斜置静叶对喷嘴内固体颗粒冲蚀作用的影响

Effect of Oblique Stator Blade to Solid Particles Erosion in Nozzle

汽轮机调节级采用斜置静叶可有效降低固体颗粒的冲蚀率。通过fluent软件进行数值模拟,建立汽轮机静叶的不同斜置角度的计算模型,基于三维定常可压缩流体的N-S方程,在连续相流场的基础上添加离散相模型,分析不同斜置角度下不同粒径的固体颗粒的运动轨迹及其对叶片的冲蚀作用。分析表明:静叶斜置角度的改变对固体颗粒的运动轨迹是有影响的,斜置角度为45°时,固体颗粒的运动轨迹最好,对壁面的冲蚀作用最小。随着斜置角度的增大,固体颗粒的运动速度减小,固体颗粒与壁面的碰撞角减小,对壁面的冲蚀率减小,汽轮机组的安全性提高。

The oblique stationary blade of the turbine governing stage can effectively reduce the erosion rate of the solid particles. The models with different oblique angle were established, simulation calculation which was based on the 3D viscous N-S equations of three dimensional steady compressible fluid introduced the discrete phase model, and analyzed the trajectory of different oblique angles of solid particles of different sizes and its erosion effect on the blade with Fluent software detail. The result showed that change of the oblique angle of the stationary blade will affect the trajectory of solid particles,at the angle of 45 °, the trajectory of solid particles is best and the erosion is minimize. With the increase of oblique angle, velocity of solid particles is reduced, the collision of solid particles and wall angle is decrease, the erosion rate is decrease, the safety of steam turbine is improved.