blockStageProcesses

Sequence for process of staging cells
Diagram of StageProcessesOpen the diagram
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Information

This block outputs new status vector of cells. When staging up cells, the cells should be enabled only when their supply isolation valves have been proven fully open. It is implemented according to ASHRAE Guideline 36-2021, section 5.20.12.1, item e and f which specifies the process of enabling and disabling tower fan cells.

  • When tower fan cells need to be enabled, which means that it is in the staging process (not all uChaCel are false) and the cells that should change status (uChaCel=true) are not enabled (uTowSta=true), the supply isolation valves position (uIsoVal) of the enabling cells should change to fully open with moving time (nominal valve timing) chaTowCelIsoTim. Once the enabling supply isolation valves have been fully open, then enable the additional fans.
  • When disabling tower cells, command the fan off and shut its supply isolation valve, and outlet isolation valves if provided.

Parameters

TypeNameDefaultDescription
IntegernTowCel4Total number of cooling tower cells
Booleanhave_inlIsoValtrueTrue: tower cells have the inlet isolation valve
Booleanhave_outIsoValfalseTrue: tower cells have the outlet isolation valve
Booleanhave_endSwifalseTrue: tower cells isolatiove valve have the end switch feedback
RealchaTowCelIsoTim90Nominal time needed for open or close isolation valve

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nTowCel]uChaCelVector of boolean flags to show if a cell should change its status: true = the cell should change status (be enabled or disabled)
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nTowCel]u1InlIsoValOpeTower cells inlet isolation valve open end switch. True: the isolation valve is fully open
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nTowCel]u1OutIsoValOpeTower cells outlet isolation valve open end switch. True: the isolation valve is fully open
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nTowCel]u1InlIsoValCloTower cells inlet isolation valve close end switch. True: the isolation valve is fully closed
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nTowCel]u1OutIsoValCloTower cells outlet isolation valve close end switch. True: the isolation valve is fully closed
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nTowCel]uTowStaVector of tower cells proven on status: true=enabled tower cell
Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput[nTowCel]y1IsoValCooling tower cells isolation valve command
Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput[nTowCel]yTowStaVector of tower cells command
Buildings.Controls.OBC.CDL.Interfaces.BooleanOutputyEndStaRising edge to indicate the staging process is done

Revisions

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