喷动床异径颗粒混合的离散元气固耦合模拟  

DEM Simulation of Mixing Behaviors of Binary Particles With Different Sizes in Spouted Beds

作　　者：任冰[1] 钟文琪[1] 金保昇[1] 邵应娟[1] 袁竹林[1] 

机构地区：[1]能源热转换及其过程测控教育部重点实验室(东南大学),能源与环境学院,江苏南京210096

出　　处：《工程热物理学报》2013年第8期1475-1478,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51206026);国家重点基础研究发展计划(973计划)(No.2011CB201505);霍英东教育基金会青年教师基金(No.131053)

摘　　要：采用离散元气固耦合模拟方法(CFD-DEM),对三维柱锥形喷动床中双组分异径颗粒的混合过程进行了模拟研究。对不同粒径比的双组分颗粒混合物在达到稳定混合后的流动结构进行了分析。采用Lacey混合指数来衡量总体颗粒混合的均匀程度,探讨了粒径比和喷动气速对颗粒浓度分布和床内混合质量的影响。结果表明,粒径比对流动结果的影响主要体现在喷泉区,粒径比的增加显著增加了喷泉的高度和宽度。床内混合质量随粒径比的降低和喷动气速的升高而增加,颗粒浓度沿轴向和径向的分布呈现明显的不均匀性。当双组分异径颗粒混合物达到稳定混合后,单位质量下粒径较小的颗粒所受曳力略高于粒径较大的颗粒。Three dimensional coupled CFD-DEM method is used to study the mixing behaviors of binary particles with different sizes in spouted bed. The flow patterns of binary particle mixtures at steady mixing state are discussed. The mixing quality is described by Lacey mixing index, and the effect of size differences and spouting gas on the mixing quality and particle concentration distribution is discussed. The results show that the effect of the size difference on the flow patterns mainly reflect in the fountain region, with the increasing of particle size difference, the height and width of the fountain increases. The mixing quality of the mixture increases with the decrease of particle size difference and increase of spouting gas velocity. The distribution of particle concentration in the radial and axial distribution tend to be evidently spatial inhomogeneous. At the steady mixing state, particle with the smaller radius have larger drag force.

关 键 词：直接数值模拟 气固两相流动 喷动床 颗粒混合 

分 类 号：TK051.1[动力工程及工程热物理]