modelController

Information

This example validates Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Towers.Staging.Controller. It shows the process of staging tower cells when there is chiller stage setpoint change and the enabling-disabling waterside economizer.

• At beginning, the current chiller stage is 1 and it starts to staging up tower cell 1. During the beginning stage, according to the vector staVec current plant stage is 1 (the 3rd element of vector staVec). Thus according to the vector towCelOnSet, the total number of cell is 1. It takes 90 seconds to fully open the isolation valve 1 (chaTowCelIsoTim=90) and then the cell 1 becomes enabled (uTowSta[1]=true) at 90 seconds.
• At 300 seconds, the waterside economizer is enabled. Thus the current plant stage is 1.5 (the 4th element of vector staVec). Thus according to the vector towCelOnSet, the total number of cell is 2. It takes 90 seconds to fully open the isolation valve 2 and then the cell 2 becomes enabled (uTowSta[2]=true) at 390 seconds.
• At 840 seconds, the waterside economizer becomes disabled. Thus the current plant stage changes to 1 (the 3rd element of vector staVec). Thus according to the vector towCelOnSet, the total number of cell is 1. The cell 2 becomes disabled (uTowSta[2]=false) and the isolation valve 2 is commanded off.
• At 1500 seconds, the chiller stage setpoint changes to 2 and the current stage is still 1. Therefore the chiller plant begins staging up. However, the plant staging up process has not yet been into the step of staging up the tower (uTowStaCha=false). Thus there is no change to the tower cells and their valves.
• At 2700 seconds, it is still in the plant staging up process and it now requires staging up tower cells. The plant stage is 2 (the 5th element of vector staVec). Thus according to the vector towCelOnSet, the total number of cell is 2. It takes 90 seconds to fully open the isolation valve 2 (yIsoVal[2]=1) and then the cell 2 becomes enabled (uTowSta[2]=true) at 2790 seconds.

Components

Revisions

• September 12, 2019, by Jianjun Hu:
  First implementation.