鼓泡床密相区多组分床料扩散的CPFD模拟  

CPFD Simulation of Multicomponent Bed MaterialDiffusion in Dense Phase Zone of Bubbling Bed

作　　者：陈鸿伟[1] 刘玉强 刘博朝 梁锦俊 贾建东 宋杨凡 王睿坤[1] CHEN Hongwei;LIU Yuqiang;LIU Bochao;LIANG Jinjun;JIA Jiandong;SONG Yangfan;WANG Ruikun(School of Energy Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,河北保定071003

出　　处：《华北电力大学学报（自然科学版）》2021年第1期114-120,共7页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51606067).

摘　　要：鼓泡床密相区颗粒的混合和扩散对炉内反应速率影响巨大,研究冷态鼓泡床密相区的混合情况,对热态锅炉研究提供参考。采用计算颗粒流体力学(CPFD)方法,对158 mm(长)×158 mm(宽)×400 mm(高)的长方体模型进行模拟。主要研究不同流速下,不同质量分数的压缩木屑、稻壳的颗粒体积分数和横向扩散系数。模拟结果表明,与稻壳相比,压缩木屑颗粒体积分数更大,床层膨胀程度更小;生物质的质量分数越大,密相区颗粒体积分数越大,床层膨胀程度越小,床层整体流化不均匀性越小;扩散系数随流化风速、生物质的质量分数的增加而增大;相同质量分数下,压缩木屑的扩散系数略小于稻壳。The mixing and diffusion of particles in the dense phase zone of the bubbling bed have great influence on the reaction rate in the furnace.This paper studied the mixing of particles in dense phase zone of the cold bubbling bed,thereof providing reference for the research of hot boiler.This paper adopted a computational particle fluid dynamics(CPFD)method to simulate a 158 mm×158 mm×400 mm cuboid model.In the cuboid model,we studied the particle volume fraction and lateral diffusion coefficient of compressed wood chips and rice husks with different mass fractions at different flow rates.The simulation results show that compared with rice husks,the larger the volume fraction of compressed wood chips is,the smaller the degree of expansion of the bed is.As the mass fraction of biomass increases,the volume fraction of particles in dense phase zone is larger,while the expansion of bed and the overall fluidization inhomogeneity of the layer is smaller.The diffusion coefficient increases with the fluidization wind speed and biomass mass fraction.Under the same mass fraction,the diffusion coefficient of compressed wood chips is slightly smaller than that of rice husk.

关 键 词：鼓泡床 密相区 CPFD模拟 多组分床料 横向扩散 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]