超临界汽轮机再热第一级叶片固粒冲蚀特性的数值分析

Numerical Analysis of the Erosion Characteristics of Solid Particles in the First Reheat Stage Blades of a Supercritical Steam Turbine

采用数值方法计算与分析了超临界汽轮机再热第一级的固体颗粒三维运动特性 ,根据固体颗粒撞击叶片的位置、速度与撞击角以及叶片材料的抗冲蚀性能综合分析了静叶与动叶的冲蚀机理及冲蚀特性 ,指出静叶吸力面冲蚀是从动叶反弹回来的固粒撞击所引起的。此外 ,还分析了动静叶轴向间距及机组负荷对反弹至静叶的颗粒数量的影响 ,结果表明 ,随着轴向间距的减小和负荷的降低 ,反弹回静叶的颗粒数量增加。

The three-dimensional motion characteristics of solid particles in the first reheat stage of a supercritical steam turbine were calculated and analyzed by using a numerical method. A comprehensive analysis was performed of the erosion mechanism and features specific to stator and rotor blades on the basis of the impact location and velocity of solid particles on blades, impact angle and blade material erosion-resistance behavior. It is noted that the suction side erosion of the stator blades is caused by the impact of solid particles rebounding from the rotor blades. Furthermore, also analyzed was the influence of the turbine load and the axial clearance between the stator and rotor blades on the number of particles rebounding to stator blades. The results of the analysis indicate that an decrease in axial clearance and a reduction in turbine load has given rise to an increase in the quantity of particles rebounding to the stator blades.