多孔收尘电极电场中荷电粒子的沉降规律及其除尘性能预测

为了探究多孔收尘电极电除尘器的除尘性能，采用COMSOL Multiphysics建立电除尘器气固两相流数值模型，对多孔收尘电极电除尘器中的颗粒荷电沉降过程进行数值模拟，研究其电场、流场分布及粒子荷电、运动和沉降过程。结果表明，电除尘器气固两相流模型计算值与实验值符合良好。多孔收尘电极电除尘器能够有效提高微细粒子有效驱进速度约30%。极板开孔后显著提高了电场通道中距板表面25 mm内电场强度，开孔不会对空间电荷密度与颗粒荷电过程产生影响；多孔板结构表面5 mm处电场风速水平分量相较于平板结构降低了12.5%，消弱了气流对收尘区域的冲刷作用，进入多孔板空腔内的粒子最终沉降在多孔板壁面上。本研究结果可为多孔收尘电极电除尘器对微细粒子提效捕集的机理探究及新型电除尘器的选型设计提供参考。

Sedimentation law of charged particles in electric field of porous dust collecting electrode and prediction of dust removal performance

In order to explore the dust removal performance of the Porous-dust-collecting-electrode electrostatic precipitators(PDCE-ESPs), COMSOL Multiphysics was used to establish a numerical model of the gas-solid two-phase flow of the electrostatic precipitators, and the particle charge sedimentation process in the PDCE-ESPs was numerically simulated in this study. The distributions of electric and flow fields and the charging, motion, and precipitation of particles in this specific structure were studied. The results showed that the calculated value of the gas-solid two-phase flow model of the electrostatic precipitators was in good agreement with the experimental value. The PDCE-ESPs can effectively increase the effective driving speed of fine particles by about 30%. After opening the plate, the electric field intensity within 25 mm from the plate surface in the electric field channel was significantly increased, and the opening had no effect on the space charge density and particle charge process. The horizontal component of electric field wind speed at 5 mm on the surface of porous plate structure decreased by 12.5% compared with that of flat plate structure, which weakened the scouring effect of air flow on dust collecting area, and the particles entering the cavity of porous plate eventually settle on the wall of porous plate. The results can explain the mechanism of the PDCE-ESPs for improving the trapping of fine particles, and provide a reference for the selection and design of the new type of electrostatic precipitators.