A new insight of temperature distribution on superhydrophilic surface horizontal tubes falling film at low spray density

摘要

Falling film on horizontal tube banks is widely used in heat and mass transfer processes, because it leads to a higher heat and mass transfer performance. In this paper, a series of experiments were conducted to investigate the temperature distribution and local temperature evolution feature of liquid film at low spray density on superhydrophilic surfaces by thermal tracing method. The experimental results revealed that the temperature distribution of liquid film on the superhydrophilic surfaces presented a sub-region effect for different flow mode, a uniform and repeated distribution for jet mode and two totally different zones for droplet mode. Besides, for there existed a new high temperature band, which was first observed in the center of saddle-shaped lamella for droplet mode and a lower temperature region coinciding with the interaction ring between each pair of jets for local temperature feature due to the effect of the collision and overlap of spread film on superhydrophilic surfaces.