垂直管内不同物性降液膜流动的实验研究与应用  

Experimental Study and Application of Different Physical Properties Falling Film Flow in Vertical Tube

作　　者：刘璐[1] 陈琴珠[1] 王学生[1] 范宇[1] 

机构地区：[1]华东理工大学机械与动力工程学院,上海200237

出　　处：《实验室研究与探索》2015年第2期34-37,共4页Research and Exploration In Laboratory

摘　　要：通过实验比较不同物性的液体在不同管径的换热管中的成膜流动情况,得到一种根据物性及工况条件选择换热管径的有效方法.不同配比的乙二醇水溶液有不同的密度、黏度及表面张力等物性,以此溶液为实验液体,进行垂直管内降膜冷模实验.观察记录不同流量下管内液膜流动稳定性,综合考虑液膜厚度等因素,选取最佳液膜流动状态.引入一个与黏度、表面张力、管内液膜流速有关的无量纲参数A,发现A值在（8.8～10.2） ＆#215;10-2范围内时,管内液膜流动稳定、膜厚均匀、厚度适中.实践应用证明：根据A值范围选取换热管管径的方法是可行的.此方法为设计降膜式热交换器时选择管径提供了一种简便的新思路.Experiments were done to study and compare the liquid of different physical properties flow in the heat exchange pipes of different diameters. And an effective method was proposed to choose heat pipe diameter according to the physical properties and working conditions. Ethylene glycol aqueous solution with different ratio whose density, viscosity, surface tension and other properties were different were taken as experimental liquid and flowed in the vertical tube. Observing the falling film flow process, and considering the liquid film thickness and other factors, the best film flow was selected. A non dimensional parameter was proposed. The parameter is related to the viscosity, surface tension, and velocity of the liquid. A more stability flow and a more uniform film can be observed when the parameter ranges in 8.8 × 10-2--10.2× 10-2. The engineering application of the method was also carried out in present work. The method can provide certain directive significance to the design of falling film evaporator.

关 键 词：垂直管 物性 降液膜 

分 类 号：TQ053.6[化学工程]