高温线板式静电除尘器颗粒捕集  

Particle collection in wire-plate electrostatic precipitators at high temperature

作　　者：许希[1] 徐甸[1] 严佩[1] 朱唯卓 郑成航[1] 高翔[1] 骆仲泱 倪明江[1] 岑可法[1] 

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2017年第3期487-493,507,共8页Journal of Zhejiang University：Engineering Science

基　　金：国家"973"重点基础研究发展规划资助项目(2013CB228504);国家科技支撑计划资助项目(2015BAA05B02);杭州市产学研合作项目(G20150101);国家"863"高技术研究发展计划资助项目(2013AA065002)

摘　　要：建立高温线板式静电除尘实验系统,研究400~700℃烟气中的电晕放电、颗粒迁移和捕集规律.探究温度、电压、流速等关键因素对颗粒捕集效率和驱进速度的影响规律;分析温度变化对电晕放电和颗粒捕集的作用机制.温度上升会影响电子平均自由程、气体分子电离能、颗粒荷电量、颗粒所受电场力和黏性力,导致放电电压、颗粒捕集效率和驱进速度均有所下降.当温度从400℃上升到700℃时,最大运行电压从21.9kV下降到14.3kV;颗粒捕集效率从98.1%下降到68.2%;颗粒有效驱进速度从8.54cm/s下降到2.45cm/s.高温工况下的温度变化对电晕放电特性和颗粒捕集效率的影响较低温工况下产生的影响更为明显.烟气流速增大会降低除尘器对颗粒的捕集效率,但是颗粒驱进速度有所提高.700℃下,当烟气流速从0.15m/s上升到0.35m/s时,颗粒捕集效率从81.2%下降到64.5%,有效驱进速度从1.79cm/s增加到2.59cm/s.An experimental-scale wire-plate electrostatic precipitator（ESP）system at high temperature was built to investigate the behaviors of corona discharge,particle migration and particle collection from 400℃up to 700 ℃.The Influence rule was explored that of temperature,applied voltage and gas velocity on particle collection and particle migration velocity.The mechanism of temperature variation on corona discharge and particle collection was discussed.The increase of temperature affects the mean free path of electrons,the ionization energy of the gas molecules,particle charge,Coulomb force and viscous force of particle,leading to the decrease of applied voltage,particle collection efficiency and particle migration velocity.When temperature increases from 400 ℃to 700 ℃,the applied voltage decreases from 21.9kV to 14.3kV,the particle collection efficiency decreases from 98.1%to 68.2%,and the particle migration velocity decreases from 8.54cm/s to 2.45cm/s.The influence of temperature on particle efficiency is more obvious at high temperature than that at low temperature.As the gas velocity increases,the particle collection efficiency decreases,but the particle migration velocity increases. When the gas velocity increases from 0.15m/s to 0.35m/s at 700 ℃,the particle collection efficiency decreases from 81.2%to64.5%,but the particle migration velocity increases from 1.79cm/s to 2.59cm/s.

关 键 词：电晕放电 颗粒捕集 静电除尘器(ESP) 驱进速度 

分 类 号：X701.2[环境科学与工程—环境工程]