medium =
        Medium) "Mass flow rate sensor";
  Buildings.Fluid.Sensors.MassFlowRate senMasFlo1(redeclare package Medium =
        Medium) "Mass flow rate sensor";
  Buildings.Fluid.Sensors.MassFlowRate senMasFlo2(redeclare package Medium =
        Medium) "Mass flow rate sensor";
  Buildings.Fluid.Sensors.MassFlowRate senMasFlo3(redeclare package Medium =
        Medium) "Mass flow rate sensor";
  Buildings.Utilities.Diagnostics.AssertEquality assertEquality;
  Buildings.Utilities.Diagnostics.AssertEquality assertEquality1;
equation 
  connect(res.port_b, res1.port_a);
  connect(res3.port_b, res2.port_a);
  connect(res4.port_b, res5.port_a);
  connect(res7.port_b, res6.port_a);
  connect(sou.ports[1], res.port_a);
  connect(bou.ports[1], res4.port_a);
  connect(bou1.ports[1], res7.port_a);
  connect(sou1.ports[1], res3.port_a);
  connect(P.y, sou.p_in);
  connect(P.y, sou1.p_in);
  connect(res1.port_b, senMasFlo.port_a);
  connect(res2.port_b, senMasFlo1.port_a);
  connect(res5.port_b, senMasFlo2.port_a);
  connect(res6.port_b, senMasFlo3.port_a);
  connect(senMasFlo2.port_b, sin1.ports[1]);
  connect(senMasFlo3.port_b, sin1.ports[2]);
  connect(senMasFlo.port_b, sin.ports[1]);
  connect(senMasFlo1.port_b, sin2.ports[1]);
  connect(senMasFlo2.m_flow, assertEquality1.u1);
  connect(senMasFlo3.m_flow, assertEquality1.u2);
  connect(senMasFlo.m_flow, assertEquality.u1);
  connect(senMasFlo1.m_flow, assertEquality.u2);
end FixedResistancesExplicit;

Buildings.Fluid.FixedResistances.Examples.FixedResistancesParallel

Information

Modelica definition

model FixedResistancesParallel
  import Buildings;
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.ConstantPropertyLiquidWater;
    Modelica.Blocks.Sources.Constant PAtm(k=101325);
    Modelica.Blocks.Sources.Ramp P(
      duration=1,
    height=20,
    offset=101315);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res1(
    redeclare package Medium = Medium,
    m_flow_nominal=5,
    dp_nominal=10,
    deltaM=0.3,
    linearized=false,
    from_dp=false);
  Buildings.Fluid.Sources.Boundary_pT sou1(          redeclare package Medium
      = Medium,
    T=293.15,
    nPorts=2,
    use_p_in=true);
  Buildings.Fluid.Sources.Boundary_pT sin1(          redeclare package Medium
      = Medium,
    T=283.15,
    nPorts=2,
    use_p_in=true);
    Buildings.Fluid.FixedResistances.FixedResistanceDpM res2(
    redeclare package Medium = Medium,
    m_flow_nominal=5,
    dp_nominal=10,
    deltaM=0.3,
    linearized=false,
    from_dp=false);
  Buildings.Fluid.Sensors.MassFlowRate masFlo2(redeclare package Medium = Medium) 
    "Mass flow rate sensor";
  Buildings.Utilities.Diagnostics.AssertEquality assEqu(threShold=1E-4, message=
        "Inputs differ, check that lossless pipe is correctly implemented.") 
    "Assert equality of the two mass flow rates";
  Buildings.Fluid.Sensors.MassFlowRate masFlo1(redeclare package Medium = Medium) 
    "Mass flow rate sensor";
  inner Modelica.Fluid.System system(p_ambient=101325);
equation 
  connect(PAtm.y, sin1.p_in);
  connect(P.y, sou1.p_in);
  connect(res2.port_b, masFlo2.port_a);
  connect(res1.port_b, masFlo1.port_a);
  connect(sou1.ports[1], res1.port_a);
  connect(sou1.ports[2], res2.port_a);
  connect(sin1.ports[1], masFlo1.port_b);
  connect(sin1.ports[2], masFlo2.port_b);
  connect(masFlo2.m_flow, assEqu.u1);
  connect(masFlo1.m_flow, assEqu.u2);
end FixedResistancesParallel;

Buildings.Fluid.FixedResistances.Examples.FixedResistancesSeries

Information

Parameters

Type	Name	Default	Description
Pressure	dp_nominal	5	Nominal pressure drop for each resistance [Pa]
Integer	nRes	10	Number of resistances

Modelica definition

model FixedResistancesSeries "Test of multiple resistances in series"
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.IdealGases.SimpleAir;

    Modelica.Blocks.Sources.Constant PAtm(k=101325);
   parameter Modelica.SIunits.Pressure dp_nominal = 5 
    "Nominal pressure drop for each resistance";
    Modelica.Blocks.Sources.Ramp P(
      duration=1,
    height=2*dp_nominal*nRes,
    offset=101325 - dp_nominal*nRes);
  Buildings.Fluid.Sources.Boundary_pT sou(             redeclare package Medium
      =        Medium, T=273.15 + 20,
    use_p_in=true,
    nPorts=1);
  Buildings.Fluid.Sources.Boundary_pT sin(             redeclare package Medium
      =        Medium, T=273.15 + 10,
    use_p_in=true,
    nPorts=1);
  parameter Integer nRes( min=2) = 10 "Number of resistances";
    Buildings.Fluid.FixedResistances.FixedResistanceDpM[
                       nRes] res(
    redeclare each package Medium = Medium,
    each dp_nominal=dp_nominal,
    each from_dp = false,
    each m_flow_nominal=2);
  inner Modelica.Fluid.System system(p_ambient=101325);
equation 
  for i in 1:nRes-1 loop
  connect(res[i].port_b, res[i+1].port_a);
  end for;
  connect(PAtm.y, sin.p_in);
  connect(P.y, sou.p_in);
  connect(sin.ports[1], res[nRes].port_b);
  connect(sou.ports[1], res[1].port_a);
end FixedResistancesSeries;

Buildings.Fluid.FixedResistances.Examples.SplitterFixedResistanceDpM

Information

Modelica definition

model SplitterFixedResistanceDpM
  extends Modelica.Icons.Example;

 package Medium = Buildings.Media.IdealGases.SimpleAir;

  Buildings.Fluid.FixedResistances.SplitterFixedResistanceDpM spl(
    m_flow_nominal={1,2,3},
    dh={1,2,3},
    redeclare package Medium = Medium,
    dp_nominal(displayUnit="Pa") = {5,10,15}) "Splitter";
  Buildings.Fluid.Sources.Boundary_pT bou1(             redeclare package
      Medium = Medium, T=273.15 + 10,
    use_p_in=true,
    nPorts=1);
  Buildings.Fluid.Sources.Boundary_pT bou2(             redeclare package
      Medium = Medium, T=273.15 + 20,
    use_p_in=true,
    nPorts=1);
  Buildings.Fluid.Sources.Boundary_pT bou3(             redeclare package
      Medium = Medium, T=273.15 + 30,
    use_p_in=true,
    nPorts=1);
    Modelica.Blocks.Sources.Constant P2(k=101325);
    Modelica.Blocks.Sources.Ramp P1(
    offset=101320,
    height=10,
    duration=0.5);
    Modelica.Blocks.Sources.Ramp P3(
      offset=101320,
      height=10,
    duration=0.5,
    startTime=0.5);
  inner Modelica.Fluid.System system(p_ambient=101325);
equation 
  connect(P1.y, bou1.p_in);
  connect(P2.y, bou2.p_in);
  connect(bou3.p_in, P3.y);
  connect(bou1.ports[1], spl.port_1);
  connect(bou3.ports[1], spl.port_3);
  connect(spl.port_2, bou2.ports[1]);
end SplitterFixedResistanceDpM;

Buildings.Fluid.FixedResistances.Examples.Pipe

Information

This model demonstrates the use of a pipe model. Both pipe models have the same mass flow rates and temperatures. Otherwise, the assert block would terminate the simulation.

The model on the top is connected to the ambient with one heat port, whereas the model at the bottom uses a vector of heat ports. Since they are all connected to the same temperature, they result in the same energy balance for the medium that flows through the pipe.

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

Parameters

Type	Name	Default	Description
replaceable package Medium		Buildings.Media.ConstantProp...

Connectors

Type	Name	Description
replaceable package Medium

Modelica definition

model Pipe "Test of a pipe with multiple segments"
  import Buildings;
  extends Modelica.Icons.Example;

  replaceable package Medium = Buildings.Media.ConstantPropertyLiquidWater;

  Modelica.Blocks.Sources.Ramp P(
    duration=1,
    height=2*pip.dp_nominal,
    offset=101325 - pip.dp_nominal);
  Buildings.Fluid.Sources.Boundary_pT sou(
    redeclare package Medium = Medium,
    use_p_in=true,
    T=273.15 + 50,
    nPorts=2);
  Buildings.Fluid.Sources.Boundary_pT sin(
    redeclare package Medium = Medium,
    T=273.15 + 10,
    nPorts=2,
    use_p_in=false,
    p(displayUnit="Pa") = 101325);

  inner Modelica.Fluid.System system(p_ambient=101325);
  HeatTransfer.Sources.FixedTemperature TEnv(T=263.15);
  Buildings.Fluid.FixedResistances.Pipe pip(
    thicknessIns=0.01,
    lambdaIns=0.01,
    m_flow_nominal=10,
    redeclare package Medium = Medium,
    length=10);
  HeatTransfer.Sources.FixedTemperature TEnv1[10](each T=263.15);
  Buildings.Fluid.FixedResistances.Pipe pip1(
    thicknessIns=0.01,
    lambdaIns=0.01,
    m_flow_nominal=10,
    redeclare package Medium = Medium,
    length=10,
    useMultipleHeatPorts=true);
  Buildings.Fluid.Sensors.TemperatureTwoPort senTem(redeclare package Medium =
        Medium, m_flow_nominal=pip.m_flow_nominal) "Temperature sensor";
  Buildings.Fluid.Sensors.TemperatureTwoPort senTem1(redeclare package Medium
      = Medium, m_flow_nominal=pip.m_flow_nominal) "Temperature sensor";
  Buildings.Utilities.Diagnostics.AssertEquality assEqu;
equation 

  connect(P.y, sou.p_in);
  connect(sou.ports[1], pip.port_a);
  connect(TEnv.port, pip.heatPort);
  connect(sou.ports[2], pip1.port_a);
  connect(TEnv1.port, pip1.heatPorts);
  connect(pip.port_b, senTem.port_a);
  connect(senTem.port_b, sin.ports[1]);
  connect(pip1.port_b, senTem1.port_a);
  connect(senTem1.port_b, sin.ports[2]);
  connect(assEqu.u1, senTem.T);
  connect(senTem1.T, assEqu.u2);
end Pipe;