[Erc21] Energy recovery, rotary heat exchanger, temperature-controlled
Program block, name / node subtype: [Erc21] Energy recovery, rotary heat exchanger, temperature-controlled
Library hierarchy: Ventilation and air conditioning equipment
Family: Erc
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Configurator
Program blocks are stored in the library without I/Os. Use the auto-create and auto-connect functions to create I/Os and/or to connect them to the interface blocks, e.g., R_A, CMD_B. Alternatively, take the I/Os from the folder containing the predefined I/Os in the library and/or from the plant and connect them to the interface blocks.
Controls the supply air temperature (heating and cooling) by modulating an output signal to the control unit of the rotary heat exchanger and changing its rotation speed.
The temperature controller dynamically changes its control action for heating or cooling based on conditions from another program block.
This program block has the following optional functions:
Option: After purge, start with 100 % for a configured time
Provides an interface to the state of the "Start-up purge" function and logic to keep the energy recovery at 100 % for a configurable time, e.g., 4 minutes, after the "Start-up purge" function has finished.
Option: Command (1xBO)
Enables the operation of the control unit of the rotary heat exchanger.
Option: Differential pressure monitor (1xBI)
Reads the signal from a differential pressure monitor over the energy recovery. If the differential pressure increases due to ice forming on the surface of the energy recovery aggregate, it reduces the output of the temperature controller for anti-icing protection.
Option: Disable temperature control in case of dehumidification
Provides an interface (most likely to the cooling coil) and logic to disable the temperature control in case of dehumidification to not preheat the air when the cooling coil performs dehumidification.
If the energy recovery is set for cooling, it runs at 100 %.
Option: Efficiency
Calculates the efficiency of the energy recovery. The function block MON_ERC is used in the program.
This efficiency calculation needs the option "Exhaust temperature after energy recovery".
Option: Exhaust temperature after energy recovery (1xAI)
Reads the signal from the exhaust temperature sensor after energy recovery. Performs anti-icing protection with a PID controller that limits the output of the temperature controller.
Option: Fault (1xBI)
Reads the fault signal from the control unit of the rotary heat exchanger and generates an alarm.
Option: Generate disturbance signal switching off the plant at very low outside temperature
If there is a problem with the energy recovery at very low outside temperature, the heating power may be insufficient, and the resulting supply air temperature may drop to a level that is above the frost protection, but still very uncomfortable. This is why a disturbance signal that shuts down the air handling unit plant is generated.
Option: Two-position control for cooling
2-position control mode for the temperature controller in case of cooling.
Name | Description | Type | Alarm / Notification class | Trend / Type |
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Spd | Speed | AO: Analog output | No | Yes, 2 |
TCtr | Temperature controller | Ctr: Controller | N/A | N/A |
Name | Description | Type | Alarm / Notification class | Trend / Type |
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Cmd | Command Off, On | BO: Binary output | No | No |
Flt | Fault | BI: Binary input | Yes, 4 | No |
TEhAfErc | Exhaust air temperature after energy recovery | AI: Analog input | No | Yes, 2 |
Further elements that belong to this element: IcPrtCtr | Anti-icing protection controller | Ctr: Controller | ||||
Efcy | Efficiency | ACalcVal: Analog calculated value | No | No |
DiffPMon | Differential pressure monitor | BI: Binary input | Yes, 8 | No |
Description |
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2-position control for cooling |
After purge start with 100 % for a configured time. |
Generate disturbance signal that switches off the plant at very low outside temperature. |
Disable temperature control in case of dehumidification |