循环流态化自动清洗式换热器的传热强化  

Heat transfer enhancement of self-cleaning heat exchangers of fludization

作　　者：俞天兰[1] 刘桂英[1] 李桂芳 任卫红 

机构地区：[1]湖南工业大学清洗研究所,湖南株洲412008 [2]长沙华海节能装备公司,湖南长沙410000

出　　处：《热科学与技术》2006年第3期227-230,共4页Journal of Thermal Science and Technology

基　　金：国家九五重点推广计划项目(96050403A);湖南省教育厅资助项目(03C596)

摘　　要：液-固流态化传热强化的机理尚未完全清楚，已有文献对流态化粒子的粒度与传热系数的影响关系有较大分歧。从传热强化角度对水-沙流态化自动清洗的运行参数进行优化试验研究。得到的结果是：沙子粒度不是愈细愈好，而是Dp2mm（8目）左右为好；粒子体积分数以2．4％比较好；流速在0．2～0．28m／s（Re为6000～9000）较好。虽然粒子体积分数低，但是在优化条件下的流态化传热强化幅度几乎可以达到一倍左右，并且阻力又很低。The mechanism of heat transfer enhancement of liquid-solid fluidization is not clear yet. There are many different views on the relationship between the particles size and heat transfer coefficient in the present documents. From the point view of heat transfer enhancement, the optimum experimental study of operation parameters was studied. Results indicate that heat transfer coefficient is not always increased when the particle size is decreased. The size of Dp 8mm is the best. The optimal volume density of particles is 2. 4%. The optimal range of flowing velocity is form 0.2 m/s to 0. 28 m/s（Re = 6 000 ～ 9 000）. The heat transfer enhancement is as great as nearly 100% and the total resistance is low under the above conditions.

关 键 词：流态化 传热强化 粒子体积分数 粒子粒度 流速最佳化 

分 类 号：TK124[动力工程及工程热物理—工程热物理]