modelWSEOperation

Validates cooling tower fan speed control sequence for WSE running only

Information

In the beginning period, the chilled water supply temperature is greater than the setpoint. The direct acting PID controller increases the output to the maximum output so that the fan speed setpoint is 1. The measured fan speed becomes 1.
In the following period, the chilled water supply temperature gradually reduces until it becomes lower than the setpoint, the PID controller decreases the output to the minimum so that the fan speed setpoint becomes the minimum. The measured speed becomes the minimum as well.
In the next period, after 300 seconds during which both the chilled water supply temperature is lower than the setpoint and the fan speed stays at the minimum value, the fan cycles off that the fan speed setpoint becomes zero. Thus, the measured speed becomes zero.
After the fan has cycled off for more than 180 seconds, and the chilled water supply temperature becomes greater than the setpoint plus 1 °F, the fan turns on, and the direct PID controller increases the output to the maximum output and so the fan speed setpoint becomes 1. The measured speed becomes 1.

Type	Name	Description
Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Towers.FanSpeed.EnabledWSE.Subsequences.WSEOperation	wseOpe	Tower fan speed control when there is only waterside economizer is running
Buildings.Controls.OBC.CDL.Reals.Sources.Sin	chiSup	Chilled water supply temperature
Buildings.Controls.OBC.CDL.Reals.Sources.Constant	chiSupSet	Chilled water supply water setpoint
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp	ram1	Ramp
Buildings.Controls.OBC.CDL.Reals.Add	add2	Add real inputs
Buildings.Controls.OBC.CDL.Discrete.UnitDelay	fanSpe	Current fan speed
Buildings.Controls.OBC.CDL.Logical.Sources.Constant	wseSta	WSE enabling status
CDL.Logical.Sources.Constant[2]	chiSta	Chillers enabling status