modelWithWSE

Information

This example validates Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Towers.Controller. It demonstrates the cooling tower control of a less coupled chiller plant that has two chillers with waterside economizer.

• At beginning, the water level is lower than the minimum thus the tower starts to adding water (yMakUp). When the water level becomes greater than the maximum, it stops adding water at 1500 seconds.
• The plant is enabled to waterside economizer mode at 540 seconds. The lead tower cell becomes enabled when there is any condenser water pump enabled.
• After 300 seconds (chaTowCelIsoTim) at 840 seconds, it turns on the leading cell.
• The tower fan speed is controlled under the waterside economizer only mode. The direct-acting PID controls the chilled water supply temperature at setpoint.
• At 1440 seconds, the chiller 1 becomes enabled. Thus, the tower fan speed is then controlled under the integrated operation mode. However, before switching to the integrated operation mode, the fan hold its speed at the maximum. According to the vector towCelOnSet, which specifies number of cells at each plant stage (staVec), two tower cell should be enabled. Thus, after chiller 1 being enabled at 1440 seconds, when the 300 seconds is passed (chaTowCelIsoTim), the cell 2 become enabled at 1740 seconds.
• Both cells run at the maximum speed till 2040 seconds, the fan speed is then controlled under integrated mode.

Components

Revisions

• September 16, 2019, by Jianjun Hu:
  First implementation.