建筑环境与能源应用工程专业英语15

UnitFifteenCommissioningofVariableAirVolumeSystemsWhatisCommissioning(Cx)?•Definition:“Aquality-focusedprocessforenhancingthedeliveryofaproject.Theprocessfocusesonverifyinganddocumentingthatthefacilityandallofitssystemsandassembliesareplanned,designed,installed,tested,operated,andmaintainedtomeettheOwner’sProjectRequirements.”ASHRAEGuideline0-2005,TheCommissioningProcess–Commissioningisoftenperformedbyanindependentthird-partyengineeringcompany.–Operatesasanowner’srepresentativetoinsuretheinstalledsystemsmeettheownersrequirementsandtheplansandspecifications–Usuallyhiredbytheowner,sometimesbythearchitect,orgeneralcontractor.CommissioningPersonAllparticipantsintheconstructionprojecthaveacommissioningresponsibility.Participantsincludethecommissioningauthority,owner,designprofessionals,constructionmanager,generalcontractor,subcontractors,operationandmaintenancemanager,suppliers,andequipmentmanufacturers.BenefitsofCommissioning•Reducedchangeorders•Lesswarrantyandcallbacksforcontractor•Smootherturnovertomaintenance•Improvedequipmentreliability•ReducedIEQproblems–Reducedoccupantcomplaints–Improvedproductivity•Correctsystemoperationandinstallation•FacilitymeetsOwner’sexpectationandoperationalneeds•ReducedutilityconsumptionandoperationalcostsCommissioningObjectives•Ensurethefacilitymeetstheowner’sperformancerequirements•Provideasafeandhealthyenvironment•Provideoptimumenergyperformance•Provideafacilitythatcanbeefficientlyoperatedandmaintained•Providecompleteorientationandtrainingtofacilitystaffandoccupants•ProvideimproveddocumentationofsystemcharacteristicsCommissioning-Whatdidweusetodoandwhydoweneedit?•CXofmechanicalandelectricalsystemswasdonebytheinstallingcontractors•Nostandardization,orclearapproach•MostoftherealCXoccurredduringthewarrantyperiodaswarrantycalls•Buildingsoperatedlessefficiently•Firstyearofoccupancywasfrustratingfortheowner•Contractorsspentmoremoneyduringthewarrantyperiods•Contractorscanberushedwithoutenoughtimetodouble-checktheirwork•DesignEngineersdonothaveenoughbudgettooverseetheconstructionindetail•Ownershavehadbadexperienceswithprolongedprojectcloseout,andseeCXasasolution•HoldcontractorsaccountableforthespecificationsCommissioningScope•MechanicalSystems–AllHVACequipment–Buildingautomationsystemandhardwiredcontrols•ElectricalSystems–Switchgear,majordisconnects,backupgeneratorsandUPS(UninterruptedPowerSupply)•FireSafetySystems•SecuritySystems•Kitchenequipment•Irrigationsystem•LaboratoryFumehoods,gascontrolCommissioningandConstructionPhasesPrepare,DesignIntent,CXPlan,andSpecificationsReviewSubmittals,PrepareChecklistsandTestingPlansVerifyComponents,WitnessStart-UpandComponentTestingPerformFunctionalTesting,ResolveDeficiencies,ReviewO&MPrepareCXReport,StaffTraining,DefineSeasonalTestingPlanningDesignConstructionOccupancyAcceptanceOtherTypesofCommissioning•Retro-commissioning–Performedtoexistingbuildingsthathavenotpreviouslybeencommissioned,aftertheyhavebeenoccupied–Usuallyinstigatedasaresultofhighenergybillsorpooroccupantcomfort•Recommissioning–Performed5to10yearsafterabuildingwaspreviouslycommissioned–SometimeusedasaformofdeferredmaintenanceVariableAirVolume(VAV)useofvaryingairflowtocontroltheconditionofair,incontrasttotheuseofconstantflow(often)withvaryingtemperature.VAVsystemcontrolstemperatureinaspacebyvaryingthequantityofsupplyairratherthanvaryingthesupplyairtemperature.AVAVterminalunitatthezonevariesthequantityofsupplyairtothespace.Thesupplyairtemperatureisheldrelativelyconstant:whilesupplyairtemperaturecanbemoderatelyresetdependingontheseason,itmustalwaysbelowenoughtomeetthecoolingloadinthemostdemandingzone,andtomaintainappropriatehumidity.WhyuseVAV?–Providesmultiplezonesofcomfort–LifecyclecostwillbelessthanotherHVACSystemstryingtoaccomplishsimilarcomfortlevels–Loaddiversity•Smallerequipment(lowerACunitfirstcostcomparedtoConstantVolume)•Lesssupplyair(lessenergyconsumption)–AbletoadapttochangesinbuildinguseWhyNot??–Higherfirstcostthancomparablesinglezone•Controls,equipment,commissioning–Increasedmaintenancecost•MorepiecestolookafterConstantvolume-variabletemperaturesystemhavebeendominatingtheHVACapplicationsinthepastforobviousreasons.Theimplementationofvariablevolumecontrolhasbeendonewithdampersorothermechanicalcontrolmethods.Theadvantagesofvariableairvolumesystemimplementedwithvariablespeedcontrolare:FastcontroltokeepthecomfortzonelimitsLowconsumptionofelectricalenergyLowerconsumptionofheatingandcoolingenergythaninconstantairvolumesystemsSimplertokeepnoiseleveldown1.Introduction2.Commissioningmethodstatement3.Systemcomponents4.Preliminarychecks5.Commissioningsequence6.Settingtowork7.Terminalunits8.Secondaryairdistribution9.Returnairspigots10.Systemdiversity11.Fandesignperformancecheck12.SystemperformancechecksFrequentlyusedwordsandphrases:Variableairvolume(VAV)system变风量系统commissioning试运行调试airvolumeflowrate空气体积流量terminalunit终端设备flexibleduct柔性风管Pitottube毕托管thermalanemometer热线风速仪supplyfan送风风机extractfan排风机over-pressurization压力过高spigot套管、栓、龙头1.Variableairvolume(VAV)systemsaredynamicairdistribu