modelAir_Top
Temperature of air in top compartment computed by static equation because of
its small heat capacity
Information
This is a simplified model of the Air model. The top air zone has a very low capacity and is only modeled when the screen is drawn (i.e. mostly at night, to mitigate losses in the lack of short-wave radiation). For this reason, in this model the heat input from short-wave radiation is neglected.
The model has the same parameters than the Air model, considering that the height of the top air zone is equal to the mean greenhouse height minus the height of the thermal screen.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.SpecificHeatCapacity | c_p | 1e3 | |
| Modelica.Units.SI.Length | h_Top | Height of the top air compartment (mean greenhouse height minus thermal screen height) | |
| Modelica.Units.SI.Area | A | Greenhouse floor surface | |
| Initialization | |||
| Modelica.Units.SI.Temperature | T_start | 298 | |
| Initialization › Initialization options | |||
| Boolean | steadystate | false | if true, sets the derivative of T to zero during Initialization |
| Boolean | steadystateVP | true | if true, sets the derivative of vapour pressure (VP) to zero during Initialization |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort | Heat port for sensible heat input | |
| Interfaces.Vapour.WaterMassPort_a | massPort |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.HeatFlowRate | Q_flow | Heat flow rate from port_a -> port_b | |
| Modelica.Units.SI.Temperature | T | ||
| Modelica.Units.SI.Density | rho | ||
| Real | RH | Relative humidity of the air | |
| Modelica.Units.SI.Volume | V | ||
| Modelica.Units.SI.Pressure | P_atm | 101325 | Atmospheric pressure |
| Real | R_a | 287 | Gas constant for dry air R_a = R_d (J/(kg.K)) |
| Real | R_s | 461.5 | |
| Modelica.Units.SI.MassFraction | w_air | Air humidity ratio (kg water / kg dry air) | |
| BasicComponents.AirVP | air |