基于DEM模拟液固流化床粒度级配对颗粒流动特性的影响  

Influence of particle size distribution in liquid-solid fluidized bed on particle flow characteristics based on DEM

作　　者：丁冬峰 程可[1] 陆晓峰[1] 朱晓磊[1] 朱凌雪 DING Dongfeng;CHENG Ke;LU Xiaofeng;ZHU Xiaolei;ZHU Lingxue(College of Mechanical and Power Engineering, Nanjing Technology University, Nanj ing 211816, China;Jinling Institute of Technology, Nanjing 211816, China)

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京211816 [2]金陵科技学院,江苏南京211816

出　　处：《中国粉体技术》2018年第2期18-25,共8页China Powder Science and Technology

基　　金：国家自然科学基金青年项目;编号:11772147;江苏省高校自然科学基金项目;编号:16KJB130003

摘　　要：采用离散单元方法(DEM)对三维液固流化床进行数值模拟。考虑润滑力的作用,对比二元混合、窄级配和宽级配3种粒度级配方式对颗粒分布、速度、温度波动和混合程度的影响。分析结果表明:大颗粒有向床层下部运动的趋势,而小颗粒则有向床层上部聚集的趋势;与窄级配相比,二元混合和宽级配的轴向速度在不同高度上差异较明显,且颗粒温度波动也较小,颗粒更加容易出现偏析;2种颗粒粒径差距越大,越容易分离,而粒径越接近,越难分离,混合程度越好。A three-dimensional liquid-solid fluidized bed was numerically simulated by discrete element method （DEM）. The lubrication force was taken into consideration. The influence of the binary mixture, wide size distribution and narrow size distribution on the particle size distribution , particle velocity, particle temperature and particle mixed degree were compared. The results show that large particles tend to move toward the lower part of the bed, while small ones toward the upper part of the bed; compared with narrow size distribution, there are obviously different on the axial velocity of binary mixture and wide distribution in different heights, and particle is lower in temperature and more prone to segregation ;the greater the size disparity is between diameter of two particles, the more easily they are separated. On the contrary, the closer the diameter of two particles is, the more difficult they are separated, and thus the better the mixed degree is.

关 键 词：流化床 多相流 粒度级配 离散单元法 计算流体力学 

分 类 号：TQ018[化学工程]