喷动床内气固两相流动纵向涡流效应数值模拟  

Numerical Simulation of Hydrodynamic Characteristics in a Spouted Bed with Longitudinal Vortex

作　　者：张洁洁[1] 吴峰[1] 马晓迅[1,2] 杨剑[3] ZHANG Jie-jie;WU Feng;MA Xiao-xun;YANG Jian(School of Chemical Engineering, Northwest University, Xi' an 710069, China;Shaanxi Research Center of Engineering Technology for Clean Coal Conversion, Xi' an 710069, China;School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China)

机构地区：[1]西北大学化工学院,陕西西安710069 [2]陕西省洁净煤转化工程技术中心,陕西西安710069 [3]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《高校化学工程学报》2017年第4期776-783,共8页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金项目(21476181);中国博士后科学基金第8批特别资助项目(2015T81048);第54批中国博士后面上一等基金资助项目(2013M540768)

摘　　要：为了深入了解纵向涡流对喷动床内气固两相流动特性的影响规律,采用计算流体力学方法对喷动床内气固两相流动的纵向涡流效应进行三维数值模拟。采用RUC曳力系数模型描述气、固相间作用力,通过欧拉-欧拉双流体模型和颗粒动力学理论对气固两相流动进行模型处理。分别对无扰流件、加入一对小球扰流件及加入一对纵向涡流发生器喷动床结构进行了模拟分析及对比。研究表明:加入球体扰流件及纵向涡流发生器之后,喷泉区的喷动高度明显下降,并在球形扰流件及纵向涡流发生器附近产生了二次漩涡。纵向涡流的存在显著地增加了喷动床内环隙区颗粒相的径向速度,增加了喷射区及喷泉区内颗粒体积分数及其密集度,有效增强了喷动床内气体、颗粒沿径向与轴向的湍动能及拟温度值,进而强化了环隙区与喷射区内颗粒、流体两相的横向混合效果及颗粒间的动量交换过程。Effects of longitudinal vortex on gas-solid two phase flow in a spouted bed was numericallystudied by Eulerian-Eulerian two-fluid model(TFM)and kinetic theory of granular flow.RUC drag model waschosen to describe interface momentum exchange.Simulation and analysis were performed on three cases(without disturbance units,with a pair of balls and with a pair of longitudinal vortex generators)to study thestructure of the spouted bed.Simulation results show that fountain height decreases significantly when thespouted bed has longitudinal vortex generator due to the increase of particle phase flow resistance.Thesecondary vortex flow emerges in the spouted bed with longitudinal vortex generators and spherical obstacles,which increases the particle radial velocity in annulus zones.Particle concentration increases in spout andfountain zones of the spouted bed,and the turbulent kinetic energy of gas phase and granular temperature areenhanced by longitudinal vortex effects.Therefore,transverse mixing of particles between spout and annuluszones in the spouted bed can be significantly enhanced by longitudinal vortex.

关 键 词：喷动床 纵向涡流 多相传递强化 数值模拟 

分 类 号：TQ021.3[化学工程]