排尘口直径对旋风分离器壁面磨损影响的数值模拟

基于计算流体动力学(Computational fluid dynamic,CFD)的数值模拟方法,在FLUENT软件平台上,应用雷诺应力模型、离散相模型和磨损值计算模型系统地研究排尘口直径对旋风分离器壁面磨损的影响。计算结果表明,旋风分离器壁面磨损的整体变化趋势不随排尘口直径的改变而变化,都呈现局部磨损的形态。排尘口直径减小,环形空间壁面磨损值保持不变,分离空间壁面磨损值有不同程度的增加,在锥体末端附近增加幅度最大,而这种变化主要是由于排尘口直径变化后分离器内部流动结构的变化引起的。分离空间锥体末端附近壁面的严重磨损主要受气固两相的旋转速度、颗粒浓度、旋进涡核和颗粒受力情况的影响。通过研究揭示合理地进行结构设计在减少磨损中的重要作用,为旋风分离器壁面的防磨提供数值试验方法和依据。

Effect of Dust Discharge Diameter on Wall Erosion in Cyclone Separator

Numerical approach of computational fluid dynamic(CFD) is conducted to systematically study the effects of dust discharge diameters on wall erosion in cyclone separator by using Reynolds stress model,discrete phase model and erosion value computing model in FLUENT software platform.The results show that the wall erosion appears local erosion and its overall trend hardly changes with dust discharge diameter in cyclone separator.Wall erosion values of annular space remain the same with the decrease of dust discharge diameter,while those of separation space increase differently and the difference reaches maximum near the bottom of cone.It is found that the changing regularity of wall erosion is mainly caused by the variation of internal flow structure in cyclone separator.Furthermore,the severe erosion near the bottom of cone is chiefly influenced by gas-solid rotation velocity,granular concentration,vortex core and the forces acting on particles.This research could reveal the important role of reasonable structure design in wall erosion reduction and provide numerical experiment method and basis for preventing cyclone separator’s wall erosion.