modelLookUpTable2D
Extends from AixLib.Obsolete.Year2024.DataBase.Chiller.PerformanceData.BaseClasses.PartialPerformanceData (Model with a replaceable for different methods of data aggregation).
Information
This model uses the 2-dimensional table data given in the DIN EN 14511 (formerly EN255) to calculate QEva and P_el. To model an inverter controlled chiller, the relative compressor speed n is scaled linearly with the ouput of the tables. Furthermore, the design of a chiller is modeled via a scaling factor. As a result, the equations follow below:
QEva,n = n * scalingFactor * TableQEva.y
P_el = n * scalingFactor * TablePel.y
To simulate possible icing of the evaporator on air-source chillers, the icing factor is used to influence the output as well. As the factor resembles the reduction of heat transfer between refrigerant and source, the factor is implemented as follows:
QEva = iceFac * QEva,n
With iceFac as a relative value between 0 and 1:
iceFac = kA/kA_noIce
Finally, to follow the first law of thermodynamics:
QCon = P_el,n + QEva
Known Limitations
The model CombiTable2DExtra is able to disallow extrapolation by holding the last value. If one extrapolates the given perfomance data, warnings about occuring extrapolations are emitted. CAUTION: Checking for possible extrapolations will trigger state events which results in higher computing time.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Types.Smoothness | smoothness | Modelica.Blocks.Types.Smoothness.LinearSegments | Smoothness of table interpolation |
| AixLib.Obsolete.Year2024.DataBase.Chiller.ChillerBaseDataDefinition | dataTable | AixLib.Obsolete.Year2024.DataBase.Chiller.EN14511.Vitocal200AWO201() | Data Table of Chiller |
| Boolean | extrapolation | true | False to hold last value |
| Boolean | printAsserts | false | WARNING: This will lead to a lot of state-events if extrapolation occurs frequently! If extrapolation is enabled, the user will get warnings when extrapolation occurs. |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | Pel (from PartialPerformanceData) | Electrical Power consumed by HP | |
| Modelica.Blocks.Interfaces.RealOutput | QCon (from PartialPerformanceData) | Heat flow rate through Condenser | |
| AixLib.Obsolete.Year2024.Controls.Interfaces.VapourCompressionMachineControlBus | sigBus (from PartialPerformanceData) | Bus-connector used in a chiller | |
| Modelica.Blocks.Interfaces.RealOutput | QEva (from PartialPerformanceData) | Heat flow rate through Evaporator |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Utilities.Tables.CombiTable2DExtra | Qdot_EvaTable | ||
| Utilities.Tables.CombiTable2DExtra | P_eleTable | Electrical power table | |
| Modelica.Blocks.Math.UnitConversions.To_degC | t_Co_in | ||
| Modelica.Blocks.Math.UnitConversions.To_degC | t_Ev_ou | ||
| Modelica.Blocks.Math.Product | nTimesPel | ||
| Modelica.Blocks.Math.Product | nTimesQEva | ||
| Modelica.Blocks.Math.Product | proRedQEva | Based on the icing factor, the heat flow to the evaporator is reduced | |
| Modelica.Blocks.Math.Add | calcRedQCon | Based on redcued heat flow to the evaporator, the heat flow to the condenser is also reduced | |
| Modelica.Blocks.Math.Product | nTimesSF | Create the product of the scaling factor and relative compressor speed |
Revisions
-
May 22, 2019 by Julian Matthes:
First implementation (see issue #715)