多场耦合作用下静电除尘器粉尘颗粒运动轨迹模拟

Simulation of particle trajectory in electrostatic precipitator under multi-field coupling

为了描述静电除尘器内流动特性以及粉尘颗粒的捕集过程,建立了气体流场、颗粒动力场与电场相互耦合作用的数学模型,构造了更贴近燃煤发电厂实际生产过程中的Rosin-Rammler粒度分布模型,讨论了多场耦合作用下不同工作电压、含尘气流入口速度对颗粒运动轨迹的影响。数值结果表明:随着工作电压的增高,逃逸粉尘的平均粒径呈现非线性递减的关系,粉尘颗粒向着收尘板方向偏移运动的趋势逐渐变强。此外,随着入口含尘气流速度的增大,出口处逃逸粉尘的平均粒径呈线性递增的关系,颗粒向收尘板电极方向偏移的趋势明显减弱。

In order to describe the flow characteristics and the trapping process for dust particles in electrostatic precipitators,a mathematic model with coupled effects among the gas flow field,particle dynamic field and electric field were built,and the Rosin-Rammler distribution model of particles＇ sizes,which was closer to the coal-fired power plants in the process of real production,was constructed.Influence of different operating voltages and inlet velocities on particles trajectory under multi-field coupling were discussed.The numerical results indicate that the average diameter of escaping particle sizes is nonlinearly decreasing with the increase of operating voltage,and that the movement trend towards the direction of dust collection plate is gradually strengthened.Furthermore,the average diameter of escaping particle sizes is linearly increasing with the increase of inlet velocity,the movement trend to the direction of dust collection plate is obviously weakened.