水轮机甩负荷过程金属蜗壳瞬态应力及疲劳分析  

Transient Stress and Fatigue Analysis of Metal Spiral Case During Load Rejection of Hydraulic Turbine

作　　者：李湧博 鞠小明[1,2] 杨帅 王文全 LI Yong-bo;JU Xiao-ming;YANG Shuai;WANG Wen-quan(College of Water Resources and Hydropower,Sichuan University,Chengdu 610065,China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学水利水电学院,四川成都610065 [2]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065

出　　处：《水电能源科学》2022年第12期161-164,132,共5页Water Resources and Power

基　　金：国家自然科学基金项目(52179087)。

摘　　要：为研究水电站水轮机金属蜗壳在甩负荷过渡过程中的瞬态应力变化,按某水电站输水发电系统布置,采用瞬变流特征线法确定导叶关闭过程中蜗壳内压力变化过程,再在其基础上利用三维有限元数值计算方法进行甩负荷过渡过程的瞬态应力仿真计算,获得蜗壳在压力升高过程中各时刻的应力分布情况,最后根据有限元计算结果分析蜗壳疲劳寿命。结果表明,蜗壳的等效应力波动过程与水流压力的变化过程基本保持一致,最大应力发生在蜗壳进口锥管段与座环连接处,最大值可达105.75 MPa,且蜗壳应力的分布规律受座环影响较大;在该瞬态载荷下蜗壳无疲劳破坏的风险。To study the transient stress variation process of metal spiral case during load rejection,the characteristic line method of transient flow was used to calculate the pressure variation process of spiral case during guide vane closing according to the layout of the water conveyance and hydropower system of a hydropower plant.Then,the transient dynamic stress of the spiral case in the process of load rejection was simulated by using three-dimensional finite element method(FEM),and the stress distribution diagram of the spiral case at each time in the process of water pressure rise were obtained.Finally,the fatigue life of spiral case structure was analyzed according to the FEM results.The results show that the stress variation process of the spiral case is basically consistent with that of water pressure.The maximum stress occurs at the connection between spiral case inlet cone pipe section and stay ring,with the maximum value of 105.75 MPa.The stay ring has a great impact on the stress distribution law of the spiral case.There is no risk of fatigue failure of the spiral case under this transient load.

关 键 词：水轮机蜗壳 水力过渡过程 瞬态应力 有限元计算 疲劳分析 

分 类 号：TV734.1[水利工程—水利水电工程]