modelReverseFlowMassExchanger

Model that tests the reverse flow for a mass exchanger
Diagram of ReverseFlowMassExchangerOpen the diagram
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Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

This model tests whether the results for a mass exchanger are identical for forward flow and reverse flow.

Note that if the latent heat transfer effectiveness is non-zero, then the results will differ. The reason is that the maximum capacity stream is computed using the mass flow rates at port_a1 and port_a2. For reverse flow, they are not equal if moisture is added to the mass flow rate. Using an average mass flow rate in computing the heat and moisture transfer would lead to identical results, but it would introduce additional nonlinear equations that need to be solved. Therefore, the model uses the mass flow rates at port_a1 and port_a2.

Note: This problem fails to translate in Dymola 2012 due to an error in Dymola's support of stream connector. This bug will be corrected in future versions of Dymola.

Components

TypeNameDefaultDescription
Modelica.Blocks.Math.AddcheTemCheck whether the outputs of the forward flow and reverse flow model are identical
Modelica.Blocks.Math.AddcheEntCheck whether the outputs of the forward flow and reverse flow model are identical
Modelica.Blocks.Math.AddcheMasCheck whether the outputs of the forward flow and reverse flow model are identical
Modelica.Fluid.Sources.MassFlowSource_Tsource2
Buildings.Fluid.MassExchangers.ConstantEffectivenessmasExcForMass exchanger with forward flow
Buildings.Fluid.MassExchangers.ConstantEffectivenessmasExcRevMass exchanger with reverse flow
Buildings.Fluid.Sources.Boundary_pTsink2Fluid sink
FixedResistances.PressureDropres3Fixed resistance
FixedResistances.PressureDropres4Fixed resistance
Sensors.SpecificEnthalpysenEnt3
Buildings.Fluid.Sensors.TemperaturesenTem3
Sensors.MassFractionsenMas3
Sensors.SpecificEnthalpysenEnt4
Buildings.Fluid.Sensors.TemperaturesenTem4
Sensors.MassFractionsenMas4
Modelica.Blocks.Math.AddcheTem1Check whether the outputs of the forward flow and reverse flow model are identical
Modelica.Blocks.Math.AddcheEnt1Check whether the outputs of the forward flow and reverse flow model are identical
Modelica.Blocks.Math.AddcheMas1Check whether the outputs of the forward flow and reverse flow model are identical
Modelica.Fluid.Sources.MassFlowSource_Tsource3
Modelica.Fluid.Sources.MassFlowSource_Tsource4
Modelica.Fluid.Sources.MassFlowSource_Tsource1
Sources.Boundary_pTsink1Fluid sink
Sensors.SpecificEnthalpysenEnt1
Buildings.Fluid.Sensors.TemperaturesenTem1
Sensors.MassFractionsenMas1
Buildings.Fluid.Sensors.TemperaturesenTem2
Sensors.SpecificEnthalpysenEnt2
Sensors.MassFractionsenMas2
FixedResistances.PressureDropres1Fixed resistance
FixedResistances.PressureDropres2Fixed resistance

Contents

NameDescription
Medium

Revisions

  • September 20, 2020, by Michael Wetter:
    Updated model to use one port temperature sensor from Modelica Standard Library.
    This is for #1399.
  • May 2, 2019, by Jianjun Hu:
    Replaced fluid source. This is for #1072.
  • November 2, 2016, by Michael Wetter:
    Changed assertions to blocks that compute the difference, and added the difference to the regression results.
    This is for issue 564.
  • October 9, 2013, by Michael Wetter:
    Replaced Modelica.Fluid.Sources.FixedBoundary with Buildings.Fluid.Sources.FixedBoundary as otherwise, the pedantic model check fails in Dymola 2014 FD01 beta3.
  • August 19, 2010, by Michael Wetter:
    First implementation.