颗粒直径对向心透平冲蚀磨损的影响

Effect of Particle Diameter on Erosion Wear Performance of Radial Flow Turbine

为了探讨不同直径颗粒对无导叶向心透平输送气固两相流过程中的冲蚀磨损问题,对颗粒与各过流部件的冲击速度与冲击角度进行数值模拟。结果表明:小直径颗粒在蜗壳和叶轮流道中分布相对均匀,几乎不与过流部件表面发生碰撞,对过流部件的冲蚀磨损率相对较小。大直径颗粒运动中更倾向于从蜗壳尾部进入叶轮,在叶轮流道中,颗粒轨迹易向叶片压力面靠拢,且易与叶片压力面发生碰撞。随着颗粒直径的增加,颗粒将以更大的角度和速率撞击叶片压力面,且存在多次撞击过程,造成压力面中部靠近前盘处和吸力面靠近出口区域严重磨损。

In order to investigate the influence of particle diameter on erosion performance of radial flow turbine delivering solid-gas two-phase flow medium,the impinging velocity,impact angle and other parameters between solid particle and the surface of flow-passing parts were evaluated numerically. According to simulation results,the particles with small diameters were distributed relatively homogeneously in the flow path of volute and blade,and almost had no collision with the surface of flow-passing parts,so the erosion wear of flow-passing parts was relatively weak. By contrary,the solid particles with large diameters tended to pass into the flow pass of the impeller in the tail of the volute,in the flow pass of the impeller,and the particle was apt to move forward to the pressure surface and impacted the pressure surface of the blade. With the increase of particle diameter,the particle would impact the pressure surface with a larger angle and velocity,and there are multiple collisions with the pressure surface,resulting exacerbated erosion wear of the middle of the pressure surface near the shroud and the suction surface near the exit.