modelAntiFreeze

Model to prevent source from freezing

Extends from BaseClasses.PartialSafetyWithCounter (Safety control which adds an error counter to the I/O).

Information

This model is used to prevent freezing of the condenser or evaporator side. A real device would shut off as well.

This models takes the minimum of the two temperatures evaporator outlet and condenser inlet. If this minimal temperature falls below the given lower boundary, the hystereses will trigger an error and cause the device to switch off.

Assumptions

This block does not check the evaporator inlet or condenser outlet temperatures because they are assumed to be always higher than the other side.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.ThermodynamicTemperatureTAntFre276.15Limit temperature for anti freeze control
RealdTHys2Hysteresis interval width

Connectors

TypeNameDefaultDescription
Buildings.Fluid.HeatPumps.ModularReversible.BaseClasses.RefrigerantMachineControlBussigBus (from PartialSafety)Bus-connector for the heat pump
Modelica.Blocks.Interfaces.IntegerOutputerr (from PartialSafetyWithCounter)Integer for displaying number of errors during simulation
Modelica.Blocks.Interfaces.BooleanInputonOffSet (from PartialSafetyWithCounter)Device is set to turn on
Modelica.Blocks.Interfaces.BooleanOutputcanOpe (from PartialSafetyWithCounter)True if device can operate

Components

TypeNameDefaultDescription
Modelica.Blocks.MathInteger.TriggeredAdddisErr (from PartialSafetyWithCounter)Used to show if the error was triggered
Modelica.Blocks.Logical.NotnotVal (from PartialSafetyWithCounter)=true indicates a error
Modelica.Blocks.Sources.IntegerConstantintConOne (from PartialSafetyWithCounter)Used for display of current error
Modelica.Blocks.Routing.BooleanPassThroughbooPasThr (from PartialSafetyWithCounter)Used to keep the connection to the counter
Modelica.Blocks.Logical.AnderrAndSetOn (from PartialSafetyWithCounter)Error occured and the device should be on
Modelica.Blocks.Logical.HysteresishysHysteresis to indicate if freezing occurs
Modelica.Blocks.Math.MinminMinimum of evaporator outlet and condenser inlet temperatures

Revisions

  • May 27, 2025 by Fabian Wuellhorst:
    Make safety checks parallel (see issue IBPSA #2015)
  • May 26, 2025 by Fabian Wuellhorst and Michael Wetter:
    Increase error counter only when device should turn on (see issue IBPSA #2011)
  • October 2, 2022 by Fabian Wuellhorst:
    Adapted based on Buildings implementation (see issue #1576)
  • November 26, 2018 by Fabian Wuellhorst:
    First implementation (see issue AixLib #577)