blockSupplySignals

Multizone VAV AHU coil valve positions

Information

Block that outputs the supply temperature control loop signal, and the coil valve postions for VAV system with multiple zones, implemented according to the ASHRAE Guideline G36, PART 5.N.2 (Supply air temperature control).

The supply air temperature control loop signal uTSup is computed using a PI controller that tracks the supply air temperature setpoint TSupSet. If the fan is off, then uTSup = 0.

Heating valve control signal (or modulating electric heating coil if applicable) yHea and cooling valve control signal yCoo are sequenced based on the supply air temperature control loop signal uTSup. From uTSup = uHeaMax to uTSup = -1, yHea increases linearly from 0 to 1. Similarly, uTSup = uCooMin to uTSup = +1, yCoo increases linearly from 0 to 1.

The output uTSup can be used in a controller for the economizer.

Parameters

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Types.SimpleControllercontrollerTypeBuildings.Controls.OBC.CDL.Types.SimpleController.PIType of controller for supply air temperature signal
RealkTSup0.05Gain of controller for supply air temperature signal
RealTiTSup600Time constant of integrator block for supply temperature control signal
RealTdTSup0.1Time constant of derivative block for supply temperature control signal
RealuHeaMax-0.25Upper limit of controller signal when heating coil is off. Require -1 < uHeaMax < uCooMin < 1.
RealuCooMin0.25Lower limit of controller signal when cooling coil is off. Require -1 < uHeaMax < uCooMin < 1.

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.RealInputTSupMeasured supply air temperature
Buildings.Controls.OBC.CDL.Interfaces.RealInputTSupSetSetpoint for supply air temperature
Buildings.Controls.OBC.CDL.Interfaces.BooleanInputuSupFanSupply fan status
Buildings.Controls.OBC.CDL.Interfaces.RealOutputyHeaControl signal for heating
Buildings.Controls.OBC.CDL.Interfaces.RealOutputyCooControl signal for cooling
Buildings.Controls.OBC.CDL.Interfaces.RealOutputuTSupSupply temperature control signal

Revisions

  • November 1, 2017, by Jianjun Hu:
    First implementation.