2023年——ASHRAE手册——第19章-数据处理和电信设施.docx

CHAPTER19DATAPROCESSINGANDTELECOMMUNICATIONFACILITIES第19章数据处理和电信设施DesignCriteriaHVACLoadconsiderationsHVACSystemsandComponentsAirDistributionAncillaryspacesOtherSystemsandconsiderations19.1设计标准19.2 空调负荷留意事项19.3 空调系统和组件19.4 气流组织19.5 关心空间19.6 其它系统和留意事项DATACOM(dataprocessingandtelecommunications)facilitiesarepredominantlyoccupiedbycomputers,networkingequipment,electronicequipment,andperipherals.ThemostdefiningHVACcharacteristicofdataandcommunicationsequipmentcentersisthepotentialforexceptionallyhighsensiblehea(loads(oftenordersofmagnitudegreaterthanatypicalofficebuilding).Inaddition,theequipmentinstalledinthesefacilitiestypically:数据通信数据处理和电信)设施主要由计算机、网络设备、电子设备和其它关心设备组成。数据和通讯设备中心空调最主要的特征是，需要应对极高的显热冷负荷(要比一般的商业办公楼负荷大得多)。另外，空调系统要具有以下这些功能：.Servesmission-criticalapplications(i.e.,continuousoperation).Hasspecialenvironmentalrequirements(temperature,humidity,andcleanliness).Hasthepotentialfordisruptiveoverheatingandequipmentfailurecausedbylossofcling 满足特定的应用(例如：持续运行)； 具备特别环境要求(温度、湿度和干净度)； 在突发性过热和由于设备损坏不能持续制冷的状况下，系统能连续冷却电子设备。Designofanydatacomfacilityshouldalsoaddressthefactthatmostdatacomequipmentwillbereplacedmultipletimeswithmorecurrenttechnologyduringthelifeofthefacility.AsdescribedinDatacomEquipmentPowerTrendsandCoolingapplications(ASHRAE2023a)ztypicaldatacomequipmentproductcyclesare1to5years,whereasfacilitiesandinfrastructureHAVClifecyclesof10to25years.Replacementequipmenthashistoricallyrequiredmoredemandingpowerandcoolingrequirements.任何数据通信设施的设计时，都要面对这样一个事实：在通信设施的使用寿命期间，随着技术的进展，大量现有的通信设备将会被将来的设备更换掉。在数据通信设备电源的进展过程和冷却应用中(ASHRAE2023a),典型的数据通讯设备产品寿命为1至5年，而空调设施和根底设施的寿命为10年至25年。设备对电功和制冷量要求的会更大。Understandingthesecriticalparametersisessentialtodatacomfacilitydesign.了解这些关键因素对数据通信设施的设计是必不行少的。ThepreparationofthischapterisassignedtoTE9.9zMission-criticalFacilities,TechnologySpaces,andElectronicEquipment.由ASHRAE中负责“重要设施、工艺房间与电子设备”的技术委员会TC9.9编著。DesignCriteria19.1设计标准Typesofdatacom(ASHRAE2023a)equipmentthatrequireairconditioningtomaintainproperenvironmentalconditionsinclude数据通信中心(ASHRAE2023a)的空调系统的工作环境中，包含的数据通信设备类别有： Computerservers(2Uandgreater) Computerservers(lUzblade,andcustom) Communication(High-density) Communication(Extreme-density) tapestorage Storageservers Workstations(standalone) Otherrack-andcabinet-mountedequipment 效劳器(2台或更多) 效劳器(1台，black,andcustom) 通讯(高密度) 通讯(超高密度) 磁带存储器 存储效劳器 工作站(独立) 其它机架和机柜安装设备Personnelalsooccupydatacomfacilities,buttheiroccupancyistypicallytransientandenvironmentalconditions(e.g.,temperature,noise)aremoretypicallydictatedbyequipmentneeds.However,humanoccupancyinsmallerdatacomfacilitiesmayinfluencetheventilationairquantity.Adatacenterisabuildingorportionofabuildingwhoseprimaryfunctionistohouseacomputerroomanditssupportareas;datacenterstypicallycontainhigh-endserversandstorageproductswithmission-criticalfunctions.Personnelalsooccupydatacomfacilities,buttheiroccupancyistypicallytransientandenvironmentalconditionsareusuallymoredictatedbyequipmentneeds,therebymakingitmoreofaprocesscoolingapplicationratherthancomfortcooling.However,humanoccupancyinsmallerdatacomfacilitiesmayinfluenceventilationairrequirements.工作人员也占用数据通信中心，但其通常是临时的，所以机房环境条件(如温度，噪音)常由设备的需求打算。虽然工作人员占用的数据通信机房较小，但通风量也会受影响。数据中心可能一个建筑物或建筑物的一局部，其主要功能是容纳一个计算机房和其他附属设施；数据中心通常包含高端效劳器和具有重要功能的存储设备。工作人员也占用数据通信中心，但其通常是临时的，所以机房环境条件如温度，噪音)常由设备的需求打算，因此空调系统更多的是冷却功能而不是舒适功能。虽然工作人员占用的数据通信机房较小，但对通风设计也会有要求。Overview19.1.1 概述Environmentalrequirementsofdatacomequipmentvarydependingonthetypeofequipmentand/ormanufacturer.However,aconsortiumofservermanufacturershasagreedonasetoffourstandardizedconditions(Classes1to4),listedinThermalGuidelinesforDataProcessingEnvironments(ASHRAE2023).Afifthclassification,theNetworkEquipment-BuildingSystems(NEBS)class,istypicallyusedintelecommunications.不同类型的设备或制造商，他们的数据通信设备为环境的要求都有所不同。然而，效劳器制造厂家们达成了四个标准原则，此四条标准原则列于数据中心冷却指南(ThermalGuidelinesforDataProcessingEnvironmentsASHRAE2023)第五个分类，网络设备构建系统(NEBS)类，通常用于通信。 Class1:typicallyadatacomfacilitywithtightlycontrolledenvironmentalparameters(dewpoint,temperature,andrelativehumidity)andmission-criticaloperations;typesofproductstypicallydesignedfortheseenvironmentsareenterpriseserversandstorageproducts. 第一类：通常数据通信设施有严格掌握环境参数(露点，温度和相对湿度)和重要操作；通信设备效劳器和存储设备一般依据此条规定的环境参数设计。 Class2:typicallyadatacomspaceorofficeorlabenvironmentwithsomecontrolofenvironmentalparameters(dewpoint,temperature,andrelativehumidity);typesofproductstypicallydesignedforthisenvironmentaresmallservers,storageproducts,personalcomputers,andworkstations. 其次类：通常数据通信机房或办公室或试验室环境中，会安装有环境参数掌握设备1露点温度、温度和相对湿度)；小型效劳器、存储设备、个人电脑和工作站一般依据此条规定的环境参数设计。 Class3:typicallyanoffice,home,ortransportableenvironmentwithlittlecontrolofenvironmentalparameters(temperatureonly);typesofproductstypicallydesignedforthisenvironmentarepersonalcomputers,workstations,laptops,andprinters. 第三类：通常办公室、家庭或者运输环境只需要掌握环境温度(温度)；个人电脑、工作站、笔记本电脑和打印机一般依据此条规定的环境参数设计。 Class4:typicallyapoint-of-saleorlightindustrialorfactoryenvironmentwithweatherprotection,sufficientwinterheating,andventilation;typesofproductstypicallydesignedforthisenvironmentarepoint-of-saleequipment,industrialcontrollers,orcomputersandhandheldelectronicssuchasPDAs. 第四类：通常销售点或轻工业或工厂，需要有冬季采温存通风条件。设备销售点、工业掌握器、计算机和手持式电子设备如掌上电脑(PDAs)一般依据此条规定的环境参数设计。.NEBS:perTelcordia(2023,2023)zandtypicallyatelecommunicationscentralofficewithsomecontrolofenvironmentalparameters(dewpoint,temperatureandrelativehumidity);typesofproductstypicallydesignedforthisenvironmentareswitches,transportequipment,androuters. NEBS(网络设备构建系统):依据TelCOrdia(2023,2023)规定，通常电信中心需要有环境掌握装置(露点，温度和相对湿度)；交换机、传输设备和路由器一般依据此条规定的环境参数设计。BecauseClass3and4environmentsarenotdesignedprimarilyfordatacomequipment,theyarenotcoveredfurtherinthischapter;refertoASHRAE,s(2023)ThermalGuidelinesforDataCenterenvironmentsforfurtherinformation.由于第三和第四条不以数据通信设备为主，将不在下面章节中争论。如想了解更多信息请参考数据中心冷却指南(ThermalGuidelinesforDataProcessingEnvironmentsASHRAE2023)。EnvironmentalSpecifications19.1.2 环境说明Table1listsrecommendandallowableconditionsforClass1,Class2,andNEBSenvironments,asdefinedbytheftnotedsources.Figure1Ashowsrecommendedtemperatureandhumidityconditionsfortheseclassesonapsychrometricchart,andFigure1Bshowsallowabletemperatureandhumidityconditions.Notethatdew-pointtemperatureandrelativehumidityarealsospecified.表1列出了一类、二类和NEBS的建议和允许环境要求，具体介绍见脚注。图IA中，在焰湿图上给出了这两类推举的环境要求；图IB中，在焰湿图上给出了这两类允许的环境要求。请留意，露点温度和相对湿度也已给出。图IA数据中心CgSS1、Class2和NEBS推举的环境参数表1数据中心GaSS1、Qass2和NEBS设计参数CiMdIdun11%eIend2NF睡AlMBableLcVdKLcouuiBciMledLedAIIuhableLvdRcomMddLvciTcfnpcrAiLiironntr<lUIMCI5to12C'<CU¾*bto2TCs114<ro,IW>2rcMatmumIcmpaMurvHnCofchtnjcRduuvchundiyculrdrun*IOtoJSC,<Cbb.2>SKII20h>m.NHPoiMISloiSiC.(Cgbnl113。KJfl(wrmnUAKAJ5u>85.MaxMVEriuu)quoll>I?*Cmus.<kwpoICm>Ii21。Ci叩InHCaB213,.ma3叫<MRVIhnunMIRVKprlImthan60%28rCaPOMMiikKS%(MmMEKVl3，a.InletconditionsrecommendedinASHRAE(2023).a. ASHRAE(2023)推举送风温度；b. PercentagevaluesperASHRAEStandard52.1dustspotefficiencytest.MERVvaluesperASHRAEStandard52.2b.平均值依据ASHRAE标准52.1除尘点效率测试，MERV(MinimumEfficiencyReportingVaIUe)值依据ASHRAE标准52.2c. Telcordia(2023).d.Telcordia(2023).e. Generallyacceptedtelecommunicationspractice.Telecommunicationscentralofficesarenotgenerallyhumidified,butpersonnelareoftengroundedtoreduceelectrostaticdischarge(ESD)e.通信行业常规做法。通信中心通常不需要加湿，但人员需要常常接地，以削减静电放电(ESDzElectro-Staticdischar)gef. SeeFigure2fortemperaturederatingwithaltitudef.见图2温度梯级Airdensityalsoaffectstheabilityofdatacomequipmenttobeadequatelycooled.ASHRAEws(2023)ThermalGuidelinesforDataProcessingEnvironmentssuggeststhatdatacenterproductsbedesignedtooperateupto3050maltitude,butrecognizesthatthereisreducedmassflowandconvectiveheattransferassociatedwithlowerairdensityathigherelevations.Toaccountforthiseffect,theguidelineincludesaderatingchartforthemaximumallowabletemperatureof1Kper300maltitudeabove900m(Classes1to4).Figure2showsthealtitudederatingrecommendedbyASHRAE(2023)forClasses1and2,andforNEBS.空气的密度也会影响数据通信设备的冷却效果。ASHRAE(2023)数据中心冷却指南(ThermalGuidelinesforDataProcessingEnvironmentsASHRAE2023指出，数据中心设备工作环境的海拔高度不要超过3050m,同时也指出，随着海拔高度的增加，空气的密度渐渐降低，对空气的质量流量和设备的对流换热有肯定的影响。考虑到这些因素，数据中心冷却指南给出了一张阶梯图，在海拔90Om以上，每上升300m,设备的最大允许温度下降1(1至4类)。ASHRAE(2023)给出，随着海拔高度的增加1类、2类和NEBS的工作环境温度范围。Thestatedenvironmentalconditionsareasmeasuredattheinlettothedataandcommunicationsequipment,andnotaveragespaceorreturnairconditions.规定的测试条件是：以数据通信设备的进口作为参考点，而不是机房内平均温度或者回风温度。Temperature19.1.3温度Theallowabletemperaturerangeisastatementoffunctionality,whereastherecommendedrangeisastatementofreliability.Thus,equipmentexposedtoprolongedhightemperatures(and/ortosteeptemperaturegradients)canexperienceincreasedfailurerates,reducedserviceIifezhardwareand/orsoftwarefailures,and/orthermalshutdown.Exceedingtherecommendedlimitsforshortperiodsoftimeshouldnotbeaproblem,butrunningneartheallowablelimitsformonthscouldresultinincreasedreliabilityissues.Facilitydesignersandoperatorsshouldstriveforcontinuousoperationintherecommendedrange.ASHRAE(2023)andTelcordia(2023)recommendedrangeis18to27。尽管建议的设备的允许温度范围是牢靠的，但它只是一个功能说明。因此，当设备长期暴露在高温环境下(温度波动频率或幅度大)，就会提高设备的故障率，降低设备使用寿命，硬件/软件故障率提高，传热性能下降。短时间超过允许温度范围不会对设备造成影响，但假设几个月始终在接近温度范围边界运行，设备的上述问题消灭的概率会提高。设计师和治理者都应当努力使设备在允许温度区间内运行。ASHRAE(2023)和TeICordia(2023)推举的温度范围是18到27。e Fnhrt 一 k :JrXeIPRIIc23dF二Fig.IBAllowableDataCenterClasslfClass2fandNEBSOperatingConditions图IB数据中心1类、2类和NEBS的允许运行参数Notonlyisairtemperatureintotheelectronicscriticalforreliableoperationofcomponentsintheelectronicbox,buttheairdischargedfromtheelectronicsandflowingoverthecomponents(cabling,connectors,etc.)attheexitmustalsobeaddressed.Therecommendedrangesapplytoinletsofallequipmentinthedatacenter(exceptwhereITmanufacturersspecifyotherranges).送风不仅进入机柜冷却机柜内的电子器件，同时送风从机柜出来后还要冷却其它组件，如电缆，连接器件等。送风的允许温度区间适用于数据中心全部设备，除了制造商指定的其它范围。AttentionisneededtomakesuretheappropriateinletconditionsareachievedforthetopportionofITequipmentracks.需要留意的是，选择适当的入口空气参数，以保证IT设备机架的顶部的散热。Theinletairtemperatureinmanydatacenterstendstobewarmernearthetopofracks,particularlyifwarmrackexhaustairdotsnotHAVCadirectreturnpathtotheCRACs.Thiswarmerairalsoaffectstherelativehumidity,resultinginlowervaluesatthetopoftherack.Theairtemperaturegenerallyfollowsahorizontallintonthepsychometricchartwhereabsolutehumidityremainsconstantbutrelativehumiditydecreases.DENSITY, kgm3tUJynLUJdwUJ.L(n1nclFig.2Class1,Class2,andNEBSAllowableTemperatureRangeVersusAltitudeTemperatureRateofChangeSomedatacommanufacturersHAVCestablishedcriteriaforallow-ableratesofenvironmentalchangetopreventshocktothedataandcommunicationsequipment.Thesecriterianeedtobereviewedforallinstalleddatacomequipment.Amaximuminlettemperaturechangeof5K/hisrecommendedbyASHRAE(2023)forClasses1and2.Humidityrateofchangeistypicallymostimportantfortapeandstorageproducts.Typicalrequirementsfortapearearateofchangeoflessthan2K/handarelativehumiditychangeoflessthan5%/h(ASHRAE2023).Intelecommunicationscentraloffices,theNEBSarequirementperTelcordia(2023)fortestingnewequipmentisaratechange(cooling)of30K/h.However,intheeventofanair-conditioningfailure,therateoftemperaturechangecaneasilybesignificantlyhigher.Consequently,Telcordia(2023,2023)prescribestestingwithawarminggradientof96K/hfor15min.Manufacturers7/requirementsshouldbereviewedandfulfilledtoensurethatthesystemfunctionsproperlyduringnormaloperationandduringstart-upandshutdownProceduresmustbeinplaceforresponsetoaneventthatshutsdowncriticalclingsystemswhilecriticalloadscontinuetooperate,causingthespacetemperaturetobeginrisingimmediately.Proceduresshouldalsobeinplacegoverninghowquicklyelevatedspacetemperaturescanbereturnedtonormaltoavoidthermalshockdamage.DatacomequipmentusuallytoleratesasomewhatwiderrangeofenvironmentalconditionswhennotinusesecTable2.1inASHRAE(2023).Howevzeritmaybedesirabletoprovideuninterruptiblecoolingintheroomtomaintainoperatinglimitsandminimizethermalshocktotheequipment.26日HumidityHighrelativehumiditymaycauseconductiveanodicfailures(CAF),hygroscopicdustfailures(HDF),tapemediaerrorsandexcessivewear,andcorrosion.Inextremecasts,condensationcanoccuroncoldsurfacesofliquid-cooledequipment.Lowrelativehumiditymayresultinelectrostaticdischarge(ESD),whichcandestroyequipmentoradverselyaffectoperation.TapeproductsandmediamayHAVCexcessiveerrorswhenexposedtolowrelativehumidity.Ingeneral,facilitiesshouldbedesignedandoperatedtomaintaintherecommendedhumidityrangeinTable1,butexcursionsintotheallowablerange(moretypicallytheequipmentspecification)shouldnotsignificantlyshortenequipmentoperatinglift.FiltrationandContaminationBeforebeingintroducedintothedataandcommunicationsequipmentroom,outsideairshouldbefilteredandpreconditionedtoremoveparticulatesandcorrosivegases.Table1containsbothrecommendedandminimumfiltrationguidelinesforrecirculatedairinadatacenter.Particulatescanadverselyaffectdataandcommunicationsequipmentoperation,sohigh-qualityfiltrationandproperfiltermaintenanceareessential.Corrosivegasescanquicklydestroythethinmetalfilmsandconductorsusedinprintedcircuitboards,andcorrosioncancausehighresistanceatterminalconnectionpoints.Inaddition,theaccumulationofparticulatesonsurfacesneededforheatremoval(e.g.,heatsinkfins)candegradeheatremovaldeviceperformance.FurtherinformationonfiltrationandcontaminationindatacenterscanbefoundinChapter8ofDesignConsiderationsforDatacomEquipmentCenters(ASHRAE2023b)andParticulateandGaseousContaminationinDatacomEnvironmeets(ASHRAE2023)VentilationDataandcommunicationsequipmentroomairconditioningmustprovideadequateoutsideairtoachievethefollowingcriteria: Maintaintheroomundopositivepressurerelativetosurroundingspaces. DiluteindoorgeneratedpollutantssuchasVOCs. SatisfyASHRAEStandard62.1requirements.Meetlocalcodesforventilationfordatacomfacilitiesinallspaces,includingmechanical,uninterruptiblepowersupply(UPS)zandbatteryroomsTheneedforpositivepressuretokeepcontaminantsoutofthermisusuallythecontrollingdesigncriterionindataandcommunicationequipmentrooms.PressurizationcalculationscanbeperformedusingtheproceduresoutlinedinChapter16ofthe20234SHR4EHandbook-Fundamentals.Chapter53ofthisvolumehascalculationformulasforachievingpressurizationaswellaslossofpressurethroughcracksinwallsandatwindows.AlthoughmostcomputerroomsHAVCfewoccupants,calculationsshouldalwaysbeperformedtoensurethatadequateventilationforhumanoccupancyisprovidedinaccordancewithASHRAEStandard62.1andlocalcodes.Internallygeneratedcontaminantsmaymaketheindoorairqualitymethodthemoreappropriateprocedure;however,maintainingpositivepressureusuallyrequiresahigheroutsideairflow.EnvelopeconsiderationsInadditiontomeetingstate,national,andlocalcodes,thereareseveralotherparametersthatshouldbeconsideredindesigningtheenvelopeofdatacomfacilities,includingpressurization,isolation,vaporretardants,sealing,andcondensation. Pressurization.Datacomfacilitiesaretypicallypressurizedtopreventinfiltrationofairandpollutantsthroughthebuildingenvelope.Anairlockormantrapisr