modelRotaryCompressor

Model that describes a simple rotary compressor

Extends from BaseClasses.PartialCompressor (Partial model for compressor that contains basic definitions used in various compressor models).

Information

This is a model of a simple rotary compressor that is used, for example, in close-loop systems like heat pumps or chillers. It inherits from PartialCompressor which inherits from PartialCompression. Therefore, please checkout these sub-models for further information of underlying modeling approaches and parameterisation:

For this model, no further losses are assumed at inlet and outlet of the compressor.

Parameters

TypeNameDefaultDescription
General › Geometry
Modelica.Units.SI.VolumeVDis (from PartialCompressor)13e-6Displacement volume of the compressor
Modelica.Units.SI.EfficiencyepsRef (from PartialCompressor)0.04Ratio of the real and the ideal displacement volume
Modelica.Units.SI.DiameterdiameterInl (from PartialCompressor)12e-3Diameter of the pipe at compressor's inlet
Modelica.Units.SI.DiameterdiameterOut (from PartialCompressor)8e-3Diameter of the pipe at compressor's outlet
General › Compressor's characterisitcs
Modelica.Units.SI.FrequencyrotSpeMax (from PartialCompressor)120Maximal rotational speed executable by the compressor
RealpiPreMax (from PartialCompressor)15Maximal pressure ratio executable by the compressor
Transient behaviour
BooleanuseInpFil (from PartialCompressor)true= true, if transient behaviour of rotational speed is computed
Modelica.Units.SI.TimerisTim (from PartialCompressor)0.5Time until rotational speed reaches 99.6 % of its set value
Pressure losses › General
RealzetInl (from PartialCompressor)((1/0.59 - 1)^2 + (1 - (diameterInl/0.066)^2))*(1 - (diameterInl/0.066)^2)Pressure loss factor at compressor's inlet for flow of port_a -> port_b
RealzetOut (from PartialCompressor)((1/0.59 - 1)^2 + (1 - (diameterOut/0.1122)^2))*(1 - (diameterOut/0.1122)^2)Pressure loss factor at compressor's outlet for flow of port_a -> port_b
Pressure losses › Advanced
Booleanfrom_dp (from PartialCompressor)false= true, use m_flow = f(dp) else dp = f(m_flow)
BooleanhomotopyInitialization (from PartialCompressor)true= true, use homotopy method for initialisation
Booleanlinearized (from PartialCompressor)false= true, use linear relation between m_flow and dp for any flow rate
Heat losses › General
Utilities.Types.HeatTransferModelsheaTraMod (from PartialCompressor)Utilities.Types.HeatTransferModels.SimplifiedChoose heat transfer model for heat losses at compressor's inlet and outlet
Heat losses › Geometry
Modelica.Units.SI.MassmWal (from PartialCompressor)2.5Mass of the fictitious wall
Modelica.Units.SI.SpecificHeatCapacitycpWal (from PartialCompressor)450Specific heat capacity of the fictitious wall
Heat losses › Thermal conductances
Modelica.Units.SI.ThermalConductancekAMeaInl (from PartialCompressor)25Effective mean thermal conductance between medium and fictitious wall at inlet
Modelica.Units.SI.ThermalConductancekAMeaOut (from PartialCompressor)35Effective mean thermal conductance between medium and fictitious wall at outlet
Modelica.Units.SI.ThermalConductancekAMeaAmb (from PartialCompressor)5Effective mean thermal conductance coefficient between fictitious wall and ambient
Heat losses › Initialisation
BooleaniniTWal0 (from PartialCompressor)true= true, if wall is initialised at fixed temperature; Otherwise, steady state initialisation
Modelica.Units.SI.TemperatureTWal0 (from PartialCompressor)293.15Temperature of wall at initialisation
Assumptions
BooleanallowFlowReversal (from PartialCompressor)true= false to simplify equations, assuming, but not enforcing, no flow reversal
Utilities.Types.SimpleCompressorsimCom (from PartialCompressor)Utilities.Types.SimpleCompressor.DefaultParameter used to activate or deactivate menue choices
Advanced › General
Modelica.Units.SI.PressureDifferencedp_start (from PartialCompressor)-20e5Guess value of compressor's dp = port_a.p - port_b.p
Medium.MassFlowRatem_flow_start (from PartialCompressor)0.5*m_flow_nominalGuess value of compressor's m_flow = port_a.m_flowr
Medium.MassFlowRatem_flow_small (from PartialCompressor)1e-6*m_flow_nominalSmall mass flow rate for regularization of compressor's zero flow
Modelica.Units.SI.MassFlowRatem_flow_nominal (from PartialCompressor)0.1Nominal mass flow rate
Advanced › Diagnostics
Booleanshow_T (from PartialCompressor)false= true, if compressor's temperatures at port_a and port_b are computed
Booleanshow_V_flow (from PartialCompressor)false= true, if compressor's volume flow rate at inflowing port is computed
Booleanshow_staEff (from PartialCompressor)false= true, if thermodynamic states and efficiencies are computed
Booleanshow_qua (from PartialCompressor)false= true, if vapour qualities are computed
Advanced › Initialisation
Modelica.Units.SI.FrequencyrotSpe0 (from PartialCompressor)60Compressor's rotational spped at initialisation
Modelica.Units.SI.AbsolutePressurepInl0 (from PartialCompressor)3e5Pressure at compressor's inlet at initialisation
Modelica.Units.SI.TemperatureTInl0 (from PartialCompressor)283.15Temperature at compressor's inlet at initialisation

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a (from PartialCompressor)Fluid connector a (positive design flow direction is from port_a to port_b)
Modelica.Fluid.Interfaces.FluidPort_bport_b (from PartialCompressor)
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_bheatPort (from PartialCompressor)Heat port connector to calculate heat losses to ambient
Modelica.Blocks.Interfaces.RealInputmanVarCom (from PartialCompressor)Prescribed compressor's rotational speed
Modelica.Blocks.Interfaces.RealOutputcurManVarCom (from PartialCompressor)Current compressor's rotational speed

Components

TypeNameDefaultDescription
CompressionProcesscomPro (from PartialCompressor)Model describing compression process

Revisions

  • October 20, 2017, by Mirko Engelpracht:
    First implementation (see issue 467).