中文摘要：

基于海南大广坝水电站水轮机改造项目,通过分析电站运行中存在的水力不稳定现象和水轮机效率水平偏低的原因,提出了水轮机的改造方案和目标;讨论了水力参数和设计理念;介绍了改造前后转轮流道的本质差异。通过全流道数值仿真计算,定性评估了改造后水轮机的稳定性,定量标定了水轮机的效率水平,预期了模型水轮机的综合特性曲线。结论认为,改造后模型水轮机最优效率大于93.8%,额定效率91%,加权平均效率89.3%;原型水轮机最优效率95.1%,额定效率92.4%,加权平均效率90.8%;与改造前相比,加权平均效率增幅可达2.0%。

英文摘要：

A new retrofitting method and target are presented by means of analyzing the phenomenon of hydraulic instability and the reason of relatively low turbine efficiency based on the transformation project referring to Daguangba Hydropower station in Hainan,meanwhile,hydraulic parameters selection and design conception are discussed in details.Also,this paper introduces the essential difference of runner channel between pre-and-post retrofit.According to the full passage numerical simulation computation,the hydraulic stability of retrofitted Francis runner is qualitatively evaluated and the efficiency level is quantitatively indicated.Finally,the paper has predicted the comprehensive feature curves of the model water-turbine.The conclusions indicate that the model turbine optimum efficiency exceeds 93.8%,the rated efficiency and weighted average efficiency are respectively 91%and 89.3%compared with 95.1%optimum efficiency,92.4%rated efficiency,and 90.8% weighted average efficiency originating from the prototype turbine;the weighted average efficiency of the model turbine significantly increases 2.0% by contrast with the one of the prototype turbine.