PMI培训资料：汽轮机1

汽轮机

steamturbine汽轮机在石油化工厂的作用Theapplicationofsteamturbineinpetrochemicalplant汽轮机是将蒸汽的热能转换成机械功的旋转式动力机械convertedintoshaftrotation，汽轮机具有功率大、转速高、经济性好等显著优点，因此被广泛用于电力、冶金，石油化工等行业，作为原动机来驱动发电机、压缩机、鼓风机、水泵等工作机械。

A

steamturbineisarotationtypedrivingmachinewhichconvertthermalenergy

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

steamturbine

isadevicethatextractsthermal

energy

frompressurized

steam

andusesittodo

mechanicalwork

onarotatingoutputshaft.汽轮机的分类Typesofsteamturbine按作用原理分类Classificationsaccordingtoworkingprinciples冲动式汽轮机Impulseturbines冲动式汽轮机，蒸汽只在汽轮机的静叶栅中降压膨胀加速，在动叶栅内不降压不膨胀，动叶只是把蒸汽动能转换成机械功，同时改变汽流方向Intheimpulseturbine,pressuredrop,expansionandvelocityincreaseofsteamoccursacrossonlythestationaryblades.Pressuredropandexpansiondon’toccurinmovingblades.Themovingbladesonlyconvertsteamkineticenergyintomechanicalworkwhilechangingflowdirection.Apressuredropoccursacrossonlythestationaryblades,withanetincreaseinsteamvelocityacrossthestage.Asthesteamflowsthroughthenozzleitspressurefallsfrominletpressuretotheexitpressure(atmosphericpressure,ormoreusually,thecondenservacuum).Duetothishighratioofexpansionofsteam,thesteamleavesthenozzlewithaveryhighvelocity.Thesteamleavingthemovingbladeshasalargeportionofthemaximumvelocityofthesteamwhenleavingthenozzle.Thelossofenergyduetothishigherexitvelocityiscommonlycalledthecarryovervelocityorleavingloss.反动式汽轮机Reactionturbines反动式汽轮机，蒸汽在汽轮机的静叶栅中被降压、膨胀和加速，在动叶栅中也被进一步降压、膨胀加速。动叶不但将蒸汽的动能，同时也将蒸汽的部分内能转换成机械功，这种汽轮机称为反动式汽轮机Inthe

reactionturbine,pressuredrop,expansionandvelocityincreaseofsteamisundergoneacrossthefixedvanesofthestatorandpressuredrop,expansionandvelocityincreaseofsteamisfurtherresultedacrossthemovingblades.Movingbladesconvertbothsteamkineticenergyandpartofitsinternalenergyintomechanicalwork.Inthe

reactionturbine,the

rotor

bladesthemselvesarearrangedtoformconvergent

nozzles.Thistypeofturbinemakesuseofthereactionforceproducedasthesteamacceleratesthroughthenozzlesformedbytherotor.Steamisdirectedontotherotorbythefixedvanesofthestator.Itleavesthestatorasajetthatfillstheentirecircumferenceoftherotor.Thesteamthenchangesdirectionandincreasesitsspeedrelativetothespeedoftheblades.Apressuredropoccursacrossboththestatorandtherotor,withsteamacceleratingthroughthestatoranddeceleratingthroughtherotor,withnonetchangeinsteamvelocityacrossthestagebutwithadecreaseinbothpressureandtemperature,reflectingtheworkperformedinthedrivingoftherotor.衡量蒸汽在动叶栅内膨胀过程度的参数叫反动度。Degreeofreactionisameasurementofsteamexpansiondegreeacrossmovingblades.

反动度定义：在叶栅中蒸汽膨胀的过程占级中总的应该膨胀程度的比例数，或是动栅中的理想焓降于级的总焓降之比，通常用β表示。Degreeofreactionorreactionratio(R)isdefinedastheratioofstaticpressuredropintherotortothestaticpressuredropinthestageorastheratioofstaticenthalpydropintherotortothestaticenthalpydropinthestage.Averywidelyuseddesignhashalf

degreeofreaction

or50%reactionandthisisknownasParson’sturbine.Thisconsistsofsymmetricalrotorandstatorblades.Forthisturbinethevelocitytriangleissimilarandwehave:

汽轮机的特点Thecharacteristicsofsteamturbine

汽轮机转速高，高速汽轮机转速在10000r/min以上，可直接与离心泵或离心压缩机联接；一般电动机转速只能达到工频3000r/min(3600r/min)，与高转速的泵或离心压缩机联接时，还需要设置增速设备。Rotatingspeedofsteamturbinecanbeveryhigh.Thespeedofahighspeedturbinecanbeashighasabove10000r/minandcanbedirectlycoupledtocentrifugalpumporcentrifugalcompressor;Rotatingspeedofacommonlyusedmotorcanreach3000r/minpowerfrequency(3600r/min),andaspeedincreasingequipmentisneededwhencoupledtohighspeedpumporcentrifugalcompressor.Theturbinesusedforelectricpowergenerationaremostoftendirectlycoupledtotheirgenerators.汽轮机的转速在一定范围内变动，增加了调节手段和操作的灵活性，电机的转速是固定的，调速需要增加调速设备。（机械可用液力耦合器、电子的可使用变频）Therotatingspeedofasteamturbinecanvarywithinarangewhichmakeitflexibleandadjustable.However,motorhasaconstantrotatingspeedanditwillneedadditionalspeedregulationequipmentforspeedchange(fluidcoupling(mechanical)orfrequencyconverter(electronic)).汽轮机驱动适应输送或压缩易燃易爆介质，即使有泄漏也不会由原动机引起事故，电机驱动必须采取有效的防爆措施。Steamturbinesaresuitableforbeingusedasdriveintransportingandcompressingexplosivematerialandevenaleakagecannotresultinanaccidentfromdrivingmachine.However,amotordrivemusttakeeffectiveexplosionpreventionmeasures.汽轮机使用蒸汽驱动，炼厂都有自备的热电厂，蒸汽来源稳定，而电动机要受电网的影响，正由于汽轮机可直接驱动较大型的高速炼油化工机器。而且具有启动扭矩大，容易实现转速调节，适宜在防爆区域工作，故在炼油化工行业得到广泛的运用。Steamturbinesusesteamasdrivingpowerwhichcanbereceivedfromreliablesourcesofself-containedthermalpowerplantinrefinery.However,amotorhavetodependonpowergridandsusceptibletoitsinfluence.Theadvantagesofitscapablecouplingdirectlytolargehighspeedmachineforpetrochemicalplant,greatstartuptorque,easyofspeedregulation,suitableforoperationinexplosion-proofareas,thesteamturbinesarewidelyusedinpetrochemicalindustry.按排气方式分类Classificationsaccordingtoexhaustconditions凝汽式汽轮机Condensingturbines背压式汽轮机Backpressureturbines抽气式汽轮机Extractingtypeturbines还有按能量传递方式分类、蒸汽流道数目分类、蒸汽流道类型分类。Therearealsotypesclassifiedaccordingtoenergytransfer,numberofsteamchannelsandtypesofsteamchannels.凝气式汽轮机Condensingturbine背压式汽轮机Backpressureturbine抽气式汽轮机Extractingtypeturbine汽轮机Steamturbine汽轮机主要零部件的结构与作用Structureandfunctionsofthemainpartsofsteamturbine汽轮机调速系统Speedregulationofsteamturbine汽轮机的辅助设备Auxiliaryequipmentofsteamturbine汽轮机开停机Startupandstopofsteamturbine汽轮机常见故障及处理

Commonfaultsandtroubleshooting汽轮机主要结构与作用Themainstructuresandfunctions

汽轮机典型结构Typicalstructureofsteamturbine转子Rotor轴承Bearings调节阀Control(governing)valve气缸Casing蒸汽室Steamchest静叶持环Stationarybladering汽封Vapourseal汽轮机典型结构（背压式）Typicalstructureofsteamturbine(Backpressuretype)调节阀Regulatingvalve

转子Rotor危机保安器Emergencygovernor前轴承支座

Frontbearinghousing汽缸Casing盘车装置

Turninggear汽轮机典型结构（凝汽式）Typicalstructureofsteamturbine(Condensingtype)调节阀Regulatingvalve

转子Rotor危机保安器

Emergencygovernor前轴承支座

Frontbearinghousing汽缸Casing盘车装置

Turninggear后轴承支座

Rearbearinghousing转子Rotor转子为整体锻件，转子上的动叶分为调节级动叶governingstageblade和压力级动叶。叶片的型线及叶根结构是不同的，各级叶片均为不调频，以适应机组大范围变速运行的要求。Therotorissolidforged.Themovingbladesonrotorincludegoverningstagebladesandpressuringstageblades.Thebladeprofilesandbladerootstructuresaredifferent.Allthebladesofeverystageareuntunedbladestomeetwide-rangespeedregulatingrequirement.危急保安器的作用是在汽轮机转速超过规定值时产生作用，起到停机保护作用。它是与危急遮断油门配对的。Theemergencygovernorwillactwhensteamturbinespeedexceedtherequiredvaluetostopandprotectthemachine.Itactsthroughemergencygovernorpilotvalve.推力盘承受汽轮机运行产生的轴向力，也是转子与静止部件的定位部件。Thrustcollar

bearthethrustforceresultedwhensteamturbinerunning.Itisalsoapositioningpartbetweenrotorandstationaryparts.凝汽式汽轮机转子Steamturbinerotor(Condensingtype)背压式汽轮机转子Steamturbinerotor(Backpressuretype)前轴承支座Frontbearinghousing用以支持汽缸及转子，并可准确地保持相互间的位置，另外汽缸和前轴承座通过两拉杆螺钉的连接，使汽缸和轴承座在调整好的正确位置上固定下来。Forcasingandrotorsupportingandtokeepaccuraterelativepositionsbetweenthem.CasingandFrontbearinghousingareconnectedbytworodscrewstoadjusttherelativepositionsandfixthem.推力轴承Thrustbearing推力盘Thrustcollar油封Oilseal径向轴承Radialbearing测速讯号盘Signalpanelforspeeddetection后轴承支座Rearbearinghousing后支座是支承汽缸和转子，并用于这些部件相互位置的调整。

Itisusedforcasingandrotorsupportingandtoadjusttherelativepositionsbetweenthem.油封Oilseal径向瓦Radialpad盘车棘轮Barringratchet径向轴承Radialbearing

作用：Functions:汽轮机转子通过径向轴承支持在轴承座上，故轴承的作用是承受着转子在启动增速，稳定运行及停在降速时所产生的全部静负荷和动负荷（包括可能出现的振动）。同时还要保持转子中心与汽轮机汽缸、汽封、导叶持环等设计的间隙。Steamturbinerotorissupportedonbearinghousingthroughradialbearing,therefore,thefunctionsofthebearingsistobearallthestaticloadanddynamicloads(andanyvibrationpossiblyoccurred)

atthetimeofstartup,normaloperationandspeeddown.Italsokeepsthedesignclearancesbetweenrotorandcasing,vaporsealandguidebladering.结构：Structure:径向轴承由上下两半轴瓦组成，轴瓦由锥形销钉来固定，并通过螺栓把上下两半连接起来。轴承的承载面浇有巴氏合金。下半轴瓦与下半轴承箱中分面用圆柱销钉定位，以阻止轴瓦径向或轴向移动。Radialbearingcomprisesupperhalfandlowerhalfbearingbushwhichisfixedbytapereddowelandconnectedbybolts.TheloadingsurfacesofthebearingispouredwithBabbitt.Thelowerhalfbushisfixedonthebearinghousingsplitsurfacewith

cylindricalpintostopitsradialoraxelmovement.瓦块轴承体油封防转销推力轴承Thrustbearing作用：Functions:用来承受未被平衡的转子轴向推力，并传递给轴承座、推力大小主要决定于汽轮机运行工况，另外推力轴承限定了转子与汽缸的轴向相对位置。Tobeartheaxelunbalancedthrustfromrotorandtransmittheforcetobearinghouse.Thrustmagnitudemainlydependsonthesteamturbineoperationcondition.Thrustbearingalsofixtherelativepositionbetweenrotorandcasing.结构：Structure:推力轴承安装在前轴承座中，其由推力轴承体及倾斜式推力瓦块组成。推力瓦块上浇有巴氏合金，瓦块分布在推力盘两边的圆周上，可绕径向棱边适量迥转，因此推力盘与推力瓦块表面形成理想润滑油楔。推力瓦块用径向园柱销钉限位，防止周向移位，轴承体外部有两凸肩，并配有调整垫片，用以调整轴承体（或转子）与轴承座的相对位置。Thrustbearingisinstalledinthefrontbearinghousingandcomprisesbearingbodyandtiltingpadswithbabbittpouredonit.Thepadsarearrangedinacirclearoundtheshaft,andwhicharefreetopivot.Thesecreatewedge-shapedregionsofoilinsidethebearingbetweenthepadsandarotatingdisk,whichsupporttheappliedthrustandeliminatemetal-on-metalcontact.Thethrustpadsarefixedwithcylindricalpintostopcirclemovement.Therearetwoshouldersontheoutsideofthebearingbodywhichareequippedwithadjustingshimfortherelativepositionadjustingbetweenbearingbody(orrotor)andbearinghousing.轴承体Bearingbody瓦块Pad热电偶Thermalcouple调节阀Regulatingsteamvalve

调节阀是由调速系统控制液压油缸带动杠杆上下移动，油缸向下移动，拉杆带动阀梁上移，在阀梁上的阀碟也随之上移，调节气门的间隙增大，进入的蒸汽也随之增大，汽轮机的输出功率增大。注：阀碟在阀梁上的活动的寸是不同的，也不是按顺序排列的。Thegovernorisoperatedbyspeedgoverningsystemtocontrolhydrauliccylinderwhichmovetheleverupanddown.Downwardmovementofhydrauliccylinderwillpullthevalverodmoveupwhichliftsvalvesettingtogetherwithvalvebeam.Thisincreasesthegapoftheregulatingvalveresultinglargeramountofcomingsteamwithlargersteamturbinepoweroutput.Note:Themovementrangeofthevalvesettingsaredifferentandtheyarenotarrangedregularly.阀梁Valvestem阀碟Valvedisc拉杆孔Theholeforrod1Lever2Connectingplate3Valvecover4Cylindersteamchamber5Valvestem6Valvedisc7Bush8Valveseat9Valvepole10Lowerguidesleeve11Bracket12Upperguidesleeve13Support14Springcomponents15Oilmotivator汽缸Cylinder汽缸包括：Comprises:外缸Outercylinder内缸Innercylinder前气封Frontgasseal后气封Reargasseal蒸汽室Steamchest高压导叶持环Highpressureguidebladeretainingring低压导叶持环