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Buildings.Fluid.Movers.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.Movers.

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

Package Content

NameDescription
Buildings.Fluid.Movers.Examples.FlowMachine_y FlowMachine_y  
Buildings.Fluid.Movers.Examples.FlowMachine_y_linear FlowMachine_y_linear Test model for pump with linear characteristic for pressure vs. flow rate
Buildings.Fluid.Movers.Examples.FlowMachine_Nrpm FlowMachine_Nrpm  
Buildings.Fluid.Movers.Examples.FlowMachine_dp FlowMachine_dp  
Buildings.Fluid.Movers.Examples.FlowMachine_m_flow FlowMachine_m_flow  
Buildings.Fluid.Movers.Examples.ControlledFlowMachineDynamic ControlledFlowMachineDynamic  
Buildings.Fluid.Movers.Examples.ControlledFlowMachine ControlledFlowMachine  
Buildings.Fluid.Movers.Examples.FlowMachine FlowMachine  
Buildings.Fluid.Movers.Examples.FlowMachineFeedbackControl FlowMachineFeedbackControl Flow machine with feedback control
Buildings.Fluid.Movers.Examples.FlowMachineParallel_y FlowMachineParallel_y Test model for two flow machines in parallel
Buildings.Fluid.Movers.Examples.FlowMachineSeries_y FlowMachineSeries_y Test model for two flow machines in series
Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves FlowMachine_y_pumpCurves Test model for pump that illustrates the pump curves
Buildings.Fluid.Movers.Examples.BaseClasses BaseClasses Package with base classes for Buildings.Fluid.Movers.Examples

Buildings.Fluid.Movers.Examples.FlowMachine_y Buildings.Fluid.Movers.Examples.FlowMachine_y

Buildings.Fluid.Movers.Examples.FlowMachine_y

Information

This example demonstrates and tests the use of a flow machine whose mass flow rate is reduced to zero.

The fans have been configured as steady-state models. This ensures that the actual speed is equal to the input signal.

Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow (Base class to test flow machines with zero flow rate).

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal1Nominal mass flow rate [kg/s]
Pressuredp_nominal500Nominal pressure difference [Pa]

Modelica definition

model FlowMachine_y
  extends Modelica.Icons.Example;
 extends Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow(
    gain(k=1),
    redeclare Buildings.Fluid.Movers.FlowMachine_y floMacSta(
      redeclare package Medium = Medium,
      pressure(V_flow={0,m_flow_nominal,2*m_flow_nominal}/1.2,
               dp={2*dp_nominal,dp_nominal,0}),
      filteredSpeed=false),
    redeclare Buildings.Fluid.Movers.FlowMachine_y floMacDyn(
      redeclare package Medium = Medium,
      pressure(V_flow={0,m_flow_nominal,2*m_flow_nominal}/1.2,
               dp={2*dp_nominal,dp_nominal,0}),
      filteredSpeed=false));

equation 
  connect(gain.y, floMacDyn.y);
  connect(gain.y, floMacSta.y);
end FlowMachine_y;

Buildings.Fluid.Movers.Examples.FlowMachine_y_linear Buildings.Fluid.Movers.Examples.FlowMachine_y_linear

Test model for pump with linear characteristic for pressure vs. flow rate

Buildings.Fluid.Movers.Examples.FlowMachine_y_linear

Information

This example demonstrates and tests the use of a flow machine whose speed is reduced to zero. In the top model, the pressure drop across the pump is constant, and in the bottom model, the mass flow rate across the pump is constant. In the top model, a small flow resistance has been added since a pump with zero speed cannot produce a non-zero pressure raise. For this operating region, the pressure drop ensures that the model is non-singular.

The fans have been configured as steady-state models. This ensures that the actual speed is equal to the input signal.

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

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal0.5Nominal mass flow rate [kg/s]
Pressuredp_nominal10000Nominal pressure [Pa]

Modelica definition

model FlowMachine_y_linear 
  "Test model for pump with linear characteristic for pressure vs. flow rate"
  extends Modelica.Icons.Example;
  package Medium = Buildings.Media.ConstantPropertyLiquidWater "Medium model";

  parameter Modelica.SIunits.MassFlowRate m_flow_nominal = 0.5 
    "Nominal mass flow rate";
  parameter Modelica.SIunits.Pressure dp_nominal = 10000 "Nominal pressure";

  Modelica.Blocks.Sources.Ramp y(
    offset=1,
    duration=0.5,
    startTime=0.25,
    height=-1) "Input signal";
  Buildings.Fluid.Sources.Boundary_pT sou(
    redeclare package Medium = Medium,
    use_p_in=false,
    p=300000,
    T=293.15,
    nPorts=1);
  Buildings.Fluid.Movers.FlowMachine_y pumFixDp(
    redeclare package Medium = Medium,
    energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
    dynamicBalance=false,
    pressure(V_flow=2/1000*{0, m_flow_nominal}, dp={2*dp_nominal, 0}),
    filteredSpeed=false) "Pump with fixed pressure raise";
  inner Modelica.Fluid.System system;
  Buildings.Fluid.Sources.Boundary_pT sou1(
    redeclare package Medium = Medium,
    use_p_in=false,
    p(displayUnit="Pa") = 300000 + 0.01*dp_nominal,
    T=293.15,
    nPorts=1);
  Buildings.Fluid.FixedResistances.FixedResistanceDpM dp1(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dp_nominal=0.01*dp_nominal) "Pressure drop";
  Buildings.Fluid.Sources.MassFlowSource_T
                                      sou2(
    redeclare package Medium = Medium,
    nPorts=1,
    m_flow=m_flow_nominal*0.01,
    T=293.15);
  Buildings.Fluid.Movers.FlowMachine_y pumFixM_flow(
    redeclare package Medium = Medium,
    energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
    dynamicBalance=false,
    pressure(V_flow=2/1000*{0, m_flow_nominal}, dp={2*dp_nominal, 0}),
    filteredSpeed=false) "Pump with fixed mass flow rate";
  Buildings.Fluid.Sources.Boundary_pT sou3(
    redeclare package Medium = Medium,
    use_p_in=false,
    p(displayUnit="Pa") = 300000 + 0.01*dp_nominal,
    T=293.15,
    nPorts=1);
equation 
  connect(pumFixDp.port_b, sou1.ports[1]);
  connect(dp1.port_b, pumFixDp.port_a);
  connect(dp1.port_a, sou.ports[1]);
  connect(pumFixM_flow.port_b, sou3.ports[1]);
  connect(sou2.ports[1], pumFixM_flow.port_a);
  connect(y.y, pumFixDp.y);
  connect(y.y, pumFixM_flow.y);
end FlowMachine_y_linear;

Buildings.Fluid.Movers.Examples.FlowMachine_Nrpm Buildings.Fluid.Movers.Examples.FlowMachine_Nrpm

Buildings.Fluid.Movers.Examples.FlowMachine_Nrpm

Information

This example demonstrates and tests the use of a flow machine whose mass flow rate is reduced to zero.

The fans have been configured as steady-state models. This ensures that the actual speed is equal to the input signal.

Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow (Base class to test flow machines with zero flow rate).

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal1Nominal mass flow rate [kg/s]
Pressuredp_nominal500Nominal pressure difference [Pa]

Modelica definition

model FlowMachine_Nrpm
  extends Modelica.Icons.Example;
 extends Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow(
    gain(k=1500),
    redeclare Buildings.Fluid.Movers.FlowMachine_Nrpm floMacSta(
      redeclare package Medium = Medium,
      pressure(V_flow={0,m_flow_nominal,2*m_flow_nominal}/1.2,
               dp={2*dp_nominal,dp_nominal,0}),
      filteredSpeed=false),
    redeclare Buildings.Fluid.Movers.FlowMachine_Nrpm floMacDyn(
      redeclare package Medium = Medium,
      pressure(V_flow={0,m_flow_nominal,2*m_flow_nominal}/1.2,
               dp={2*dp_nominal,dp_nominal,0}),
      filteredSpeed=false));

equation 
  connect(gain.y, floMacSta.Nrpm);
  connect(gain.y, floMacDyn.Nrpm);
end FlowMachine_Nrpm;

Buildings.Fluid.Movers.Examples.FlowMachine_dp Buildings.Fluid.Movers.Examples.FlowMachine_dp

Buildings.Fluid.Movers.Examples.FlowMachine_dp

Information

This example demonstrates and tests the use of a flow machine whose mass flow rate is reduced to zero.

The fans have been configured as steady-state models. This ensures that the actual speed is equal to the input signal.

Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow (Base class to test flow machines with zero flow rate).

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal1Nominal mass flow rate [kg/s]
Pressuredp_nominal500Nominal pressure difference [Pa]

Modelica definition

model FlowMachine_dp
  extends Modelica.Icons.Example;
 extends Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow(
    gain(k=dp_nominal),
    redeclare Buildings.Fluid.Movers.FlowMachine_dp floMacSta(
      redeclare package Medium = Medium,
      m_flow_nominal=m_flow_nominal,
      filteredSpeed=false),
    redeclare Buildings.Fluid.Movers.FlowMachine_dp floMacDyn(
      redeclare package Medium = Medium,
      m_flow_nominal=m_flow_nominal,
      filteredSpeed=false));

equation 
  connect(gain.y, floMacSta.dp_in);
  connect(gain.y, floMacDyn.dp_in);
end FlowMachine_dp;

Buildings.Fluid.Movers.Examples.FlowMachine_m_flow Buildings.Fluid.Movers.Examples.FlowMachine_m_flow

Buildings.Fluid.Movers.Examples.FlowMachine_m_flow

Information

This example demonstrates and tests the use of a flow machine whose mass flow rate is reduced to zero.

The fans have been configured as steady-state models. This ensures that the actual speed is equal to the input signal.

Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow (Base class to test flow machines with zero flow rate).

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal1Nominal mass flow rate [kg/s]
Pressuredp_nominal500Nominal pressure difference [Pa]

Modelica definition

model FlowMachine_m_flow
  extends Modelica.Icons.Example;
 extends Buildings.Fluid.Movers.Examples.BaseClasses.FlowMachine_ZeroFlow(
    gain(k=m_flow_nominal),
    redeclare Buildings.Fluid.Movers.FlowMachine_m_flow floMacSta(
      redeclare package Medium = Medium,
      m_flow_nominal=m_flow_nominal,
      filteredSpeed=false),
    redeclare Buildings.Fluid.Movers.FlowMachine_m_flow floMacDyn(
      redeclare package Medium = Medium,
      m_flow_nominal=m_flow_nominal,
      filteredSpeed=false));

equation 
  connect(gain.y, floMacSta.m_flow_in);
  connect(gain.y, floMacDyn.m_flow_in);
end FlowMachine_m_flow;

Buildings.Fluid.Movers.Examples.ControlledFlowMachineDynamic Buildings.Fluid.Movers.Examples.ControlledFlowMachineDynamic

Buildings.Fluid.Movers.Examples.ControlledFlowMachineDynamic

Information

This example demonstrates the use of the flow model with four different configurations. At steady-state, all flow models have the same mass flow rate and pressure difference.

Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.Movers.Examples.BaseClasses.ControlledFlowMachine.

Modelica definition

model ControlledFlowMachineDynamic
  extends Modelica.Icons.Example;
  extends Buildings.Fluid.Movers.Examples.BaseClasses.ControlledFlowMachine(
    fan4(dynamicBalance=true, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial),
    fan1(dynamicBalance=true, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial),
    fan2(dynamicBalance=true, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial),
    fan3(dynamicBalance=true, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial));

end ControlledFlowMachineDynamic;

Buildings.Fluid.Movers.Examples.ControlledFlowMachine Buildings.Fluid.Movers.Examples.ControlledFlowMachine

Buildings.Fluid.Movers.Examples.ControlledFlowMachine

Information

This example demonstrates the use of the flow model with four different configurations. At steady-state, all flow models have the same mass flow rate and pressure difference. Note that addPowerToMedium=false since otherwise, Dymola computes the enthalpy change of the component as a fraction (k*m_flow+P_internal)/m_flow which leads to an error because of 0/0 at zero flow rate.

Extends from Modelica.Icons.Example (Icon for runnable examples), Buildings.Fluid.Movers.Examples.BaseClasses.ControlledFlowMachine.

Modelica definition

model ControlledFlowMachine
  extends Modelica.Icons.Example;
  extends Buildings.Fluid.Movers.Examples.BaseClasses.ControlledFlowMachine(
    fan4(addPowerToMedium=false, filteredSpeed=false),
    fan1(addPowerToMedium=false, filteredSpeed=false),
    fan2(addPowerToMedium=false, filteredSpeed=false),
    fan3(addPowerToMedium=false, filteredSpeed=false));

end ControlledFlowMachine;

Buildings.Fluid.Movers.Examples.FlowMachine Buildings.Fluid.Movers.Examples.FlowMachine

Buildings.Fluid.Movers.Examples.FlowMachine

Information

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

Modelica definition

model FlowMachine
  extends Modelica.Icons.Example;

   package Medium = Buildings.Media.IdealGases.SimpleAir;
    Modelica.Blocks.Sources.Ramp P(
    height=-1500,
    offset=101325,
    duration=1.5);
  Buildings.Fluid.Movers.FlowMachinePolynomial fan(
    D=0.6858,
    a={4.2904,-1.387,4.2293,-3.92920,0.8534},
    b={0.1162,1.5404,-1.4825,0.7664,-0.1971},
    mNorMin_flow=1,
    mNorMax_flow=2,
    redeclare package Medium = Medium,
    m_flow_nominal=10);
  Modelica.Blocks.Sources.Constant N(k=22.3333);
  Buildings.Fluid.Sources.Boundary_pT sou(             redeclare package Medium
      = Medium,
    use_p_in=true,
    T=293.15,
    nPorts=1);
  Buildings.Fluid.Sources.Boundary_pT sin(             redeclare package Medium
      = Medium,
    use_p_in=true,
    T=293.15,
    nPorts=1);
    Modelica.Blocks.Sources.Constant PAtm(k=101325);
  Buildings.Utilities.Reports.Printer printer(
    nin=6,
    header="time dp dpNorm mNorm m_flow power",
    samplePeriod=0.1);
  Modelica.Blocks.Sources.RealExpression fan_mFlow(y=fan.m_flow);
  Modelica.Blocks.Sources.RealExpression simTim2(y=time);
  Modelica.Blocks.Sources.RealExpression fan_dp(y=fan.dp);
  Modelica.Blocks.Sources.RealExpression fan_dpNor(y=fan.pNor);
  Modelica.Blocks.Sources.RealExpression fan_mNor(y=fan.mNor_flow);
  Modelica.Blocks.Sources.RealExpression fan_PSha(y=fan.PSha);
  inner Modelica.Fluid.System system;
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      TIn(redeclare package Medium = Medium,
      m_flow_nominal=10);
  Buildings.Fluid.Sensors.TemperatureTwoPort
                                      TOut(redeclare package Medium = Medium,
      m_flow_nominal=10);
equation 

  connect(simTim2.y, printer.x[1]);
  connect(fan_dp.y, printer.x[2]);
  connect(fan_dpNor.y, printer.x[3]);
  connect(fan_mNor.y, printer.x[4]);
  connect(fan_PSha.y, printer.x[6]);
  connect(fan_mFlow.y, printer.x[5]);
  connect(N.y, fan.N_in);
  connect(P.y, sou.p_in);
  connect(PAtm.y, sin.p_in);
  connect(sou.ports[1], TIn.port_a);
  connect(TIn.port_b, fan.port_a);
  connect(fan.port_b, TOut.port_a);
  connect(TOut.port_b, sin.ports[1]);
end FlowMachine;

Buildings.Fluid.Movers.Examples.FlowMachineFeedbackControl Buildings.Fluid.Movers.Examples.FlowMachineFeedbackControl

Flow machine with feedback control

Buildings.Fluid.Movers.Examples.FlowMachineFeedbackControl

Information

This example demonstrates the use of a fan with closed loop control. The fan is controlled to track a required mass flow rate.

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

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal0.1Nominal mass flow rate [kg/s]
Pressuredp_nominal500Nominal pressure difference [Pa]

Modelica definition

model FlowMachineFeedbackControl "Flow machine with feedback control"
  extends Modelica.Icons.Example;

  package Medium = Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated;

  inner Modelica.Fluid.System system;

  parameter Modelica.SIunits.MassFlowRate m_flow_nominal= 0.1 
    "Nominal mass flow rate";
  parameter Modelica.SIunits.Pressure dp_nominal = 500 
    "Nominal pressure difference";

  Modelica.Blocks.Sources.Pulse y(
    offset=0.25,
    startTime=0,
    amplitude=0.5,
    period=15*60) "Input signal";
  Buildings.Fluid.Sources.Boundary_pT sou(
    redeclare package Medium = Medium,
    use_p_in=false,
    p=system.p_ambient,
    T=293.15,
    nPorts=2);
  FixedResistances.FixedResistanceDpM dp1(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dp_nominal=dp_nominal/2) "Pressure drop";
  Buildings.Fluid.FixedResistances.FixedResistanceDpM dp2(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dp_nominal=dp_nominal/2) "Pressure drop";
  Buildings.Fluid.Movers.FlowMachine_y fan(
      redeclare package Medium = Medium,
      pressure(V_flow={0,m_flow_nominal,2*m_flow_nominal}/1.2,
               dp={2*dp_nominal,dp_nominal,0}),
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) "Fan";
  Buildings.Fluid.Sensors.MassFlowRate senMasFlo(redeclare package Medium =
        Medium);
  Buildings.Controls.Continuous.LimPID conPID(
    Td=1,
    controllerType=Modelica.Blocks.Types.SimpleController.PI,
    k=0.5,
    Ti=15);
  Modelica.Blocks.Math.Gain gain1(k=1/m_flow_nominal);
equation 
  connect(sou.ports[1], senMasFlo.port_a);
  connect(senMasFlo.port_b, dp1.port_a);
  connect(dp1.port_b, fan.port_a);
  connect(fan.port_b, dp2.port_a);
  connect(dp2.port_b, sou.ports[2]);
  connect(senMasFlo.m_flow, gain1.u);
  connect(gain1.y, conPID.u_m);
  connect(y.y, conPID.u_s);
  connect(conPID.y, fan.y);
end FlowMachineFeedbackControl;

Buildings.Fluid.Movers.Examples.FlowMachineParallel_y Buildings.Fluid.Movers.Examples.FlowMachineParallel_y

Test model for two flow machines in parallel

Buildings.Fluid.Movers.Examples.FlowMachineParallel_y

Information

This example tests the configuration of two flow machines that are installed in parallel. Both flow machines start with full speed. At t=150 second, the speed of the flow machine on the top is reduced to zero. As its speed is reduced, the mass flow rate changes its direction in such a way that the flow machine at the top has reverse flow.

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

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal1Nominal mass flow rate [kg/s]
ThermodynamicStatestate_startMedium.setState_pTX(T=Medium...Start state
Densityrho_nominalMedium.density(state_start)Density, used to compute fluid mass [kg/m3]

Modelica definition

model FlowMachineParallel_y 
  "Test model for two flow machines in parallel"
  extends Modelica.Icons.Example;
  package Medium = Buildings.Media.ConstantPropertyLiquidWater;

  parameter Modelica.SIunits.MassFlowRate m_flow_nominal=
     1 "Nominal mass flow rate";

  Buildings.Fluid.FixedResistances.FixedResistanceDpM dpIn1(
    redeclare package Medium = Medium,
    dp_nominal=1000,
    m_flow_nominal=0.5*m_flow_nominal) "Pressure drop";
  Buildings.Fluid.Movers.FlowMachine_y floMac1(
    redeclare package Medium = Medium,
    pressure(V_flow={0, m_flow_nominal/1000}, dp={2*4*1000, 0}),
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Model of a flow machine";

  Buildings.Fluid.FixedResistances.FixedResistanceDpM dpOut1(
    redeclare package Medium = Medium,
    dp_nominal=1000,
    m_flow_nominal=0.5*m_flow_nominal) "Pressure drop";
  Buildings.Fluid.Sources.Boundary_pT sou(
    redeclare package Medium = Medium,
    use_p_in=false,
    nPorts=2,
    T=293.15);

  Buildings.Fluid.FixedResistances.FixedResistanceDpM dpIn(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dp_nominal=1000) "Pressure drop";
  Buildings.Fluid.FixedResistances.FixedResistanceDpM dpOut3(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dp_nominal=1000) "Pressure drop";
  Modelica.Blocks.Sources.Constant const2(k=1);

  parameter Medium.ThermodynamicState state_start = Medium.setState_pTX(
      T=Medium.T_default,
      p=Medium.p_default,
      X=Medium.X_default) "Start state";
  parameter Modelica.SIunits.Density rho_nominal=Medium.density(
     state_start) "Density, used to compute fluid mass";
  inner Modelica.Fluid.System system;
  Buildings.Fluid.FixedResistances.FixedResistanceDpM dpIn2(
    redeclare package Medium = Medium,
    dp_nominal=1000,
    m_flow_nominal=0.5*m_flow_nominal) "Pressure drop";
  Buildings.Fluid.Movers.FlowMachine_y floMac2(
    redeclare package Medium = Medium,
    pressure(V_flow={0, m_flow_nominal/1000}, dp={2*4*1000, 0}),
    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) 
    "Model of a flow machine";
  Buildings.Fluid.FixedResistances.FixedResistanceDpM dpOut2(
    redeclare package Medium = Medium,
    dp_nominal=1000,
    m_flow_nominal=0.5*m_flow_nominal) "Pressure drop";
  Modelica.Blocks.Sources.Step     const1(
    height=-1,
    offset=1,
    startTime=150);
equation 
  connect(dpIn1.port_b, floMac1.port_a);
  connect(floMac1.port_b, dpOut1.port_a);
  connect(sou.ports[1], dpIn.port_a);
  connect(dpIn.port_b, dpIn1.port_a);
  connect(dpOut1.port_b, dpOut3.port_a);
  connect(dpOut3.port_b, sou.ports[2]);
  connect(dpIn2.port_b,floMac2. port_a);
  connect(floMac2.port_b,dpOut2. port_a);
  connect(const2.y, floMac2.y);
  connect(dpIn.port_b, dpIn2.port_a);
  connect(dpOut2.port_b, dpOut3.port_a);
  connect(const1.y, floMac1.y);
end FlowMachineParallel_y;

Buildings.Fluid.Movers.Examples.FlowMachineSeries_y Buildings.Fluid.Movers.Examples.FlowMachineSeries_y

Test model for two flow machines in series

Buildings.Fluid.Movers.Examples.FlowMachineSeries_y

Information

This example tests the configuration of two flow machines that are installed in series. Both flow machines start with full speed. At t=150 seconds, the speed of the flow machine on the left is reduced to zero. As its speed is reduced, the mass flow rate is reduced. Note that even at zero input, the mass flow rate is non-zero, but the pressure drop of the pump floMac1.dp is positive, which means that this pump has a flow resistance. However, flowMac2.dp is always negative, as this pump has a constant control input of 1.

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

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal1Nominal mass flow rate [kg/s]
ThermodynamicStatestate_startMedium.setState_pTX(T=Medium...Start state
Densityrho_nominalMedium.density(state_start)Density, used to compute fluid mass [kg/m3]

Modelica definition

model FlowMachineSeries_y 
  "Test model for two flow machines in series"
  extends Modelica.Icons.Example;
  package Medium = Buildings.Media.ConstantPropertyLiquidWater;

  parameter Modelica.SIunits.MassFlowRate m_flow_nominal=
     1 "Nominal mass flow rate";

  Buildings.Fluid.Movers.FlowMachine_y floMac1(
    redeclare package Medium = Medium,
    pressure(V_flow={0, m_flow_nominal/1000}, dp={2*4*1000, 0}),
    dynamicBalance=false) "Model of a flow machine";

  Buildings.Fluid.Sources.Boundary_pT sou(
    redeclare package Medium = Medium,
    use_p_in=false,
    p(displayUnit="Pa") = 300000,
    T=293.15,
    nPorts=1);

  Modelica.Blocks.Sources.Constant const2(k=1);

  parameter Medium.ThermodynamicState state_start = Medium.setState_pTX(
      T=Medium.T_default,
      p=Medium.p_default,
      X=Medium.X_default) "Start state";
  parameter Modelica.SIunits.Density rho_nominal=Medium.density(
     state_start) "Density, used to compute fluid mass";
  inner Modelica.Fluid.System system;
  Buildings.Fluid.Movers.FlowMachine_y floMac2(
    redeclare package Medium = Medium,
    pressure(V_flow={0, m_flow_nominal/1000}, dp={2*4*1000, 0}),
    dynamicBalance=false) "Model of a flow machine";
  Modelica.Blocks.Sources.Step     const1(
    height=-1,
    offset=1,
    startTime=150);
  Buildings.Fluid.Sources.Boundary_pT sou1(
    redeclare package Medium = Medium,
    use_p_in=false,
    p(displayUnit="Pa") = 300000 + 4000,
    T=293.15,
    nPorts=1);
equation 
  connect(const2.y, floMac2.y);
  connect(const1.y, floMac1.y);
  connect(floMac1.port_b, floMac2.port_a);
  connect(sou.ports[1], floMac1.port_a);
  connect(floMac2.port_b, sou1.ports[1]);
end FlowMachineSeries_y;

Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves

Test model for pump that illustrates the pump curves

Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves

Information

This example demonstrates how the pump curves changes for different (constant) input signal y. If y ≥ delta = 0.05, the pump curves are polynomials. For y < delta = 0.05, the pump curves convert to linear functions to avoid a singularity at the origin.

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

Parameters

TypeNameDefaultDescription
MassFlowRatem_flow_nominal0.5Nominal mass flow rate [kg/s]
Pressuredp_nominal10000Nominal pressure [Pa]

Modelica definition

model FlowMachine_y_pumpCurves 
  "Test model for pump that illustrates the pump curves"
  extends Modelica.Icons.Example;
  package Medium = Buildings.Media.ConstantPropertyLiquidWater "Medium model";

  parameter Modelica.SIunits.MassFlowRate m_flow_nominal = 0.5 
    "Nominal mass flow rate";
  parameter Modelica.SIunits.Pressure dp_nominal = 10000 "Nominal pressure";

   model pumpModel = Buildings.Fluid.Movers.FlowMachine_y (
    redeclare package Medium = Medium,
    energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
    dynamicBalance=false,
    pressure(V_flow=2/1000*m_flow_nominal*{0.2, 0.4, 0.6, 0.8},
                  dp=dp_nominal*{0.9, 0.85, 0.6, 0.2})) 
    "Declaration of pump model";

  pumpModel pum(filteredSpeed=false) "Pump";
  pumpModel pum1(filteredSpeed=false) "Pump";
  pumpModel pum2(filteredSpeed=false) "Pump";
  pumpModel pum3(filteredSpeed=false) "Pump";

  Modelica.Blocks.Sources.Ramp y(
    offset=1,
    duration=0.5,
    startTime=0.25,
    height=-1) "Input signal";
  Buildings.Fluid.Sources.Boundary_pT sou(
    redeclare package Medium = Medium,
    use_p_in=false,
    p=300000,
    T=293.15,
    nPorts=4);

  inner Modelica.Fluid.System system;
  Buildings.Fluid.Sources.Boundary_pT sou1(
    redeclare package Medium = Medium,
    use_p_in=false,
    nPorts=4,
    p(displayUnit="Pa") = 300000,
    T=293.15);
  Buildings.Fluid.Actuators.Valves.TwoWayLinear dp1(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dpValve_nominal=0.01*dp_nominal,
    filteredOpening=false) "Pressure drop";
  Modelica.Blocks.Sources.Constant
                               y1(k=1) "Input signal";

  Buildings.Fluid.Actuators.Valves.TwoWayLinear dp2(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dpValve_nominal=0.01*dp_nominal,
    filteredOpening=false) "Pressure drop";
  Modelica.Blocks.Sources.Constant
                               y2(k=0.5) "Input signal";

  Buildings.Fluid.Actuators.Valves.TwoWayLinear dp3(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dpValve_nominal=0.01*dp_nominal,
    filteredOpening=false) "Pressure drop";
  Modelica.Blocks.Sources.Constant
                               y3(k=0.05) "Input signal";
  Buildings.Fluid.Actuators.Valves.TwoWayLinear dp4(
    redeclare package Medium = Medium,
    m_flow_nominal=m_flow_nominal,
    dpValve_nominal=0.01*dp_nominal,
    filteredOpening=false) "Pressure drop";
  Modelica.Blocks.Sources.Constant
                               y4(k=0.01) "Input signal";
equation 
  connect(dp1.port_b, pum.port_a);
  connect(dp1.port_a, sou.ports[1]);
  connect(y1.y, pum.y);
  connect(y.y, dp1.y);
  connect(dp2.port_b, pum1.port_a);
  connect(y.y,dp2. y);
  connect(sou.ports[2], dp2.port_a);
  connect(y2.y, pum1.y);
  connect(dp3.port_b, pum2.port_a);
  connect(y.y,dp3. y);
  connect(y3.y, pum2.y);
  connect(dp3.port_a, sou.ports[3]);
  connect(dp4.port_b, pum3.port_a);
  connect(y.y,dp4. y);
  connect(y4.y, pum3.y);
  connect(dp4.port_a, sou.ports[4]);
  connect(pum3.port_b, sou1.ports[1]);
  connect(pum2.port_b, sou1.ports[2]);

  connect(pum1.port_b, sou1.ports[3]);
  connect(pum.port_b, sou1.ports[4]);
end FlowMachine_y_pumpCurves;

Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves.pumpModel Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves.pumpModel

Declaration of pump model

Buildings.Fluid.Movers.Examples.FlowMachine_y_pumpCurves.pumpModel

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
BooleanaddPowerToMediumtrueSet to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations)
Characteristics
Booleanuse_powerCharacteristicfalseUse powerCharacteristic (vs. efficiencyCharacteristic)
BooleanmotorCooledByFluidtrueIf true, then motor heat is added to fluid stream
efficiencyParametersmotorEfficiency Normalized volume flow rate vs. efficiency
efficiencyParametershydraulicEfficiency Normalized volume flow rate vs. efficiency
powerParameterspower Volume flow rate vs. electrical power consumption
Initialization
Realr_V.start1Ratio V_flow/V_flow_max [1]
MassFlowRatem_flow.start0Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) [kg/s]
Pressuredp.start0Pressure difference between port_a and port_b [Pa]
Advanced
BooleanhomotopyInitializationtrue= true, use homotopy method
MassFlowRatem_flow_small1E-4*abs(m_flow_nominal)Small mass flow rate for regularization of zero flow [kg/s]
Diagnostics
Booleanshow_Tfalse= true, if actual temperature at port is computed
Dynamics
Filtered speed
BooleanfilteredSpeedtrue= true, if speed is filtered with a 2nd order CriticalDamping filter
TimeriseTime30Rise time of the filter (time to reach 99.6 % of the speed) [s]
InitinitModelica.Blocks.Types.Init.I...Type of initialization (no init/steady state/initial state/initial output)
RealN_start0Initial value of speed
Equations
DynamicsenergyDynamicsModelica.Fluid.Types.Dynamic...Formulation of energy balance
DynamicsmassDynamicsenergyDynamicsFormulation of mass balance
BooleandynamicBalancefalseSet to true to use a dynamic balance, which often leads to smaller systems of equations
Nominal condition
Timetau1Time constant of fluid volume for nominal flow, used if dynamicBalance=true [s]
Initialization
AbsolutePressurep_startMedium.p_defaultStart value of pressure [Pa]
TemperatureT_startMedium.T_defaultStart value of temperature [K]
MassFractionX_start[Medium.nX]Medium.X_defaultStart value of mass fractions m_i/m [kg/kg]
ExtraPropertyC_start[Medium.nC]fill(0, Medium.nC)Start value of trace substances
ExtraPropertyC_nominal[Medium.nC]fill(1E-2, Medium.nC)Nominal value of trace substances. (Set to typical order of magnitude.)
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)

Connectors

TypeNameDescription
output RealOutputPElectrical power consumed [W]
output RealOutputN_actual[1/min]
replaceable package MediumMedium in the component
FluidPort_aport_aFluid connector a (positive design flow direction is from port_a to port_b)
FluidPort_bport_bFluid connector b (positive design flow direction is from port_a to port_b)
HeatPort_aheatPortHeat dissipation to environment
input RealInputyConstant normalized rotational speed [1]

Modelica definition

model pumpModel = Buildings.Fluid.Movers.FlowMachine_y (
 redeclare package Medium = Medium,
 energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
 dynamicBalance=false,
 pressure(V_flow=2/1000*m_flow_nominal*{0.2, 0.4, 0.6, 0.8},
               dp=dp_nominal*{0.9, 0.85, 0.6, 0.2})) 
  "Declaration of pump model";

Automatically generated Fri Dec 13 11:35:34 2013.