[DhwCrgCrt23] Domestic hot water, charge circuit, direct domestic hot water treatment
Program block, name / node subtype: [DhwCrgCrt23] Domestic hot water, charge circuit, direct domestic hot water treatment
Library hierarchy: Heating equipment
Family: DhwCrgCrt
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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.
The charge circuit feeds a heat exchanger for direct hot water treatment.
The optional primary pump is switched. A PID controller controls the domestic hot water temperature (temperature controller (primary valve)) by comparing it to a setpoint and opening and closing the primary mixing valve.
The PID controller has a neutral zone of, e.g., 4 K, that can be changed dynamically by the program. If there is an optional flow detector, the value for the neutral zone of the PID controller is dynamically switched to 0 if flow is detected.
This program block has the following optional functions:
Option: Primary pump (1xBO, 4xBI)
Controls a pump (Pu21). The primary pump switches on when the charge circuit is switched on.
Option: Charge priority
Gives priority to the charge circuit when it is on and it cannot reach its setpoint by decreasing the power of parallel consumers.
A PID controller compares the reduced flow temperature setpoint, e.g., by -5 K, with the flow temperature. Its inverted output is shown on BACnet and read by other plants, e.g., heating circuits for pre-control or radiator heating.
Option: Consider legionella prevention state
Reads the state of the legionella prevention functionality (LglPrev21). If necessary, it dynamically changes the neutral zone of the PID controller for the domestic hot water temperature to 0 and increases the setpoint for the optional return temperature maximum limitation.
Option: Flow detector (1xBI)
If flow is detected, the neutral zone of the PID controller for the domestic hot water temperature is set to 0 and its minimum controller output to, e.g., 25 %, to increase the speed of its reaction.
Option: Primary flow temperature (1xAI)
Creates an analog input for the primary flow temperature and reads its signal.
Option: Primary return temperature (1xAI)
Creates an analog input for the primary return temperature and reads its signal.
Option: Return temperature controller for maximum limitation
A PID controller compares the primary return temperature to a maximum setpoint and limits the maximum controller output of the temperature controller for domestic hot water (temperature controller (primary valve)).
Name | Description | Type | Alarm / Notification class | Trend / Type | |
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HwDmd | Hot water demand | BCalcVal: Binary calculated value | No | No | |
PrSpTDhw | Present setpoint domestic hot water temperature | ACalcVal: Analog calculated value | No | No | |
Vlv(Prim) | Valve (Primary) | N/A | N/A | ||
TCtr(VlvPrim) | Temperature controller (Primary valve) | Ctr: Controller | No | No | |
Name | Description | Type | Alarm / Notification class | Trend / Type |
|---|---|---|---|---|
Pu(Prim) | Pump (Primary) | N/A | N/A | |
| Charge priority | |||
Further elements that belong to this element: LmCtrCrgPrio | Limitation controller for charging priority | Ctr: Controller LmCrgPrio | Limitation for charging priority | ACalcVal: Analog calculated value | ||||
TFlPrim | Primary flow temperature | AI: Analog input | No | Yes, 2 |
TRtPrim | Primary return temperature | AI: Analog input | No | Yes, 2 |
TRtCtrMax | Return temperature controller for maximum limitation | Ctr: Controller | No | No |
FlDet | Flow detector | BI: Binary input | Yes, 4 | No |
The extension for alarming for the predefined I/O for the optional element "Feedback" must be deactivated.
Description |
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Consider legionella prevention status. |