N25型汽轮机末级叶片的气动优化及分析

Aerodynamic optimization and analysis on last stage blades of N25 steam turbine

为提高N25型汽轮机效率,通过对其末级叶片进行CFD数值计算,分析其气动性能并提出优化改进方案。通过分析末级叶片等熵效率沿轴向分布变化、静动叶片表面压力变化、平均截面处熵值分布和速度分布,优化静、动叶片的叶型,调整了动叶片角度、前缘和尾缘、级间匹配关系。计算结果表明,优化后等熵效率提高了1.74%,轴功率提高8.58%,达到了气动性能优化的目的。

In order to improve the efficiency of the N25 steam turbine,a CFD numerical calculation on the final stage blade was conducted to analyze the blade’s aerodynamic performance and propose an optimized improvement plan.By analyzing the varying distribution of isentropic efficiency along the axial direction of the last stage blade,the varying surface pressure of the static and dynamic blades,the entropy and velocity distributions at the average cross section,the blade profiles are optimized for the static and dynamic blades,and the blade angle,leading edge,trailing edge,and the matching relationship between the stages are adjusted.The results show that the isentropic efficiency is increased by 1.74%and the shaft power is increased by 8.58%after optimization.The aerodynamic optimization is realized.