PowerEngineeringThirdClassTestOld3rdTLMModule5student动力工程三级考试试题试卷

Section4Lecture5Try:1d.Preventfirefromoccurringinthereceiver

1.Controlsystemscanusecompressedairasa8.Themainadvantageofareciprocatingcompressorovera

mediumandrotarycompressoris:

alsotopoweractuatingdevicessuchasaircylinders.

a.Itismorecompact

a.Heatingb.Ithasfewermovingparts

b.Dryingc.Itismoreefficient

c.Coolingd.Itrequireslittleornolubrication

d.Signaling

9.With(twowords)typesofaircompressors

2.Airtoolsareusuallylighterthanelectrichandtoolstheair

because:iscompressedbythepushingactionofpistons,,

or.

a.Airislighterthancopperwire

b.Airtoolsdon*thaveaheavyarmature10.Advantagestheslidingvanecompressorhasover

c.Airtoolcasingsaremadeofthinaluminumreciprocatingcompressorsare:

d.Airtoolsareverycompactbecausetheydo

nothaveanyinternalmovingparts1.Lowerinitialcost

2.Lowerrunningspeed

3.Akindofrotarycompressoris:3.Steadierflow

4.Higherstartingtorque

a.Atwolobe5.Noinletordischargevalves

b.Across-compounddoublecylinder6.Alloftheabove

c.Slidingpiston

d.Alloftheabovea.2,3,5

b.6

4.Afreepistonaircompressor:c.1,245

d.1,3,5

a.Hasaspareorfreepistonforaircompression

b.UsesonesteamcylindertodrivetwocompressionSection4Lecture5Try:2

pistons

c.Hasacommonintakeanddischargevalvesystem1.Compressedairmachinerymaybeusedinexplosive

d.Hasacushioncylinderthatactsasaflywheelatmosphereswithouthazard

becausethey:

5.Theoperatingspeedofatypicaltwo-stageslidingvane

compressorrangesupto:a.Runcoolerthanelectricmotors

b.Absorbtheflammablegases

a.250rpmc.Runatlowerrpm

b.5000rpmd.Noneoftheabove

c.1800rpm

d.3000rpm2.Areciprocatingcompressor:

6.Compressorvalvesareusuallyautomaticandopenanda.Hasitspistonmadeofviscousliquid

closeby:b.Isapositivedisplacementcompressor

c.Requiresaminimumoffourstages

a.actionofapoppetvalved.Usesahydrogencooledcasing

b.Movementofthepistoncoveringoruncovering

ports3.Slidingvanecompressorsrequires:

c.Operationofanairsolenoidvalvea.Internallubrication

d.Apressuredifferenceb.Timinggears

c.Apumpwithreductiongears

7.Theprimepurposeofwatercoolingoraircoolingofaird.Aninletanddischargevalve

compressorsisdoneto:

4.Watercoolingbywaterjacketingofaircompressor

a.Cooltheaircylindersispreferredoveraircooling

b.Helpincreasemoistureandvolumeoftheairbecause:

c.Keepthecylinderatareasonabletemperature

a.Theconstructionofthecompressorischeaperthan1.Compressedairisnotusedfor:

thefinnedtype

b.Thereislesspipinginvolveda.Startingmotorsoflargedieselengines

c.Theconstructionisfairlysimpleb.Sootblowingforboilerfurnaces

d.Moreefficientcoolingisobtainedc.Mixingoragitatingmaterialsforaprocess

d.Coolingandaeratingthesteaminasteamcondenser

5.Inmultistagecompressionthehighpressurecylindersare

smallerbecausethevolumeis2.Anadvantageofdynamiccompressorsandsomerotary

lessandthepressureishigherthanthelowerpressurecompressorsascomparedto

stages.reciprocatingcompressorsisthattheycan:

TorFa.Bequicklyshutdown

b.Beopenedforinternalinspection

6.Auseofcompressedairisinsystemswhichmovec.Deliveroil-freeair

powderedd.Alleffectivelyuseslowspeeddrivers

andgranularmaterialsbymeansofcompressedair.

3.Atypeofrotarycompressorthatissuitableforhigh

7.Thefreepistoncompressorhasacentralspeedsandmayhavetohaveaspeed

(twowords)ofincreasinggearimplementedwithanelectricinduction

thedieseltypewhichfeaturespistonseachmotordriveis:

ofwhichdrivesanotherpiston

withinanaircylinder.a.Ascrewtype

b.Aslidingvanetype

8.Single-stagerotaryscrewcompressorswilldevelopc.Arotarylobetype

dischargepressurestoabout700kPad.Noneoftheabove

gauge,forpressuresabovethis,(two

words)designsareused.4.Compressorvalvesareusuallyautomaticandopenand

closeby:

9.Cylinderarrangementsofreciprocatingaircompressors

maybe:a.actionofapoppetvalve

b.Movementofthepistoncoveringoruncovering

1.Verticalorhorizontalports

2.Rotaryorsimplexc.Operationofanairsolenoidvalve

3.TheVorYtyped.Apressuredifference

4.Anangletype

5.Twinimpellertype5.Ananglecompressorhaspistonsseparatedby45℃and

connectedtoa

a.1,3,4commoncrankshaft.

b.1,3,5

c.2,4,5TorF

d.1,2,3

6.Compressedaircanbeusedforsootblowinginboiler

10.Positivedisplacementcompressortypesinclude:furnaces.

1.SlidingvaneTorF

2.Axialflow

3.Internalgear7.Allpositivedisplacementcompressorsrequireintakeand

4.Volutecasingdischargevalves.

5.Rotaryscrew

6.Multi-lobeTorF

a.1,3,4,68.Acompressorwithonecylinderonthe

b.2,4,5,6axisandthe

c.1,3,5,6otherontheaxisisknownasa/an

d.1,2,4,5__________compressor.

Section4Lecture5Try:3

3.Adouble-actingreciprocatingaircompressor:

a.Musthaveatleasttwopistons

b.Receivesanddischargesairatbothendsofthe

cylinder

c.Increasesthepressuretwicefrominletpressure

value

d.Noneoftheabove

4.Theprimepurposeofwatercoolingoraircoolingofair

9.Reciprocatingcompressorshaveseveraldisadvantagesascompressorsisdoneto:

comparedtootherpositivedisplacementcompressors,

suchas:a.Cooltheair

b.Helpincreasemoistureandvolumeoftheair

1.Theycannotbemademulti-stagedc.Keepthecylinderatareasonabletemperature

2.Theygiveapulsatingdischarged.Preventfirefromoccurringinthereceiver

3.Theyrequireinternallubrication

4.Theyhavemanymovingparts5.Slidingvanecompressorsrequires:

5.Theyareusuallylowspeed

6.Alloftheabovea.Internallubrication

b.Timinggears

a.6c.Apumpwithreductiongears

b.1,2,5d.Aninletanddischargevalve

c.2,3,4

d.1,3,56.Ofallthepositivedisplacementcompressors,the

10.Sincerotaryscrewcompressorsaresuitableforhighcompressorcandeliverthehighestdischargepressure.

speedsthey:

a.Slidingvane

1.Requireanoverspeedtripb.Reciprocating

2.Maybedirectlydrivenbyasteamorgasturbinec.Rotarylobe

3.Requireacentrifugalgovernord.Rotaryscreen

4.Canusespeedincreasinggearifdrivenbyan

inductionmotor7.Intherotaryscrewcompressorthemalerotorhas

5.Requireanairbypasslinetothesuctionside

(twowords)andthefemalerotorhas.(two

a.2,4words)

b.1,2,4

c.1,3,58.With(twowords)typesofaircompressors

d.4,5theair

iscompressedbythepushingactionofpistons,,or

Section4Lecture5Try:4

1.Compressedairisnotusedfor:9.Reciprocatingcompressorshaveseveraldisadvantagesas

comparedtootherpositivedisplacementcompressors,

a.Startingmotorsoflargedieselenginessuchas:

b.Sootblowingforboilerfurnaces

c.Mixingoragitatingmaterialsforaprocess1.Theycannotbemademulti-staged

d.Coolingandaeratingthesteaminasteamcondenser2.Theygiveapulsatingdischarge

3.Theyrequireinternallubrication

2.Centrifugalcompressorsmayhave:4.Theyhavemanymovingparts

5.Theyareusuallylowspeed

a.Avolutecasing6.Alloftheabove

b.Diffuservanes

c.Doublebarrelcasinga.6

d.Alloftheaboveb.1,2,5

c.2,3,4

d.1,3,5a.Malelobedriven

b.Maleflutedriven

10.Airtoolsarepreferredoversteamdriventoolsbecause:c.Femaleflutedriven

d.Femalelobedriven

I.Thereislesschanceofbeingburned

2.Lessequipmentisrequired7.Inmultistagecompressionthehighpressurecylindersare

3.Airtoolsrequirelesslubricationsmallerbecausethevolume

4.Airtoolsarequieterthansteamdrivenequipmentislessandthepressureishigherthanthelowerpressure

stages.

a.1and3

b.1and2TorF

c.3and4

d.2and48.Positivedisplacementcompressorsmaybedividedinto

two

generaltypes,compressorsand

compressors.

Section4Lecture5Try:5

1.Controlsystemscanusecompressedairasa

mediumand

alsotopoweractuatingdevicessuchasaircylinders.9.Threedifferentdesignsofrotarycompressorsare:

a.Heating1.Slidingvane

b.Drying2.Rotaryscrew

c.Cooling3.Axialflow

d.Signaling4.Volutecentrifugal

5.Rotarylobe

2.Airtransmissionpipingisthanelectricalwiring.6.Diffuservanecentrifugal

A.Longera.2,4,6

b.Lighterb.1,2,5

c.Smootherc.3,4,6

d.Moreexpensived.1,3,5

3.Areciprocatingcompressor:10.Cylinderarrangementsofreciprocatingaircompressors

maybe:

a.Hasitspistonmadeofviscousliquid

b.Isapositivedisplacementcompressor1.Verticalorhorizontal

c.Requiresaminimumoffourstages2.Rotaryorsimplex

d.Usesahydrogencooledcasing3.TheVorYtype

4.Anangletype

4.Theprimepurposeofwatercoolingoraircoolingofair5.Twinimpellertype

compressorsisdoneto:

a.1,3,4

a.Cooltheairb.1,3,5

b.Helpincreasemoistureandvolumeoftheairc.2,4,5

c.Keepthecylinderatareasonabletemperatured.1,2,3

d.Preventfirefromoccurringinthereceiver

Section4Lecture5Try:6

5.Slidingvanecompressorsare:

1.Controlsystemscanusecompressedairasa

a.Moreefficientthanreciprocatingcompressorsmediumand

b.Lessefficientthanreciprocatingcompressorsalsotopoweractuatingdevicessuchasaircylinders.

c.Madeonlyasasinglestageunit

d.Madewiththerotorbeingconcentrictothecasinga.Heating

b.Drying

6.Therotaryscrewcompressorusuallyhasthe:c.Cooling

d.Signaling

b.Lighter

2.Afreepistonaircompressor:c.Smoother

d.Moreexpensive

a.Hasaspareorfreepistonforaircompression

b.Usesonesteamcylindertodrivetwocompression2.Transmissionlossesarelesswithairthanwithsteamsince

pistonsnone

c.Hasacommonintakeanddischargevalvesystemoftheairwillinthepipelinesasisthecasewith

d.Hasacushioncylinderthatactsasaflywheelsteam.

3.AllpositivedisplacementcompressorsrequireintakeandA.Evaporate

dischargevalves.b.Expand

c.Explode

TorFd.Condense

4.Largedieselenginescanbestartedbyuseofacompressed3.Anaircompressorwithinternalcombustiondrivemay

airstartinghave:

motororapplyinghighpressureairdirectlytostarting

cylinders.a.Asteamturbineprimemover

b.Acommoncrankshafttobothdriverandcompressor

TorFc.Thecompressedairforenginescavenging

d.Acentrifugalcompressorincorporated

5.Themainpurposeoftheslidingvanesinaslidingvane

compressoristoacceleratetheair.4.Becauserotarylobeaircompressorsdonothavethe

impellersincontactwitheachotherthey:

TorF

a.Donotrequireinternallubrication

6.Sinceasteamturbineoperatesatarelativelyhighspeed,b.Mustincorporateatiminggear

asadriverforareciprocatingc.Willnotwearasquickly

compressor,aspeedreducinggeararrangementmustbed.Alloftheabove

used.

5.Rotarylobecompressorshavetheirelements:

TorF

a.Lubricatedbygraphite

7.Anadvantageofdrivingacompressorbyasteamengineisb.Enclosedbyanaluminumcasing

thatitc.Asspringloadedvanes

canbeoperatedmoreatlowerspeed.d.Revolvinginoppositedirections

8.With(twowords)typesofaircompressors

theair6.Dynamiccompressorsarepositivedisplacement

iscompressedbythepushingactionofpistons,,orcompressors.

TorF

9.Single-stagerotaryscrewcompressorswilldevelop

dischargepressurestoabout700kPa7.Areciprocatingcompressorissuitedforallrangesof

gauge,forpressuresabovethis,(two

words)designsareused.

8.Compressorconnectingrodsareconstructedof

10.Thefreepistoncompressorhasacentral(twowords).

(twowords)ofthe

dieseltypewhichfeaturespistonseachof9.Reciprocatingcompressorshaveseveraldisadvantagesas

whichdrivesanotherpistonwithincomparedtootherpositivedisplacementcompressors,

anaircylinder.suchas:

Section4Lecture5Try:71.Theycannotbemademulti-staged

2.Theygiveapulsatingdischarge

1.Airtransmissionpipingisthanelectricalwiring.3.Theyrequireinternallubrication

4.Theyhavemanymovingparts

A.Longer5.Theyareusuallylowspeed

6.Alloftheaboved.Alloftheabove

a.65.Themainadvantageofareciprocatingcompressorovera

b.1,2,5rotarycompressoris:

c.2,3,4

d.1,3,5a.Itismorecompact

b.Ithasfewermovingparts

10.Cylinderarrangementsofreciprocatingaircompressorsc.Itismoreefficient

maybe:d.Itrequireslittleornolubrication

I.Verticalorhorizontal6.Aircoolingofaircompressorcylindersismoreefficient

2.Rotaryorsimplexthanwatercoolingthecylinders

3.TheVorYtypebecauselesspipingisrequiredandthereisnofreezing.

4.Anangletype

5.TwinimpellertypeTorF

a.1,3,47.Allpositivedisplacementcompressorsrequireintakeand

b.1,3,5dischargevalves.

c.2,4,5

d.1,2,3TorF

8.Intherotarylobecompressortheairistrappedbetween

thelobes,thenreducedinvolume

andincreasedinpressurebeforebeingdischargedtothe

use.

TorF

Section4Lecture5Try:8

9.Thereisdangerofpersonnelbeingfrom

1.Reciprocatingcompressorsaresuitablefor:contact

withairpipingcomparedtosteampiping.

a.Lowpressureservice

b.Onlyhighpressureservice10.Fouradvantagesofusingcompressedairtodrivetools

c.Allrangesofpressureandother

d.Noneoftheabovemachineryovertheuseofelectricityare:

2.Animportantadvantageofaslidingvanecompressoris1.Airtoolsareusuallylessexpensive

thatit:2.Compressedairtoolscanbeusedinexplosive

atmospheres

a.Doesnotrequireinternallubrication3.Compressedairtoolscannotbedamagedby

b.Hasahighstartingtorqueoverloading

c.Doesnotrequireinletordischargevalves4.Airlinesaremoredifficulttoinstallcompared

d.Requireslightnylontiminggearstoelectricwiring

5.Airdoesn'trequireanylubrication

3.Adouble-actingreciprocatingaircompressor:6.Airdrivenhandtoolsarelighterinweightthan

theelectrictypes

a.Musthaveatleasttwopistons

b.Receivesanddischargesairatbothendsofthea.1,2,4,6

cylinderb.2,4,5,6

c.Increasesthepressuretwicefrominletpressurec.1,2,3,6

valued.1,3,4,5

d.Noneoftheabove

Section4Lecture5Try:9

4.Aircompressorpistonsareconstructedof:

1.Airtransmissionpipingisthanelectricalwiring.

a.Steel

b.CastironA.Longer

c.Aluminumb.Lighter

c.Smoother2.Lessequipmentisrequired

d.Moreexpensive3.Airtoolsrequirelesslubrication

4.Airtoolsarequieterthansteamdrivenequipment

2.Anadvantageofdynamiccompressorsandsomerotary

compressorsascomparedtoa.1and3

reciprocatingcompressorsisthattheycan:b.1and2

c.3and4

a.Bequicklyshutdownd.2and4

b.Beopenedforinternalinspection

c.Deliveroil-freeairSection4Lecture5Try:

d.Alleffectivelyuseslowspeeddrivers10

3.Animportantadvantageofaslidingvanecompressoris1.Airtoolsareusuallylighterthanelectrichandtools

thatit:because:

a.Doesnotrequireinternallubricationa.Airislighterthancopperwire

b.Hasahighstartingtorqueb.Airtoolsdon*thaveaheavyarmature

c.Doesnotrequireinletordischargevalvesc.Airtoolcasingsaremadeofthinaluminum

d.Requireslightnylontiminggearsd.Airtoolsareverycompactbecausetheydonothave

anyinternalmovingparts

4.Aircompressorpistonsareconstructedof:

2.Controlsystemscanusecompressedairasa

a.Steelmediumand

b.Castironalsotopoweractuatingdevicessuchasaircylinders.

c.Aluminum

d.Alloftheabovea.Heating

b.Drying

5.Sinceasteamturbineoperatesatarelativelyhighspeed,c.Cooling

asadriverforareciprocatingd.Signaling

compressor,aspeedreducinggeararrangementmustbe

used.3.Adouble-actingreciprocatingaircompressor:

TorFa.Musthaveatleasttwopistons

b.Receivesanddischargesairatbothendsofthe

6.Intherotaryscr