modelDefrostControl
Control block to ensure no frost limits heat flow at the evaporator
Information
Basic model for a defrost control. The icing factor is calculated in the heat pump based on functions or other models.
If a given lower boundary is surpassed, the mode of the heat pump will be set to false(eq. Chilling) and the compressor speed is set to 1 to make the defrost process as fast as possible.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | minIceFac | Minimal value above which no defrost is necessary | |
| Real | deltaIceFac | 0.1 | Bandwitdth for hystereses. If the icing factor is based on the duration of defrost, this value is necessary to avoid state-events. |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.BooleanInput | hea | ||
| Modelica.Blocks.Interfaces.RealInput | ySet | Set value relative speed of compressor. Analog from 0 to 1 | |
| Utilities.Logical.SmoothSwitch | swiErr | If an error occurs, the value of the conZero block will be used(0) | |
| Modelica.Blocks.Sources.Constant | conOne | If Defrost is enabled, HP runs at full power | |
| Modelica.Blocks.Interfaces.RealOutput | yOut | Relative speed of compressor. From 0 to 1 | |
| Modelica.Blocks.Interfaces.BooleanOutput | heaOut | ||
| Fluid.HeatPumps.ModularReversible.BaseClasses.RefrigerantMachineControlBus | sigBus | ||
| Modelica.Blocks.Logical.Hysteresis | iceFacGreMinChi | Check if icing factor is greater than a boundary | |
| Modelica.Blocks.Logical.LogicalSwitch | logicalSwitch | If a chiller is used to defrost, mode will be false | |
| Modelica.Blocks.Sources.BooleanConstant | conTrueUseChi | Set mode to false to simulate the defrost cycle |