modelOptions
A model that provides different options for ground temperature output
Information
This model provides a block to choose from different options to model ground temperature:- a constant value
- a sine curve (yearly)
- a table stored in a file
- a simple model (called Kusuda here) that was originally created for use with district heating grids or LTN in order to model thermal pipe losses
Assumption and limitations
The model does not model any influence on the ground temperature. The ground temperature is only dependent on the set parameters.
Typical use and important parameters
The model is used as a boundary condition for ROM model floors outside surfaces.
Differently then stated in the parameter description below for Kusuda, α needs to be declared in m2/day! (The Modelica SI unit diffusivity does not support m2/day as a display unit.)
A typical value for α is bewteen 0.03 and 0.05 m2/day.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| General | |||
| AixLib.BoundaryConditions.GroundTemperature.DataSourceGroTem | datSou | AixLib.BoundaryConditions.GroundTemperature.DataSourceGroTem.Constant | Choice by which option for ground temperature is to be provided |
| Modelica.Units.SI.Temperature | TMea | constant or mean ground temperature (for sine) or average air temperature over the year (for Kusuda) | |
| Real | offTime | 0 | Offset time from simulation time 0 until minimum ground temperature in s (for sine and Kusuda) |
| Modelica.Units.SI.TemperatureDifference | ampTGro | 0 | amplitude of ground temperature (for sine option) or of surface temperature [(maximum air temperature - minimum air temperature)/2] (for Kusuda) |
| String | filDatSou | "NoName" | path to a (.mos) file that has the temperature stored in a table called TGround |
| Special Kusuda parameters | |||
| Modelica.Units.SI.ThermalDiffusivity | theDifKusPerDay | 0.04 | Thermal diffusivity of the ground for Kusuda. Declare in m2/day! |
| Modelica.Units.SI.Distance | depTGroKus | 0 | Depth of ground temperature for Kusuda |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | TGroOut | Ground temperature |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.BoundaryConditions.GroundTemperature.GroundTemperatureKusuda | kusUnd | ||
| Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor | TSenKus | Sensor to show Kusuda ground temperature | |
| Modelica.Blocks.Sources.Sine | sin | Source for sine function for temperature | |
| Modelica.Blocks.Sources.Constant | TGroConSou | Constant ground temperature | |
| Modelica.Blocks.Sources.CombiTimeTable | tabTGro | Ground temperatures from table |
Revisions
- April 23, 2023, by Philip Groesdonk:
First implementation (see issue 1080).