BAC_AC_ErcRot_02
Application
The template BAC_AC_ErcRot_02 is used for control and anti-icing of an energy recovery unit with rotary heat exchanger.
The template BAC_AC_ErcRot_02 is a call template.
Within the call template, the following subtemplates are called and linked together:
- ErcSuA_PID: control of the supply air temperature
- ErcExhA_PID: minimum limitation of exhaust air temperature
- ErcMot: control of WRG control unit
- ErcIcPrt: anti-icing of the heat exchanger by means of a differential pressure switch
The exhaust air minimum limiter ErcExhA_PID and the frost protection program ErcIcPrt limit the control value of the supply air temperature controller ErcSuA_PID of the energy recovery unit via the minimum value option, in order to prevent icing up of the heat exchanger.
The supply air controller is enabled in the subtemplate BAC_AC_ErcT_PID_01, depending on the plant operation mode. In operation modes such as summer night cooling, for example, the supply air controller is disabled.
Interface
Plant diagram 01
Plant diagram 02
Block diagram
VAR_INPUT
rSuAT : REAL;
rSpErc : REAL;
udiPltStp : UDINT;
udiOpMod : UDINT;
bDeHum : BOOL;
rExhAT : REAL;
rExtAT : REAL;
rSuAT: Measured value supply air temperature
rSpErc: Set value supply air temperature
udiPltStp: Plant start sequence steps. The plant steps are generated in the system start program BAC_AC_StartT_01.
udiOpMod: Plant operation mode. The plant operation mode is determined in the mode selection program BAC_AC_OpMod_01.
bDeHum: Status message dehumidification mode. If dehumidification is active, energy recovery is disabled in heating mode. If the heat recovery unit recovers ‘coolth’ from the outlet air, it is switched to 100% in dehumidification mode.
rExhAT: Measured value exhaust air temperature
rExtAT: Measured value outlet air temperature
VAR_OUTPUT
bActn : BOOL;
bActn: control direction of the supply air temperature control SuA_PID. The control direction of the energy recovery is required by various setpoint programs or cascade controllers for determining setpoint for the supply air temperature of the energy recovery unit, e.g. BAC_AC_SpSuAT_02, BAC_AC_CasCtrlT_02.
Program description
Instance | Type | Task |
|---|---|---|
SuA_PID | Subtemplate supply air temperature control. The temperature control is analog via PID sequence controller | |
ExhA_PID | Subtemplate exhaust air temperature control for anti-icing | |
IcPrt | Subtemplate for anti-icing of an energy recovery unit via differential pressure switch | |
Mot | Subtemplate for controlling a frequency converter, which then controls the motor of the rotary heat exchanger. | |
| MIN, MIN | MIN selection of the control signals for supply air temperature control SuA_PID,exhaust air temperature control ExhA_PID and the frost protection ramp function |
Version history
Version number | Comments |
|---|---|
1.0.1 | First release |