blockController
Information
Controller for terminal box of VAV system with reheat according to ASHRAE
Guideline 36, Part 5.E. It outputs damper position yDam,
hot water valve position yVal, AHU cooling supply temperature
setpoint reset request yZonTemResReq, and static pressure setpoint
reset request yZonPreResReq.
The sequence consists of four subsequences.
a. Heating and cooling control loop
The subsequence is implementd according to Part 5.B.5. The measured zone
temperature TZon, zone setpoints temperatures TZonHeaSet and
TZonCooSet are inputs to the block conHeaLoo and
conCooLoo to generate the control loop signal.
b. Active airflow setpoint calculation
This sequence sets the active maximum and minimum airflow according to
Part 5.E.3-5. Depending on operation modes uOpeMod, it sets the
airflow rate limits for cooling and heating supply. See
Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.SetPoints.ActiveAirFlow.
c. Damper and valve control
This sequence sets the damper and valve position for VAV reheat terminal unit.
The implementation is according to Part 5.E.6. According to heating and cooling
control loop signal, it calculates the discharge air temperature setpoint
TDisHeaSet. Along with the defined maximum and minimum airflow, measured
zone temperature, the sequence outputs yDam, yVal,
TDisHeaSet and discharge airflow rate setpoint VDisSet_flow.
See
Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.DamperValves.
d. System reset requests generation
According to Part 5.E.9, this sequence outputs the system reset requests, i.e.
cooling supply air temperature reset requests yZonTemResReq,
static pressure reset requests yZonPreResReq, hot water reset
requests yHeaValResReq, and the boiler plant reset requests
yHeaPlaReq. See
Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.SystemRequests.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | samplePeriod | Sample period of component, set to the same value as the trim and respond that process yPreSetReq | |
| Real | V_flow_nominal | Volume flow rate of this thermal zone | |
| Real | AFlo | Area of the zone | |
| Cooling loop signal | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerTypeCoo | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | kCoo | 0.1 | Gain for cooling control loop signal |
| Real | TiCoo | 900 | Time constant of integrator block for cooling control loop signal |
| Real | TdCoo | 0.1 | Time constant of derivative block for cooling control loop signal |
| Heating loop signal | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerTypeHea | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | kHea | 0.1 | Gain for heating control loop signal |
| Real | TiHea | 900 | Time constant of integrator block for heating control loop signal |
| Real | TdHea | 0.1 | Time constant of derivative block for heating control loop signal |
| Valve | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerTypeVal | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | kVal | 0.5 | Gain of controller for valve control |
| Real | TiVal | 300 | Time constant of integrator block for valve control |
| Real | TdVal | 0.1 | Time constant of derivative block for valve control |
| Damper | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerTypeDam | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | kDam | 0.5 | Gain of controller for damper control |
| Real | TiDam | 300 | Time constant of integrator block for damper control |
| Real | TdDam | 0.1 | Time constant of derivative block for damper control |
| Airflow setpoint › Zone sensors | |||
| Boolean | have_occSen | false | Set to true if the zone has occupancy sensor |
| Boolean | have_winSen | false | Set to true if the zone has window status sensor |
| Boolean | have_CO2Sen | false | Set to true if the zone has CO2 sensor |
| Airflow setpoint › Nominal conditions | |||
| Real | VDisCooSetMax_flow | V_flow_nominal | Zone maximum cooling airflow setpoint |
| Real | VDisSetMin_flow | 0.15*V_flow_nominal | Zone minimum airflow setpoint |
| Real | VDisHeaSetMax_flow | 0.3*V_flow_nominal | Zone maximum heating airflow setpoint |
| Real | VDisConMin_flow | 0.1*V_flow_nominal | VAV box controllable minimum |
| Real | VOutPerAre_flow | 3e-4 | Outdoor air rate per unit area |
| Real | VOutPerPer_flow | 2.5e-3 | Outdoor air rate per person |
| Real | CO2Set | 894 | CO2 setpoint in ppm |
| Damper and valve › Parameters | |||
| Real | dTDisZonSetMax | 11 | Zone maximum discharge air temperature above heating setpoint |
| Real | TDisMin | 283.15 | Lowest discharge air temperature |
| System requests › Parameters | |||
| Boolean | have_heaWatCoi | true | Flag, true if there is a hot water coil |
| Boolean | have_heaPla | false | Flag, true if there is a boiler plant |
| Real | errTZonCoo_1 | 2.8 | Limit value of difference between zone temperature and cooling setpoint for generating 3 cooling SAT reset requests |
| Real | errTZonCoo_2 | 1.7 | Limit value of difference between zone temperature and cooling setpoint for generating 2 cooling SAT reset requests |
| Real | errTDis_1 | 17 | Limit value of difference between discharge air temperature and its setpoint for generating 3 hot water reset requests |
| Real | errTDis_2 | 8.3 | Limit value of difference between discharge air temperature and its setpoint for generating 2 hot water reset requests |
| System requests › Duration times | |||
| Real | durTimTem | 120 | Duration time of zone temperature exceeds setpoint |
| Real | durTimFlo | 60 | Duration time of airflow rate less than setpoint |
| Real | durTimDisAir | 300 | Duration time of discharge air temperature is less than setpoint |
Connectors
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.SetPoints.ActiveAirFlow | actAirSet | Active airflow rate setpoint | |
| Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.DamperValves | damVal | Damper and valve controller | |
| Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.SystemRequests | sysReq | Number of system requests | |
| Buildings.Controls.OBC.CDL.Reals.PIDWithReset | conHeaLoo | Heating loop signal | |
| Buildings.Controls.OBC.CDL.Reals.PIDWithReset | conCooLoo | Cooling loop signal |
Revisions
-
November 5, 2021 by Karthik Devaprasad:
Added missing outputsyHeaValResReqandyHeaPlaReqfor requests to heating plant. -
October 9, 2020, by Jianjun Hu:
Changed the default heating maximum airflow setpoint to 30% of the zone nominal airflow.
This is for issue 2172. -
April 18, 2020, by Jianjun Hu:
Added actual VAV damper position as the input for generating system request.
This is for issue 1873. -
March 06, 2020, by Jianjun Hu:
Added default component name.
This is for issue 1809. -
November 15, 2017, by Michael Wetter:
Added integrator reset. -
October 27, 2017, by Jianjun Hu:
Moved it from example package. -
September 25, 2017, by Michael Wetter:
First implementation.