FB_BA_HX
Enthalpy calculation
Functional description
This function block is used to calculate the dew point temperature, the specific enthalpy and the absolute humidity. The temperature, the relative humidity and the barometric pressure are required for calculating these parameters.
The enthalpy is a measure for the energy of a thermodynamic system.
Inputs/outputs
VAR_INPUT
rT : REAL;
rHumRel : REAL;
rAP : REAL;
rT: temperature [°C]
rHumRel: relative humidity [%]
rAP: hydrostatic air pressure at 1013.25 hPa
VAR_OUTPUT
lrHumAbs : LREAL;
lrDewPnt : LREAL;
lrE : LREAL;
lrDHA : LREAL;
lrSpecV : LREAL;
lrTWet : LREAL;
lrHumAbs: absolute humidity g water per kg dry air [g/kg]
lrDewPnt: dew point temperature [°C]
lrE: enthalpy [kJ/kg]
lrDHA: density of moist air ρ [kg mixture/m³]
lrSpecV: specific volume [m³/kg]
lrTWet: wet bulb temperature [°C]
Requirements
Development environment | Target system | required library | required supplement |
|---|---|---|---|
TwinCAT 2.11 R3/x64 | PC/CX | TcBA library from V1.0.0 | TS8040 | TwinCAT Building Automation from V1.0.0 |