哈工程轮机英语-lesson 17

Lesson17BoilerManagementHarbinEngineeringUniversity精品资料Generalmanagementprinciplesandoperatingproceduresarewellknownandmustalwaysbefollowedtoavoidboilermishaps(意外事故(yìwàishìɡù)、损坏).Inparticular:HarbinEngineeringUniversity精品资料Withmanysmallpackageboilers,theautomaticcontrolsequenceusuallyensuresthattheboilerfireisinitiallyignited[lighted]

fromadieseloilsupply,HarbinEngineeringUniversity精品资料andchangedovertotheusualsourcewhenignitioniscompleted.HarbinEngineeringUniversity精品资料Withgoodmanagement,tofacilitatesubsequentstartingfromcold,thefuelsystemoflargeboilerswillhavebeenflushedthroughwithdieseloilwhentheboilerwasonlightdutyimmediatelypriortobeingsecured.HarbinEngineeringUniversity精品资料Whenburningsuchdieselfuelitisessentialforsafetythatonlythecorrect(small)burnertip(锅炉(guōlú)燃烧器喷油嘴)shouldbeused.HarbinEngineeringUniversity精品资料Itshouldbekeptinmindthatiffiredoesnotlight,immediatelyshutofffuelandventfurnace.HarbinEngineeringUniversity精品资料Completeignitionoffuelinthefurnaceisessential.Theburnerflame,thesmokeindicator(烟气(yānqì)指示器)andthefunnelshouldbefrequentlyobserved.HarbinEngineeringUniversity精品资料Withsatisfactorycombustion,theflameshouldappearincandescent(发白(fābái)热光的)withanorangeshade(色度)attheflametip,andafaintbrownishhaze(烟雾、薄雾)shouldshowatthefunnel.HarbinEngineeringUniversity精品资料Ifonfirstignitiontheflameisuncertain,badlyshapedandseparatedfromtheprimaryswirler(旋流(xuánliú)),momentaryopeningorclosingofairregister(调风门)[airregulator]maycorrect.HarbinEngineeringUniversity精品资料ThepHvalueoftheboilerfeedwatershouldbekeptbetween8and9andtheboilerdensitylessthan300ppm.HarbinEngineeringUniversity精品资料But,ifwatersamplesshowaheavyconcentration

ofsuspendedmater,shortblow-downsof20secondsdurationshouldbegivenuntilthesludgecontentisseenreduced.HarbinEngineeringUniversity精品资料Theboilershouldbeblowndownwhentheoilburnerisoperating,thewaterlevelloweredandthenrestoredtoprovethefunctioningofthelowwatercut-outandtheoilburnerstart-upequipment.HarbinEngineeringUniversity精品资料Theboilerscumvalveshouldalsobeoperatedatthistimetokeepthewaterlevelclearfromfloatingscum.HarbinEngineeringUniversity精品资料Fuelburnercomponentsandigniter

electrodesshouldbecleanedweeklyandthefurnaceexaminedtoensurethattherearenoexcesscarbondeposits.HarbinEngineeringUniversity精品资料Tubesintheexhaustgassectionoftheboilershouldbebrushedthroughataboutsix-monthlyintervals,andthoseintheoilburningsectionperiodicallyexaminedandcleanedasnecessarywithawirebristlebrush.HarbinEngineeringUniversity精品资料Withcorrectfeedwatertreatment,blowdownproceduresandsludgecontentsinwatersamplesatastablelevel,itshouldnotbenecessarytowashoutthewatersideoftheboilermorethanonceeverythreeorfourmonths.HarbinEngineeringUniversity精品资料Boilerfiresmaybeoutforlongperiodswhenashipisatseaandtheboilersteamingmaintainedbyheatinputfromwasteheatrecoveryplant.HarbinEngineeringUniversity精品资料Thisoperationisfreefromhazard(危险(wēixiǎn)),butfeedwaterandboilerwatertreatmentmustbemaintainedtopreventinternaldeteriorationorscaleformation.HarbinEngineeringUniversity精品资料Waterlevelcontrollersmustbekeptoperabletoprotectexternalsteam-usingplantfromwater“carry-over”(蒸汽(zhēnɡqì)携水、汽水共腾)danger.HarbinEngineeringUniversity精品资料Ifaboiler

isisolatedfromthesteam-usingsystemitmustbekepteitherincloseddrystoragewithasuitableinternaldesiccant(干燥剂),

orcompletelyfulloftreatedwater,HarbinEngineeringUniversity精品资料orunderalowsteampressurepreferablymaintainedbyasteam-heatedcoil.HarbinEngineeringUniversity精品资料Regulartestingofboilerprotectivedevicesmustbeimplemented(执行(zhíxíng)).HarbinEngineeringUniversity精品资料Frequentcomparisonofdrum-mountedandremote-reading

waterlevelindicators:HarbinEngineeringUniversity精品资料discrepanciesbetweenthesehavecontributedtofailuresbecauseofoverheatingthroughshortageofwater,whenaboilerwasbeingoil-fired.HarbinEngineeringUniversity精品资料Ifindoubtastothetrueboilerwaterlevel,i.e.whetherawaterlevelindicatorsightglassiscompletelyfullorempty,whenaunitisbeingoil-firedthefireshouldbeimmediatelyextinguisheduntilthetruelevelisresolved(恢复(huīfù)).HarbinEngineeringUniversity精品资料Proceduresshouldbepredeterminedandfollowedintheeventofshortageofwater,bulging(凸出(tūchū))orfracture(破裂)ofplatesorfurnace,orburstingofwatertubes.HarbinEngineeringUniversity精品资料Ingeneral,firesshouldbeimmediatelyextinguishedbyremotetrippingoffuelsupplyvalves(供油远程(yuǎnchéng)速闭阀);HarbinEngineeringUniversity精品资料forceddraughtairpressuremaintainedifthereisanyriskofescapingsteamenteringtheboilerroom;HarbinEngineeringUniversity精品资料steampressurerelievedifmetallic(金属(jīnshǔ)的)fracturesseempossible;andboilerwaterlevelmaintained,wherepracticable,untiltheboilerbeginstocooldown.HarbinEngineeringUniversity精品资料Regularoperationofsootblowers,ifthesearefitted,whentheboilerisonoil-firedoperation.HarbinEngineeringUniversity精品资料Thesteamsupplylinemustbethoroughlywarmedanddrainedbeforetheblowersareused,theair/fuelratioincreasedthroughouttheaction,andblowersgreasedafteruse.HarbinEngineeringUniversity精品资料Immediateinvestigationofanyhighsalinity(盐度(yándù))alarmsincondensatesystem,andeliminationofanysaltwateroroilcontaminationofboilerfeedwatersystem.HarbinEngineeringUniversity精品资料Safetyprecautions(shouldbe)takenbeforeenteringaboilerconnectedtoanotherboilerundersteam.HarbinEngineeringUniversity精品资料Themainenginemaybekeptinoperationwiththeboilerdryandthegasespassingthroughtheexhaustgassection.HarbinEngineeringUniversity精品资料Ifthisistobedoneforaprolongedperioditisadvisabletoallowacurrentofairtoflowthroughtheboilerbyremovingmanhole,sightholeandmudholecovers.HarbinEngineeringUniversity精品资料Ifrefillingahotboilerthemainenginespeedshouldbereducedtoslowforhalfanhourandthefeedwatersuppliedbeashotaspossible;thereafterthemainenginemaybebroughtuptopoweroverasimilarperiod.HarbinEngineeringUniversity精品资料ReadingMaterialsA.Raisingsteam(升汽)HarbinEngineeringUniversity精品资料Theboilershouldbefilledtonormallevel(1/2[gauge]glass)whenthefeedcontrolvalveisautomaticallyclosedandthepanelindicatinglightextinguished(off).HarbinEngineeringUniversity精品资料Theforceddraughtfanshouldbestartedandairpassedthroughthefurnaceforseveralminutesto‘purge(清扫(qīngsǎo))’itofanyexhaustgasoroilvapors.HarbinEngineeringUniversity精品资料Theoperatingburnercannowbelitandadjustedtoprovidealowfiringratewithgoodcombustion.HarbinEngineeringUniversity精品资料Thefueloilpressureandforceddraughtpressureshouldbematchedtoensuregoodcombustionwithafullsteadyflame.HarbinEngineeringUniversity精品资料Whenwaterlevelnearsthetopofthegaugeglass,duetoexpansion,theinitiallevelshouldberestoredbydrainingoffwaterthroughthescumvalve.HarbinEngineeringUniversity精品资料Whenadrumpressureofabout210KN/m2hasbeenreached,thedrumairventmaybeclosed.HarbinEngineeringUniversity精品资料TheboilermustbebroughtslowlyuptoworkingpressureinordertoensuregradualexpansionandHarbinEngineeringUniversity精品资料andtoavoidoverheatingthesuperheaterelementsanddamaginganyrefractory(难熔的)materialduetoexpansionstresses.HarbinEngineeringUniversity精品资料Thetimerequiredwillvarywithboilertypesandconstruction.HarbinEngineeringUniversity精品资料Ifnecessaryblowdownsomeofthecontentstoseatodisplacecoldwaterfromthelowestpartoftheboilershell,tominimizetemperaturedifferentialsandthethermalstresses.HarbinEngineeringUniversity精品资料Themainandauxiliarysteamlinesshouldnowbewarmedbycrackopeningoftheboilermainandauxiliarystopvalves.Whenthelinesarehotclosethedrains.HarbinEngineeringUniversity精品资料Inadditionthewaterlevelgaugesshouldbeblownthroughandcheckedforcorrectreading.HarbinEngineeringUniversity精品资料Whenthesteampressureisabout300KN/m2belowthenormaloperatingvalue,thesafetyvalvesshouldbeliftedandreleasedusingtheeasinggear(放松装置(zhuāngzhì)、释放装置(zhuāngzhì)).HarbinEngineeringUniversity精品资料Onceatoperatingpressure,theboilermaybeputonloadandthesuperheatercirculatingvalvesclosed.HarbinEngineeringUniversity精品资料Allothervents,drainsandby-passesshouldthenbeclosed.Thewaterlevelintheboilershouldbemaintained.HarbinEngineeringUniversity精品资料B.Boilershut-downandsecuring(封炉)Thisoperationmayhavetobedonenormallyattheendofavoyageorinemergency.HarbinEngineeringUniversity精品资料Fornormalshut-downthesuitableprocedureis:-Carryoutsootblowing,ifpermissible.HarbinEngineeringUniversity精品资料-Changecombustioncontrolfromautomatictomanual.-Changefuelsupplytodieseloil;shutsteamoff

fuelheatersandtraceheating(伴热管).HarbinEngineeringUniversity精品资料Closeburnersupplyvalvesandmainfuelshutoffvalve.-Purgeboilerfurnaceswithairforthreetofiveminutes;stopforceddraughtfan.HarbinEngineeringUniversity精品资料-Closesteamstopvalvesonboilerwhenpressureisreduced.Drainboilerwhenithascooleddownorfillwithtreatedwater.HarbinEngineeringUniversity精品资料C.BoilerwatertestingTestsrequiredarehardness(硬度(yìngdù)),alkalinity(碱度),chloride(氯化物),dissolved(溶解)solids(orconductivity传导率),hydrazine(联氨),phosphate(磷酸盐),pHandoccasionallysilica(二氧化硅).HarbinEngineeringUniversity精品资料Theessentialtestforcontroloftreatmentarealkalinity,chlorideordissolvedsolids,phosphateandhydrazine.HarbinEngineeringUniversity精品资料Phenolphthalein(酚酞(fēntài))AlkalinityinboilerwaterFivetotendropsofphenolphthaleinareaddedtoameasured,filteredvolumeofsample.Ifalkaline,apinkcolorisproduced.HarbinEngineeringUniversity精品资料Titrate(以滴定法测定(cèdìng))withsulphuricacid(硫酸)ofknownstrengthwithcontinuousstirringofthesamplewithaglassroduntilthepinkcolourjustdisappears.HarbinEngineeringUniversity精品资料Theboileralkalinityinpartspermillioniscalculatedfromthestrengthoftheacidandvolumeoftheboilerwatersample.HarbinEngineeringUniversity精品资料1.Measure20,50or100mloffilteredboilerwaterfromagraduatedcylinder(量筒(liángtǒng))intoacasserole(烧杯).HarbinEngineeringUniversity精品资料Add10dropsofphenolphthaleinindicatorsolution.Thesamplewillturnpinkifphenolphthaleinalkalinityispresent.HarbinEngineeringUniversity精品资料2.Addsulphuricacidsolution,strength0.02Nfroma10mlautomaticburette(滴管(dīɡuǎn)),stirringcontinuouslyuntilthepinkcolourjustdisappears.Notetheburettereading.HarbinEngineeringUniversity精品资料3.Calculatetheresultasfollows:Alkalinitytophenolphthalein=1000×mlofsulphuricacid(0.02N)used volumeofsampleinml(expressedinppmintermsofCaCO3)HarbinEngineeringUniversity精品资料Chloridesinboilerwater1.Tothesampleusedforthephenolphthaleinalkalinitytestaddafurther1.0mlofsulphuricacidsolution,0.02N.HarbinEngineeringUniversity精品资料2.Add10dropsofpotassiumchromate(铬酸钾)

indicatorsolution.Thesamplewillturnyellow.HarbinEngineeringUniversity精品资料Addsilvernitrate(硝酸银)solution,strength0.02Nfroma10mlautomaticburette,stirringcontinuouslyuntiltheyellowjustchangestoareddish

range.Notetheburettereading.HarbinEngineeringUniversity精品资料3.Calculatetheresultasfollows:Chloride=1000×mlofsilvernitrate(0.02N)used,less0.2

VolumeofsampleinmlHarbinEngineeringUniversity精品资料Hardnessby

EDTA(乙二胺四乙酸)

inBoilerWaterIncorrectlytreatedboilerwaters,thehardnessisverysmall.HarbinEngineeringUniversity精品资料Thehardnessisdeterminedbytitratinga100mlsampleofboilerwaterwithastandardsolution().02N)ofEDTAusingMordantBlack(黑色煤染剂)asindicatorwhichHarbinEngineeringUniversity精品资料whichgivesaredcolourinthepresenceofanalkalinesolutionofcalcium(钙)

andmagnesium(镁)salts.HarbinEngineeringUniversity精品资料Thesampleofboilerwatermustbefilteredbeforetesting.1.Measure100mloffilteredboilerwaterfromagraduatedcylinderintoacasserole.HarbinEngineeringUniversity精品资料2.Add2mlofammonia(氨)buffersolution,anda