哈工程輪機英語-lesson 17

Lesson17BoilerManagementHarbinEngineeringUniversity精品資料Generalmanagementprinciplesandoperatingproceduresarewellknownandmustalwaysbefollowedtoavoidboilermishaps(意外事故(yìwàishìɡù)、損壞).Inparticular:HarbinEngineeringUniversity精品資料Withmanysmallpackageboilers,theautomaticcontrolsequenceusuallyensuresthattheboilerfireisinitiallyignited[lighted]

fromadieseloilsupply,HarbinEngineeringUniversity精品資料andchangedovertotheusualsourcewhenignitioniscompleted.HarbinEngineeringUniversity精品資料Withgoodmanagement,tofacilitatesubsequentstartingfromcold,thefuelsystemoflargeboilerswillhavebeenflushedthroughwithdieseloilwhentheboilerwasonlightdutyimmediatelypriortobeingsecured.HarbinEngineeringUniversity精品資料Whenburningsuchdieselfuelitisessentialforsafetythatonlythecorrect(small)burnertip(鍋爐(guōlú)燃燒器噴油嘴)shouldbeused.HarbinEngineeringUniversity精品資料Itshouldbekeptinmindthatiffiredoesnotlight,immediatelyshutofffuelandventfurnace.HarbinEngineeringUniversity精品資料Completeignitionoffuelinthefurnaceisessential.Theburnerflame,thesmokeindicator(煙氣(yānqì)指示器)andthefunnelshouldbefrequentlyobserved.HarbinEngineeringUniversity精品資料Withsatisfactorycombustion,theflameshouldappearincandescent(發(fā)白(fābái)熱光的)withanorangeshade(色度)attheflametip,andafaintbrownishhaze(煙霧、薄霧)shouldshowatthefunnel.HarbinEngineeringUniversity精品資料Ifonfirstignitiontheflameisuncertain,badlyshapedandseparatedfromtheprimaryswirler(旋流(xuánliú)),momentaryopeningorclosingofairregister(調(diào)風(fēng)門)[airregulator]maycorrect.HarbinEngineeringUniversity精品資料ThepHvalueoftheboilerfeedwatershouldbekeptbetween8and9andtheboilerdensitylessthan300ppm.HarbinEngineeringUniversity精品資料But,ifwatersamplesshowaheavyconcentration

ofsuspendedmater,shortblow-downsof20secondsdurationshouldbegivenuntilthesludgecontentisseenreduced.HarbinEngineeringUniversity精品資料Theboilershouldbeblowndownwhentheoilburnerisoperating,thewaterlevelloweredandthenrestoredtoprovethefunctioningofthelowwatercut-outandtheoilburnerstart-upequipment.HarbinEngineeringUniversity精品資料Theboilerscumvalveshouldalsobeoperatedatthistimetokeepthewaterlevelclearfromfloatingscum.HarbinEngineeringUniversity精品資料Fuelburnercomponentsandigniter

electrodesshouldbecleanedweeklyandthefurnaceexaminedtoensurethattherearenoexcesscarbondeposits.HarbinEngineeringUniversity精品資料Tubesintheexhaustgassectionoftheboilershouldbebrushedthroughataboutsix-monthlyintervals,andthoseintheoilburningsectionperiodicallyexaminedandcleanedasnecessarywithawirebristlebrush.HarbinEngineeringUniversity精品資料Withcorrectfeedwatertreatment,blowdownproceduresandsludgecontentsinwatersamplesatastablelevel,itshouldnotbenecessarytowashoutthewatersideoftheboilermorethanonceeverythreeorfourmonths.HarbinEngineeringUniversity精品資料Boilerfiresmaybeoutforlongperiodswhenashipisatseaandtheboilersteamingmaintainedbyheatinputfromwasteheatrecoveryplant.HarbinEngineeringUniversity精品資料Thisoperationisfreefromhazard(危險(wēixiǎn)),butfeedwaterandboilerwatertreatmentmustbemaintainedtopreventinternaldeteriorationorscaleformation.HarbinEngineeringUniversity精品資料Waterlevelcontrollersmustbekeptoperabletoprotectexternalsteam-usingplantfromwater“carry-over”(蒸汽(zhēnɡqì)攜水、汽水共騰)danger.HarbinEngineeringUniversity精品資料Ifaboiler

isisolatedfromthesteam-usingsystemitmustbekepteitherincloseddrystoragewithasuitableinternaldesiccant(干燥劑),

orcompletelyfulloftreatedwater,HarbinEngineeringUniversity精品資料orunderalowsteampressurepreferablymaintainedbyasteam-heatedcoil.HarbinEngineeringUniversity精品資料Regulartestingofboilerprotectivedevicesmustbeimplemented(執(zhí)行(zhíxíng)).HarbinEngineeringUniversity精品資料Frequentcomparisonofdrum-mountedandremote-reading

waterlevelindicators:HarbinEngineeringUniversity精品資料discrepanciesbetweenthesehavecontributedtofailuresbecauseofoverheatingthroughshortageofwater,whenaboilerwasbeingoil-fired.HarbinEngineeringUniversity精品資料Ifindoubtastothetrueboilerwaterlevel,i.e.whetherawaterlevelindicatorsightglassiscompletelyfullorempty,whenaunitisbeingoil-firedthefireshouldbeimmediatelyextinguisheduntilthetruelevelisresolved(恢復(fù)(huīfù)).HarbinEngineeringUniversity精品資料Proceduresshouldbepredeterminedandfollowedintheeventofshortageofwater,bulging(凸出(tūchū))orfracture(破裂)ofplatesorfurnace,orburstingofwatertubes.HarbinEngineeringUniversity精品資料Ingeneral,firesshouldbeimmediatelyextinguishedbyremotetrippingoffuelsupplyvalves(供油遠程(yuǎnchéng)速閉閥);HarbinEngineeringUniversity精品資料forceddraughtairpressuremaintainedifthereisanyriskofescapingsteamenteringtheboilerroom;HarbinEngineeringUniversity精品資料steampressurerelievedifmetallic(金屬(jīnshǔ)的)fracturesseempossible;andboilerwaterlevelmaintained,wherepracticable,untiltheboilerbeginstocooldown.HarbinEngineeringUniversity精品資料Regularoperationofsootblowers,ifthesearefitted,whentheboilerisonoil-firedoperation.HarbinEngineeringUniversity精品資料Thesteamsupplylinemustbethoroughlywarmedanddrainedbeforetheblowersareused,theair/fuelratioincreasedthroughouttheaction,andblowersgreasedafteruse.HarbinEngineeringUniversity精品資料Immediateinvestigationofanyhighsalinity(鹽度(yándù))alarmsincondensatesystem,andeliminationofanysaltwateroroilcontaminationofboilerfeedwatersystem.HarbinEngineeringUniversity精品資料Safetyprecautions(shouldbe)takenbeforeenteringaboilerconnectedtoanotherboilerundersteam.HarbinEngineeringUniversity精品資料Themainenginemaybekeptinoperationwiththeboilerdryandthegasespassingthroughtheexhaustgassection.HarbinEngineeringUniversity精品資料Ifthisistobedoneforaprolongedperioditisadvisabletoallowacurrentofairtoflowthroughtheboilerbyremovingmanhole,sightholeandmudholecovers.HarbinEngineeringUniversity精品資料Ifrefillingahotboilerthemainenginespeedshouldbereducedtoslowforhalfanhourandthefeedwatersuppliedbeashotaspossible;thereafterthemainenginemaybebroughtuptopoweroverasimilarperiod.HarbinEngineeringUniversity精品資料ReadingMaterialsA.Raisingsteam(升汽)HarbinEngineeringUniversity精品資料Theboilershouldbefilledtonormallevel(1/2[gauge]glass)whenthefeedcontrolvalveisautomaticallyclosedandthepanelindicatinglightextinguished(off).HarbinEngineeringUniversity精品資料Theforceddraughtfanshouldbestartedandairpassedthroughthefurnaceforseveralminutesto‘purge(清掃(qīngsǎo))’itofanyexhaustgasoroilvapors.HarbinEngineeringUniversity精品資料Theoperatingburnercannowbelitandadjustedtoprovidealowfiringratewithgoodcombustion.HarbinEngineeringUniversity精品資料Thefueloilpressureandforceddraughtpressureshouldbematchedtoensuregoodcombustionwithafullsteadyflame.HarbinEngineeringUniversity精品資料Whenwaterlevelnearsthetopofthegaugeglass,duetoexpansion,theinitiallevelshouldberestoredbydrainingoffwaterthroughthescumvalve.HarbinEngineeringUniversity精品資料Whenadrumpressureofabout210KN/m2hasbeenreached,thedrumairventmaybeclosed.HarbinEngineeringUniversity精品資料TheboilermustbebroughtslowlyuptoworkingpressureinordertoensuregradualexpansionandHarbinEngineeringUniversity精品資料andtoavoidoverheatingthesuperheaterelementsanddamaginganyrefractory(難熔的)materialduetoexpansionstresses.HarbinEngineeringUniversity精品資料Thetimerequiredwillvarywithboilertypesandconstruction.HarbinEngineeringUniversity精品資料Ifnecessaryblowdownsomeofthecontentstoseatodisplacecoldwaterfromthelowestpartoftheboilershell,tominimizetemperaturedifferentialsandthethermalstresses.HarbinEngineeringUniversity精品資料Themainandauxiliarysteamlinesshouldnowbewarmedbycrackopeningoftheboilermainandauxiliarystopvalves.Whenthelinesarehotclosethedrains.HarbinEngineeringUniversity精品資料Inadditionthewaterlevelgaugesshouldbeblownthroughandcheckedforcorrectreading.HarbinEngineeringUniversity精品資料Whenthesteampressureisabout300KN/m2belowthenormaloperatingvalue,thesafetyvalvesshouldbeliftedandreleasedusingtheeasinggear(放松裝置(zhuāngzhì)、釋放裝置(zhuāngzhì)).HarbinEngineeringUniversity精品資料Onceatoperatingpressure,theboilermaybeputonloadandthesuperheatercirculatingvalvesclosed.HarbinEngineeringUniversity精品資料Allothervents,drainsandby-passesshouldthenbeclosed.Thewaterlevelintheboilershouldbemaintained.HarbinEngineeringUniversity精品資料B.Boilershut-downandsecuring(封爐)Thisoperationmayhavetobedonenormallyattheendofavoyageorinemergency.HarbinEngineeringUniversity精品資料Fornormalshut-downthesuitableprocedureis:-Carryoutsootblowing,ifpermissible.HarbinEngineeringUniversity精品資料-Changecombustioncontrolfromautomatictomanual.-Changefuelsupplytodieseloil;shutsteamoff

fuelheatersandtraceheating(伴熱管).HarbinEngineeringUniversity精品資料Closeburnersupplyvalvesandmainfuelshutoffvalve.-Purgeboilerfurnaceswithairforthreetofiveminutes;stopforceddraughtfan.HarbinEngineeringUniversity精品資料-Closesteamstopvalvesonboilerwhenpressureisreduced.Drainboilerwhenithascooleddownorfillwithtreatedwater.HarbinEngineeringUniversity精品資料C.BoilerwatertestingTestsrequiredarehardness(硬度(yìngdù)),alkalinity(堿度),chloride(氯化物),dissolved(溶解)solids(orconductivity傳導(dǎo)率),hydrazine(聯(lián)氨),phosphate(磷酸鹽),pHandoccasionallysilica(二氧化硅).HarbinEngineeringUniversity精品資料Theessentialtestforcontroloftreatmentarealkalinity,chlorideordissolvedsolids,phosphateandhydrazine.HarbinEngineeringUniversity精品資料Phenolphthalein(酚酞(fēntài))AlkalinityinboilerwaterFivetotendropsofphenolphthaleinareaddedtoameasured,filteredvolumeofsample.Ifalkaline,apinkcolorisproduced.HarbinEngineeringUniversity精品資料Titrate(以滴定法測定(cèdìng))withsulphuricacid(硫酸)ofknownstrengthwithcontinuousstirringofthesamplewithaglassroduntilthepinkcolourjustdisappears.HarbinEngineeringUniversity精品資料Theboileralkalinityinpartspermillioniscalculatedfromthestrengthoftheacidandvolumeoftheboilerwatersample.HarbinEngineeringUniversity精品資料1.Measure20,50or100mloffilteredboilerwaterfromagraduatedcylinder(量筒(liángtǒng))intoacasserole(燒杯).HarbinEngineeringUniversity精品資料Add10dropsofphenolphthaleinindicatorsolution.Thesamplewillturnpinkifphenolphthaleinalkalinityispresent.HarbinEngineeringUniversity精品資料2.Addsulphuricacidsolution,strength0.02Nfroma10mlautomaticburette(滴管(dīɡuǎn)),stirringcontinuouslyuntilthepinkcolourjustdisappears.Notetheburettereading.HarbinEngineeringUniversity精品資料3.Calculatetheresultasfollows:Alkalinitytophenolphthalein=1000×mlofsulphuricacid(0.02N)used volumeofsampleinml(expressedinppmintermsofCaCO3)HarbinEngineeringUniversity精品資料Chloridesinboilerwater1.Tothesampleusedforthephenolphthaleinalkalinitytestaddafurther1.0mlofsulphuricacidsolution,0.02N.HarbinEngineeringUniversity精品資料2.Add10dropsofpotassiumchromate(鉻酸鉀)

indicatorsolution.Thesamplewillturnyellow.HarbinEngineeringUniversity精品資料Addsilvernitrate(硝酸銀)solution,strength0.02Nfroma10mlautomaticburette,stirringcontinuouslyuntiltheyellowjustchangestoareddish

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

VolumeofsampleinmlHarbinEngineeringUniversity精品資料Hardnessby

EDTA(乙二胺四乙酸)

inBoilerWaterIncorrectlytreatedboilerwaters,thehardnessisverysmall.HarbinEngineeringUniversity精品資料Thehardnessisdeterminedbytitratinga100mlsampleofboilerwaterwithastandardsolution().02N)ofEDTAusingMordantBlack(黑色煤染劑)asindicatorwhichHarbinEngineeringUniversity精品資料whichgivesaredcolourinthepresenceofanalkalinesolutionofcalcium(鈣)

andmagnesium(鎂)salts.HarbinEngineeringUniversity精品資料Thesampleofboilerwatermustbefilteredbeforetesting.1.Measure100mloffilteredboilerwaterfromagraduatedcylinderintoacasserole.HarbinEngineeringUniversity精品資料2.Add2mlofammonia(氨)buffersolution,anda