强电场对低速气固两相流体运动影响的模拟试验研究

Simulation Experiment of the Impact on the Motion of the Particle in Dual-phase Distribution of Gas & Solid Under Strong Electric Field

研究小粒径固—气混合流体在强电场区域的运动规律对于解释沙尘气候环境下线路绝缘子表面污秽沉积、间隙击穿、不明闪络等绝缘事故具有促进作用。文中基于人工模拟试验,利用PIV技术系统研究了低速混合流体的流电耦合运动规律,综合对比了电场不均匀度、电压等级、风速等因素对于流场分布的影响。结论发现:在不均匀电场下,电场对于流场的作用要明显强于均匀电场,且随着外施电场强度的增加而增加,随风速的增加而有所减弱;均匀电场下粒子有向负极板运动的趋势,而不均匀电场下粒子因为电晕作用而荷电明显,易于向正极板运动。相关结论对于深化沙尘环境下输电线路外绝缘特性研究,特别是小粒径颗粒荷电机理具有积极意义。

The research on the law of motion of small particles in the dual-phase distribution of gas ＆ solid under strong electric field could better explain why the contamination depositing on the surface of the insulators, the gap breakdown,the unknown flashover or some other insulation accident happened. Based on the simulation experiments,the law of motion of small particles were discussed under low velocity and the coupled fluid and electric field with the using of PIV. With comprehensive comparison of the Electric field distribution,the applied voltage,the wind velocity,the obtained results show that the effect of electric field on the fluid field under the nonuniform electric field is significantly stronger than under uniform electric field. What＇s more, with the applied voltage increased,the effect increased obviously,while the wind velocity increased,the effect decreased significantly. The particles have a trend motion to the negative electrode under uniform electric field. While under nonuniform electric field,the particles have a trend motion to the positive electrode,because the effect of the cathode corona the particles are more easily to be charged.