混流式水轮机尾水管涡带及改善措施研究  

Study on Vortex Zone of Draft Tube and Improvement Measures of Francis Turbine

作　　者：吴在强 林亚涛 关英波 陈泽钦 徐君蕙 郑源[3] WU Zai-qiang;LIN Ya-tao;GUAN Ying-bo;CHEN Ze-qin;XU Jun-hui;ZHENG Yuan(Fujian Provincial Electric Power Company Limited Electric Research Insititute,Fuzhou 350007,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210024,China;College of Energy and Electrical Engineering,Hohai University,Nanjing 21l100,China)

机构地区：[1]国网福建省电力有限公司电力科学研究院,福建福州350007 [2]河海大学水利水电学院,江苏南京210024 [3]河海大学能源与电气学院,江苏南京211100

出　　处：《水电能源科学》2023年第7期197-200,196,共5页Water Resources and Power

基　　金：国网福建省电力有限公司科技项目(52130420001F)。

摘　　要：水电机组长期运行在偏离最优运行区域的低负荷区会产生机组振动大、水流流态不良等情况,从而导致转轮叶片出现裂纹、机组汽蚀严重等不良后果。针对尾水管内复杂的流动状况,提出了两种型式的导流装置改进方案,基于雷诺时均N-S方程,采用标准SSTκ-ω湍流模型,对0.45Pr(Pr为额定出力)、0.60Pr、0.75Pr三种工况进行定常和非定常求解计算。结果表明,安装导流装置可有效削减尾水管的偏心涡带,且大幅降低压力脉动振幅,从而减小机组的振动。综合尾水管流线、尾水管涡带、水轮机效率及压力脉动幅值,尤其是压力脉动的强弱对水轮机稳定运行的重要性,最终认为两种方案中,在尾水管进口处对称布置两块导流板对该混流式水轮机改善效果更好。研究结果为混流式水轮机组低负荷安全运行提供一定的理论基础。Due to the long-term operation in the low-load area,the hydropower unit deviates from the optimal operation area,resulting in large vibration of the unit,poor flow state of water flow,and other adverse consequences,such as cracks in runner blades and serious cavitation of the unit.In view of the complex flow conditions in the draft tube,this paper proposes two improvement schemes.Based on RANS equation,the standard SSTκ-ωturbulence model is adopted to calculate the steady and unsteady solutions for three operating conditions of 0.45P_r(P_r is rated output),0.60P_r,and 0.75P_r.The results show that the installation of the guiding device can effectively reduce the eccentric vortex band of the draft tube,and greatly reduce the pressure pulsation amplitude,so as to reduce the vibration of the unit.Considering the streamline of draft tube,vortex zone of draft pipe,turbine efficiency and pressure pulsation amplitude,especially the importance of pressure pulsation intensity to the stable operation of the turbine,it is concluded that the symmetrical arrangement of two diversion plates at the inlet of the draft tube has the better improvement effect on the Francis turbine.The results provide a certain theoretical basis for the safe operation of the hydraulic turbine unit under low load.

关 键 词：混流式水轮机 低负荷 非定常 压力脉动 导流装置 

分 类 号：TK733[交通运输工程—轮机工程] TV734.1[动力工程及工程热物理—流体机械及工程]