第三章燃料系统

3FUELSYSTEM燃料系统3.1GENERALDESCRIPTION总体描述Thegasfuelsystem,inconjunctionwithcontrolsystemandtheairsystem,automaticallyschedulesfuelflowduringengineaccelerationandloadoperation.Thesystemalsoprovidesovertemperatureandoverspeedtoppingcontroloffuelflowandautomaticshutdownintheeventofmalfunction.燃料系统与控制系统及空气系统连接。在发动机加速和负载操作期间，自动进行调节控制。系统也提供超温、超速及燃料流量控制。在故障时自动关断。Thegasfuelsystemincludesthefollowing:气体燃料系统包括：Gasfuelmeteringandcontrol气体燃料计量与控制Pilotpressurefortheoperationofpilot-operatedshutoffvalves导向操作型关断阀操作的导向压力3.1.1GasFuelRequirements气体燃料要求Theselectionofasatisfactoryfueldependsuponthephysicalandchemicalcompositionofthefuel.Naturalgasfuelandservicegasrequirementsforenginegasfuel,andservicegasusedforauxiliarygas-drivenmotorsandgas-drivenstartermotorsaregiveninTable3.1.1.GassupplymustconformtoSolarSpecificationES9-98.满足要求的燃料取决于燃料的物理及化学组分。天然气燃料、伺服气体、辅助气体驱动马达用气及气体驱动起动器马达用气要求如表3.1.1所示。Table3.1.1GasFuelandServiceGasRequirements气体燃料与伺服气体要求Nomenclature命名Description描述GasTemperature气体温度-40°Fto160°F(-40°Cto71°C)LowerHeatingValueofFuel燃料低热值1098to1342WI(WOBBEindex)(43.2to52.8MJ/m3).WOBBEindexisequaltotheLowerHeatingValueinBtu/Scfdividedbythesquarerootofthespecificgravityofthefuel.AWOBBEindexvalueoutsidethisrangeisacceptablewiththeapprovalofSolarEngineering.1098到1342沃贝指数（43.2～52.8MJ/m2）沃贝指数等于燃气重力的平方根除以低热值索拉透平可接受超出这一范围的沃贝指数Composition成分FuelandServicegascompositionshallbesuchthatdewpointatmaximumenginesupplypressuremustbeatleast10°F(5.6°C)belowgasfuelsupplytemperature.Thedewpointofagascanbecalculatedfromthecompositionordeterminedexperimentallywithaninstrument.燃气及伺服气成份应该为：发动机最大供气压力时，气体露点至少为10F（5.6C）低于气体燃料温度。气体露点可以从成份中计算出来，或是用仪器试验性测得。Contaminants:杂质：GasFuel气体燃料Totalcontaminantsshallnotexceed:总杂质不应超过：30ppmx(lowerheatingvaluebyweightBtu/lb÷21500Btu/lb)30ppmx（低热值/21500）（Btu/lb单位）or30ppmx(lowerheatingvaluebyweightMJ/kg÷50MJ/kg).30ppmx（低热值/50）（MJ/kg单位）Particlesshallnotexceed10microns.微粒不应超过10micronsNoentrainedwaterinthegasisallowed:thatis,nowaterinexcessofsaturationatmaximumoperatingpressure.气体中不夹带水分：即在最大操作压力下，过饱和时无水分Thepercentbyweighttotalsulfur,includinghydrogensulfide,shallnotexceed:1%x(lowerheatingvaluebyweightBtu/lb÷21500Btu/lb)or1%x(lowerheatingvaluebyweightMJ/kg÷50MJ/kg).总含硫量包括氢硫化物的比例不应超过：1％×（低热值/21500）Btu/lb或1％×（低热值/50）MJ/kgServiceGas伺服气体Notmorethan0.7gramofsolidcontaminantsper1000cuft(28.3m3)ofgasisallowed,and99percentofthe0.7gram/1000cuftsolidsshallbesmallerthantenmicrons.每1000cuft（28.3m3）中不超过0.7克固体杂质Noentrainedwaterinthegasisallowed:thatis,nowaterinexcessofsaturationatmaximumoperatingpressure.气体中不夹带水分：即在最大操作压力下过饱和时无水分Notmorethan0.5pound(0.23kg)totalsulfurper1000cuft(28.3m3)ofgas,includinghydrogensulfide.每1000cuft(28.3m3)气体中总含硫量，包括氢硫化物不超过0.5磅（0.23kg）Gasfuelshouldbefreeofcontaminants,entrainedwater,andsulfur.ThegasfuelsystemrequiresaconstantsupplyofgasattheflowrateandpressurerangespecifiedontheTurbomachineryGeneralArrangementInstallationDrawing(149673).气体燃料不应含杂质、夹带水分及硫。气体燃料系统要求流量及压力在一定范围内的稳定的气源。参看管道总体布置安装图（149673）NOTE注意Usersareurgedtoconsultlocalauthoritiesforsulfuremissionlimitations.Limitsinthisspecificationarebasedsolelyondesignconsiderations,andmuchlowerlevelsmayberequiredbyantipollutionregulations.用户应咨询当地政府关于硫排放的限制。说明文件中的限制只针对设计考虑，防污染规定可能要求更低的排放标准。3.2FUNCTIONALDESCRIPTION功能描述Thefollowingisafunctionaldescriptionofthegasfuelsystem.Forsettingsandsystemnormaloroperatingdesignvalues,refertotheFuelSystemSchematic(149537),andEngineDrainSchematic(149538).以下为气体燃料系统的功能描述、设置及系统正常或操作设计值。请参考燃料系统简图（149537）及发动机排放简图（149538）。3.2.1SequenceOfOperation操作程序VALVECHECKSEQUENCE阀检查程序Beforetheenginecranks,thecontrolsystemperformsavalvechecksequencetoverifytheshutoffvalvesarefunctioning.Ifashutoffvalvemalfunctions,thecontrolsystemannunciatesavalvefailureandabortsthestartcycle.在发动机转动前，控制系统执行阀检查程序，以验证关断阀的功能。如果关断阀故障，控制系统发出阀故障警报放弃此次起动周期。PURGECRANKCYCLE吹扫曲柄程序Afterthevalvechecksequence,thepurgecrankcycleisinitiatedtoremovecombustiblesfromtheengineexhaustsystem.Thestartsystemcrankstheenginetocreateairmovementthoughtheexhaustsystem.Thepurgecrankcycletimerisprogrammedaccordingtopackageexhaustsystemvolume.在阀检查程序完成后，开始吹扫曲柄周期，以清除发动机排放系统的燃烧物。起动器转动发动机产生流通过排放系统的空气流，吹扫曲柄定时器可根据装置的排放系统排放量编程。IGNITIONSEQUENCE点火程序Afterpurgecrankcycle,gasfuelflowsthroughthetorchandisignitedinthepresenceofcombustionair.Thetorchflameflaresintotheairflowinsidetheenginecombustorliner.在吹扫程序完成后，气体燃料流过火炬，与空气一起点燃。火焰闪入发动机燃烧室管线内的空气流。Thefuelinjectors,spacedequallyaroundthecombustor,mixfuelintheairstreaminsidethecombustorliner.Thetorchignitesthefuelairmixtureandlightoffoccurs.燃料喷射器其空间与燃烧室相等，在燃烧室管线里空气流与燃料混合，火炬中的燃料气混合物发生燃烧。ACCELERATIONSEQUENCE加速程序Followinglightoff,theenginetemperature(T5)rapidlyincreasesandthetorchextinguishes.ThecontrolsystemincreasesthefuelflowtograduallyelevateT5temperatureandenginespeed(Ngp).随着燃烧的进行，发动机温度（T5）快速上升，火炬熄灭。控制系统增加燃烧量以逐渐抬升T5温度及发动机速度（NGP）。Atapproximately60-65percentNgp,thestartsystemisde-energized.Astheenginecontinuestoaccelerate,theinletvariablevanesmovetowardmaximumopenposition,whilethecompressorbleedvalvecloses,furtherincreasingT5temperature.Thecontrolsystemincreasest