轮机英语关联题108题.docx

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