Lecture-15-Energyplus-Air-Primary-Loops-and-Contro

Lecture15:AirPrimaryLoopsandControlsMaterialpreparedbyGARDAnalytics,Inc.andUniversityofIllinoisatUrbana-ChampaignundercontracttotheNationalRenewableEnergyLaboratory.AllmaterialCopyright2002-2003U.S.D.O.E.-Allrightsreserved2PurposeofthisLectureGainanunderstandingofhowto:DefineprimaryairloopsinEnergyPlusControltheiroperationandavailabilityforconditioningthermalzones3KeywordsCoveredinthisLectureAirPrimaryLoopSystemAvailabilityManagerListSystemAvailabilityManager:ScheduledSystemAvailabilityManager:NightCycleControllerListController:Simple4DescribingaCentralForcedAirSystemCanbethoughtofasan“AirLoop”with2“sides”:Supplyside:airprimaryloopanditsassociatedobjectscentralfans,coils,etc.Demandside:controlledzoneequipconfigurationanditsassociatedobjectsairterminalunits,fancoils,etc.5DescribingaCentralForcedAirSystem(cont’d)Whenwesay“AirLoop”wewillnormallymeanthesupplysideoftheoverallairloop“ZoneEquipment”willmeanthedemandside:allthestuffspecifictoazoneIfnocentralairsystem,thentherewillbeonlyzoneequipment6DescribingaCentralForcedAirSystem(cont’d)NorthZoneEastZoneResistiveZoneSupplyFanReturnAirMixerZoneAirSplitterCoolingCoilCCVAVBox:ReHeatVAVBox:ReHeatMixedOutsideAirBoxReliefAirOutsideAirVAVBox:ReHeatSupplySide/AirPrimaryLoopDemandSide/ZoneEquipment7AirLoopSimulationSimulatescentralairdistribution,mixing,andconditioningEquipment:supply&returnfans,centralheatingandcoolingcoils,heatrecovery,mixedairboxControl:supplyairtemperature,outsideaireconomizer8HotBranchColdBranchAirLoopLayoutMainSupplyBranchSplitterZoneEquipmentGroupZoneSplitterZonesZoneSplitterZoneMixerZoneEquipmentGroupInletsZoneEquipGroupOutlet9AirLoopLayout(cont’d)SupplyFanMixedOutsideAirBoxReliefAirOutsideAirHeating/CoolingCoilSupplyFanReliefAirOutsideAirHeating/CoolingCoilAirLoopOutletNodeAirLoopInletNodeZoneEquipInletNodeZoneEquipOutletNode10AirLoopSyntaxMap11AirPrimaryLoopControllerListSystemAvailabilityManagerListBranchListConnectorListConnectiontoZoneEquipmentReturnAirAirLoopInletNodeZoneEquipGroupOutletNodeSupplyAirPathZoneEquipGroupInletNodesAirLoopOutletNodes12AirPrimaryLoop-ExampleAIRPRIMARYLOOP,UnitarySystem,!-PrimaryAirLoopName,!-Name:ControllerListAvailList,!-Name:SystemAvailabilityManagerListautosize,!-Primaryairdesignflowrate{m3/s}AirLoopBranches,!-AirLoopBranchListName,!-AirLoopConnectorListNameAirLoopInletNode,!-ReturnAirAirLoopInletNodeZONEEQUIPOUTLETNODE,!-ZoneEquipGroupOutletNodeZoneEquipmentInletNode,!-SupplyAirPathZoneEquipGroupInNodesAirLoopOutletNode;!-AirLoopOutletNodes13SystemControlHighLevelSimilartoanenergymanagementsystemSetPointManagersalgorithmsestablishfluidloopsetpointsAvailabilityManagersmakeglobalon/offdecisions14SystemControl(cont’d)ComponentControlControllerssensestateatonepointinsystemcontrolflowatanotherpointtomatchsetpointIntegratedcontrolcontrolintegratedwithincomponent15SystemControl(cont’d)Plant:componentsequencing&loadmanagementControlisidealPI/PIDcontrolisnotmodeled–wouldrequireshortertimesteps16SystemAvailabilityManagersScheduledSystemavailabilitydeterminedbyanon/offscheduleNightCycleUsedtocycleanairsystemonwhenoneormorezonesbecomestoohotortoocold17SystemAvailabilityManagerListListsalloftheapplicablesystemavailabilitymanagersforagivenairloopSYSTEMAVAILABILITYMANAGERLIST,Furnace-AvailList,!-NameSYSTEMAVAILABILITYMANAGER:SCHEDULED,!-TypeFurnace-Avail;!-SystemAvailabilityManagerName118SystemAvailabilityManager:ScheduledSimpleon/offscheduleSYSTEMAVAILABILITYMANAGER:SCHEDULED,Furnace-Avail,!-NameFanAndCoilAvailSched;!-Schedulename19SystemAvailabilityManager:NightCycleApplicabilityschedulenameFanschedulenameControltypeStayOff,CycleOnAny,CycleOnControlZone,CycleOnAny-ZoneFansOnlyThermostaton/offtoleranceCyclingruntimeControlzonename20SystemAvailabilityManager:NightCycle-ExampleSYSTEMAVAILABILITYMANAGER:NIGHTCYCLE,VAVSys1Avail,!-NameSysAvailApplicSch,!-ApplicabilityschedulenameFanAvailSched,!-FanschedulenameCycleOnAny,!-Controltype4.0,!-thermostaton/offtolerance{deltaC}7200.;!-Cyclingruntime{s}21SetPointManagersScheduledUsesascheduletodetermineoneormoresetpointsOutsideAirSetsthesupplyairtemperatureaccordingtotheoutsideairtemperatureusingaresetruleResetscheduledeterminedbythesupplyairsetpointtemperatureattheoutsidehighandlowtemperature22SetPointManagers(cont’d)SingleZoneReheatCalculatesasetpointtemperatureforthesupplyairthatwillsatisfytheloadofacontrolledzoneSingleZoneMinimumHumidityCalculatesthesupplyairhumidityrationeededtomaintainthezonerelativehumidityatoraboveagivensetpoint23SetPointManagers(cont’d)MixedAirUsedtoestablishatemperaturesetpointatthemixedairnodeSetpointmusttakeintoaccountanydownstreamsystemfanheatOutsideaircontrolleroperatestheoutsideairdampertomeetthissetpointforeconomizer24ControllersSimpleControlsvariableatonenodebasedontheconditionatanothernodeForacoolingcoil,thecontrolnodemightbetheoutletairtemperaturewhiletheactuatedvariableistheflowratethroughthecoilOutsideAirControlsmixedairboxtouseoutsideairforfreecoolingwheneverpossible25Cont