blockResetMinBypass
Sequence for minimum chilled water flow setpoint reset
Information
Block that generates minimum bypass flow reset status when there is a stage-change command. This development is based on ASHRAE Guideline 36-2021, section 5.20.4.16, item b.
When there is a stage-change command (uStaPro = true) and the upstream
device has finished its adjustment process (uUpsDevSta = true),
like in the stage-up process the operating chillers have reduced the demand,
check if the minimum chilled water flow rate VChiWat_flow has achieved
its new setpoint VMinChiWat_setpoint.
After new setpoint is achieved, wait for 1 minute (aftByPasSetTim) to
allow loop to be stabilized. It will then set yMinBypRes to true.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | byPasSetTim | Time constant for resetting minimum bypass flow | |
| Real | aftByPasSetTim | 60 | Time after setpoint achieved |
| Advanced | |||
| Real | relFloThr | 0.95 | Relative flow rate to check if the flow has achieved setpoint |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uUpsDevSta | Status of resetting status of device before reset minimum flow setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uStaPro | Indicate if there is stage change | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | VChiWat_flow | Measured chilled water flow rate | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | VMinChiWat_setpoint | Minimum chilled water flow setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uSetChaPro | True: it is in the setpoint change process | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput | yMinBypRes | True: minimum chilled water flow bypass valve has been reset successfully |
Revisions
-
September 17, 2019, by Jianjun Hu:
First implementation.