modelReceiver

Receiver model for vapor cycle applications

Extends from Boundaries.PhaseSeparator (Base model for receiver and accumulator models).

Information

Model of a receiver for application in vapor-cycle systems.


It inherits the basic balance equations from the volume model.


The purpose of this model is to separate the phases and provide liquid phase to the expansion valve. The liquid is extracted through a pipe. The low and high end of the pipe can be set by the respective parameters. Depending on the liquid level of the receiver, the outlet enthalpy is set:


If the liquid level is higher than the upper end of the pipe, liquid is extracted.

If the liquid level is lower then the lower end of the pipe, the actual enthalpy of the medium in the receiver is extracted.

If the liquid level is between the lower and the upper end of the pipe, the outlet enthalpy is weighted on the liquid level in the pipe.

Known problems: full phaseSeparator is very stiff, therefore simulation might get slow then, especially at the moment when the separator fills up. Consider changing the timeconstant and check if the mass-flow dynamic is fast enough.


Parameters

TypeNameDefaultDescription
StringinstanceName (from DropOfCommonsPlus)getInstanceName()Instance name
BooleanuseHeatport (from PartialVolume)false=true, if heatport is enabled
BooleanuseInlet (from PartialVolume)true= true, if inlet is enabled
BooleanuseOutlet (from PartialVolume)true= true, if outlet is enabled
SI.AreaA (from PartialVolume)1Heat transfer area
SI.CoefficientOfHeatTransferU (from PartialVolume)200Thermal transmittance
SI.VolumeV_par (from PhaseSeparator)0.01Volume
Realpipe_low (from PhaseSeparator)Low end of pipe
Realpipe_high (from PhaseSeparator)High end of pipe
Layout
BooleandisplayInstanceName (from DropOfCommonsPlus)dropOfCommons.displayInstanceNames= true, if instance name is displayed
BooleandisplayParameters (from DropOfCommonsPlus)dropOfCommons.displayParameters= true, if displaying parameters is enabled
Initialization › Pressure
Booleaninitialize_pressure (from PartialVolume)true=true, if pressure is initialized
Medium.AbsolutePressurep_start (from PartialVolume)Medium.p_defaultInitial pressure set value
Initialization › Temperature
Booleaninitialize_energy (from PartialVolume)true= true, if internal energy is initialized
Medium.TemperatureT_start (from PartialVolume)Medium.T_defaultInitial Temperature set value
Initialization › Mass fractions
Booleaninitialize_Xi (from PartialVolume)true=true, if mass fractions are iinitialized
Medium.MassFraction[Medium.nXi]Xi_0 (from PartialVolume)Medium.X_default[1:Medium.nXi]Initial mass fractions set values
Initialization › Specific enthalpy
Booleanuse_hstart (from PartialVolume)false=true, if internal energy is initialized with specific enthalpy
Medium.SpecificEnthalpyh_start (from PartialVolume)Medium.h_defaultInitial specific enthalpy set value
Advanced
BooleanenableFreeInlet (from PartialVolume)falsetrue, if inlet is free (volume creates no pressure boundary condition)
BooleanconsiderInertance (from PartialVolume)dropOfCommons.considerInertance=true, if transient momentum (inertance) term is considered; disable only for advanced use
Utilities.Units.InertanceL (from PartialVolume)dropOfCommons.LInertance of inlet/outlet
SI.MassFlowRatem_flow_assert (from PartialVolume)-dropOfCommons.m_flow_regAssertion threshold for negative massflow
BooleanusePreferredMediumStates (from PartialVolume)false=true, if preferred medium states are used
Advanced › Damping
Realk_volume_damping (from PartialVolume)dropOfCommons.k_volume_dampingDamping factor multiplicator
Booleandensity_derp_h_from_media (from PhaseSeparator)false= true, if the derivative of density by pressure at const specific enthalpy is calculated from media model (only available for some media models)
Medium.DerDensityByPressuredensity_derp_h_set (from PhaseSeparator)1e-6Derivative of density by pressure at const specific enthalpy set value (e.g approx. 1e-5 for air, 1e-7 for water)
Initialization
Initinit_method (from PhaseSeparator)ThermofluidStream.Boundaries.Internal.InitializationMethodsPhaseSeperator.lInitialization method
Medium.SpecificEnthalpyh_0 (from PhaseSeparator)Medium.h_defaultInitial specific enthalpy
SI.MassM_0 (from PhaseSeparator)1Initial mass
Reall_0 (from PhaseSeparator)0.5Initial liquid level
Realx_0 (from PhaseSeparator)0.5Initial vapor quality

Connectors

TypeNameDefaultDescription
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_aheatPort (from PartialVolume)
Interfaces.Inletinlet (from PartialVolume)
Interfaces.Outletoutlet (from PartialVolume)

Components

TypeNameDefaultDescription
Medium.BasePropertiesmedium (from PartialVolume)
SI.VolumeV (from PartialVolume)Volume
SI.MassM (from PartialVolume)V*medium.dMass
SI.Mass[Medium.nXi]MXi (from PartialVolume)M*medium.XiMasses of species
SI.EnergyU_med (from PartialVolume)M*medium.uInternal energy
SI.HeatFlowRateQ_flow (from PartialVolume)Heat flow rate
SI.PowerW_v (from PartialVolume)Work due to change of volume
Realliquid_level (from PhaseSeparator)Level of liquid line
Realliquid_level_pipe (from PhaseSeparator)Level of liquid line in pipe
Realvapor_quality (from PhaseSeparator)max(0, min(1, x))