【摘要】 为提升混流式水轮机稳定运行效率，以某电站现有混流式转轮为研究对象，基于原型结构，提出在转轮叶片间增设隔板结构的改造方案。基于CFX数值模拟软件，采用剪应力输运(SST)湍流模型，针对0.3Q_d、0.5Q_d、0.6Q_d、0.8Q_d和Q_d(Q_d为设计流量)共5种常用设计工况，对两种不同转轮结构的混流式水轮机开展三维全流道数值模拟，系统分析隔板结构对转轮内部流场、叶片表面流动特性及尾水管流态影响。结果表明：隔板结构对各工况水轮机流动特性具有显著影响，转轮增设隔板结构在各工况下运行效率均高于原型转轮。其中，Q_d工况下，转轮运行效率达到最大值，高达93.8%,较原型提高0.6%;低流量工况运行效率提升更为显著，0.3Q_d工况下，改造转轮效率为54%,较原型提高6%。增设隔板后，转轮叶片表面及尾水管流线趋于平顺，涡流与流动紊乱现象减少，显著改善转轮及尾水管的水流流态；同时，转轮内部物理量分布更为均匀，波动范围减小，有效提升过流部件运行可靠性。转轮增设隔板结构后展现出更优多工况适应性，研究成果为混流式水轮机转轮结构改造提供重要理论参考与工程依据。更多还原

【Abstract】 In order to improve the stable operation efficiency of Francis turbine, the existing Francis runner of a power station was taken as the research object, and based on its prototype structure, the modification scheme of adding a baffle structure between the runner blades was proposed. Based on CFX numerical simulation software and shear stress transport(SST) turbulence model, three-dimensional full-flow channel numerical simulation was carried out for five design conditions, namely 0.3Q_d, 0.5Q_d, 0.6Q_d, 0.8Q_d and Q_d(Q_d is the design flow rate), for the Francis turbine of the two types of structures was systematically analyzed the influence of the baffle structure on the internal flow field of the runner, the flow characteristics of the blade surfaces, and the draft tube flow pattern. The results show that the baffle structure has a significant effect on the flow characteristics of the turbine under various operating conditions, and the efficiency of the turbine with an additional baffle structure is higher than that of the prototype turbine under various operating conditions. Among them, the optimised runner efficiency reaches 93.8% at Q_d, which is 0.6% higher than the prototype. The efficiency improvement is more significant at low operating conditions, and the optimised runner efficiency is 54% at 0.3Qd, which is 6% higher than the prototype. After adding the baffle, the flow lines on the surface of the runner blades and in the draft tube tend to be smoother, and the vortex and flow turbulence are reduced, which significantly improves the flow pattern of the runner and the draft tube. At the same time, the distribution of physical quantities inside the runner is more uniform, and the fluctuation range is reduced. The runner shows better adaptability to multiple operating conditions, and the research results provide important theoretical reference and engineering basis for the optimisation of the runner of the Francis turbine.更多还原