英语部分资料.docx

英语部分资料.docx

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英语部分资料

1.Whichofthefollowingvalvesshouldbeclosedfirstaftertakingonballastorbeforestoppingpumping?

A.pumpsuctionB.pumpdischargeC.deckfillingvalveD.seacock

2.Approximatelywhatpercentoftankspaceshouldbeleftforexpansionofoilduetopossibletemperatureincrease.

a.1%to3%b.1%to2%c.4%d.2%to4%

3.Whichofthefollowingrepresentsthemaximumpercentofoxygen,byvolume,requiredtobeachievedbyaship’sinertgassystem,priortothecommencementofcrudeoiltankwashing?

a.6%b.8%c.10%d.12%

4.WhichofthefollowingwouldnotbecauseforarefrigeratingsystemtoshortcycleonHPcutout?

a.dischargevalveleakingb.pressurecutoutsetincorrectly

c.systemoverchargedwithrefrigerantd.insufficientcoolingwater

5.Abridgegageisnormallyusedtodetermineturbine___.

a.bearingoilclearanceb.diaphragmtipclearancec.bladeaxialclearanced.bearingwear

6.Whenamixtureofsteamandwaterinaboilerhasreachedthepointatwhichnofurtherchangeinstatecanoccurwiththeadditionofheat,themixtureisconsideredtohavereachedits__.

a.supercriticalendpointb.criticalendpointc.vaporizationendpointd.saturationendpoint

7.Ifacentrifugalmainfeedpumpwereoperatedatshutoffheadwiththerecirculatinglineclosed,whichofthefollowingconditioncouldoccur?

a.decreasedwaterlevelintheDCheaterb.anincreasewaterlevelinthesteamdrumc.flashingatthesuctionsideofthepumpd.excessivediaphragmsealwearinthefeed-waterregulator.

8.Whentheboilerisoperatingathighfiringrates,inadditiontothegeneratingtubes,whichofthefollowingtubeswillalsofunctionasgeneratingtubes?

a.Down–comerandwaterwalltubesb.Super–heatersupport,waterscreen,andwaterwalltubesc.waterscreen,super–heatersupport,andeconomizertubesd.waterwall,waterscreen,andeconomizertubes.

9.Whenwaterwashingaboiler,thepropersequenceforwashingthesectionsshouldbethe__.

a.generatingtubes,super-heater,andtheneconomizer

b.super-heater,economizer,andthengeneratingtubes

c.screentubes,generatingtubes,andthensuper–heater

d.economizer,super-heater,generating,andthenscreentubes

10.TopreventasmallplasticrefractorywallpatchrepairfromfallingintothefurnaceofaD–typeboiler,youshould__.

a.attachanchorboltstothefurnacecasingb.reinforcethepatchwithfinemeshmetalscreenc.mixtheplasticwithconcretepriortousingd.undercuttheexistingbrickaroundtheareatobepatched

11.Wet–typeexhaustsilencers,usedwithsomedieselengines,havewhichofthefollowingdesignfeaturesincommon?

a.thesilencerisequippedwithawatersealb.theexhaustgasesarenotmixedwithcoolingwater.c.theinternalbafflesbreakuptheexhaustgaspulsation.d.theexhaustnoiseiscompletelyeliminated.

12.Whichofthetypesofmotorslistedisusedinahydraulicstarter?

a.pistonb.gearc.turbined.centrifugal

13.Duringdieselenginewarm-up,whichtypeofvalvelashadjusterlistedallowsforthechangeinlengthoftheexhaustvalves?

a.mechanicalb.hydraulicc.pneumaticd.electrical

14.Thecetanenumberratesfuelsfordieselengineaccordingtoits__

a.antiknockcharacteristicsb.ignitionqualityc.ratesofvaporizationd.viscosity

15.Inadieselengine,anintegrallinerisoneinwhichthecoolingwater__.I.flowsthroughthecylinderlinerjacketsII.touchestheoutersideoftheliner

a.Ionlyb.IIonlyc.bothIandIId.neitherInorII

16.Modernmarinedieselenginesusingmechanicalfuelinjection,operateonacombustioncyclewhichis

a.acombinationofconstantvolumeandconstantpressure

b.acombinationofconstanttemperatureandconstantpressure

c.entirelyconstantpressured.entirelyconstantvolume

17.Pittingintheareaclosetothepitchlineandonthesameendofeachgeartoothofareductiongearunitwouldbecausedby__.

a.corrosiononthegearsb.excessivegearspeedc.dirtintheoil

d.misalignmentofthegears

18.Thethermostaticexpansionvalveinarefrigerationsystemopenswhenthepressure___.

a.decreasesintheevaporatorb.decreasesintheexpansionvalvecontrolbulbc.increasesabovetheexpansionvalvediaphragmd.increasesinthesolenoidvalve

19.Thebackpressureregulatingvalveusedinarefrigerationsystemservesto__.

a.maintainaconstantpressureinthesuctionlineheatexchanger

b.limittheminimumpressureintheevaporator

c.limitthemaximumpressureinthesuctionlineheatexchanger

d.maintainaminimumdischargeheadonthecompressor

20.Thedefinitionofsuperheatreferstotheamountofheatnecessarytoraisethetemperatureofafluidandappliesto__.I.vaporII.liquids

a.Ionlyb.IIonlyc.bothIandIId.neitherInorII

21.Thesteamdruminstalledin‘D‘typeboilersservetoprovide__

I.awaterreserveforproperboileroperationII.anareaforsteamandmoisturetoseparate.

a.Ionlyb.IIonlyc.bothIandIId.neitherInorII

22.Themosttroublesomecorrosivesubstancesinboilerwaterareoxygenand____.

a.hydrogensulfideb.sulfurdioxidec.carbondioxided.ammonia

23.Arupturedboilertubeshouldberemovedby__.I.splittingtheremainingtubesectionswithasafetyrippingchisel.II.cuttingoutmostofthetubeandthenallowingtheremainingportiontodisintegrateastheboilerisnormallyfired.

a.Ionlyb.IIonlyc.bothIandIId.neitherInorII

24.Theformationofapitinaboilertubeismostlikelytooccurwhen__

a.watersidedepositsarepresentb.sludgeispresentc.dissolvedoxygenispresentd.thetubemetalactsasacathode

25.Ifaboilerisbroughtonthelinewithitssteampressuremuchhigherthanthatoftheboileralreadyontheline,thereisdangerof__

a.thermalshockb.primingandcarryoverc.lowwaterd.anoverloadedsuperheater.

答案：

DABAD,BCBDD,CABBA,ADCBA,CCACB

1.Thereciprocatingmotionofthepistonisconvertedto____motionofthecrankshaftbytheconnectingrod,whichswivelsaboutthewrist（pistonorgudgeon）pinatthetop,andatitsbottomendrotatesaboutthecrankpin.

a.turningb.relativec.rollingd.backandforth

2.Whilethesearetheoreticalcyclesthatareonly____inreality,itisthedualcombustioncyclethatmostaccuratelyrepresentstheoperationofmostdieselenginesofcurrentdesign.

a.approximatedb.closedc.approachd.accurate

3,IntheOttocycle,achargeoffuelandairisignitedbyasparkandburnsexplosively,sorapidlythatcombustioniscompletedbeforethepistonbeginstomovedownandtherefore____atconstantvolume.

a.taketheplaceofb.occursc,istakenplaced.carryout

4.Practicalconsiderationspreventalltheseotherfactorsfrom___,butthefactorremainsthatthecloserthedualcombustioncyclecanbemadetoapproachanOttocycle,withalargefractionofthefuelburningrapidlybeforethepistoncommenceitsdownwardstroke,thehigherwillbeitstheoreticalthermalefficiency.

a.beingthesameb.equalc.isequald,equation

5.Ottoanddualcombustioncyclesarerelatedbythemannerinwhichcombustiontakesplace,ifallotherfactorswereequal,thetheoreticalthermalefficiency__higherforanOttocycle.

a.wouldbeb.willbec.wasd.is

6.Insteamturbineshighpressuresteamisdirectedinto__bladesorvanesattachedtoashaft,causingittorotate.

a.aseriesofb.aseriousofc,seriesofd.serious

7.Gasturbinesdifferfromsteamturbines__gasratherthansteamisusedtoturnashaft.

a.since（inthat）b.sothatc.therefored.thus

8.Asthecylindervolumeincreases,howeverthecontinuedcombustionmaintainsthepressureinthecylinderuntilinjectionandthencombustion__.

a.stopb.increasec.ceased.tocease

9.Theexhauststrokeactuallybeginsjustbeforethepistonreachesbottomdeadcenter,whentheexhaustvalveopensandtheresidualhighpressureinthecylinder__theexhaustmanifoldasthegasesblowdown.

a.isrelievedintob.isreducedintoc.isdischargingtod.ischargedinto

10.Fuelinjectionbeginsduringthe__stroke,beforethepistonreachestopdeadcenter.

a.expansionb.suctionc.compressiond.exhaust

11.Withoutexception,modernoil-burningdieselenginesachievethese__withsolidinjectionsystems.

a.objectivesb.gatec.doord.object

12.Itisimportantto__thatinahighspeedenginethecrankshaftrotatesfartherinagivenperiodoftimethaninalowspeedengine,whichexplainsthegenerallylowertoleranceofhighspeedenginesforfueloflowignitionquality.

a.indicateb.writec.explaind.show

13.Ifthepressurerisestoosharplythecombustionbecomesaudible,aphenomenonknownas__.

a.dieselknockb.dieselenginec.mechanicald.fireknock

14.Oncethecombustionhasbeenestablishedinthecylinder,furtherfueldropletsenteringthecylinderwillburnassoonastheyhavepenetrated,heated,vaporized,andmixed,sothatthecombustionrate__theinjectionratebythepreparationtime.

a.lagsbehindb.leadingc.isslowerthand.isthesameas

15.Typically,however,__someirregularitiesreflectingcombustionofincompletelyburnedfuelorofintermediatecombustionproducts,andsomedelayedchemicalendreactions.

a.therewillbeb.thereisc.therewillhaved.therehas

16.Compressordischargepressureisusuallydescribedbyitsratioto__,calledthepressureratio.

a.intakepressureb.dischargepressurec.waterpressured.exhaustpressure

17.Currently,turbo-chargersaresuitableforpressureratios__4.0.

a.ashighasb.suchhighasc.aslowasd.a