荷电液滴吸附细颗粒物的数值模拟分析

Numerical simulation of dust particle collection by charged droplet

为了研究静电湿式除尘中荷电液滴对细颗粒物的吸附特性,考虑了黏性阻力、重力以及静电引力的作用,通过求解牛顿方程获得耦合场下荷电液滴周围细颗粒物的运动轨迹方程,建立了静电力和气动力共同作用下细颗粒物粒子运动的数值模型,模拟2维空间中荷电液滴周围细颗粒物的运动轨迹,给出了不同斯托克斯数以及库仑数下细颗粒物的沉积效率,获得影响荷电液滴吸附细颗粒物效率的主要参数及其作用机制,模拟结果与试验数据较为吻合.结果表明:单个大尺寸的液滴的吸附面积比略高于小尺寸的液滴,而相同气液比下小粒径液滴具有更高的吸附效率,静电湿式除尘对粒径在1到10μm间的细颗粒物具有最佳的吸附效果.

To investigate the adsorption mechanism of dust particles on a single charged droplet, air drag force, gravity force and electrostatic force were considered. By solving Newton equation, the motion e- quation for dust particles in the vicinity of charged droplets was achieved. A numerical model was estab- lished to track the dust particle trajectories in the vicinity of charged droplets. The collection efficiency of dust particles was mainly affected by Stokes and Coulomp number. The primary effect parameters and ac- ting mechanism on the collection process were obtained. The simulation results agree well with the experi- mental data. The results show that larger size of charged droplet leads to bigger collection area ratio, while for the same vapor liquid ratio, the collection efficiency is larger for smaller droplet. The dust parti- cles with size among 1 μm to 10 μm have good collection efficiency.