外加电场作用下颗粒层除尘器过滤性能的数值研究  

Numerical study on filtration performance of granular bed filter under applied electric field

作　　者：朱康宁 李源 沈小又 吴晶晶 蔡杰[1] 顾中铸[1] ZHU Kangning;LI Yuan;SHEN Xiaoyou;WU Jingjing;CAI Jie;GU Zhongzhu(School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京师范大学能源与机械工程学院,江苏南京210023

出　　处：《中国粉体技术》2024年第3期88-99,共12页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:51878356。

摘　　要：【目的】研究外加电场和细颗粒物粒径对固定床颗粒层除尘器(granular bed filter,GBF)过滤性能的影响。【方法】建立GBF的三维过滤模型和电场力模型并验证其准确性;研究有、无外加电场及不同电场强度情况下GBF对粒径为1~21μm的细颗粒物的过滤情况,并分析不同粒径的细颗粒物在GBF内部的分布规律。【结果】外加电场的存在能显著提高GBF对粒径为3~21μm的细颗粒物的过滤效率,且外加电场强度越大,细颗粒物粒径越大,GBF过滤效率提升越明显;随着粒径的增大,细颗粒物在堆积颗粒层内部的分布更加集中在高气流速度区域,且更容易通过堆积颗粒层与GBF壁面之间形成的通道;外加电场的存在使得堆积颗粒层内部的细颗粒物数量减少,分布散乱,且大粒径细颗粒物在GBF壁面附近区域发生较大规模聚集。【结论】外加电场和细颗粒物粒径的增大与GBF内部细颗粒物的分布规律密切联系,且对GBF过滤性能的提升发挥积极作用。Objective Fine particles are ubiquitous in various settings including industrial production,daily activities,and natural environ⁃ments,exerting a profound influence on atmospheric conditions,industrial operations,and human health.Notably,PM2.5,in particular,poses significant health risks,such as cardiopulmonary dysfunction,respiratory ailments,and cardiovascular dis⁃eases,thus necessitating urgent attention to their mitigation.The granular bed filter(GBF)emerges as a promising solution by employing granular materials like silica sand,gravel,slag,or coke to form an efficient filter layer capable of capturing fine par⁃ticles from polluted air streams.Owing to its adeptness in dust removal,along with its resilience to elevated temperatures and pressures,corrosion,and abrasion,as well as its cost-effectiveness and simplistic design,GBF technology has garnered rapid adoption across diverse sectors encompassing energy,chemical processing,metallurgy,and environmental conservation.How⁃ever,current comprehension of the dust removal mechanisms and operational dynamics of GBF remains inadequate,necessitat⁃ing further research.This paper aims to advance our understanding of GBF technology,thereby facilitating its progress and application.Methods This paper established a three-dimensional filtering model for fixed bed granular bed filters(GBF),incorporationg both geometric and mathematical aspects.The geometric model,illustrated in Fig.1,portrayed the entire structure as a cylin⁃drical tube with three distinct sections:entrance,filter layer(composed of stacked granular material),and exit.The mathemati⁃cal model adopted a gas-solid unidirectional coupling approach,focusing solely on the influence of airflow on fine particles,while disregarding the reverse effect.Gas phase dynamics were simulated using the Reynolds-averaged Navier-Stokes(RAN)method with standard equations serving as the closed model,while the solid phase(fine particles)was analyzed via Lagrangebased force calculations.The model's accuracy was veri

关 键 词：颗粒层除尘器 电场 细颗粒物 过滤效率 数值模拟 

分 类 号：TK284.5[动力工程及工程热物理—动力机械及工程]