Evaporation for Lithium Bromide Aqueous Solution in a Vertical Falling Film Type of Generator under Reduced Pressure

Numerical Analysis by One-dimentional Difference Method

Abstract

Experiments on evaporation for lithium bromide aqueous solutions (0-55wt% LiBr) were made in a vertical falling film type of stainless steel generator under reduced pressure, 8kPa. A simple calculation method is proposed to analyze the heat and mass transfer in falling film of lithium bromide aqueous solutions. The method is to solve the one-dimensional differance equation driven using the previous equations for coefficients of heat transfer and mass transfer in falling film, and the unidirectional diffusion model.
The results of the new calculation method agree with those of author's previous two-dimentional difference method, and the new method reduces computation time to one sixtyth. The calculated values for evaporation rate and falling film temperatures in the generator agree well with the observed values of them.