循环流化床提升管内聚团速度的研究  

A study on cluster velocities in CFB riser

作　　者：顾素敏 陈恒志[1] 盛伟 耿超[1] GU Su-min;CHEN Heng-zhi;SHENG Wei;GENG Chao(College of Chemistry and Chemical Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学化学化工学院

出　　处：《高校化学工程学报》2019年第6期1354-1360,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(51374261,91334109);重庆大学大型仪器开放基金(201712150024)

摘　　要：聚团是气固循环流化床(CFB)中最常见的现象,对气固之间的热量和质量传递有重要影响。为了考察循环流化床内不同运动方向聚团速度的特性,采用高速相机对提升管内气固流动进行摄像,并利用Matlab图像处理程序,分离出颗粒聚团区域并计算颗粒的运动速度。采用拉格朗日(Lagrange)法计算聚团速度,并根据聚团运动方向对上行和下行聚团的速度分别研究。研究结果表明:采用拉格朗日法能准确地计算聚团速度,上行聚团速度略大于下行聚团速度,聚团速度主要分布在[-3,3] m·s^-1且随表观气速的增加而增加;边壁区域下行聚团数量远大于上行聚团数量,中心区域上行聚团数量略大于下行聚团,下行聚团数量占聚团总数的60%~70%。聚团速度沿轴向高度略有增加,在顶部受出口的影响略有减小。聚团横向移动在边壁区域较小,中心区域较大。A thin 2 D circulating fluidized bed(CFB) was used to investigate cluster velocities at different moving directions through analyzing images captured by a high-speed digital camera. Image processing program based on Matlab language was developed to separate the clusters from gas-solid flow and calculate cluster velocity. The experimental results show that the cluster velocity can be accurately calculated by Lagrange approach. The velocity of the up-moving clusters was slightly higher than that of the down-moving cluster. The cluster velocity increased with the increase of superficial gas velocity with majority in the range of -3~3 m·s^-1. The number of down-moving clusters was more than that of the up-moving clusters in the peripheral region, while the up-moving clusters were slightly over the down-moving cluster in the central region of the riser. The number of the down-moving clusters was 60%~70% of the total clusters. The x-component of cluster velocity was low, which increased in the central region and decreased in the peripheral region of the riser.

关 键 词：流态化 循环流化床 聚团速度 LAGRANGE 图像处理技术 

分 类 号：TQ01[化学工程]