modelOptimalDefrostTimeWangEtAl
Optimal defrost point based on ice factor in Wang et al.
Extends from BaseClasses.PartialDefrost (Partial model for defrost control).
Information
This defrost control uses the optimal defrost icing factor by Wang et al. Every time the current icing factor is lower than the optimal icing factor to start the defrost, defrost is performed.
References
Wang, W., Zhang, S., Li, Z., Sun, Y., Deng, S., and Wu, X. (2020). Determination of the optimal defrosting initiating time point for an ASHP unit based on the minimum loss coefficient in the nominal output heating energy. Energy, 191, 116505. https://doi.org/10.1016/j.energy.2019.116505.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | minIceFac | 0.5 | Minimal allowed icing Factor to trigger the defrost |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.Fluid.HeatPumps.ModularReversible.BaseClasses.RefrigerantMachineControlBus | sigBus (from PartialDefrost) | Bus with the most relevant information for hp frosting calculation | |
| Modelica.Blocks.Interfaces.BooleanOutput | hea (from PartialDefrost) | Heating mode for heat pump |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.Fluid.HeatPumps.ModularReversible.Controls.Defrost.BaseClasses.HysteresisVariableLowerBound | hys | For the iceFac control. Output signal is used internally | |
| Modelica.Blocks.Logical.Not | not1 | ||
| Modelica.Blocks.Logical.And | andDefrost | Either hys or crit min time | |
| Modelica.Blocks.Logical.Not | notHea | If defrost, we set hea=false | |
| AixLib.Fluid.HeatPumps.ModularReversible.Controls.Defrost.BaseClasses.OptimalDefrostWangEtAl | optDefWuEtAl | Optimal defrost time | |
| Modelica.Blocks.Logical.Switch | swi | ||
| Modelica.Blocks.Sources.Constant | constMinIceFac | Infinite defrost time | |
| Modelica.Blocks.Logical.GreaterThreshold | posFro | If in any frosting zone | |
| Modelica.Blocks.Math.IntegerToReal | andIsOn1 | In frosting zone and on leads to possible frosting | |
| Modelica.Blocks.Logical.And | andIsOn | In frosting zone and on leads to possible frosting | |
| AixLib.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.Frosting.BaseClasses.ZhuFrostingZone | froZon | Current zone |
Revisions
-
December 22, 2025 by Fabian Roemer:
First implementation (see issue AixLib #1623)