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静电除尘器中的电晕放电特性是影响颗粒荷电及捕集的重要影响因素,本文基于试验及数值分析方法,研究了高湿烟气中硫酸气溶胶在不同浓度下的颗粒粒径分布特性及其对电晕放电的影响机制.结果表明,硫酸气溶胶颗粒数目浓度和粒径随SO3浓度和烟气湿度的升高而增大,当SO3浓度由17.5mg/m3增大至179.6mg/m3时,颗粒数目浓度由2.34×107cm-3增大至4.49×107cm-3,中值粒径由0.08μm增大至0.15μm.当SO3浓度为179.6mg/m3时,电流相比空载时降低78%,烟气湿度的提高将进一步导致电晕电流的降低.颗粒粒径小及数目浓度高是导致电晕电流下降的重要原因:粒径为0.1μm附近的颗粒数目浓度高,易形成高密度的空间电荷,降低极线附近的电场强度及离子浓度,最终导致电晕电流降低.采用增大颗粒粒径,减小颗粒数目浓度方法有利于减小电晕封闭的影响.“,”Corona discharging characteristics is of crucial significance to particle charging and migration procedures in Electrostatic Precipitator (ESP). In this article, the effect of SO3 aerosol on discharging characteristics of ESP was investigated based on the results of experimental and numerical simulation method. The results showed that an increase in SO3 concentration and relative humidity of flue gas lead to larger number concentration and particle size. Particle number concentration increased from 2.34×107cm-3 to 4.49×107cm-3 while SO3 concentration increased from 17.5mg/m3 to 179.6mg/m3, which also resulted in an increase of median diameter from 0.08μm to 0.15μm. The corona current decreased by 78% compared with blank condition when SO3 concentration was 179.6mg/m3, and higher flue gas humidity further deteriorated the corona suppression phenomenon. Meanwhile, the particle size and number concentration were important reason for the decrease of corona current. Particle with the size of near 0.1μm had large number concentration, which induced a high space charge density, suppressing the electric field and ion concentration around the electrode and then lowering the corona current.