静电除尘器中纳米颗粒运动与荷电特性  

Particle transport and charging mechanism of the nano particle within an electrostatic precipitator

作　　者：冯宇轩 罗坤[1] 樊建人[1] FENG Yuxuan;LUO Kun;FAN Jianren(State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China)

机构地区：[1]浙江大学能源清洁利用国家重点实验室,杭州310027

出　　处：《中国科学院大学学报（中英文）》2021年第3期297-305,共9页Journal of University of Chinese Academy of Sciences

基　　金：国家自然科学基金(91741203)资助。

摘　　要：通过建立静电除尘器(electrostatic precipitator,ESP)内纳米颗粒沉积及荷电的数值模型,耦合流场、电场、颗粒荷电及颗粒运动等子模型,研究ESP内纳米颗粒的运动与荷电特性。研究发现纳米颗粒在ESP中的受力方向和大小会随着其运动而不断改变,其沉积效率曲线相较于微米级颗粒,呈现出U型的特征,经证明这是由纳米颗粒所受体积力的主要类型和大小随着粒径不断变化决定的。此外纳米颗粒的荷电机理也会发生变化,荷电量与粒径和喷射浓度的大小紧密相关,直接影响颗粒所受库仑力的同时还会间接影响电晕放电,甚至造成电晕封闭,严重影响颗粒沉积效率。Based on the Ansys Fluent platform along with its secondary development programs,this research developed a comprehensive numerical model for nano particle migration within an electrostatic precipitator(ESP).The multi-field model coupled sub-models such as flow field,electric field,particle charging,and particle motion.The moving and charging behavior of nano particles in the ESP are fully discussed.The results show that both the amount and the direction of the body force on the particles will change periodically before collecting or escaping.The deposition efficiency curve of the nano particle presents the U-shape which is different from that of the micron particle.It proved that it is resulted from the changes of the main type and magnitude of the body force on the particle.Moreover,the charging mechanism of nano particles will also change.The charge is closely related to the particle size and particle concentration,directly affecting the Coulomb force on particles and corona discharge,which may lead to corona obstruction and seriously lower the particle deposition efficiency.

关 键 词：静电除尘器 纳米颗粒 颗粒运动 颗粒荷电 数值模拟 

分 类 号：TK123[动力工程及工程热物理—工程热物理]