modelScrollCompressor
Extends from Buildings.Fluid.HeatPumps.Compressors.BaseClasses.PartialCompressor (Partial compressor model).
Information
Model for a scroll processor, as detailed in Jin (2002). The rate of heat transferred to the evaporator is given by:
Q̇Eva = ṁref ( hVap(TEva) - hLiq(TCon) ).
The power consumed by the compressor is given by a linear efficiency relation:
P = PTheoretical / η + PLoss,constant.
Variable speed is achieved by multiplying the full load suction volume flow rate by the normalized compressor speed. The power and heat transfer rates are forced to zero if the resulting heat pump state has higher evaporating pressure than condensing pressure.
Assumptions and limitations
The compression process is assumed isentropic. The thermal energy of superheating is ignored in the evaluation of the heat transferred to the refrigerant in the evaporator. There is no supercooling.
References
H. Jin. Parameter estimation based models of water source heat pumps. PhD Thesis. Oklahoma State University. Stillwater, Oklahoma, USA. 2002.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | volRat | Built-in volume ratio | |
| Modelica.Units.SI.VolumeFlowRate | V_flow_nominal | Refrigerant volume flow rate at suction at full load conditions | |
| Modelica.Units.SI.MassFlowRate | leaCoe | Leakage mass flow rate at a pressure ratio of 1 | |
| Modelica.Units.SI.Efficiency | etaEle | Electro-mechanical efficiency of the compressor | |
| Modelica.Units.SI.Power | PLos | Constant part of the compressor power losses | |
| Modelica.Units.SI.TemperatureDifference | dTSup | Superheating at compressor suction |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | port_a (from PartialCompressor) | Refrigerant connector a (corresponding to the evaporator) | |
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_b | port_b (from PartialCompressor) | Refrigerant connector b (corresponding to the condenser) | |
| Modelica.Blocks.Interfaces.RealInput | y (from PartialCompressor) | Modulating signal for compressor frequency, equal to 1 at full load conditions | |
| Modelica.Blocks.Interfaces.RealOutput | P (from PartialCompressor) | Electric power consumed by compressor |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.SpecificEnthalpy | hEva (from PartialCompressor) | Specific enthalpy of saturated vapor at evaporator temperature | |
| Modelica.Units.SI.SpecificEnthalpy | hCon (from PartialCompressor) | Specific enthalpy of saturated liquid at condenser temperature | |
| Modelica.Units.SI.AbsolutePressure | pEva (from PartialCompressor) | Pressure of saturated vapor at evaporator temperature | |
| Modelica.Units.SI.AbsolutePressure | pCon (from PartialCompressor) | Pressure of saturated liquid at condenser temperature | |
| Modelica.Units.SI.AbsolutePressure | pDis (from PartialCompressor) | Discharge pressure of the compressor | |
| Modelica.Units.SI.AbsolutePressure | pSuc (from PartialCompressor) | Suction pressure of the compressor | |
| Modelica.Units.SI.Temperature | TSuc (from PartialCompressor) | Temperature at suction of the compressor | |
| Boolean | isOn (from PartialCompressor) | State of the compressor, true if turned on | |
| Modelica.Units.SI.SpecificVolume | vSuc (from PartialCompressor) | Specific volume of the refrigerant at suction of the compressor | |
| Modelica.Units.SI.MassFlowRate | m_flow | Refrigerant mass flow rate | |
| Modelica.Units.SI.MassFlowRate | mLea_flow | Refrigerant leakage mass flow rate | |
| Modelica.Units.SI.Power | PThe | Theoretical power consumed by the compressor | |
| Modelica.Units.SI.Efficiency | COP | Heating COP of the compressor |
Revisions
-
January 25, 2019, by Michael Wetter:
Added start value to avoid warning in JModelica. -
May 30, 2017, by Filip Jorissen:
Removedpressure_erroras this is replaced by Buildings.Fluid.HeatPumps.Compressors.BaseClasses.TemperatureProtection. See #769. -
November 11, 2016, by Massimo Cimmino:
First implementation.