改装泄水锥对水轮机水力激振的影响分析  

Analysis of influence of modified drain cone on hydraulic excitation of hydraulic turbine

作　　者：于安 吕舒键 唐庆宏 周大庆[1] YU An;LYU Shujian;TANG Qinghong;ZHOU Daqing(School of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China;School of Water Resources and Hydropower,Hohai University,Nanjing 211100,China)

机构地区：[1]河海大学能源与电气学院,江苏南京211100 [2]河海大学水利水电学院,江苏南京211100

出　　处：《华中科技大学学报（自然科学版）》2020年第11期115-119,132,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金青年基金资助项目(51806058)。

摘　　要：为提高水轮机尾水管的空化性能,提出在泄水锥上加螺纹并在泄水锥尾部安装延伸到尾水管进口处的可拆卸圆柱台的改装方案.对混流式水轮机模型进行全流道的网格划分,进口边界按照试验水头条件给定总压为290k Pa,出口边界根据计算工况的空化数设置静压为19 kPa.采用理论研究和数值模拟相结合的方法探究改装泄水锥对尾水管内部的流体流动、压力脉动及空化性能的影响.研究结果表明:在低负荷小流量工况下对泄水锥进行改装可以降低尾水管内空化程度,提高尾水管内部流体流动稳定性,并且减少流体间的撞击以及由于空化造成的压力脉动.To improve the cavitation performance of the draft tube of hydraulic turbine,a modification plan was proposed to add threads on the drain cone and install a detachable cylindrical platform extending to the inlet of the draft tube at the tail of the drain cone.The Francis turbine model was meshed in the whole flow channel.The inlet boundary was given a total pressure of 290 kPa according to the test head conditions,and the outlet boundary was set to a static pressure of 19 kPa according to the cavitation number of the calculation conditions.Theoretical research and numerical simulation was combined to explore the influence of the modified drain cone on the fluid flow,pressure pulsation and cavitation performance inside the draft tube.Research results show that the modification of the drain cone under low load and low flow conditions can reduce the degree of cavitation in the draft tube,improve the stability of fluid flow in the draft tube,reduce the impact between fluids,and reduce the pressure pulsation caused by cavitation.

关 键 词：混流式水轮机 尾水管 泄水锥 空化 压力脉动 

分 类 号：TH311[机械工程—机械制造及自动化]