blockController
Sequences to control chilled water pumps in primary-only plant system
Information
Primary chilled water pump control sequence per ASHRAE Guideline 36-2021, section 5.20.6.1 to section 5.20.6.11, except section 3 and 4. It includes:
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Subsequences to enable the lead pump,
- for plants with dedicated pumps Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.EnableLead_dedicated
- for plants with headered pumps Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.EnableLead_headered
- Subsequence to stage lag pumps of primary-only plants with headed variable-speed chilled water pump using differential pressure pump speed control Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.EnableLag_primary_dP
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Subsequences to control pump speed for primary-only plants,
- where the remote DP sensor(s) is not hardwired to the plant controller, but a local DP sensor is hardwired Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.Speed_primary_localDp
- where the remote DP sensor(s) is hardwired to the plant controller Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.Speed_primary_remoteDp
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | have_heaPum | true | Flag of headered chilled water pumps design: true=headered, false=dedicated |
| Boolean | have_senDpChiWatRemWir | true | True=remote DP sensor hardwired to controller |
| Boolean | have_WSE | false | True: the plant has waterside economizer |
| Integer | nPum | 2 | Total number of chilled water pumps |
| Integer | nChi | 2 | Total number of chillers |
| Integer | nSen | 2 | Total number of remote differential pressure sensors |
| Real | minPumSpe | 0.1 | Minimum pump speed |
| Real | maxPumSpe | 1 | Maximum pump speed |
| Nominal conditions | |||
| Integer | nPum_nominal | nPum | Total number of pumps that operate at design conditions |
| Real | VChiWat_flow_nominal | 0.5 | Total plant design chilled water flow rate |
| Speed controller | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerType | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | k | 1 | Gain of controller |
| Real | Ti | 0.5 | Time constant of integrator block |
| Real | Td | 0.1 | Time constant of derivative block |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.IntegerInput[nPum] | uPumLeaLag | Index of chilled water pumps in lead-lag order: lead pump, first lag pump, second lag pump, etc. | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uPla | True: plant is enabled | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nPum] | uChiWatPum | Chilled water pumps proven on status | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiEna | Lead chiller enabling status | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiSta | Lead chiller proven on status | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uLeaChiWatReq | Status indicating if lead chiller is requesting chilled water | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | uWse | True: the plant has waterside economizer | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput[nChi] | u1ChiWatIsoVal | Chilled water isolation valve commanded position | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | VChiWat_flow | Chilled water flow | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | dpChiWat_local | Chilled water differential static pressure from local sensor | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | dpChiWatSet_local | Chilled water differential static pressure setpoint for local sensor | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput[nSen] | dpChiWat_remote | Chilled water differential static pressure from remote sensor | |
| Buildings.Controls.OBC.CDL.Interfaces.RealInput[nSen] | dpChiWatSet_remote | Chilled water differential static pressure setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput | yLea | Lead pump status setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput[nPum] | yChiWatPum | Chilled water pump status setpoint | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yPumSpe | Enabled chilled water pump speed |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.EnableLead_dedicated | enaDedLeaPum | Enable lead pump of dedicated pumps | |
| Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.EnableLead_headered | enaHeaLeaPum | Enable lead pump of headered pumps | |
| Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.EnableLag_primary_dP | enaLagChiPum | Enable lag pump for primary-only plants using differential pressure pump speed control | |
| Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.Speed_primary_localDp | pumSpeLocDp | Chilled water pump speed control with local DP sensor | |
| Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Pumps.ChilledWater.Subsequences.Speed_primary_remoteDp | pumSpeRemDp | Chilled water pump speed control with remote DP sensor |
Revisions
-
February 13, 2019, by Jianjun Hu:
First implementation.