modelReverseCycleDefrostHeatPump
Heat pump in reverse cycle operation during defrost
Extends from AixLib.Fluid.Chillers.ModularReversible.RefrigerantCycle.BaseClasses.PartialChillerCycle (Partial model of refrigerant cycle used for chiller applications).
Information
This model can be used to estimate the heat pumps behavior during defrost. It assumes a constant COP and a constant compressor speed (usually low to have efficient defrost). The default values were calibrated for the custom build heat pump at the Institute EBC. Still, note that the model heavily simplifies the real dynamics during defrost. The model was used for studies in the PhD of Fabian Römer, e.g. the publication Römer et al.References
Römer, Fabian and Fuchs, Nico and Fuchs, Nico and Müller, Dirk, Practical, Near-Optimal Design Rule Extraction for Heat Pumps in Single-Family Buildings (September 03, 2025). Available at SSRN: https://ssrn.com/abstract=5633891
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| String | devIde (from PartialRefrigerantCycle) | "" | Indicates the data source, used to warn users about different vapor compression devices in reversible models |
| Boolean | useInChi (from PartialChillerCycle) | =false to indicate that this model is used as a heat pump | |
| Real | COP_constant | 6.25 | COP during defrost (useful side is the evaporator) |
| Real | y_constant | 0.275 | Constant defrost compressor speed |
| Nominal condition | |||
| Modelica.Units.SI.Power | PEle_nominal (from PartialRefrigerantCycle) | Nominal electrical power consumption | |
| Modelica.Units.SI.Temperature | TCon_nominal (from PartialRefrigerantCycle) | Nominal temperature at secondary condenser side | |
| Modelica.Units.SI.Temperature | TEva_nominal (from PartialRefrigerantCycle) | Nominal temperature at secondary evaporator side | |
| Modelica.Units.SI.HeatFlowRate | QCoo_flow_nominal (from PartialChillerCycle) | Nominal cooling capacity | |
| Advanced › Medium properties | |||
| Modelica.Units.SI.SpecificHeatCapacity | cpCon (from PartialRefrigerantCycle) | Evaporator medium specific heat capacity | |
| Modelica.Units.SI.SpecificHeatCapacity | cpEva (from PartialRefrigerantCycle) | Evaporator medium specific heat capacity | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | PEle (from PartialRefrigerantCycle) | Electrical Power consumed by the device | |
| Modelica.Blocks.Interfaces.RealOutput | QCon_flow (from PartialRefrigerantCycle) | Heat flow rate through condenser | |
| AixLib.Fluid.HeatPumps.ModularReversible.BaseClasses.RefrigerantMachineControlBus | sigBus (from PartialRefrigerantCycle) | Bus-connector | |
| Modelica.Blocks.Interfaces.RealOutput | QEva_flow (from PartialRefrigerantCycle) | Heat flow rate through evaporator |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.Frosting.NoFrosting | iceFacCal (from PartialRefrigerantCycle) | ||
| Modelica.Blocks.Math.Add | redQCon (from PartialRefrigerantCycle) | Reduce heat flow to the condenser based on the reduction to the evaporator | |
| Modelica.Blocks.Math.Product | proRedQEva (from PartialRefrigerantCycle) | Reduce heat flow to the evaporator based on the icing factor | |
| Modelica.Blocks.Sources.Constant | conPEle | ||
| Modelica.Blocks.Sources.Constant | conQEva_flow |
Revisions
-
December 22, 2025 by Fabian Roemer:
First implementation (see issue AixLib #1623)