Buildings.Fluid.Movers.Examples

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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

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

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

Type Name Default Description

MassFlowRate m_flow_nominal 1 Nominal mass flow rate [kg/s]

Pressure dp_nominal 500 Nominal pressure difference [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	1	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	500	Nominal 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

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

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

Type Name Default Description

MassFlowRate m_flow_nominal 0.5 Nominal mass flow rate [kg/s]

Pressure dp_nominal 10000 Nominal pressure [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	0.5	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	10000	Nominal 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

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

Type Name Default Description

MassFlowRate m_flow_nominal 1 Nominal mass flow rate [kg/s]

Pressure dp_nominal 500 Nominal pressure difference [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	1	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	500	Nominal 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

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

Type Name Default Description

MassFlowRate m_flow_nominal 1 Nominal mass flow rate [kg/s]

Pressure dp_nominal 500 Nominal pressure difference [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	1	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	500	Nominal 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

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

Type Name Default Description

MassFlowRate m_flow_nominal 1 Nominal mass flow rate [kg/s]

Pressure dp_nominal 500 Nominal pressure difference [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	1	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	500	Nominal 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

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

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

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

Flow machine with feedback control

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

Type Name Default Description

MassFlowRate m_flow_nominal 0.1 Nominal mass flow rate [kg/s]

Pressure dp_nominal 500 Nominal pressure difference [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	0.1	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	500	Nominal 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

Test model for two flow machines in parallel

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

Type Name Default Description

MassFlowRate m_flow_nominal 1 Nominal mass flow rate [kg/s]

ThermodynamicState state_start Medium.setState_pTX(T=Medium... Start state

Density rho_nominal Medium.density(state_start) Density, used to compute fluid mass [kg/m3]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	1	Nominal mass flow rate [kg/s]
ThermodynamicState	state_start	Medium.setState_pTX(T=Medium...	Start state
Density	rho_nominal	Medium.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

Test model for two flow machines in series

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

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	1	Nominal mass flow rate [kg/s]
ThermodynamicState	state_start	Medium.setState_pTX(T=Medium...	Start state
Density	rho_nominal	Medium.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

Test model for pump that illustrates the pump curves

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

Type Name Default Description

MassFlowRate m_flow_nominal 0.5 Nominal mass flow rate [kg/s]

Pressure dp_nominal 10000 Nominal pressure [Pa]

Type	Name	Default	Description
MassFlowRate	m_flow_nominal	0.5	Nominal mass flow rate [kg/s]
Pressure	dp_nominal	10000	Nominal 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

Declaration of pump model

Parameters

Type Name Default Description

replaceable package Medium PartialMedium Medium in the component

Boolean addPowerToMedium true Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations)

Characteristics

Boolean use_powerCharacteristic false Use powerCharacteristic (vs. efficiencyCharacteristic)

Boolean motorCooledByFluid true If true, then motor heat is added to fluid stream

efficiencyParameters motorEfficiency Normalized volume flow rate vs. efficiency

efficiencyParameters hydraulicEfficiency Normalized volume flow rate vs. efficiency

powerParameters power Volume flow rate vs. electrical power consumption

Initialization

Real r_V.start 1 Ratio V_flow/V_flow_max [1]

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]

Advanced

Boolean homotopyInitialization true = true, use homotopy method

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

Diagnostics

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

Dynamics

Filtered speed

Boolean filteredSpeed true = true, if speed is filtered with a 2nd order CriticalDamping filter

Time riseTime 30 Rise time of the filter (time to reach 99.6 % of the speed) [s]

Init init Modelica.Blocks.Types.Init.I... Type of initialization (no init/steady state/initial state/initial output)

Real N_start 0 Initial value of speed

Equations

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

Dynamics massDynamics energyDynamics Formulation of mass balance

Boolean dynamicBalance false Set to true to use a dynamic balance, which often leads to smaller systems of equations

Nominal condition

Time tau 1 Time constant of fluid volume for nominal flow, used if dynamicBalance=true [s]

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

ExtraProperty C_nominal[Medium.nC] fill(1E-2, Medium.nC) Nominal value of trace substances. (Set to typical order of magnitude.)

Assumptions

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

Type	Name	Default	Description
replaceable package Medium	PartialMedium	Medium in the component
Boolean	addPowerToMedium	true	Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations)
Characteristics
Boolean	use_powerCharacteristic	false	Use powerCharacteristic (vs. efficiencyCharacteristic)
Boolean	motorCooledByFluid	true	If true, then motor heat is added to fluid stream
efficiencyParameters	motorEfficiency		Normalized volume flow rate vs. efficiency
efficiencyParameters	hydraulicEfficiency		Normalized volume flow rate vs. efficiency
powerParameters	power		Volume flow rate vs. electrical power consumption
Initialization
Real	r_V.start	1	Ratio V_flow/V_flow_max [1]
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]
Advanced
Boolean	homotopyInitialization	true	= true, use homotopy method
MassFlowRate	m_flow_small	1E-4*abs(m_flow_nominal)	Small mass flow rate for regularization of zero flow [kg/s]
Diagnostics
Boolean	show_T	false	= true, if actual temperature at port is computed
Dynamics
Filtered speed
Boolean	filteredSpeed	true	= true, if speed is filtered with a 2nd order CriticalDamping filter
Time	riseTime	30	Rise time of the filter (time to reach 99.6 % of the speed) [s]
Init	init	Modelica.Blocks.Types.Init.I...	Type of initialization (no init/steady state/initial state/initial output)
Real	N_start	0	Initial value of speed
Equations
Dynamics	energyDynamics	Modelica.Fluid.Types.Dynamic...	Formulation of energy balance
Dynamics	massDynamics	energyDynamics	Formulation of mass balance
Boolean	dynamicBalance	false	Set to true to use a dynamic balance, which often leads to smaller systems of equations
Nominal condition
Time	tau	1	Time constant of fluid volume for nominal flow, used if dynamicBalance=true [s]
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
ExtraProperty	C_nominal[Medium.nC]	fill(1E-2, Medium.nC)	Nominal value of trace substances. (Set to typical order of magnitude.)
Assumptions
Boolean	allowFlowReversal	system.allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)

Connectors

Type Name Description

output RealOutput P Electrical power consumed [W]

output RealOutput N_actual [1/min]

replaceable package Medium Medium in the component

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)

HeatPort_a heatPort Heat dissipation to environment

input RealInput y Constant normalized rotational speed [1]

Type	Name	Description
output RealOutput	P	Electrical power consumed [W]
output RealOutput	N_actual	[1/min]
replaceable package Medium	Medium in the component
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)
HeatPort_a	heatPort	Heat dissipation to environment
input RealInput	y	Constant 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.