blockSupplyAirTemperature
Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Information
This block implements the control logic for the supply air temperature, as described in the control sequence VAV 2A2-21232 of the Sequences of Operation for Common HVAC Systems (ASHRAE, 2006).
The heating coil valve, outdoor air damper, and cooling coil valve are modulated in sequence to maintain the supply air temperature set point. A deadband between heating and economizer cooling is also modeled.
Note that the economizer lockout when the outdoor air temperature is higher than the return air temperature is implemented in Buildings.Examples.VAVReheat.BaseClasses.Controls.Economizer.
References
ASHRAE. Sequences of Operation for Common HVAC Systems. ASHRAE, Atlanta, GA, 2006.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | have_heating | true | Set to true for heating and cooling functions (false for cooling only) |
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerType | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | k | 0.01 | Gain of controller |
| Modelica.Units.SI.Time | Ti | 120 | Time constant of integrator block |
| Modelica.Units.SI.Time | Td | 0.1 | Time constant of derivative block |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uEna | Signal enabling set point tracking | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TSup | Supply air temperature measurement | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | TSupSet | Supply air temperature set point | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yHea | Control signal for heating coil valve | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yOA | Control signal for outdoor air damper | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yCoo | Control signal for cooling coil valve |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Reals.PIDWithReset | con | Supply temperature controller | |
| Buildings.Controls.OBC.CDL.Reals.Line | mapHea | Mapping function for actuating the heating coil valve | |
| Buildings.Controls.OBC.CDL.Reals.Line | mapOA | Mapping function for actuating the outdoor air damper | |
| Buildings.Controls.OBC.CDL.Reals.Line | mapCoo | Mapping function for actuating the cooling coil valve | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | limInfHea | Inferior limit of the control signal for heating coil control | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | limSupHea | Superior limit of the control signal for heating coil control | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | limInfOA | Inferior limit of the control signal for outdoor air damper control | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | limSupOA | Superior limit of the control signal for outdoor air damper control | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | limSupCoo | Superior limit of the control signal for cooling coil control | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | zero | Zero | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | one | one | |
| Buildings.Controls.OBC.CDL.Reals.Switch | swiHea | Switch to close heating coil valve | |
| Buildings.Controls.OBC.CDL.Reals.Switch | swiCoo | Switch to close cooling coil valve | |
| Buildings.Controls.OBC.CDL.Reals.Switch | swiOA | Switch to close outdoor air damper | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Constant | limInfCoo | Inferior limit of the control signal for cooling coil control |
Revisions
-
October 27, 2020, by Antoine Gautier:
First implementation.