Modelica.Fluid.Sensors

Ideal sensor components to extract signals from a fluid connector

Information


Package Sensors consists of idealized sensor components that provide variables of a medium model and/or fluid ports as output signals. These signals can be, e.g., further processed with components of the Modelica.Blocks library. Also more realistic sensor models can be built, by further processing (e.g., by attaching block Modelica.Blocks.FirstOrder to model the time constant of the sensor).

For the thermodynamic state variables temperature, specific entalpy, specific entropy and density the fluid library provides two different types of sensors: regular one port and two port sensors.

Modelica.Fluid.Examples.Explanatory.MeasuringTemperature demonstrates the differences between one- and two-port sensor at hand of a simple example.

Extends from Modelica.Fluid.Icons.VariantLibrary (Icon for a library that contains several variants of one component).

Package Content

NameDescription
Modelica.Fluid.Sensors.Pressure Pressure Ideal pressure sensor
Modelica.Fluid.Sensors.Density Density Ideal one port density sensor
Modelica.Fluid.Sensors.DensityTwoPort DensityTwoPort Ideal two port density sensor
Modelica.Fluid.Sensors.Temperature Temperature Ideal one port temperature sensor
Modelica.Fluid.Sensors.TemperatureTwoPort TemperatureTwoPort Ideal two port temperature sensor
Modelica.Fluid.Sensors.SpecificEnthalpy SpecificEnthalpy Ideal one port specific enthalpy sensor
Modelica.Fluid.Sensors.SpecificEnthalpyTwoPort SpecificEnthalpyTwoPort Ideal two port sensor for the specific enthalpy
Modelica.Fluid.Sensors.SpecificEntropy SpecificEntropy Ideal one port specific entropy sensor
Modelica.Fluid.Sensors.SpecificEntropyTwoPort SpecificEntropyTwoPort Ideal two port sensor for the specific entropy
Modelica.Fluid.Sensors.TraceSubstances TraceSubstances Ideal one port trace substances sensor
Modelica.Fluid.Sensors.TraceSubstancesTwoPort TraceSubstancesTwoPort Ideal two port sensor for trace substance
Modelica.Fluid.Sensors.MassFlowRate MassFlowRate Ideal sensor for mass flow rate
Modelica.Fluid.Sensors.VolumeFlowRate VolumeFlowRate Ideal sensor for volume flow rate
Modelica.Fluid.Sensors.RelativePressure RelativePressure Ideal relative pressure sensor
Modelica.Fluid.Sensors.RelativeTemperature RelativeTemperature Ideal relative temperature sensor
Modelica.Fluid.Sensors.BaseClasses BaseClasses Base classes used in the Sensors package (only of interest to build new component models)


Modelica.Fluid.Sensors.Pressure Modelica.Fluid.Sensors.Pressure

Ideal pressure sensor

Modelica.Fluid.Sensors.Pressure

Information


This component monitors the absolute pressure at its fluid port. The sensor is ideal, i.e., it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialAbsoluteSensor (Partial component to model a sensor that measures a potential variable), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the sensor

Connectors

TypeNameDescription
FluidPort_aport 
output RealOutputpPressure at port [Pa]

Modelica definition

model Pressure "Ideal pressure sensor"
  extends Sensors.BaseClasses.PartialAbsoluteSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput p(final quantity="Pressure",
                                          final unit="Pa",
                                          displayUnit="bar",
                                          min=0) "Pressure at port";
equation 
  p = port.p;
end Pressure;

Modelica.Fluid.Sensors.Density Modelica.Fluid.Sensors.Density

Ideal one port density sensor

Modelica.Fluid.Sensors.Density

Information


This component monitors the density of the fluid passing its port. The sensor is ideal, i.e. it does not influence the fluid.

If using the one port sensor please read the Information first.

Extends from Sensors.BaseClasses.PartialAbsoluteSensor (Partial component to model a sensor that measures a potential variable), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the sensor

Connectors

TypeNameDescription
FluidPort_aport 
output RealOutputdDensity in port medium [kg/m3]

Modelica definition

model Density "Ideal one port density sensor"
  extends Sensors.BaseClasses.PartialAbsoluteSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput d(final quantity="Density",
                                          final unit="kg/m3",
                                          displayUnit="g/cm3",
                                          min=0) "Density in port medium";

equation 
  d = Medium.density(Medium.setState_phX(port.p, inStream(port.h_outflow), inStream(port.Xi_outflow)));

end Density;

Modelica.Fluid.Sensors.DensityTwoPort Modelica.Fluid.Sensors.DensityTwoPort

Ideal two port density sensor

Modelica.Fluid.Sensors.DensityTwoPort

Information


This component monitors the density of the fluid flowing from port_a to port_b. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRatem_flow_smallsystem.m_flow_smallFor bi-directional flow, density is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

TypeNameDescription
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)
output RealOutputdDensity of the passing fluid [kg/m3]

Modelica definition

model DensityTwoPort "Ideal two port density sensor"
  extends Sensors.BaseClasses.PartialFlowSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput d(final quantity="Density",
                                          final unit="kg/m3",
                                          displayUnit="g/cm3",
                                          min=0) "Density of the passing fluid";
  parameter Medium.MassFlowRate m_flow_small(min=0) = system.m_flow_small 
    "For bi-directional flow, density is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required)";
protected 
  Medium.Density rho_a_inflow "Density of inflowing fluid at port_a";
  Medium.Density rho_b_inflow 
    "Density of inflowing fluid at port_b or rho_a_inflow, if uni-directional flow";
equation 
  if allowFlowReversal then
     rho_a_inflow = Medium.density(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     rho_b_inflow = Medium.density(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow));
     d = Modelica.Fluid.Utilities.regStep(port_a.m_flow, rho_a_inflow, rho_b_inflow, m_flow_small);
  else
     d = Medium.density(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     rho_a_inflow = d;
     rho_b_inflow = d;
  end if;

end DensityTwoPort;

Modelica.Fluid.Sensors.Temperature Modelica.Fluid.Sensors.Temperature

Ideal one port temperature sensor

Modelica.Fluid.Sensors.Temperature

Information


This component monitors the temperature of the fluid passing its port. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialAbsoluteSensor (Partial component to model a sensor that measures a potential variable).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the sensor

Connectors

TypeNameDescription
FluidPort_aport 
output RealOutputTTemperature in port medium [K]

Modelica definition

model Temperature "Ideal one port temperature sensor"
    extends Sensors.BaseClasses.PartialAbsoluteSensor;

  Modelica.Blocks.Interfaces.RealOutput T(final quantity="ThermodynamicTemperature",
                                          final unit = "K", displayUnit = "degC", min=0) 
    "Temperature in port medium";

equation 
  T = Medium.temperature(Medium.setState_phX(port.p, inStream(port.h_outflow), inStream(port.Xi_outflow)));

end Temperature;

Modelica.Fluid.Sensors.TemperatureTwoPort Modelica.Fluid.Sensors.TemperatureTwoPort

Ideal two port temperature sensor

Modelica.Fluid.Sensors.TemperatureTwoPort

Information


This component monitors the temperature of the passing fluid. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRatem_flow_smallsystem.m_flow_smallFor bi-directional flow, temperature is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

TypeNameDescription
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)
output RealOutputTTemperature of the passing fluid [K]

Modelica definition

model TemperatureTwoPort "Ideal two port temperature sensor"
  extends Sensors.BaseClasses.PartialFlowSensor;

  Modelica.Blocks.Interfaces.RealOutput T( final quantity="ThermodynamicTemperature",
                                           final unit="K",
                                           min = 0,
                                           displayUnit="degC") 
    "Temperature of the passing fluid";
  parameter Medium.MassFlowRate m_flow_small(min=0) = system.m_flow_small 
    "For bi-directional flow, temperature is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required)";

protected 
  Medium.Temperature T_a_inflow "Temperature of inflowing fluid at port_a";
  Medium.Temperature T_b_inflow 
    "Temperature of inflowing fluid at port_b or T_a_inflow, if uni-directional flow";
equation 
  if allowFlowReversal then
     T_a_inflow = Medium.temperature(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     T_b_inflow = Medium.temperature(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow));
     T = Modelica.Fluid.Utilities.regStep(port_a.m_flow, T_a_inflow, T_b_inflow, m_flow_small);
  else
     T = Medium.temperature(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     T_a_inflow = T;
     T_b_inflow = T;
  end if;

end TemperatureTwoPort;

Modelica.Fluid.Sensors.SpecificEnthalpy Modelica.Fluid.Sensors.SpecificEnthalpy

Ideal one port specific enthalpy sensor

Modelica.Fluid.Sensors.SpecificEnthalpy

Information


This component monitors the specific enthalpy of the fluid passing its port. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialAbsoluteSensor (Partial component to model a sensor that measures a potential variable), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the sensor

Connectors

TypeNameDescription
FluidPort_aport 
output RealOutputh_outSpecific enthalpy in port medium [J/kg]

Modelica definition

model SpecificEnthalpy "Ideal one port specific enthalpy sensor"
  extends Sensors.BaseClasses.PartialAbsoluteSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput h_out(final quantity="SpecificEnergy",
                                              final unit="J/kg") 
    "Specific enthalpy in port medium";

equation 
  h_out = inStream(port.h_outflow);

end SpecificEnthalpy;

Modelica.Fluid.Sensors.SpecificEnthalpyTwoPort Modelica.Fluid.Sensors.SpecificEnthalpyTwoPort

Ideal two port sensor for the specific enthalpy

Modelica.Fluid.Sensors.SpecificEnthalpyTwoPort

Information


This component monitors the specific enthalpy of a passing fluid. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRatem_flow_smallsystem.m_flow_smallFor bi-directional flow, specific enthalpy is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

TypeNameDescription
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)
output RealOutputh_outSpecific enthalpy of the passing fluid [J/kg]

Modelica definition

model SpecificEnthalpyTwoPort 
  "Ideal two port sensor for the specific enthalpy"
  extends Sensors.BaseClasses.PartialFlowSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput h_out(final quantity="SpecificEnergy",
                                              final unit="J/kg") 
    "Specific enthalpy of the passing fluid";

  parameter Medium.MassFlowRate m_flow_small(min=0) = system.m_flow_small 
    "For bi-directional flow, specific enthalpy is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required)";

equation 
  if allowFlowReversal then
     h_out = Modelica.Fluid.Utilities.regStep(port_a.m_flow, port_b.h_outflow, port_a.h_outflow, m_flow_small);
  else
     h_out = port_b.h_outflow;
  end if;

end SpecificEnthalpyTwoPort;

Modelica.Fluid.Sensors.SpecificEntropy Modelica.Fluid.Sensors.SpecificEntropy

Ideal one port specific entropy sensor

Modelica.Fluid.Sensors.SpecificEntropy

Information


This component monitors the specific entropy of the fluid passing its port. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialAbsoluteSensor (Partial component to model a sensor that measures a potential variable), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the sensor

Connectors

TypeNameDescription
FluidPort_aport 
output RealOutputsSpecific entropy in port medium [J/(kg.K)]

Modelica definition

model SpecificEntropy "Ideal one port specific entropy sensor"
  extends Sensors.BaseClasses.PartialAbsoluteSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput s(final quantity="SpecificEntropy",
                                          final unit="J/(kg.K)") 
    "Specific entropy in port medium";

equation 
  s = Medium.specificEntropy(Medium.setState_phX(port.p, inStream(port.h_outflow), inStream(port.Xi_outflow)));

end SpecificEntropy;

Modelica.Fluid.Sensors.SpecificEntropyTwoPort Modelica.Fluid.Sensors.SpecificEntropyTwoPort

Ideal two port sensor for the specific entropy

Modelica.Fluid.Sensors.SpecificEntropyTwoPort

Information


This component monitors the specific entropy of the passing fluid. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRatem_flow_smallsystem.m_flow_smallFor bi-directional flow, specific entropy is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

TypeNameDescription
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)
output RealOutputsSpecific entropy of the passing fluid [J/(kg.K)]

Modelica definition

model SpecificEntropyTwoPort 
  "Ideal two port sensor for the specific entropy"
  extends Sensors.BaseClasses.PartialFlowSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput s(final quantity="SpecificEntropy",
                                          final unit="J/(kg.K)") 
    "Specific entropy of the passing fluid";
  parameter Medium.MassFlowRate m_flow_small(min=0) = system.m_flow_small 
    "For bi-directional flow, specific entropy is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required)";

protected 
  Medium.SpecificEntropy s_a_inflow 
    "Specific entropy of inflowing fluid at port_a";
  Medium.SpecificEntropy s_b_inflow 
    "Specific entropy of inflowing fluid at port_b or s_a_inflow, if uni-directional flow";
equation 
  if allowFlowReversal then
     s_a_inflow = Medium.specificEntropy(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     s_b_inflow = Medium.specificEntropy(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow));
     s = Modelica.Fluid.Utilities.regStep(port_a.m_flow, s_a_inflow, s_b_inflow, m_flow_small);
  else
     s = Medium.specificEntropy(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     s_a_inflow = s;
     s_b_inflow = s;
  end if;

end SpecificEntropyTwoPort;

Modelica.Fluid.Sensors.TraceSubstances Modelica.Fluid.Sensors.TraceSubstances

Ideal one port trace substances sensor

Modelica.Fluid.Sensors.TraceSubstances

Information


This component monitors the trace substances contained in the fluid passing its port. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialAbsoluteSensor (Partial component to model a sensor that measures a potential variable), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the sensor
StringsubstanceName"CO2"Name of trace substance

Connectors

TypeNameDescription
FluidPort_aport 
output RealOutputCTrace substance in port medium

Modelica definition

model TraceSubstances "Ideal one port trace substances sensor"
  extends Sensors.BaseClasses.PartialAbsoluteSensor;
  extends Modelica.Icons.RotationalSensor;
  parameter String substanceName = "CO2" "Name of trace substance";

  Modelica.Blocks.Interfaces.RealOutput C "Trace substance in port medium";

protected 
  parameter Integer ind(fixed=false) 
    "Index of species in vector of auxiliary substances";
  Medium.ExtraProperty CVec[Medium.nC](
      quantity=Medium.extraPropertiesNames) 
    "Trace substances vector, needed because indexed argument for the operator inStream is not supported";
initial algorithm 
  ind:= -1;
  for i in 1:Medium.nC loop
    if ( Modelica.Utilities.Strings.isEqual(Medium.extraPropertiesNames[i], substanceName)) then
      ind := i;
    end if;
  end for;
  assert(ind > 0, "Trace substance '" + substanceName + "' is not present in medium '"
         + Medium.mediumName + "'.\n"
         + "Check sensor parameter and medium model.");
equation 
  CVec = inStream(port.C_outflow);
  C = CVec[ind];

end TraceSubstances;

Modelica.Fluid.Sensors.TraceSubstancesTwoPort Modelica.Fluid.Sensors.TraceSubstancesTwoPort

Ideal two port sensor for trace substance

Modelica.Fluid.Sensors.TraceSubstancesTwoPort

Information


This component monitors the trace substance of the passing fluid. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
StringsubstanceName"CO2"Name of trace substance
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRatem_flow_smallsystem.m_flow_smallFor bi-directional flow, trace substance is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

TypeNameDescription
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)
output RealOutputCTrace substance of the passing fluid

Modelica definition

model TraceSubstancesTwoPort 
  "Ideal two port sensor for trace substance"
  extends Sensors.BaseClasses.PartialFlowSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput C 
    "Trace substance of the passing fluid";
  parameter String substanceName = "CO2" "Name of trace substance";
  parameter Medium.MassFlowRate m_flow_small(min=0) = system.m_flow_small 
    "For bi-directional flow, trace substance is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required)";

protected 
  parameter Integer ind(fixed=false) 
    "Index of species in vector of auxiliary substances";
initial algorithm 
  ind:= -1;
  for i in 1:Medium.nC loop
    if ( Modelica.Utilities.Strings.isEqual(Medium.extraPropertiesNames[i], substanceName)) then
      ind := i;
    end if;
  end for;
  assert(ind > 0, "Trace substance '" + substanceName + "' is not present in medium '"
         + Medium.mediumName + "'.\n"
         + "Check sensor parameter and medium model.");
equation 
  if allowFlowReversal then
     C = Modelica.Fluid.Utilities.regStep(port_a.m_flow, port_b.C_outflow[ind], port_a.C_outflow[ind], m_flow_small);
  else
     C = port_b.C_outflow[ind];
  end if;

end TraceSubstancesTwoPort;

Modelica.Fluid.Sensors.MassFlowRate Modelica.Fluid.Sensors.MassFlowRate

Ideal sensor for mass flow rate

Modelica.Fluid.Sensors.MassFlowRate

Information


This component monitors the mass flow rate flowing from port_a to port_b. The sensor is ideal, i.e., it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)

Connectors

TypeNameDescription
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)
output RealOutputm_flowMass flow rate from port_a to port_b [kg/s]

Modelica definition

model MassFlowRate "Ideal sensor for mass flow rate"
  extends Sensors.BaseClasses.PartialFlowSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput m_flow(quantity="MassFlowRate",
                                               final unit="kg/s") 
    "Mass flow rate from port_a to port_b";

equation 
  m_flow = port_a.m_flow;

end MassFlowRate;

Modelica.Fluid.Sensors.VolumeFlowRate Modelica.Fluid.Sensors.VolumeFlowRate

Ideal sensor for volume flow rate

Modelica.Fluid.Sensors.VolumeFlowRate

Information


This component monitors the volume flow rate flowing from port_a to port_b. The sensor is ideal, i.e. it does not influence the fluid.

Extends from Sensors.BaseClasses.PartialFlowSensor (Partial component to model sensors that measure flow properties), Modelica.Icons.RotationalSensor (Icon representing rotational measurement device).

Parameters

TypeNameDefaultDescription
replaceable package MediumPartialMediumMedium in the component
Assumptions
BooleanallowFlowReversalsystem.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
MassFlowRatem_flow_smallsystem.m_flow_smallFor bi-directional flow, density is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

TypeNameDescription
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)
output RealOutputV_flowVolume flow rate from port_a to port_b [m3/s]

Modelica definition

model VolumeFlowRate "Ideal sensor for volume flow rate"
  extends Sensors.BaseClasses.PartialFlowSensor;
  extends Modelica.Icons.RotationalSensor;
  Modelica.Blocks.Interfaces.RealOutput V_flow(final quantity="VolumeFlowRate",
                                               final unit="m3/s") 
    "Volume flow rate from port_a to port_b";
  parameter Medium.MassFlowRate m_flow_small(min=0) = system.m_flow_small 
    "For bi-directional flow, density is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required)";

protected 
  Medium.Density rho_a_inflow "Density of inflowing fluid at port_a";
  Medium.Density rho_b_inflow 
    "Density of inflowing fluid at port_b or rho_a_inflow, if uni-directional flow";
  Medium.Density d "Density of the passing fluid";
equation 
  if allowFlowReversal then
     rho_a_inflow = Medium.density(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     rho_b_inflow = Medium.density(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow));
     d = Modelica.Fluid.Utilities.regStep(port_a.m_flow, rho_a_inflow, rho_b_inflow, m_flow_small);
  else
     d = Medium.density(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow));
     rho_a_inflow = d;
     rho_b_inflow = d;
  end if;
  V_flow = port_a.m_flow/d;

end VolumeFlowRate;

Modelica.Fluid.Sensors.RelativePressure Modelica.Fluid.Sensors.RelativePressure

Ideal relative pressure sensor

Modelica.Fluid.Sensors.RelativePressure

Information


The relative pressure "port_a.p - port_b.p" is determined between the two ports of this component and is provided as output signal. The sensor should be connected in parallel with other equipment, no flow through the sensor is allowed.

Extends from Modelica.Icons.TranslationalSensor (Icon representing translational measurement device).

Connectors

TypeNameDescription
FluidPort_aport_a 
FluidPort_bport_b 
output RealOutputp_relRelative pressure signal [Pa]

Modelica definition

model RelativePressure "Ideal relative pressure sensor"
  extends Modelica.Icons.TranslationalSensor;
  replaceable package Medium = 
    Modelica.Media.Interfaces.PartialMedium "Medium in the sensor";

  Modelica.Fluid.Interfaces.FluidPort_a port_a(m_flow(min=0),
                                redeclare package Medium = Medium);
  Modelica.Fluid.Interfaces.FluidPort_b port_b(m_flow(min=0),
                                redeclare package Medium = Medium);

  Modelica.Blocks.Interfaces.RealOutput p_rel(final quantity="Pressure",
                                              final unit="Pa",
                                              displayUnit="bar") 
    "Relative pressure signal";
equation 
  // Zero flow equations for connectors
  port_a.m_flow = 0;
  port_b.m_flow = 0;

  // No contribution of specific quantities
  port_a.h_outflow = 0;
  port_b.h_outflow = 0;
  port_a.Xi_outflow = zeros(Medium.nXi);
  port_b.Xi_outflow = zeros(Medium.nXi);
  port_a.C_outflow  = zeros(Medium.nC);
  port_b.C_outflow  = zeros(Medium.nC);

  // Relative pressure
  p_rel = port_a.p - port_b.p;
end RelativePressure;

Modelica.Fluid.Sensors.RelativeTemperature Modelica.Fluid.Sensors.RelativeTemperature

Ideal relative temperature sensor

Modelica.Fluid.Sensors.RelativeTemperature

Information


The relative temperature "T(port_a) - T(port_b)" is determined between the two ports of this component and is provided as output signal. The sensor should be connected in parallel with other equipment, no flow through the sensor is allowed.

Extends from Modelica.Icons.TranslationalSensor (Icon representing translational measurement device).

Connectors

TypeNameDescription
FluidPort_aport_a 
FluidPort_bport_b 
output RealOutputT_relRelative temperature signal [K]

Modelica definition

model RelativeTemperature "Ideal relative temperature sensor"
  extends Modelica.Icons.TranslationalSensor;
  replaceable package Medium = 
    Modelica.Media.Interfaces.PartialMedium "Medium in the sensor";
  Modelica.Fluid.Interfaces.FluidPort_a port_a(m_flow(min=0),
                                redeclare package Medium = Medium);
  Modelica.Fluid.Interfaces.FluidPort_b port_b(m_flow(min=0),
                                redeclare package Medium = Medium);

  Modelica.Blocks.Interfaces.RealOutput T_rel(final quantity="ThermodynamicTemperature",
                                              final unit = "K", displayUnit = "degC", min=0) 
    "Relative temperature signal";
equation 
  // Zero flow equations for connectors
  port_a.m_flow = 0;
  port_b.m_flow = 0;

  // No contribution of specific quantities
  port_a.h_outflow = 0;
  port_b.h_outflow = 0;
  port_a.Xi_outflow = zeros(Medium.nXi);
  port_b.Xi_outflow = zeros(Medium.nXi);
  port_a.C_outflow  = zeros(Medium.nC);
  port_b.C_outflow  = zeros(Medium.nC);

  // Relative temperature
  T_rel = Medium.temperature(Medium.setState_phX(port_a.p, inStream(port_a.h_outflow), inStream(port_a.Xi_outflow))) -
          Medium.temperature(Medium.setState_phX(port_b.p, inStream(port_b.h_outflow), inStream(port_b.Xi_outflow)));
end RelativeTemperature;

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