混流式水轮机改造前后内部流动特性对比分析  

Internal flow analysis of Francis turbines before and after update

作　　者：罗丽[1] 赖喜德[1] 朱李[1] 李景悦[1] 

机构地区：[1]西华大学能源与动力工程学院,成都610039

出　　处：《水力发电学报》2016年第8期80-86,共7页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(51379179);西华大学研究生创新基金(ycjj2015042);流体及动力机械教育部重点实验室资助

摘　　要：为探究将某高水头电站原常规混流式水轮机转轮改造为长短叶片式转轮后的能量性能、空化性能以及水力稳定性的改变,采用流场数值模拟的计算方法对改造前后水轮机运行在典型工况(小开度工况、额定工况、大开度工况)下进行全流道三维定常空化湍流计算以及全流道三维非定常湍流计算分析。计算结果表明,改造后的水轮机效率在小开度工况处提高了6.7%,额定工况处提高了6.2%,大开度工况处效率提高了6.8%;改造后水轮机空化性能在大流量工况处得到了大幅度提高;改造后水轮机压力脉动幅值在小开度工况处降低了20.9%,额定工况处降低了21.5%,大开度工况处效率降低了13.8%(监测点1处)。研究结果对类似混流式水轮机的改造有一定的指导作用。Updating the normal runner of a Francis turbine with certain long and short blades can produce significant changes in its energy performance, cavitation performance, and hydraulic stability. To apply this technique, full-passage numerical simulations of Francis turbines before and after the update have been conducted in this work to examine the three-dimensional cavitation turbulent flows and their unsteady behaviors in three typical conditions： small openings, rating conditions, and large openings. The results show that the efficiency of the updated turbine is increased by 6.7%, 6.2% and 6.8% in these three cases respectively and its cavitation performance improved significantly in the latter case. And the updating reduces pressure pulsation amplitude by 20.9% at small openings, 21.5% at rating conditions, and 13.8% at large openings （at monitoring point 1）. Thus, the runner updating is effective in improving the performance of Francis turbines.

关 键 词：混流式水轮机 空化 压力脉动 对比分析 

分 类 号：TK730.2[交通运输工程—轮机工程]