水平管降膜蒸发器管外液膜的数值模拟

Numerical Simulation of Film Formation on Horizontal-tube Falling Film Evaporators

对水平管降膜蒸发器管外液体的成膜情况进行了数值模拟,分析了喷淋密度、管径大小、周向角度等参数对管外液膜厚度及分布的影响,并与相关实验数据进行了比较.结果表明:在喷淋密度一定时,管外液膜厚度在管顶和管底区域较大,在周向120°附近最小;管壁表面的液膜厚度随着喷淋密度的减小而减小,当喷淋密度减小到一定程度时,管壁表面出现了局部"干斑"现象;在喷淋密度一定时,管壁液膜厚度随管径的增大而减小.

Numerical simulation of film formation on horizontal-tube falling film evaporators was simulated,during which factors influencing the film thickness and distribution were analyzed,such as the spray density,the tube size and the circular angle of measured point on tube surface etc.The simulated results were subsequently compared with relevant experimental data.Results show that for a fixed spray density,the thickest film forms on both the top and bottom area of tube while the thinnest appear at a circular angle of about 120°;the smaller the spray density is,the thinner the film will be,and when the spray density reduces to a certain value,dry spot will form on local area of tube;for a fixed spray density,the film thickness reduces with rising tube size.