窄筛分颗粒气固流态化特性数值模拟研究  

Numerical simulation study on gas-solid fluidization characteristics of the particles with narrow size distribution

作　　者：郭昊乾 李雪飞 李小亮 GUO Haoqian;LI Xuefei;LI Xiaoliang(Coal Chemistry Branch of China Coal Research Institute,Beijing 100013,China;Beijing Key Laboratory of Coal Based Energy Conservation and Environmental Protection Carbon Materials,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China)

机构地区：[1]煤炭科学技术研究院有限公司北京煤化工研究分院,北京100013 [2]煤基节能环保炭材料北京市重点试验室,北京100013 [3]煤炭资源高效开采与洁净利用国家重点实验室,北京100013

出　　处：《洁净煤技术》2020年第4期84-89,共6页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2018YFB0605604);国家科技重大专项资助项目(2016ZX05045-005)。

摘　　要：为更好地指导工业生产,了解不同粒径颗粒在气固流化床中的状态以及流化床中颗粒分布情况,针对气固流化床中窄筛分颗粒流态化特性进行数值模拟研究。通过流场模拟软件分析在相同流化床中不同粒径段的颗粒(46~80、106~113、185~221μm)和不同流化床进气速度条件下所能达到的体积分数和流化床层高度以及达到这一指标所需时间,并采用欧拉-欧拉模型和SIMPLE算法计算不同气速条件下的颗粒体积分数、速度分布。结果表明,在相同气速条件下,颗粒粒径增大,导致流化床内颗粒体积分数最高点与最低点的差距变大,颗粒分布不均匀性增加,同时床层整体高度下降,床层内颗粒密度上升,颗粒体积分数下降,流化效果降低;相同颗粒粒径情况下,增加气速可降低流化床内部颗粒的体积分数,增加气体与固体颗粒的接触面积,增强流化效果,但减少了流化床内部颗粒速度矢量分布达到均匀的时间,颗粒分布不均匀性更加明显。In order to better guide the industrial production,understand the state of particles of different particle sizes in the gas-solid fluidized bed and the distribution of particles in the fluidized bed,the fluidization characteristics of the narrow-screened particles in the gas-solid fluidized bed were numerically simulated.The flow field simulation software was used to analyze the volume fraction and the height of the fluidized bed and the time required to reach this target under the conditions of particles with different particle sizes(46-80,106-113,185-221μm)in the same fluidized bed and different inlet velocity of the fluidized bed.The Euler-Euler model and SIMPLE algorithm were used to calculate the particle volume fraction and velocity distribution under different gas velocity conditions.The results show that the increase in particle size causes the larger difference between the highest point and the lowest point of the particle volume fraction in the fluidized bed under the same gas velocity,meanwhile,the unevenness of particle distribution increases,the overall height of the bed decreases,the particles in the bed density increases,the fluidization decreases with the decrease of the volume fraction of the particles.In the case of the same particle size,increasing the gas velocity can reduce the volume fraction of particles inside the fluidized bed,increase the contact area of the gas and solid particles,and enhance the fluidization effect.However,the time of the particle velocity vector distribution inside the fluidized bed reaching a uniform is reduced,and the uneven distribution of particles is more obvious.

关 键 词：窄筛分 流态化 气固流化床 气泡 

分 类 号：TQ424.1[化学工程]