blockDefrostControl
Control block to ensure no frost limits heat flow at the evaporator
Extends from AixLib.Obsolete.BaseClasses.ObsoleteModel (Icon for classes that are obsolete and will be removed in later versions).
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.
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November 26, 2018 by Fabian Wüllhorst:
First implementation (see issue #577)
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | minIceFac | Minimal value above which no defrost is necessary | |
| Boolean | use_chiller | true | True if defrost operates by changing mode to cooling. False to use an electrical heater |
| Modelica.Units.SI.Power | calcPel_deFro | Calculate how much eletrical energy is used to melt ice | |
| 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. |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | Pel_deFro | Relative speed of compressor. From 0 to 1 | |
| Modelica.Blocks.Interfaces.BooleanInput | modeSet | Set value of HP mode | |
| Modelica.Blocks.Interfaces.RealInput | nSet | Set value relative speed of compressor. Analog from 0 to 1 | |
| Modelica.Blocks.Interfaces.RealOutput | nOut | Relative speed of compressor. From 0 to 1 | |
| Modelica.Blocks.Interfaces.BooleanOutput | modeOut | ||
| Interfaces.VapourCompressionMachineControlBus | sigBusHP |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Logical.Hysteresis | iceFacGreMinHea | Check if icing factor is greater than a boundary | |
| Modelica.Blocks.Sources.BooleanConstant | conTrueNotUseChi | If ice is melted with an additional heater, HP can continue running | |
| Modelica.Blocks.Sources.Constant | constPel_deFro | Calculate how much eletrical energy is used to melt ice | |
| 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 | |
| Utilities.Logical.SmoothSwitch | swiPel | If defrost is on, output will be positive | |
| Modelica.Blocks.Sources.Constant | conZero | If Defrost is enabled, HP runs at full power | |
| 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 | conFalseNotUseChi | Just to omit warnings | |
| Modelica.Blocks.Sources.BooleanConstant | conTrueUseChi | Set mode to false to simulate the defrost cycle |