搜索
《轮机英语》A卷姓名：成绩：单项选择题（每题2分共100分）1.Thedieselengineissimilartothegasolineengineinthat_______.A.BothofthemareignitedbycompressedairB.BothofthemaretheformsofexternalcombustionenginesC.BothofthemhavesparkplugsD.Thepowerisdevelopedbythepistoninthecylinder2.Theratioofthbrakehorsepowertotheindicatedbythe______.A.ThermalefficiencyB.MechanicalefficiencyC.BrakethermalefficiencyD.Volumetricefficiency3.Theignitionquality,ofdieselfueloilisindicatedbythe______.A.SpecificgravityB.CetanenumberC.ViscosityD.Calorificvalue4.Howarethepressureandtemperatureaffectedinadieselenginecylinderduringcompression?A.PressureandtemperaturedecreaseB.PressureandtemperatureincreaseC.PressuredecreasesandtemperatureincreasesD.Pressureincreasesandtemperaturedecreases5.Analuminiumpistonhaslowerinertiaandhighercoefficientof____comparedtothatofcastironA.ViscosityB.TwistingmomentsC.InertiaD.Thermalexpansion6.Eachcylinderisclosedatthetopbya_____,madeofaspecialheat-resistantsteel.A.CylinderlinerB.CouplingflangeC.CylindercoverD.Piston7.Theamountoffueldeliveredbyahelicalplungertypefuelinjectionpumpiscontrolledby_______.A.RotationofthepumpplungerB.RotationofthepumpbarrelC.VaryingthepumpsupplypressureD.Varyingthepumpreturnpressure8.Inadieselenginelubeoilsystem,whichofthefollowingpartsshouldbelubricatedfirst?A.CamshaftbearingB.MainbearingC.PistoncrownsD.Cylinder9.Sacrificialzincanodesareusedonhesaltwatersideofdieselengineheatexchangersto______.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_____theairreservoirsandairA.OpenB.closeC.DrainD.Vent15.Inreducingenginespeedtoanefficientpropellerspeedbytheuseofreductiongears,______.A.SpeedandtorquearebothreducedB.SpeedisreducedandtorqueremainsunchangedC.SpeedisreducedandtorqueisincreasedD.Speedissometimesunchangedwhiletorqueisincreased16.Whichofthefollowingstatementsconcerningfire-tubeboilersiscorrect?A.CombustiongasesflowthroughthetubesB.Flamesimpinge(撞击)onthetubeC.CombustionoccursinthetubesD.Waterflowsthroughthetubes17.Thesafetyvalvesshouldbetestedandadjustedwhentheboilersurveyis_____.A.CompletedB.CarriedoutC.CleanedD.Steamed18.Whenanauxiliaryboilerispantingandemittingblacksmoke,youshould______.A.IncreasethefueloilsupplypressureB.DecreasethefueloilC.DecreasethefueloilsupplypressureD.Increasetheairsupply19.Ifthefeedpumpforanauxiliaryboilerfailstodeliverthefeedwatertotheboiler,thecausemaybe______.A.HighsteampressureintheboilerB.Abnormallyhighfeed-watertemperatureC.AbnormallyhighboilerwatertemperatureD.Steamdemandexceedingfeedpumpcapacity20.Avanepumpbelongsto______accordingtoitsworkingprinciple.A.ReciprocatingpumpB.PositivedisplacementpumpC.CentrifugalpumpD.centripetalpump21.Thepackinginstalledinthepumpstuffingboxislubricatedby_______.A.GravityandfeedoilcupsB.GreasecupsC.HandduringinstallationD.Leakagethroughthestuffingbox22.Ifthecapacityofacentrifugalpumpdecreasesgraduallyoveralongperiodoftime,youshould______.A.PackingglandB.MechanicalsealsC.LanternringsD.Wearingrings23.Whichofthelistedconditionscanleadtocavitationinacentrifugalpump?A.VaporpocketsformedinthesuctionflowsteamB.Roughcasingvolutesurfaces.C.WornwearingringsD.Heavyfluidmtheflowstream24.Inacompressionrefrigerationplant,thehot,highpressurerefrigerantgasiscooledbytheseawaterandbecomesliquidinthe_____.A.CompressorB.CondenserC.ThrottlevalveD.Evaproator25.Thetemperatureatwinchwatervaporintheatmospherebeginstocondenseiscalledthe________.A.DewpointtemperatureB.CondensationtemperatureC.PsychometrictemperatureD.Absolutehumiditytemperature26.Inanairconditioningsystem,moistureisremovedfromtheairby_____.A.FiltersB.SeparatorC.DuctedtrapsD.Dehumidifiers27.Sludgemayforminthecrankcaseofanairconditioningcompressorasaresultof______.A.BubblingrefrigerantB.LoweredoperatingtemperaturesC.OverheatingandoxidationD.Reducingthecloudorfloepoint28.Coalescenceisthebreakdownofsurfacetensionbetweenoildropletsinanoil/watermixture.Whichcausesthemtojoinand____insize.A.ExpandB.ExtractC.IncreaseD.Decrease29.whenstarted,acompleteoilywaterseparatingunitisfirstfilled____.theoilywatermixtureis_____thenpumpedthroughtheinletpipeintothecoarseseparatingcompartment.A.WithdirtywaterB.WithcleanwaterC.ByoilywaterD.Bymixedwater30.Whichisthepollutionp