泄水锥形式对混流式水轮机压力脉动的影响分析  

Analysis of pressure oscillation characteristics in Francis hydraulic turbine with different runner cones

作　　者：钱忠东[1] 李万[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《水力发电学报》2012年第5期278-285,291,共9页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金资助项目(51079106);中央高校基本科研业务费专项资金资助(2103002)

摘　　要：本文采用Transition SST湍流模型对模型混流式水轮机三维全流道非定常湍流进行模拟。在实验验证的基础上,针对五个导叶开度工况,分析了原型泄水锥、加长型泄水锥、加长加槽型泄水锥和圆头型泄水锥对水轮机压力脉动的影响,分析结果表明:三种改型泄水锥均能改变尾水涡带的形态,使得特殊压力脉动带变窄;泄水锥改型对水力效率、尾水管压力脉动的影响与导叶开度有关,圆头型泄水锥对减小压力脉动振幅的综合效果最好;泄水锥改型只对由尾水涡带引起的低频压力脉动有效,对动静干扰引起的叶片频率压力脉动影响不明显。Three-dimensional unsteady turbulent flow in the full flow passage of a model Francis hydraulic turbine was numerically simulated with a transition SST turbulence model. This model was verified using experimental data. Pressure oscillations in this turbine in five operation conditions were analyzed for four runner cone schemes, original cone design, extended cone, extended cone with grooves, round-top cone. Results show that in all the three improved schemes, vortex rope in the draft tube takes distribution patterns different from original design, and its frequency band of pressure oscillation is narrower. As guide vane opening varies, the influence of cone shape on hydraulic efficiency and pressure oscillations is different. Round-top cone is the best in terms of peak-to-peak amplitude. The improved schemes are effective in reducing low-frequency pressure oscillations induced by this vortex rope, while little effective in reducing blade-frequency pressure oscillation caused by rotor-stator interaction.

关 键 词：混流式水轮机 压力脉动 泄水锥 数值模拟 

分 类 号：TV136.1[水利工程—水力学及河流动力学]