Abstract: Based on the 50000m³/h actual flue gas pilot test system, the Mastersizer 2000E laser particle size analyzer and electrical low pressure impactor(ELPI) were used to fully characterize the geometric particle size and aerodynamic particle size of the fly ash particles of the electrostatic precipitator(ESP) for the first time. Results showed that, the geometric size distribution of fly ash particles of ESP inlet and different electric field is bimodal distribution characteristics, which moves to the right in turn, but particles ≤ 1μm at the end of rotating electrode electric field have a slightly higher, the fly ash particle geometric median diameter of ESP inlet and 1-5 electric field were 6.607μm, 17.378μm, 2.884μm, 2.577μm, 2.460μm, 2.480μm, respectively. The fly ash particles geometric size distribution bimodal of ESP inlet moves to the right when temperature was reduced, particle agglomeration phenomenon was obvious, the fly ash particle geometric median diameter of 80℃, 90℃, 110℃, 130℃, 150℃ for ESP inlet were 13.183μm, 10.500μm, 10.171μm, 6.607μm, 7.586μm, from 130℃ to 90℃, particles ratio of ≤ 1μm, ≤ 2.5μm, ≤ 10μm decreased by 19.8%, 19.8% and 19.8% respectively. At different temperatures, the ESP collection efficiency of number and mass concentration for aeordynamic diameter 0.03μm to 10μm, which were all higher than 75%, and the highest was up to 99.9%. The number and mass concentration for different period of aerodynamic diameter reduced obviously, from 130℃ to 90℃ and 80℃, the PM_2.5 agglomeration efficiency of mass concentration for ESP inlet were 46.76% and 46.76% respectively. The PM₁₀ reduction efficiency of mass concentration for ESP outlet were 59.80% and 91.08%. PM_2.5 reduction efficiency were 45.94% and 76.22%. PM1 reduction efficiency were 40.40% and 62.12%, respectively.

Key words: low-low temperature electrostatic precipitator, PM_2.5, cooling agglomeration, particle size distribution, collection efficiency

摘要： 基于50000m³/h实烧烟气中试系统，采用Mastersizer 2000E激光粒度分析仪和电子低压冲击仪（ELPI），首次对电除尘器飞灰几何粒径和空气动力学粒径进行全面表征。结果表明，电除尘器入口及各电场的飞灰几何粒度分布均呈双峰分布特征，各电场峰值依次右移，但末级旋转电极电场≤ 1μm的颗粒占比略有升高，电除尘器入口及第1～5电场飞灰几何中位径分别为6.607μm、17.378μm、2.884μm、2.577μm、2.460μm、2.480μm；温度降低，电除尘器入口飞灰几何粒度分布的双峰均右移，颗粒团聚现象明显，80℃、90℃、110℃、130℃、150℃时电除尘器入口飞灰几何中位径分别为13.183μm、10.500μm、10.171μm、6.607μm、7.586μm，从130℃降至90℃，电除尘器入口几何粒径≤ 1μm、≤ 2.5μm、≤ 10μm的飞灰占比分别减少了19.8%、19.2%、12.6%；不同温度时，电除尘器对空气动力学粒径0.03～10μm段颗粒的个数浓度、质量浓度均有较高脱除效率，均在75%以上，最高可达99.9%；温度降低，电除尘器进出口空气动力学粒径不同粒径段颗粒个数浓度和质量浓度均有不同程度降低，从130℃降至90℃、80℃，对应电除尘器入口PM_2.5团聚效率分别为46.76%、60.08%，对应电除尘器出口PM₁₀减排分别为59.80%、91.08%，PM_2.5减排分别为45.94%、76.22%，PM1减排分别为40.40%、62.12%。

关键词: 低低温电除尘器, PM_2.5, 降温团聚, 粒度分布, 除尘效率