modelLiangAndZhu
Extends from AixLib.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.Frosting.BaseClasses.PartialVelocityBased (Partial model for velocity based frost modelling).
Information
This model estimates the frosting based on the growth velocities derived for a constant density in Liang et al., who base their work on the zones from Zhu et al.For more information, see the base-model: AixLib.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.Frosting.BaseClasses.PartialVelocityBased .
References
J.H. Zhu, Y.Y. Sun, W. Wang, S.M. Deng, Y.J. Ge, and L.T. Li. Developing a new frosting map to guide defrosting control for air-source heat pump units. Applied Thermal Engineering, November 2015 doi:10.1016/j.applthermaleng.2015.06.076.
Liang, S., Wang, W., Sun, Y., Li, Z., Zhao, J., Lin, Y., and Deng, S. (2020). A novel characteristic index for frosting suppression based on the configuration and operation of air source heat pumps. International Journal of Refrigeration, 109, 161-171. https://doi.org/10.1016/j.ijrefrig.2019.10.009.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Area | A (from PartialVelocityBased) | 15 | Area of heat exchanger, all fins from both sides |
| Boolean | use_reset (from PartialVelocityBased) | false | = true, if reset port enabled |
| Advanced › Medium properties | |||
| Modelica.Units.SI.SpecificHeatCapacity | cpEva (from PartialIcingFactor) | Evaporator medium specific heat capacity | |
| Density | |||
| Boolean | use_varDen (from PartialVelocityBased) | false | =true to use variable density based on PT1 Element, e.g. Korn et al. |
| Modelica.Units.SI.Density | den_constant (from PartialVelocityBased) | 659 | Constant density of frost, based on Korn at -5 frost temperature |
| Real | k (from PartialVelocityBased) | 3.77 | Gain |
| Modelica.Units.SI.Time | T (from PartialVelocityBased) | 8000 | Time Constant |
| Real | den_min (from PartialVelocityBased) | 50 | Minimal density |
| Ice mass | |||
| Boolean | estimateMaximalIceMass (from PartialVelocityBased) | true | =false to specify maximal ice mass directly |
| Modelica.Units.SI.Mass | mIce_max (from PartialVelocityBased) | den_constant*A*d/2 | Maximal possible mass of ice on HE surface. This value is limited by the volume between the fin tube |
| Modelica.Units.SI.Distance | d (from PartialVelocityBased) | 3e-3 | Distance between two fins. Used to calculate the maximal mass of ice on the HE |
| Melting | |||
| Real | natConvCoeff (from PartialVelocityBased) | 1e-7 | Parameter to be calibrated for natural defrost |
| Modelica.Units.SI.SpecificEnthalpy | hWatFus (from PartialVelocityBased) | 333.5e3 | Fusion enthalpy of water |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.Fluid.HeatPumps.ModularReversible.BaseClasses.RefrigerantMachineControlBus | sigBus (from PartialIcingFactor) | Bus-connector used in a heat pump | |
| Modelica.Blocks.Interfaces.RealOutput | iceFac (from PartialIcingFactor) | Icing factor from 0 to 1 to estimate influence of icing |
Components
Revisions
-
December 22, 2025 by Fabian Roemer:
First implementation (see issue AixLib #1623)