PMI培訓資料：汽輪機1

汽輪機

steamturbine汽輪機在石油化工廠的作用Theapplicationofsteamturbineinpetrochemicalplant汽輪機是將蒸汽的熱能轉換成機械功的旋轉式動力機械convertedintoshaftrotation，汽輪機具有功率大、轉速高、經濟性好等顯著優(yōu)點，因此被廣泛用于電力、冶金，石油化工等行業(yè)，作為原動機來驅動發(fā)電機、壓縮機、鼓風機、水泵等工作機械。

A

steamturbineisarotationtypedrivingmachinewhichconvertthermalenergy

ofsteamintomechanicalwork.Steamturbineshavesignificantadvantagessuchasgreatpower,highspeedandgoodeconomy.Theyarewidelyusedinpower,metallurgyandpetrochemicalindustryfordrivinggenerators,compressors,blowersandpumps.A

steamturbine

isadevicethatextractsthermal

energy

frompressurized

steam

andusesittodo

mechanicalwork

onarotatingoutputshaft.汽輪機的分類Typesofsteamturbine按作用原理分類Classificationsaccordingtoworkingprinciples沖動式汽輪機Impulseturbines沖動式汽輪機，蒸汽只在汽輪機的靜葉柵中降壓膨脹加速，在動葉柵內不降壓不膨脹，動葉只是把蒸汽動能轉換成機械功，同時改變汽流方向Intheimpulseturbine,pressuredrop,expansionandvelocityincreaseofsteamoccursacrossonlythestationaryblades.Pressuredropandexpansiondon’toccurinmovingblades.Themovingbladesonlyconvertsteamkineticenergyintomechanicalworkwhilechangingflowdirection.Apressuredropoccursacrossonlythestationaryblades,withanetincreaseinsteamvelocityacrossthestage.Asthesteamflowsthroughthenozzleitspressurefallsfrominletpressuretotheexitpressure(atmosphericpressure,ormoreusually,thecondenservacuum).Duetothishighratioofexpansionofsteam,thesteamleavesthenozzlewithaveryhighvelocity.Thesteamleavingthemovingbladeshasalargeportionofthemaximumvelocityofthesteamwhenleavingthenozzle.Thelossofenergyduetothishigherexitvelocityiscommonlycalledthecarryovervelocityorleavingloss.反動式汽輪機Reactionturbines反動式汽輪機，蒸汽在汽輪機的靜葉柵中被降壓、膨脹和加速，在動葉柵中也被進一步降壓、膨脹加速。動葉不但將蒸汽的動能，同時也將蒸汽的部分內能轉換成機械功，這種汽輪機稱為反動式汽輪機Inthe

reactionturbine,pressuredrop,expansionandvelocityincreaseofsteamisundergoneacrossthefixedvanesofthestatorandpressuredrop,expansionandvelocityincreaseofsteamisfurtherresultedacrossthemovingblades.Movingbladesconvertbothsteamkineticenergyandpartofitsinternalenergyintomechanicalwork.Inthe

reactionturbine,the

rotor

bladesthemselvesarearrangedtoformconvergent

nozzles.Thistypeofturbinemakesuseofthereactionforceproducedasthesteamacceleratesthroughthenozzlesformedbytherotor.Steamisdirectedontotherotorbythefixedvanesofthestator.Itleavesthestatorasajetthatfillstheentirecircumferenceoftherotor.Thesteamthenchangesdirectionandincreasesitsspeedrelativetothespeedoftheblades.Apressuredropoccursacrossboththestatorandtherotor,withsteamacceleratingthroughthestatoranddeceleratingthroughtherotor,withnonetchangeinsteamvelocityacrossthestagebutwithadecreaseinbothpressureandtemperature,reflectingtheworkperformedinthedrivingoftherotor.衡量蒸汽在動葉柵內膨脹過程度的參數叫反動度。Degreeofreactionisameasurementofsteamexpansiondegreeacrossmovingblades.

反動度定義：在葉柵中蒸汽膨脹的過程占級中總的應該膨脹程度的比例數，或是動柵中的理想焓降于級的總焓降之比，通常用β表示。Degreeofreactionorreactionratio(R)isdefinedastheratioofstaticpressuredropintherotortothestaticpressuredropinthestageorastheratioofstaticenthalpydropintherotortothestaticenthalpydropinthestage.Averywidelyuseddesignhashalf

degreeofreaction

or50%reactionandthisisknownasParson’sturbine.Thisconsistsofsymmetricalrotorandstatorblades.Forthisturbinethevelocitytriangleissimilarandwehave:

汽輪機的特點Thecharacteristicsofsteamturbine

汽輪機轉速高，高速汽輪機轉速在10000r/min以上，可直接與離心泵或離心壓縮機聯(lián)接；一般電動機轉速只能達到工頻3000r/min(3600r/min)，與高轉速的泵或離心壓縮機聯(lián)接時，還需要設置增速設備。Rotatingspeedofsteamturbinecanbeveryhigh.Thespeedofahighspeedturbinecanbeashighasabove10000r/minandcanbedirectlycoupledtocentrifugalpumporcentrifugalcompressor;Rotatingspeedofacommonlyusedmotorcanreach3000r/minpowerfrequency(3600r/min),andaspeedincreasingequipmentisneededwhencoupledtohighspeedpumporcentrifugalcompressor.Theturbinesusedforelectricpowergenerationaremostoftendirectlycoupledtotheirgenerators.汽輪機的轉速在一定范圍內變動，增加了調節(jié)手段和操作的靈活性，電機的轉速是固定的，調速需要增加調速設備。（機械可用液力耦合器、電子的可使用變頻）Therotatingspeedofasteamturbinecanvarywithinarangewhichmakeitflexibleandadjustable.However,motorhasaconstantrotatingspeedanditwillneedadditionalspeedregulationequipmentforspeedchange(fluidcoupling(mechanical)orfrequencyconverter(electronic)).汽輪機驅動適應輸送或壓縮易燃易爆介質，即使有泄漏也不會由原動機引起事故，電機驅動必須采取有效的防爆措施。Steamturbinesaresuitableforbeingusedasdriveintransportingandcompressingexplosivematerialandevenaleakagecannotresultinanaccidentfromdrivingmachine.However,amotordrivemusttakeeffectiveexplosionpreventionmeasures.汽輪機使用蒸汽驅動，煉廠都有自備的熱電廠，蒸汽來源穩(wěn)定，而電動機要受電網的影響，正由于汽輪機可直接驅動較大型的高速煉油化工機器。而且具有啟動扭矩大，容易實現(xiàn)轉速調節(jié)，適宜在防爆區(qū)域工作，故在煉油化工行業(yè)得到廣泛的運用。Steamturbinesusesteamasdrivingpowerwhichcanbereceivedfromreliablesourcesofself-containedthermalpowerplantinrefinery.However,amotorhavetodependonpowergridandsusceptibletoitsinfluence.Theadvantagesofitscapablecouplingdirectlytolargehighspeedmachineforpetrochemicalplant,greatstartuptorque,easyofspeedregulation,suitableforoperationinexplosion-proofareas,thesteamturbinesarewidelyusedinpetrochemicalindustry.按排氣方式分類Classificationsaccordingtoexhaustconditions凝汽式汽輪機Condensingturbines背壓式汽輪機Backpressureturbines抽氣式汽輪機Extractingtypeturbines還有按能量傳遞方式分類、蒸汽流道數目分類、蒸汽流道類型分類。Therearealsotypesclassifiedaccordingtoenergytransfer,numberofsteamchannelsandtypesofsteamchannels.凝氣式汽輪機Condensingturbine背壓式汽輪機Backpressureturbine抽氣式汽輪機Extractingtypeturbine汽輪機Steamturbine汽輪機主要零部件的結構與作用Structureandfunctionsofthemainpartsofsteamturbine汽輪機調速系統(tǒng)Speedregulationofsteamturbine汽輪機的輔助設備Auxiliaryequipmentofsteamturbine汽輪機開停機Startupandstopofsteamturbine汽輪機常見故障及處理

Commonfaultsandtroubleshooting汽輪機主要結構與作用Themainstructuresandfunctions

汽輪機典型結構Typicalstructureofsteamturbine轉子Rotor軸承Bearings調節(jié)閥Control(governing)valve氣缸Casing蒸汽室Steamchest靜葉持環(huán)Stationarybladering汽封Vapourseal汽輪機典型結構（背壓式）Typicalstructureofsteamturbine(Backpressuretype)調節(jié)閥Regulatingvalve

轉子Rotor危機保安器Emergencygovernor前軸承支座

Frontbearinghousing汽缸Casing盤車裝置

Turninggear汽輪機典型結構（凝汽式）Typicalstructureofsteamturbine(Condensingtype)調節(jié)閥Regulatingvalve

轉子Rotor危機保安器

Emergencygovernor前軸承支座

Frontbearinghousing汽缸Casing盤車裝置

Turninggear后軸承支座

Rearbearinghousing轉子Rotor轉子為整體鍛件，轉子上的動葉分為調節(jié)級動葉governingstageblade和壓力級動葉。葉片的型線及葉根結構是不同的，各級葉片均為不調頻，以適應機組大范圍變速運行的要求。Therotorissolidforged.Themovingbladesonrotorincludegoverningstagebladesandpressuringstageblades.Thebladeprofilesandbladerootstructuresaredifferent.Allthebladesofeverystageareuntunedbladestomeetwide-rangespeedregulatingrequirement.危急保安器的作用是在汽輪機轉速超過規(guī)定值時產生作用，起到停機保護作用。它是與危急遮斷油門配對的。Theemergencygovernorwillactwhensteamturbinespeedexceedtherequiredvaluetostopandprotectthemachine.Itactsthroughemergencygovernorpilotvalve.推力盤承受汽輪機運行產生的軸向力，也是轉子與靜止部件的定位部件。Thrustcollar

bearthethrustforceresultedwhensteamturbinerunning.Itisalsoapositioningpartbetweenrotorandstationaryparts.凝汽式汽輪機轉子Steamturbinerotor(Condensingtype)背壓式汽輪機轉子Steamturbinerotor(Backpressuretype)前軸承支座Frontbearinghousing用以支持汽缸及轉子，并可準確地保持相互間的位置，另外汽缸和前軸承座通過兩拉桿螺釘的連接，使汽缸和軸承座在調整好的正確位置上固定下來。Forcasingandrotorsupportingandtokeepaccuraterelativepositionsbetweenthem.CasingandFrontbearinghousingareconnectedbytworodscrewstoadjusttherelativepositionsandfixthem.推力軸承Thrustbearing推力盤Thrustcollar油封Oilseal徑向軸承Radialbearing測速訊號盤Signalpanelforspeeddetection后軸承支座Rearbearinghousing后支座是支承汽缸和轉子，并用于這些部件相互位置的調整。

Itisusedforcasingandrotorsupportingandtoadjusttherelativepositionsbetweenthem.油封Oilseal徑向瓦Radialpad盤車棘輪Barringratchet徑向軸承Radialbearing

作用：Functions:汽輪機轉子通過徑向軸承支持在軸承座上，故軸承的作用是承受著轉子在啟動增速，穩(wěn)定運行及停在降速時所產生的全部靜負荷和動負荷（包括可能出現(xiàn)的振動）。同時還要保持轉子中心與汽輪機汽缸、汽封、導葉持環(huán)等設計的間隙。Steamturbinerotorissupportedonbearinghousingthroughradialbearing,therefore,thefunctionsofthebearingsistobearallthestaticloadanddynamicloads(andanyvibrationpossiblyoccurred)

atthetimeofstartup,normaloperationandspeeddown.Italsokeepsthedesignclearancesbetweenrotorandcasing,vaporsealandguidebladering.結構：Structure:徑向軸承由上下兩半軸瓦組成，軸瓦由錐形銷釘來固定，并通過螺栓把上下兩半連接起來。軸承的承載面澆有巴氏合金。下半軸瓦與下半軸承箱中分面用圓柱銷釘定位，以阻止軸瓦徑向或軸向移動。Radialbearingcomprisesupperhalfandlowerhalfbearingbushwhichisfixedbytapereddowelandconnectedbybolts.TheloadingsurfacesofthebearingispouredwithBabbitt.Thelowerhalfbushisfixedonthebearinghousingsplitsurfacewith

cylindricalpintostopitsradialoraxelmovement.瓦塊軸承體油封防轉銷推力軸承Thrustbearing作用：Functions:用來承受未被平衡的轉子軸向推力，并傳遞給軸承座、推力大小主要決定于汽輪機運行工況，另外推力軸承限定了轉子與汽缸的軸向相對位置。Tobeartheaxelunbalancedthrustfromrotorandtransmittheforcetobearinghouse.Thrustmagnitudemainlydependsonthesteamturbineoperationcondition.Thrustbearingalsofixtherelativepositionbetweenrotorandcasing.結構：Structure:推力軸承安裝在前軸承座中，其由推力軸承體及傾斜式推力瓦塊組成。推力瓦塊上澆有巴氏合金，瓦塊分布在推力盤兩邊的圓周上，可繞徑向棱邊適量迥轉，因此推力盤與推力瓦塊表面形成理想潤滑油楔。推力瓦塊用徑向園柱銷釘限位，防止周向移位，軸承體外部有兩凸肩，并配有調整墊片，用以調整軸承體（或轉子）與軸承座的相對位置。Thrustbearingisinstalledinthefrontbearinghousingandcomprisesbearingbodyandtiltingpadswithbabbittpouredonit.Thepadsarearrangedinacirclearoundtheshaft,andwhicharefreetopivot.Thesecreatewedge-shapedregionsofoilinsidethebearingbetweenthepadsandarotatingdisk,whichsupporttheappliedthrustandeliminatemetal-on-metalcontact.Thethrustpadsarefixedwithcylindricalpintostopcirclemovement.Therearetwoshouldersontheoutsideofthebearingbodywhichareequippedwithadjustingshimfortherelativepositionadjustingbetweenbearingbody(orrotor)andbearinghousing.軸承體Bearingbody瓦塊Pad熱電偶Thermalcouple調節(jié)閥Regulatingsteamvalve

調節(jié)閥是由調速系統(tǒng)控制液壓油缸帶動杠桿上下移動，油缸向下移動，拉桿帶動閥梁上移，在閥梁上的閥碟也隨之上移，調節(jié)氣門的間隙增大，進入的蒸汽也隨之增大，汽輪機的輸出功率增大。注：閥碟在閥梁上的活動的寸是不同的，也不是按順序排列的。Thegovernorisoperatedbyspeedgoverningsystemtocontrolhydrauliccylinderwhichmovetheleverupanddown.Downwardmovementofhydrauliccylinderwillpullthevalverodmoveupwhichliftsvalvesettingtogetherwithvalvebeam.Thisincreasesthegapoftheregulatingvalveresultinglargeramountofcomingsteamwithlargersteamturbinepoweroutput.Note:Themovementrangeofthevalvesettingsaredifferentandtheyarenotarrangedregularly.閥梁Valvestem閥碟Valvedisc拉桿孔Theholeforrod1Lever2Connectingplate3Valvecover4Cylindersteamchamber5Valvestem6Valvedisc7Bush8Valveseat9Valvepole10Lowerguidesleeve11Bracket12Upperguidesleeve13Support14Springcomponents15Oilmotivator汽缸Cylinder汽缸包括：Comprises:外缸Outercylinder內缸Innercylinder前氣封Frontgasseal后氣封Reargasseal蒸汽室Steamchest高壓導葉持環(huán)Highpressureguidebladeretainingring低壓導葉持環(huán)