移动床固体颗粒绕流顺排圆管的过程  

Particles flowing process across aligned tubes in a moving bed

作　　者：邓升安 楼国锋 徐科珺[1] 温治 刘训良 豆瑞锋[1,2] 苏福永 DENG Sheng-an;LOU Guo-feng;XU Ke-jun;WEN Zhi;LIU Xun-liang;DOU Rui-feng;SU Fu-yong(School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China;Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, University of Science and Technology Beijing, Beijing 100083, China)

机构地区：[1]北京科技大学能源与环境工程学院,北京100083 [2]北京科技大学冶金工业节能减排北京市重点实验室,北京100083

出　　处：《工程科学学报》2018年第6期735-742,共8页Chinese Journal of Engineering

基　　金：国家重点研发计划资助项目(2016YFC0401201)

摘　　要：工业中常用带埋管的移动床来加热或冷却固体颗粒物料,其过程涉及颗粒流与管壁间的复杂传热,而颗粒绕流圆管的流动过程对其传热效果起着决定性作用.为简化描述颗粒的流动过程,通过分析颗粒绕流圆管的特性,建立了拟漏斗流模型,并给出了模型所需颗粒绕流圆管描述参数的取值范围,模型可用以求取颗粒绕流圆管的速度场和时长等参数.建立了埋管移动床实验系统,考察了颗粒绕流顺排管束的过程;同时利用离散单元法（DEM）对该过程进行数值模拟,获得了颗粒绕流圆管的流动过程,并利用移动床实验结果对比验证了离散单元法数值模拟结果;最后,对比了基于拟漏斗流模型的计算结果和离散单元法数值模拟结果,并根据此结果对拟漏斗流模型的描述参数进行了确定.Many solid particles in industrial processes require heating or cooling,such as calcinated petroleum coke,blast furnace slag,and steel slag. A moving bed with tubes is a viable design for facilitating such complex heat transfer processes. As particles are the primary heat carriers in this flow,the flow pattern of particles across the tubes in a moving bed is the main determinant of the heattransfer mechanism. The characteristics of particle flows across a tube structure are vastly different from those of a continuous-medium flow. Therefore,the flow pattern of particles moving across a bed of tubes must be studied prior to the heat-transfer mechanism. A simple pseudo-funnel flow model that can calculate parameters such as velocity field and residence time was established in this study for particle-flow modeling,and the range of parameters required to describe particles flowing across tubes was discussed. Using a movingbed test device made of transparent PMMA material,the flow of particles across aligned tubes banks was measured and a set of experimental results were obtained. Simultaneously,the discrete element method（ DEM） was used for numerical simulations of the particleflow distribution in the system,and the obtained results were compared and verified by experimental results. Computational results from the quasi-funnel flow model were then compared with the DEM numerical simulation results to find the set of parameters required to describe particles flowing across aligned tube banks in the pseudo-funnel flow model. By setting appropriate values of the abovementioned parameters,the relative error between the two models could be reduced to 3%. This study provides a foundation for future studies on heat transfer processes in moving granular beds and the design and optimization of similar heat exchange devices.

关 键 词：颗粒流 流动特性 移动床 离散单元法 停留时间 

分 类 号：TH172[机械工程—机械制造及自动化]