blockModeControl
Mode control and setpoint selection
Information
Mode control
If the following equation is true prior to enabling the HRC, set the control mode to heating. Otherwise, set the control mode to cooling.
QChiWatReq_flow > QHeaWatReq_flow * (1 - 1 / COPHea_nominal)
Write mode via the chiller’s BACnet interface prior to sending the chiller an enable command.
Setpoint
When the control mode is cooling, the active setpoint shall be the CHW supply temperature setpoint. When the control mode is heating, the active setpoint shall be the HW supply temperature setpoint.
Details
The condition "prior to enabling the HRC" is evaluated in the block Buildings.Templates.Plants.Controls.HeatRecoveryChillers.Enable.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Information provided by designer | |||
| Real | COPHea_nominal | Heating COP at design heating conditions | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | u1SetMod | Enable mode setting | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | QChiWatReq_flow | CHW load | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | QHeaWatReq_flow | HW load | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TChiWatSupSet | Active CHW supply temperature setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | THeaWatSupSet | Active HW supply temperature setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput | y1Coo | Mode command: true for cooling, false for heating | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | TSupSet | Active supply temperature setpoint |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter | QEvaHea_flow | Compute evaporator heat flow rate in heating mode | |
| Buildings.Controls.OBC.CDL.Reals.Less | les | True (cooling) if CHW load lower than evaporator heat flow rate in heating mode | |
| Buildings.Controls.OBC.CDL.Reals.Switch | selTSupSet | Select supply temperature setpoint | |
| Buildings.Controls.OBC.CDL.Logical.Switch | setMod | Set mode if mode setting enabled, otherwise reuse previous mode | |
| Buildings.Controls.OBC.CDL.Logical.Pre | preMod | Previous mode setting |
Revisions
-
May 31, 2024, by Antoine Gautier:
First implementation.