轮机英语关联题108题.docx
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轮机英语关联题108题
第四章关联题108题
Passage1
Valvedrivemechanism
Thevalvedrivemechanismcommandstheinletandexhaustvalvesattherequiredtiming.
Thevalvedrivemechanismconsistsofaninletandexhaustcamfollower(8)eachsuspendedinaplungerofthetappetassembly(7),twotubularpushrods(4)withballjoints,twonodularcastironrockerarms
(2)suspendedinarockerarmbearingbracket,twoyokes(5)andayokeguidepins.SeeFig.4-1.
Thetappetrollersfollowthecamprofilesandtransferthemovementsthroughpushrodstotherockerarms.Therockerarmsoperatetheinletandexhaustvalvesthroughyokes(5).Lubricationfortherockerarmscomesfromtheengine'ssecondaryoilsupplymanifoldthroughdrillingsinthecylinderheadandrockerarmbracket.
Thetappetassemblyreceiveslubricatingoilviachannelsintheengineblockfromthemainsupplymanifold.Fortherollerandshaft,theoilissuppliedthroughtheguidingplunger.
Tocompensateforheatexpansionaclearancemustexistbetweentherockerarmandyoke.Alladjustmentshavetobedoneonacoldengineonly.
Fig-4-1Valvedrivemechanism
1.Accordingtothepassage,thebesttimetoadjustthevalveclearanceis_____.
A.beforetheengineisstartedB.whentheengineisrunning
C.aftertheenginehasjustbeenstoppedD.whensomethinghasgonewrongwiththeengine
2.Therollerandthetappetassemblyarelubricatedbymeansof________.
A.themainlubesystemB.thesecondaryoilsystem
C.thespecialpumpingsystemD.theturbineoilsystem
3.Accordingtothepassage,thevalvedrivemechanismdoesnotinclude________*
A.tappetrollersB.pushrodsC.nodularcastironD.yokesandguidepins
4.Toclosevalvestightly,whichclearanceshouldbeinspectedaccordingtothemaintenance
schedule?
A.Theonebetweenthecamandthetappetroller.
B.Tlieonebetweenthepushrodsandtheballjoints.
C.Theonebetweentherockeraimsandtheyoke
D.Theonebetweentwotubularpushrods.
5.Whichstatementaboutthepassageisnottrue?
A.Alladjustmentshavetobemadeonahotengine^only.
B.Fortherollerandshaft,theoilissuppliedthroughtheguidingplunger.
C.Thevalvedrivemechanismcommandstheinletandexhaustvalvesattherequiredtiming.
D.Therockerarmsoperatetheinletandexhaustvalvesthroughyokes.
Passage2
Compressorcleaningduringengineoperation
Thecompressormaybecleanedbywaterinjectionduringtheengineoperation.Thecleaningprocesswillhavegoodresultsaslongasthedepositformationhasnotgonetoofar.Incaseaverythickhardenedcrustofdirtthecompressorhastobedismantledforcleaning.
Inthismethodofcleaningthewaterisnotactingasasolventbutinsteadremovesthedepositsmechanicallybytheimpactofthewaterdroplets.Itisthereforerecommendedtousecleanwaterwithoutadditives.ThewatershouldnotcongKnanyadditiveswhichmightremainonthecompressorblades.
Periodicallycleaningofthecompressor(Fig.4-2)preventsordelaysexcessivebuild-upofdirtbutinnowayreplacestheusualoverhaulswheretheturbochargeriscompletelydismantled.
Theturbochargerisprovidedwithawatercontainer
(1).Duringthecleaningprocedurethecontainerispressurizedwiththechargeair
(2)andfromwherethewaterisforcedtothecompressorinlet(3).
Fig.14-2Compressorcleaningdevices
1.Whichofthefollowingstatementscanbeusedtocleanthecompressorwiththeenginerunning?
A.WaterdropletsB.WaterwithadditivesC.ChargeairD.Hardcrust
2.Whatprincipalisusedinthismethodofcleaning?
A.Thecleansersolvesthedeposits.
B.Thecleansermeltsthedeposits.
C.Thecleanserbeatsthedepositsmechanically.
D.Thehighpressureofthecleanserremovesthedeposits.
3.Whichofthefollowingstatementsisnotcorrect?
A.Thecompressorneedsregularcleaning.
B.Periodicalcleaningofthecompressorcontributestoreducingbuild-upofdirt.
C.It´snotnecessarytodismantletheturbochargerifperiodicalcleaningofthecompressoris
performed.
D.Additivesshouldbetterbeavoidedduringthecleaningprocess.
4.Thecleaningwatershouldnotcontainanyadditives,because________.
A.theymaydelaybuild-upofdirtB.theymightremainonthebladesofthecompressor
C.theymaybeforcedtothecompressorinletD.theyarenotgoodsolvents
5.Thecleaningprocesswillhavegoodresultsif________.
A.thereisaverythickcrustofdirtonthecompressorB.thecompressorisnotdismantled
C.thedepositformationisnotveryseriousD.thewaterdropletsaresmallenough
Passage3
Chargeaircooler
Theengineisequippedwithachargeaircooler.Theinserttypechargeaircoolerismountedinaweldedcasing(airtrunk).Tlietrunkisboltedtotheengineblock.
Standardisatwo-stagecoolermounted.Thefirststage,throughwhichthechargeairflows,iscooledwithwaterfromtheHTcoolingsystemandcoolsthechargeairtillapprox.90-\00癈.TiesecondstageissuppliedwithwatercomingfromtheLTwatersystemandcoolsthechargeairmrthertilltherequiredtemperatureofapprox.50X..BycontrollingthewaterflowthroughtheLTcoolerthechargeairtemperaturecanbekeptconstantattherequiredtemperature.
Thecirculatingcoolantwatershouldalwaysbeunderpositivepressureandshouldbeascleanaspossible.Theoperatingairtemperatureshouldbemaintainedbycontrollingthecoolantinlettemperature.
Whilsttheengineisrunningtheairandcoolanttemperaturesandpressuresatinletandoutletshouldbecheckedandloggedperiodically.Variationsfromnormalindicatefaultsdevelopingsuchasfoulingofthefilmplatesorobstructionofthewatertubes.
Checkdaily,duringoperationoftheengine,theworkingofthetelltaleholeatthefreeendofthechargeairreceiver.Thefunctionofthisholeistoinformtheoperatorthepresenceofwaterinthechargeairreceiver.Undernormalconditiononlycompressedairshouldescapefromthishole.
1.Accordingtothepassage,theexpression"HT"probablymeans________.
A.HIGHTANKB.HIGHTEMPERATURE
C.HEATTRANSMISSIOND.HEATTRANSFER
2.Inordertomaintainthechargeairtemperatureweshouldcontrol________.
A.thecoolantinlettemperaturecomingfromthefirststagecooler
B.thecoolantflowcomingfromthesecondstagecooler
C.thecoolantoutlettemperaturecomingfromthesecondstagecooler
D.thecoolantflowcomingfromthefirststagecooler
3.Thechargeairtemperaturedepartingfromnormalmayindicatethat_____
A.condensatecanbeformed
B.onlycompressedairshouldescapefromthetelltale
C.thefilmplatesarebecomingdirtyorthewatertubesareblockedbyscale
D.coolingwatermayhavebeencarriedintothecylinders
4.Thefunctionofthetelltaleholeisto________.
A.detectwhethercompressedairhasescapedfromthehole
B.controlthecoolantinlettemperature
C.determinewhetherthecoolantwaterisunderpositivepressure
D.informtheoperatorthepresenceofwaterinthechargeairreceiver
5.Whichofthefollowingstatementsisnottrue?
A.Theengineisequippedwithachargeaircooler.
B.Atwo-stagecoolermountedisstandard.
C.ThefirststageiscooledwithwaterfromtheLHwatersystem.
D.Thesecondstagecoolsthechargeairfurthertillabout50ºC.
Passage4Thevibrationdamperservestoreducethetorsionalvibrationgeneratedbythecrankshaft.Theclamperconsistsofahousingandafreerotatinginertiaringsupportedbyanaxialbearing.Itfonnsatotallyenclosedunit.Thefreespacebetweeninertiaringanddamperhousingisfilledwithahighviscousfluid.Whenthecrankshaftrotatesatconstantspeed,theinertiaringwillfollowthismovement.Thecombustionpressureexertedoneachpistongeneratesvibrationinthecrankshaft,andeachvariationgeneratedbysuchavibrationwillaffectthemovementoftheinertiaring.Theresultingshiftoftheringtothedamperhousingisopposedbytheviscousfluidandthevibrationwillbereduced.
Theenergy,absorbedduringtheprocess,isconvertedintoheatandthenradiatedtothesurroundingair.Hence,properventilationofthedamperisessential.
Theviscousdamperfluidisduringengineoperationsubjectedtoageingandthefluidbecomesmoreviscous,hisendingfluidsamplesonaregularbasetothedampermanufacturertherateinreductionoftheviscositycanbedetennined.Assamplingintervaltimeis6000hoursadvised.Damperswithatoohighfluidviscositymaycausecrankshaftbreakdown..
Thedampercoverhastwofillingholeslocated180*oppositeeachotherandclosedbyscrew-infillerplugs.Ifoneoftheseplugsisaccessible,afluidsamplecontainercanbescrewedinandasampletakenwiththedamperinplace.Onasparedamper,samplingmustbeeffectedwiththedamperintheverticalposition.
Forliquidsampling,aspecialkitcanbeorderedfromStork-WartsilaDiesel.
1.Thegeneraldescriptionofthevibrationdampertellsusthat________,
A.thefreespacebetweeninertiaringanddamperhousingisfilledwithalowviscousfluid
B.whentheinertiaringmovesatconstantspeed,thecrankshaftfollowsthismovement
C.thedamperismadeupofahousingandafreerotatinginertiaring
D.noventilationofthedamperisnecessaryasthevibrationreductionprocessabsorbslittleenergy
2.Whichofthefollowingstatementsisnottrueaboutmaintenanceoftheviscousdamper?
A.Samplingintervaltimefordeterminingthequalityofthefluidis6000hours.
B.Forliquidsampling,aspecialkitcanbeused.
C.Onasparedamper,samplingmustbeeffectedwiththedamperinplace.
D.Theviscousfluid