轮机英语历年真题44期

中华人民共和国海事局2007年第6期海船船员适任证书全国统考试题(总第44期)科目：轮机英语试卷代号：805适用对象：无限、近洋航区3000KW及以上船舶二/三管轮（本试卷卷面总分100分，及格分为70分，考试时间为100分钟）答题说明：请选择一个最合适的答案，并将该答案按答题卡要求，在其相应位置上用2B铅笔涂黑。第1题至74题，每题1分，第75题至78题，每题1.5分,第79题至80题,每题10分。一．单项选择题1.Thedieselengineissimilartothegasolineengineinthat_________.A.bothofthemareignitedbycompressedairB.bothofthemaretheformsofexternalcombustionenginesC.bothofthemhavesparkplugsD.thepowerisdevelopedbythepistoninthecylinder2.Theratioofthebrakehorsepowertotheindicatedhorsepowerofadieselengineisits________.A.thermalefficiencyB.mechanicalefficiencyC.brakethermalefficiencyD.volumetricefficiency3.Theignitionqualityofdieselfueloilisindicatedbythe_________.A.specificgravityB.cetanenumberC.viscosityD.calorificvalue4.Howarethepressureandtemperatureaffectedinadieselenginecylinderduringcompression?A.PressureandtemperaturedecreaseB.PressureandtemperatureincreaseC.PressuredecreasesandtemperatureincreasesD.Pressureincreasesandtemperaturedecreases5.Analuminumpistonhaslowerinertiaandhighercoefficientof_________comparedtothatofcastiron.A.viscosityB.twistingmomentsC.inertiaD.thermalexpansion6.Eachcylinderisclosedatthetopbya_________,madeofaspecialheat-resistantsteel.A.cylinderlinerB.couplingflangeC.cylindercoverD.pistoncrown7.Theamountoffueldeliveredbyahelicalplungertypefuelinjectionpumpiscontrolledby_________.A.rotationofthepumpplungerB.rotationofthepumpbarrelC.varyingthepumpsupplypressureD.varyingthepumpreturnpressure8.Inadieselenginelubeoilsystem,whichofthefollowingpartsshouldbelubricatedfirst?A.CamshaftbearingsB.MainbearingsC.PistoncrownsD.Cylinderwalls9.Sacrificialzincanodesareusedonthesaltwatersideofdieselengineheatexchangersto_________.A.reduceelectrolyticactiononheatexchangermetalsB.keepheattransfersurfacesshinyandcleanC.preventrapidaccumulationofmarinegrowthD.provideaprotectivecoatingonheatexchangersurfaces10.Inaturbocharger,inletairvelocityisincreasedinthe________.A.inletnozzleringB.stationarydiffuserpassagesC.compressoroutletvoluteD.rotatingimpellervanes11.Dieselenginecylinderairstartvalvetimingiscontrolledby_________.A.engineoperatingspeedB.anairmanifoldC.ahydraulicdistributorD.theairdistributor12.Ifthecompensatingneedlevalveofahydraulicgovernorisopenedmorethannecessarythegovernorwill________.A.havealargerthannormaldeadbandB.produceexcessivespeedresponsetoaloadchangeC.respondslowlytoanychangeinengineloadD.stabilizeenginespeedatthenewgovernorsetting13.Apyrometerisaninstrumentcommonlyusedtomeasure_________.A.cylinderpressureB.flameintensityC.exhaustgastemperatureD.crankshaftaxialalignment14.Pumpupthestartingairreservoirstotheirmaximumpressureand________theairreservoirsandairsystem.A.openB.closeC.drainD.vent15.Inreducingenginespeedtoanefficientpropellerspeedbytheuseofreductiongears,________.A.speedandtorquearebothreducedB.speedisreducedandtorqueremainsunchangedC.speedisreducedandtorqueisincreasedD.speedissometimesunchangedwhiletorqueisincreased16.Whichofthefollowingstatementsconcerningfire-tubeboilersiscorrect?A.Combustiongasesflowthroughthetubes.B.Flamesimpingeonthetubes.C.Combustionoccursinthetubes.D.Waterflowsthroughthetubes.17.Thesafetyvalvesshouldbetestedandadjustedwhentheboilersurveyis__________.A.completedB.carriedoutC.cleanedD.steamed18.Whenanauxiliaryboilerispantingandemittingblacksmoke,youshould__________.A.increasethefueloiltemperatureB.decreasethefueloiltemperatureC.decreasethefueloilpressureD.increasetheairsupply19.Ifthefeedpumpforanauxiliaryboilerwaterfailstodeliverthefeedwatertotheboiler,thecausemaybe_________.A.highsteampressureintheboilerB.abnormallyhighfeed-watertemperatureC.abnormallyhighboilerwatertemperatureD.steamdemandexceedingfeedpumpcapacity20.Avanepumpbelongsto__________accordingtoitsworkingprinciple.A.reciprocatingpumpB.positivedisplacementpumpC.centrifugalpumpD.centripetalpump21.Thepackinginstalledinthepumpstuffingboxislubricatedby__________.A.gravityandfeedoilcupsB.greasecupsC.handduringinstallationD.leakagethroughthestuffingbox22.Ifthecapacityofacentrifugalpumpdecreasesgraduallyoveralongperiodoftime,youshouldreplacethe__________.A.packingglandB.mechanicalsealsC.lanternringsD.wearingrings23.Whichofthelistedconditionscanleadtocavitationinacentrifugalpump?A.Vaporpocketsformedinthesuctionflowstream.B.Roughcasingvolutesurfaces.C.Wornwearingrings.D.Heavyfluidintheflowstream.24.Inacompressionrefrigerationplant,thehot,highpressurerefrigerantgasiscooledbytheseawaterandbecomesliquidinthe_________.A.compressorB.condenserC.throttlevalveD.evaporator25.Thetemperatureatwhichwatervaporintheatmospherebeginstocondenseiscalledthe________.A.dewpointtemperatureB.condensationtemperatureC.psychometrictemperatureD.absolutehumiditytemperature26.Inanairconditioningsystem,moistureisremovedfromtheairby__________.A.filtersB.separatorsC.ductedtrapsD.dehumidifiers27.Sludgemayforminthecrankcaseofanairconditioningcompressorasaresultof_________.A.bubblingrefrigerantB.loweredoperatingtemperaturesC.overheatingandoxidationD.reducingthecloudorflocpoint28.Coalescenceisthebreakdownofsurfacetensionbetweenoildropletsinanoil/wa