modelCHWIsoVal

Information

This example validates Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Staging.Processes.Subsequences.CHWIsoVal.

It has three instances enaChiIsoVal, disChiIsoVal and enaChiIsoVal1 that shows the process of controlling chiller chilled water isolation valves during the chiller staging process.

For the instance enaChiIsoVal,

• Before 600 seconds, the plant is not in the staging up process. The isolation value 1 is fully open (y1ChiWatIsoVal[1]=true) and the valve 2 is closed (y1ChiWatIsoVal[2]=false).
• Between 600 seconds and 800 seconds, the plant is in the staging process. However, the process is not yet requiring the chilled water isolation values to change their status, as the uUpsDevSta=false.
• Since 800 seconds, the plant staging process requires the isolation valve to change their status (uUpsDevSta=true), and the chiller 2 is being enabled (y1ChiWatIsoVal[2]=false).
• Thus, the process starts opening the isolation valve 2. As specified by chaChiWatIsoTim=300 seconds, it takes 5 minutes to fully open isolation valve 2 at 1100 seconds, and yChaChiWatIsoVal becomes true.

For the instance disChiIsoVal,

• Before 600 seconds, the plant is not in the staging down process. Both the isolation value 1 and 2 are fully open (y1ChiWatIsoVal[1]=true, y1ChiWatIsoVal[2]=true).
• Between 600 seconds and 800 seconds, the plant is in the staging process. However, the process is not yet requiring the chilled water isolation values to change their status, as the uUpsDevSta=false.
• Since 800 seconds, the plant staging process requires the isolation valve to change their status (uUpsDevSta=true), and the chiller 2 is being disabled (y1ChiWatIsoVal[2]=false).
• Thus, the process starts closing the isolation valve 2. As specified by chaChiWatIsoTim=300 seconds, it takes 5 minutes to fully close isolation valve 2 at 1100 seconds, and yChaChiWatIsoVal becomes true.

For the instance enaChiIsoVal1,

• Before 600 seconds, the plant is not in the staging up process. The isolation value 1 is fully open (y1ChiWatIsoVal[1]=true) and the valve 2 is closed (y1ChiWatIsoVal[2]=false).
• Between 600 seconds and 800 seconds, the plant is in the staging process. However, the process is not yet requiring the chilled water isolation values to change their status, as the uUpsDevSta=false.
• Since 800 seconds, the plant staging process requires the isolation valve to change their status (uUpsDevSta=true), and the chiller 2 is being enabled (y1ChiWatIsoVal[2]=true). The valve 2 fully closed input becomes false (u1ChiWatIsoClo[2]=false).
• At 920 seconds, the valve 2 fully open input becomes true (u1ChiWatIsoOpe[2]=true) and the valve change process is completed (yChaChiWatIsoVal=true).

Components

Revisions

• September 24, 2019, by Jianjun Hu:
  First implementation.