高温烟气中颗粒静电脱除特性的实验研究  

Experimental investigation on particle collection performance of electrostatic precipitator at high temperatures

作　　者：朱唯卓 沈之旸 严佩[1] 郑成航[1] 高翔[1] 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：《中国环境科学》2016年第4期1009-1016,共8页China Environmental Science

基　　金：国家杰出青年科学基金项目(51125025);国家“973”项目(2013CB228504);国家863项目(2013AA065002)

摘　　要：研究温度90~450℃条件下静电除尘器的放电特性及除尘特性,分析温度、工作电压、烟气流速及颗粒浓度等关键参数对于颗粒静电脱除效率的影响.结果表明,当温度从90℃上升至450℃,在比收尘面积为46.5m^2/(m^3·s^(-1)),粉尘初始浓度约为750mg/Nm^3的工况下,颗粒脱除效率均可达到98%以上.随着电压升高,除尘效率不断提高,但其升高趋势逐渐变缓.在相同电压下,随着温度的上升,电晕电流显著增大,强化颗粒荷电,颗粒的脱除效率提高;而在相同电流下,高温下较低的空间场强使得颗粒的驱进速度减小,导致颗粒脱除效率下降.烟气流速提高降低了颗粒的脱除效率,PM_(1.0)受烟气流速的影响较PM_(10)更为明显.颗粒初始浓度的上升增强了颗粒的碰撞及团聚作用,在一定程度上有利于增强颗粒的脱除效果.An experimental-scale electrostatic precipitator was built to investigate the characteristics of corona discharge and particle collection at various temperatures ranging from 90℃ to 450℃. The influence of several key parameters（temperature, applied voltage, particle concentration and gas flow velocity） on particle collection efficiency were analyzed, and the results indicate that the collection efficiency can reach higher than 98% as the gas temperature increases form 90 ℃ to 450℃, when the specific collection area（SCA） of the ESP is 46.5m^2/（m^3·s^（-1）） and the inlet mass concentration of particles is about 750mg/Nm^3.The collection efficiency increases with the increase of applied voltage, yet the growth rate reduces gradually. At the same voltage, as the temperature increases, the corona current increases substantially, which enhances the particle charging and finally improves the collection efficiency. However, at the same corona current, the particle collection efficiency decreases because of the low electric field intensity at high temperature. The increase in gas flow velocity reduces the particle collection efficiency, and the influence of gas flow velocity on PM_（1.0） removal is much more significant than PM_（10）. The increase in particle concentration enhances the collisions among particles and leads to particle coagulation, which is conducive to particle removal.

关 键 词：温度 静电除尘器 电晕放电 颗粒 除尘效率 

分 类 号：X701.2[环境科学与工程—环境工程]