modelIndirectTankHeatExchanger

Heat exchanger typically submerged in a fluid with a second fluid circulating through it

Extends from AixLib.Fluid.Interfaces.TwoPortFlowResistanceParameters, AixLib.Fluid.Interfaces.LumpedVolumeDeclarations, AixLib.Fluid.Interfaces.PartialTwoPortInterface.

Information

This model is a heat exchanger with a moving fluid on one side and a stagnant fluid on the other. It is intended for use when a heat exchanger is submerged in a stagnant fluid. For example, the heat exchanger in a storage tank which is part of a solar thermal system.

This component models the fluid in the heat exchanger, convection between the fluid and the heat exchanger, and convection from the heat exchanger to the surrounding fluid.

The model is based on AixLib.Fluid.HeatExchangers.BaseClasses.HACoilInside and AixLib.Fluid.HeatExchangers.BaseClasses.HANaturalCylinder.

The fluid ports are intended to be connected to a circulated heat transfer fluid while the heat port is intended to be connected to a stagnant fluid.

Parameters

TypeNameDefaultDescription
BooleanhomotopyInitializationtrue= true, use homotopy method
IntegernSegNumber of segments in the heat exchanger
Modelica.Units.SI.HeatCapacityCHexCapacitance of the heat exchanger
Modelica.Units.SI.VolumevolHexFluVolume of heat transfer fluid in the heat exchanger
Modelica.Units.SI.ThermalConductanceUA_nominalabs(Q_flow_nominal/(THex_nominal - TTan_nominal))Nominal UA value for the heat exchanger
Modelica.Units.SI.DiameterdExtHexExterior diameter of the heat exchanger pipe
General › Nominal condition
Modelica.Units.SI.HeatFlowRateQ_flow_nominalHeat transfer at nominal conditions
Modelica.Units.SI.TemperatureTTan_nominalTemperature of fluid inside the tank at UA_nominal
Modelica.Units.SI.TemperatureTHex_nominalTemperature of fluid inside the heat exchanger at UA_nominal
Realr_nominal0.5Ratio between coil inside and outside convective heat transfer
Dynamics › Conservation equations
Modelica.Fluid.Types.DynamicsenergyDynamicsModelica.Fluid.Types.Dynamics.DynamicFreeInitialFormulation of energy balance for heat exchanger internal fluid mass
Modelica.Fluid.Types.DynamicsenergyDynamicsSolidenergyDynamicsFormulation of energy balance for heat exchanger solid mass
Advanced › Modeling detail
BooleanhA_flowDependenttrueSet to false to make the convective heat coefficient calculation of the fluid inside the coil independent of mass flow rate
BooleanhA_temperatureDependenttrueSet to false to make the convective heat coefficient calculation of the fluid inside the coil independent of temperature

Components

TypeNameDefaultDescription
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a[nSeg]portHeat port connected to water inside the tank
AixLib.Fluid.FixedResistances.PressureDropresCalculates the flow resistance and pressure drop through the heat exchanger
AixLib.Fluid.MixingVolumes.MixingVolume[nSeg]volHeat exchanger fluid
Modelica.Thermal.HeatTransfer.Components.HeatCapacitor[nSeg]capThermal mass of the heat exchanger

Contents

NameDescription
MediumHexHeat transfer fluid flowing through the heat exchanger
MediumTanHeat transfer fluid inside the tank

Revisions

  • March 7, 2022, by Michael Wetter:
    Set final massDynamics=energyDynamics.
    This is for #1542.
  • April 9, 2021, by Michael Wetter:
    Corrected placement of each keyword.
    See Buildings, PR #2440.
  • April 14, 2020, by Michael Wetter:
    Changed homotopyInitialization to a constant.
    This is for IBPSA, #1341.
  • June 7, 2018 by Filip Jorissen:
    Copied model from Buildings and update the model accordingly. This is for #314.
  • January 7, 2016, by Filip Jorissen:
    Propagated flowDependent and temperatureDependent in hAPipIns. This is for issue #454.
  • September 24, 2015 by Michael Wetter:
    Set fixed attribute in cap.T to avoid unspecified initial conditions.
  • July 2, 2015, by Michael Wetter:
    Set prescribedHeatFlowRate=false in control volume.
  • July 1, 2015, by Filip Jorissen:
    Added parameter energyDynamicsSolid. This is for #434.
  • March 28, 2015, by Filip Jorissen:
    Propagated allowFlowReversal.
  • August 29, 2014, by Michael Wetter:
    Introduced MediumTan for the tank medium, and assigned Medium to be equal to MediumHex. This is to correct issue #271.
  • June 18, 2014, by Michael Wetter:
    Set initial equations for cap, and renamed this instance from Cap to cap. This was done to avoid a warning during translation, and to comply with the coding convention.
  • October 8, 2013, by Michael Wetter:
    Removed parameter show_V_flow.
  • January 29, 2013, by Peter Grant:
    First implementation.