水平管降膜厚度的电导探针测量方法  

Conductance probe measurement method for falling film thickness around horizontal tube

作　　者：侯昊[1] 毕勤成[1] 马红[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《沈阳工业大学学报》2011年第4期476-480,共5页Journal of Shenyang University of Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2009CB219805)

摘　　要：为测量水平管降膜分布参数,从而揭示降膜的流动特性,根据气液两相介质的电导特性,设计出一种测量水平管降膜厚度的电导探针系统,利用该系统进行了水平管周向不同位置液膜厚度分布规律的实验研究.结果表明,水平管降膜厚度的电导探针测量方法不仅切实可行,而且还能实现大角度范围测量,可扩展应用于垂直结构外部气液两相流动参数的分布测定.此外,管外液膜厚度随管间距的增加而减小,而且液膜波动加剧.与实验数据对比,发现Nusselt公式可以用来预测圆管上半周的液膜厚度,但下半周的数值明显偏大.在不同工况下,最薄的液膜并不是出现在β=90°的单点处,而是在β=90°～115°的区域内.In order to measure the distribution parameters of falling film around a horizontal tube and reveal the flow behavior of the film,a conductance probe system for the thickness measurement of falling film around horizontal tube was developed based on the conductance characteristics of gas-liquid two-phase medium.The liquid film thickness distribution at different locations around horizontal tube was investigated with the conductance probe system.The results verify that this method is feasible in the measurememt of falling film thickness around horizontal tube.Furthermore,the method may achieve the measurements in a wide angle range,and can be expanded to the distribution measurement of gas-liquid two-phase flow parameters on vertical surface.In addition,the liquid film thickness outside the tube gets thinner with increasing the inner-tube spacing,and the liquid film flow becomes more unstable.Compared with the expenrimental data,it is found that the Nusselt equation can give a reasonable prediction for the liquid film thickness around the upper perimeter of the tube,but the data around the lower perimeter is obviously large.Under different operating conditions,the thinnest liquid film appears in an angle range from 90° to 115° rather than at the single point of β=90°

关 键 词：电导探针 测量方法 水平管 降膜 液膜厚度 分布参数 气液两相流 海水淡化 

分 类 号：TQ02[化学工程]