变速恒频水轮机变流量工况下不稳定流动数值模拟  

Numerical simulation on unsteady flow in variable speed constant frequency hydraulicturbine under variable flow condition

作　　者：毛成 苏立 沈春和 文贤馗 MAO Cheng;SU Li;SHEN Chunhe;WEN Xiankui(Electric Power Research Institute of Guizhou Power Grid Co.,Ltd.,Guiyang 550002,China)

机构地区：[1]贵州电网有限责任公司电力科学研究院,贵州贵阳550002

出　　处：《人民长江》2024年第1期157-161,共5页Yangtze River

基　　金：贵州省科技支撑计划项目(黔科合支撑[2020]2Y042)。

摘　　要：为了研究变流量条件下变速恒频水轮机正常运转时的涡流特性和水动力特性,基于STAR-CCM+软件进行了混流式变速恒频水轮机的水动力特性数值模拟,研究了定流量和正弦流量两种工况下导叶和转轮压力脉动特性和内部流动状态,对旋转速度改变引起的涡旋演化过程进行了可视化展示。结果表明:在低转速时,尾水管进口和转轮交界处存在随转速降低而聚合产生的大尺度涡,但在转速升高后其逐渐破碎、分离,最后消散;叶片靠近叶轮流道入口的吸力面上均存在涡流,尾水管中存在两个涡核中心,且位置随转速改变;无叶空间的压力脉动相对其余位置更剧烈,脉动幅值随着转速和流量的增大而增大。研究成果可为变速恒频水轮机的设计和工程应用提供依据和参考。In order to study the internal flow field and hydrodynamic characteristics of variable speed constant frequency(VSCF)turbine under the condition of variable flow rate.A numerical simulation for hydrodynamic characteristics of Francis VSCF turbine was established based on STAR-CCM+.The pressure fluctuation characteristics and internal flow state of guide vane and runner under constant flow and sinusoidal flow conditions were obtained,and the process of vortex evolution caused by the change of rotating velocity was visualized.The results show that there was a large-scale vortex at the junction of the draft tube inlet and the runner,which was converged with the decrease of rotational speed,while it gradually broke up,separated and finally dissipated after the increase of rotational speed.And there was eddy current on the suction surface of the blade near the entrance of the impeller channel,and there were two vortex core centers in the draft tube,and the position changed with the rotating speed;the pressure fluctuation in the vaneless space was more intense than the other positions,and the pulsation amplitude increased with the increase of speed and flow rate.The research results can provide basis and reference for the design and engineering application of VSCF hydraulic turbine.

关 键 词：混流式水轮机 变速恒频 变流量工况 压力脉动 数值模拟 

分 类 号：TV734.1[水利工程—水利水电工程]