建筑环境与能源应用工程专业英语14课件

UnitFourteen

ControlandBuildingAutomationSystemWhatisanintelligentbuilding?SchematicDiagramofanIntelligentBuildingSystemUptonow,therehasnotbeenauniversallyaccepteddefinitionforanIntelligentBuilding.MostexistingdefinitionsofIBaroundtheworldcentreontheneedforabuildingtobesuitablefortheoccupantstoworkandliveinsafely,comfortably,effectivelyandefficiently.“Intelligentbuildingissomethingthatmakestupid

peoplefeelnotasstupidastheyare”.SmartHomeisanintegrationofvarioussystemsathomesuchassecurity,homeautomation,lightingcontrol,CCTVandentertainmentsystemwhichiscoordinatedbyasmarthomecontrollerandcontrolledbyusersusingvariouscentralizedcommandinterfacessuchasatouchscreens,keypads,universalremotecontrollers,internetbrowser,telephone,andevenyourLCDTVscreen.SmartHomeSystemsCCTV:ClosedCircuitTelevisionCCTV:ChinaCentralTelevisionOn/offControlThecontroldevicecanbepositionedonlytoamaximumorminimumstate(e.g.,onoroff).BecauseOn/offcontrolissimpleandinexpensive,itisusedextensivelyforbothindustrialandcommercialcontrol.AtypicalhomethermostatthatstartsandstopsafurnaceisanexampleofOn/offaction.FloatingControlDead(neutral)zone盲区停滞区setpointcontrolledvariableproportionalbandoutputoffsetProportionalcontrolrequiresacontinuouslyvariableoutputofthecontrolleddevice.Thecontrolsystemproducesanoutputwhichisproportionaltotheerrorsignal,i.e.thedifferencebetweenthevalueofthecontrolledvariableandthesetpoint.Proportionalcontrol

signalresponseIntegralcontrolDerivativecontrol

signalresponseProportionalplusIntegral(PI)ControlProportional-Integral-Derivative(PID)ControlProportionalAction.ExampleofFeedbackControlRoomAirTemperatureControlOpenloopcontrolAnopenloopcontroldoesnothaveadirectlinkbetweenthevalueofthecontrolledvariableandthecontroller.Anopenloopcontrolanticipatestheeffectofanexternalvariableonthesystemandadjuststhesetpointtoavoidexcessiveoffset.Anexampleisanoutdoorthermostatarrangedtocontrolheattoabuildinginproportiontothecalculatedloadcausedbychangesinoutdoortemperature.Inessence,thedesignerpresumesafixedrelationshipbetweenoutsideairtemperatureandtheheatrequirementofthebuildingandspecifiescontrolactionbasedontheoutdoorairtemperature.Theactualspacetemperaturehasnoeffectonthiscontroller.Becausethereisnofeedbackonthecontrolledvariable(spacetemperature),thecontrolisanopenloop.Single-SeatedValvesDouble-SeatedValves

单座阀双座阀SensorsTemperatureSensorsHumiditySensorsPressureTransmittersandTransducersFlowRateSensorsIndoorAirQualitySensorsLightingLevelSensorsControllersPneumaticReceiver-ControllersElectric/ElectronicControllersDigitalControllersThermostats1.ControlModes

On/OffcontrolProportionalcontrolFloatingcontrolIntegralcontrolDerivativecontrolVariationandCombinationofbasicmodes2.Openandclosedloopcontrol

openloopcontrolclosedloopcontrol3.BuildingAutomationSystems3.1General3.2BasicConsiderations3.3ComputerBasedSystems

Frequentlyusedwordsandphrases:controlmode控制模式On/OffControl开/关控制Proportionalcontrol比例控制Floatingcontrol浮动控制Integralcontrol积分控制Derivativecontrol微分控制ProportionalplusIntegral(P+I)Control比例加积分控制ProportionalplusDerivative(P＋D)Control比例加微分控制ProportionalplusIntegralplusDerivative(P+I+D)Control

比例加积分加微分控制finalcontrolelement(FCE)终端控制元件Openloopcontrol开环控制Closedloopcontrol闭环控制signal信号heaterbattery加热器组aircurtain空气幕sensor传感器electro-mechanicalsystem电动机械系统pneumaticsystem气动系统pressureswitch压力开关humidistat湿度控制器timeswitch定时开关buildingautomationsystem(BAS)

建筑自动化系统energymanagementsystem(EMS)能源管理系统directdigitalcontrol(DDC)直接数字控制4.

Proportionalcontrolactionreferstoacontrolelementhavinganoutputsignalproportionaltoitsinputsignal.5.Ifthescalerangeofatemperaturecontrollerisfrom0oCto100oCandtheproportionalbandsettingissuchthatthecontrolledvariablemustchangefromthrough40oCto80oCtomakethevalvemovefromfullopentoshut,thentheproportionalbandis(80-40)/100=40%.6.Thismodeofoperationdependsontheuseofadead(neutral)zoneinthecontrolledvariable.Iportionalcontrol:

比例控制dead(neutral)zone:停滞区中性区correctingelement:修正元件pulsed:搏动的跳动的proportionalband:比例带fullopen:完全打开8.Thisactionisusedtoeliminateovershootduringafastloadchange.Derivativecontrolismainlyappliedinspecialprocesssystems.9.Whilefloatingandproportionalcontrolactionsmaybeusedontheirown,derivativecontrolmustalwaysbeusedincombinationwithproportionalorfloatingaction.overshoot:超出超过过分loadchange:负荷变化derivativecontrol:微分控制Howtotranslate????10.Controlsystemsareappliedtocontrolloops,eachloopnormallycomprisingonesectionofanoverallplant,e.g.reheater,smokealarm.11.Whentheconditionofthecontrolledvariablechangesinclosedloopcontrolthesensordetectsthechangeandinitiatescorrectingactiontofinalcontrolelement.12.Theeffectofthisisreflectedinthecontrolledvariableandreassessedbysensorwhichcontinuouslyprovidesfeedbacktothecontroller.controlloops:控制环路comprising:构成reheater:再热器smokealarm:烟雾报警器closedloopcontrol:闭环控制detect:探测initiate:触发开始reassess:再评估feedback:反馈16.Itisalwaysadvisabletoquestionthelevelandvalidityofthesoftwareofferedtoperformthetasksrequiredinthecontextofbuildingservicesautomation.18.Oneotherareawhichrequiresemphasisisthepossiblesusceptibilityofallprocessorbasedsystemstoelectricalinterference,howevercaused.advisable:可取的明智的question:提出问题质询validity:有效性context:上下文领域emphasis:强调susceptibility:易感性interference:干扰干涉19.Theprinciplesapp