水平管外喷淋式降膜蒸发的研究

本文探讨了水平管喷淋式降膜蒸发的研究.本实验分别采用电加热和蒸汽加热方式,对不锈钢光滑管和电化学腐蚀多孔表面管进行研究,所用工作流体为脱离子水.除了表面几何情况的研究以外,还以液体进料速率(喷淋密度)、热通量的变化、多孔表面管的热处理情况、以及管内蒸汽速度作为研究的参变量.由于多孔表面管对液膜核状沸腾的促进作用,多孔表面管与光滑管相比,其强化作用是显著的.

Investigations on theSpray Film Evaporation onthe Outside of a Single Horizontal-tube

The present paper describes a study on the evaporation in a horizontal tube spray film evaporator. Single tubes, either electrically heated or steam heated, are used for the study. Two types of tube surface properties are considered, namely an electro-chemically etched porous tube surface and a smooth tube surface. The latter also serves as a reference De-ionized water is used as working fluid. Liquid feed rate, changes in the rate of heat flux, annealing treatment of the porous tubes and steam velocity in the tube are explored as operational variables. Compared with smooth tubes and pool boiling, porous tubes proved to give much better performance as such tubes tended to promote nucleate boiling of the film.