汽轮机低压末三级耦合排汽缸气动性能研究

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1、第42卷第3期热力透平V01．42No．32013年9月THERMALTURBlNESep．2013汽轮机低压末三级耦合排汽缸的气动性能研究邵卫东，杨建道，杨锐，史立群，李军(1．西安交通大学叶轮机械研究所，西安710049；2．上海汽轮机厂有限公司特殊透平与通流叶片研究所，上海200240)摘要：为满足大型核电汽轮机低压排汽系统的开发，采用ANSYS—CFX软件数值求解ReynoldsAveragedNavier—Stokes(RANS)方程和k—s紊流模型方法研究了低压缸末三级与排汽缸的变工况气动性能。结果表明：变工况显著改变了末级动叶的气动性能，对次次末级、次末级和末级静叶的

2、气动性能几乎没有影响；排汽缸的气动性能受变工况的影响较大，小流量工况下的涡系结构发生较大变化，降低了扩压器静压恢复能力，增加了总压损失和改变了蜗壳内的流场；排汽缸背压减小导致透平级流量的降低和末级动叶出15／气流角的变化，进而改变了排汽缸进口的流场特征。研究结果可以为汽轮机排汽缸的设计和优化提供理论支持。关键词：汽轮机；排汽缸；低压透平级；气动性能；数值模拟中图分类号：TK262文献标识码：A文章编号：1672—5549(2013)03．0150。06NumericalInvestigationonAerodynamicPerformanceofLastThreeStagesand

3、ExhaustHoodforSteamTurbinesSHAOWei．dong，YANGJian—dao一，YANGRui，SHILi．qun，LIJun(1．InstituteofTurb0machinery，Xi’anJiaotongUniversity，Xi’an710049，China；2．ATBTI，ShanghaiTurbineWorksCo．，Ltd．，Shanghai200240，China)Abstract：Aerodynamicperformanceofthelastthreestagesandexhausthoodwasnumericallyinvestiga

4、tedtosatisfythedevelopmentofexhaustsysteminlargenuclearpowersteamturbinesbyusingthree-dimensionalReynolds—AveragedNavier—Stokes(RANS)andk—sturbulentmodelbasedontheCFDsoftwareANSYS—CFX．ThedetailedflowpatternoftheexhausthoodandaerodynamicparametersofthelastthreestageswasanMyzedattwodifferentflow

5、conditionsincludingthe75％designedoperations．Thenumericalresultsshowthatthevailableflowconditionsmarkedlychangetheaerodynamicperformanceoflaststagerotorandhavelittleinfluenceonthethirdlaststage，secondlaststageandlaststagestator．Thevo~exstructurehasasignificantchangeat75％designedworkingcondition

6、bycomparisonofthedesignedcase，whichdecreasesthestaticpressurerecoveryability，increasesthetotalpressurelOSSandchangestheflowfieldinthevolute．Thedecreaseofbackpressureresultsinthereductionofflowrateandyawanglevariationoflaststagerotor．Moreover，theflowfieldcharacteristicsofexhausthoodinletchangec

7、orrespondingly．Relevantresuhsofthisstudyareexpectedtosuppoflthedesignandoptimizationofexhausthoods．Keywords：steamturbine；exhausthood；lowpressurestages；aerodynamicperformance；numericalsimulation百万千瓦等级半转速核电汽轮机承担着发电在核电汽轮机中排汽缸连接着低压缸和凝汽基本负荷，