循环流化床床内结构对局部流动特性影响  

Effect of Geometry Structure on Local Flow Properties in a Circulating Fluidized Bed Riser

作　　者：田晨[1] 王勤辉[1] 张锡梅[1] 程乐鸣[1] 骆仲泱 倪明江[1] 岑可法[1] 

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《过程工程学报》2009年第S2期139-145,共7页The Chinese Journal of Process Engineering

基　　金：国家"十一五"科技支撑计划资助项目(编号:2006BAA03B01-06)

摘　　要：在尺寸为1.5m×0.864m×4.9m的循环流化床内,以粒径0.1~0.425mm的玻璃珠为床料,利用高速摄影和粒子图像测速技术,对炉膛结构对床内气固两相流动特性的影响进行了实验研究.在一次风速2m/s,静止床高300mm条件下,获得了密相区、过渡区防磨板台阶处及稀相区炉膛边角和挂屏处颗粒流动的速度分布.实验结果表明,在密相区,炉膛后墙渐扩结构使得颗粒易对后墙形成较大冲刷;过渡区防磨板的布置引起流通截面突变,台阶效应作用下颗粒对防磨板的冲刷作用明显;分离器的偏置布置加强了稀相区段的出口效应,左墙中心颗粒径向运动值0.45m/s明显高于边壁处颗粒径向速度0.2m/s,环核流动受到破坏;稀相区挂屏的布置使得颗粒速度沿径向呈现类抛物线分布,最小值为0.06m/s,最大值0.35m/s.By using high-speed video camera and particle image velocimetry(PIV) technology,the local flow properties of solid-gas two-phase flow were studied in a plexiglas rectangular CFB cold model with the size of 1.5 m×0.864 m×4.9 m.Measurements were carried out under 2 m/s superficial gas velocity and 300 mm initial bed height.0.1~0.425 mm transparent glass beads were used as bed material.The experimental results showed that in the dense region,particle movement was dominated by bubble wake and inclined to the back wall on the influence of expanding cross-section of back wall.Projection section in the transition region decreased the flow area and increased the particle lateral velocity.In the dilute region,the outlet and corner effects caused the defluxion of particles movement and the core-annular distribution was broken.The closer to the outlet,the stronger the lateral velocity was.The obstruct of hanging screen reduced the furnace outlet effect which induced a parabolic particle velocity distribution between the screen and the furnace walls.

关 键 词：PIV 矩形截面流化床 两相流 挂屏 

分 类 号：TK229.66[动力工程及工程热物理—动力机械及工程]