functionwetterAfjei1997

Correction of COP for icing and defrost according to Wetter, Afjei and Glass

Extends from Buildings.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.Frosting.Functions.partialIcingFactor (Base function for all icing factor functions).

Information

Correction of the coefficient of performance due to icing/frosting according to Wetter, Afjei and Glass (1997).

For more information on the iceFac, see the documentation of Buildings.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.BaseClasses.PartialRefrigerantCycle

References

Thomas Afjei, Michael Wetter and Andrew Glass.
TRNSYS type: Dual-stage compressor heat pump including frost and cycle losses. Model description and implementation in TRNSYS.
TRNSYS user meeting, November 1997, Stuttgart, Germany.
https://simulationresearch.lbl.gov/wetter/download/type204_hp.pdf

Inputs

TypeNameDefaultDescription
Modelica.Units.SI.ThermodynamicTemperatureTEvaInMea (from partialIcingFactor)Evaporator supply temperature. Should be equal to outdoor air temperature
Modelica.Units.SI.ThermodynamicTemperatureTEvaOutMea (from partialIcingFactor)Evaporator return temperature
Modelica.Units.SI.MassFlowRatemEva_flow (from partialIcingFactor)Mass flow rate at the evaporator

Outputs

TypeNameDefaultDescription
RealiceFac (from partialIcingFactor)Icing factor (0: no heat transfer; 1: no effect)

Revisions

  • April 17, 2025, by Fabian Wuellhorst:
    Fix degC unit, for IBPSA #1975
  • December 7, 2023, by Michael Wetter:
    Reformulated to make function once continuously differentiable, and to avoid an event that is triggered based on TEvaInMea).
  • November 26, 2018 by Fabian Wuellhorst:
    First implementation (see issue AixLib #577)