低水头混流式水轮机空化研究综述

A review of low head Francis turbine cavitation research

随着全球节能减排和可再生能源需求的日益增加,低水头水轮机发挥着重要作用。低水头混流式水轮机的空化空蚀现象将导致过流部件表面材料损坏,影响发电安全与效率。通过查阅国内外相关文献可知,造成水轮机空化空蚀的关键因素分为内因与外因,内因为水轮机的材料硬度、塑性及材料的抗空蚀性能,外因为水轮机过流部件的表面粗糙度、水轮机淹没深度、水体温度和水体中的气体含量。针对两方面原因,国内外学者讨论了改善措施以及数值模拟在研究水轮机空化空蚀的应用,认为多相瞬态流动的CFD分析对于了解水轮机流动特性和性能非常有帮助。基于满足工程实况与学科发展的需要,本文提出了未来研究混流式空化空蚀的部分参考方向,为低水头混流式水轮机空化空蚀的研究提供了一定的借鉴。

With the increasing global demand for energy conservation and renewable energy,low-head turbines play an important role.The cavitation phenomenon of low head Francis turbine will lead to the damage of surface materials of overflow components and affect the safety and efficiency of power generation.In this paper,through researching domestic and international reviews,the key factors of cavitation in hydraulic turbine are expressed,including internal and external factors.The internal factors are the material hardness,plasticity and cavitation resistance of the turbine,the external factors are the surface roughness of the turbine overflow components,the submergence depth of the turbine,the temperature of the water body and the gas content in the water body.The improvement measures were discussed by domestic and foreign scholars for both reasons,and the applications of numerical simulation in the study of cavitation of the turbine were discussed,and the CFD analysis of multiphase transient flow was obtained which is very helpful to understand the flow characteristics and performance of hydraulic turbines.In consideration of demand of engineering and scientific development,some reference directions for the future research of Francis cavitation are given to provide some reference for the research of low head Francis turbine cavitation.