modelEightPortHeatMassExchanger

Model transporting four fluid streams between eight ports with storing mass or energy

Extends from AixLib.Fluid.Interfaces.PartialEightPortInterface, AixLib.Fluid.Interfaces.EightPortFlowResistanceParameters.

Information

This component transports four fluid streams between eight ports. It provides the basic model for implementing a dynamic heat exchanger.

The model can be used as-is, although there will be no heat or mass transfer between the four fluid streams. To add heat transfer, heat flow can be added to the heat port of the four volumes.

Implementation

The variable names follow the conventions used in Modelica.Fluid.Examples.HeatExchanger.BaseClasses.BasicHX.

Parameters

TypeNameDefaultDescription
BooleanhomotopyInitializationtrue= true, use homotopy method
Dynamics › Nominal condition
Modelica.Units.SI.Timetau130Time constant at nominal flow
Modelica.Units.SI.Timetau230Time constant at nominal flow
Modelica.Units.SI.Timetau330Time constant at nominal flow
Modelica.Units.SI.Timetau430Time constant at nominal flow
Dynamics › Conservation equations
Modelica.Fluid.Types.DynamicsenergyDynamicsModelica.Fluid.Types.Dynamics.DynamicFreeInitialFormulation of energy balance
Initialization › Medium 1
Medium1.AbsolutePressurep1_startMedium1.p_defaultStart value of pressure
Medium1.TemperatureT1_startMedium1.T_defaultStart value of temperature
Medium1.MassFraction[Medium1.nX]X1_startMedium1.X_defaultStart value of mass fractions m_i/m
Medium1.ExtraProperty[Medium1.nC]C1_startfill(0, Medium1.nC)Start value of trace substances
Medium1.ExtraProperty[Medium1.nC]C1_nominalfill(1E-2, Medium1.nC)Nominal value of trace substances. (Set to typical order of magnitude.)
Initialization › Medium 2
Medium2.AbsolutePressurep2_startMedium2.p_defaultStart value of pressure
Medium2.TemperatureT2_startMedium2.T_defaultStart value of temperature
Medium2.MassFraction[Medium2.nX]X2_startMedium2.X_defaultStart value of mass fractions m_i/m
Medium2.ExtraProperty[Medium2.nC]C2_startfill(0, Medium2.nC)Start value of trace substances
Medium2.ExtraProperty[Medium2.nC]C2_nominalfill(1E-2, Medium2.nC)Nominal value of trace substances. (Set to typical order of magnitude.)
Initialization › Medium 3
Medium3.AbsolutePressurep3_startMedium3.p_defaultStart value of pressure
Medium3.TemperatureT3_startMedium3.T_defaultStart value of temperature
Medium3.MassFraction[Medium3.nX]X3_startMedium3.X_defaultStart value of mass fractions m_i/m
Medium3.ExtraProperty[Medium3.nC]C3_startfill(0, Medium3.nC)Start value of trace substances
Medium3.ExtraProperty[Medium3.nC]C3_nominalfill(1E-2, Medium3.nC)Nominal value of trace substances. (Set to typical order of magnitude.)
Initialization › Medium 4
Medium4.AbsolutePressurep4_startMedium4.p_defaultStart value of pressure
Medium4.TemperatureT4_startMedium4.T_defaultStart value of temperature
Medium4.MassFraction[Medium4.nX]X4_startMedium4.X_defaultStart value of mass fractions m_i/m
Medium4.ExtraProperty[Medium4.nC]C4_startfill(0, Medium4.nC)Start value of trace substances
Medium4.ExtraProperty[Medium4.nC]C4_nominalfill(1E-2, Medium4.nC)Nominal value of trace substances. (Set to typical order of magnitude.)

Components

TypeNameDefaultDescription
Modelica.Units.SI.HeatFlowRateQ1_flowvol1.heatPort.Q_flowHeat flow rate into medium 1
Modelica.Units.SI.HeatFlowRateQ2_flowvol2.heatPort.Q_flowHeat flow rate into medium 2
Modelica.Units.SI.HeatFlowRateQ3_flowvol3.heatPort.Q_flowHeat flow rate into medium 1
Modelica.Units.SI.HeatFlowRateQ4_flowvol4.heatPort.Q_flowHeat flow rate into medium 2
AixLib.Fluid.MixingVolumes.MixingVolumevol1Volume for fluid 1
AixLib.Fluid.MixingVolumes.MixingVolumevol2Volume for fluid 2
AixLib.Fluid.MixingVolumes.MixingVolumevol3Volume for fluid 3
AixLib.Fluid.MixingVolumes.MixingVolumevol4Volume for fluid 4
AixLib.Fluid.FixedResistances.PressureDroppreDro1Pressure drop model for fluid 1
AixLib.Fluid.FixedResistances.PressureDroppreDro2Pressure drop model for fluid 2
AixLib.Fluid.FixedResistances.PressureDroppreDro3Pressure drop model for fluid 3
AixLib.Fluid.FixedResistances.PressureDroppreDro4Pressure drop model for fluid 4

Revisions

  • April 14, 2020, by Michael Wetter:
    Changed homotopyInitialization to a constant.
    This is for IBPSA, #1341.
  • July 18, 2018, by Massimo Cimmino:
    Remove start values of m_flow and dp variables.
  • July 2014, by Damien Picard:
    First implementation.