blockController
Tower fan speed control when waterside economizer is enabled
Information
Block that outputs cooling tower fan speed ySpeSet when waterside
economizer is enabled. This is implemented according to ASHRAE Guideline 36-2021,
section 5.20.12.2, item c. It includes two subsequences:
- When the waterside economizer is enabled and chillers are running, see Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Towers.FanSpeed.EnabledWSE.Subsequences.IntegratedOperation for a description.
- When the waterside economizer is running alone, see Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Towers.FanSpeed.EnabledWSE.Subsequences.WSEOperation for a description.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | nChi | 2 | Total number of chillers |
| Real | fanSpeMin | 0.1 | Minimum tower fan speed |
| Integrated operation | |||
| Real[nChi] | chiMinCap | {1e4, 1e4} | Minimum cyclining load below which chiller will begin cycling |
| Integrated operation › Controller | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | intOpeCon | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | kIntOpe | 1 | Gain of controller |
| Real | TiIntOpe | 0.5 | Time constant of integrator block |
| Real | TdIntOpe | 0.1 | Time constant of derivative block |
| WSE-only | |||
| Real | fanSpeChe | 0.005 | Lower threshold value to check fan speed |
| WSE-only › Controller | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | chiWatCon | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | kWSE | 1 | Gain of controller |
| Real | TiWSE | 0.5 | Time constant of integrator block |
| Real | TdWSE | 0.1 | Time constant of derivative block |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | uChiLoa | Current cooling load | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nChi] | uChi | Chiller enabling status: true=ON | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uWse | Waterside economizer enabling status: true=ON | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TChiWatSup | Chilled water supply temperature | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TChiWatSupSet | Chilled water supply temperature setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | ySpeSet | Tower fan speed setpoint when WSE is enabled and there is any chiller running |
Revisions
-
August 9, 2019, by Jianjun Hu:
First implementation.