Experimental studies on the characteristics of an absorber using LiBr/H2O solution as working fluid

The absorber is an important component in absorption machines and its chara cteristics have significant effect on the overall efficiency of absorption machines. This article reports on the results of experimental studies on th e characteristics for a falling film absorber which is made up of 24 row ho rizontal smooth tubes. It shows that while the mass transfer coefficient is increased with the increase of spray density, the heat transfer coefficien t is increased only in small spray density range. There is an optimum spray density between 0.005 and 0.055 kg s(-1) m(-1) spray density at which the heat transfer coefficient is maximum. The heat transfer coefficient (Nussel t number), which is traditionally expressed using Reynolds number and Prand tl number, was modified taking the effect of inlet solution concentration i nto account. The results can be used to optimize the future design of absor ption machines having a falling film absorber and using LiBr/H2O as working fluid. (C) 1999 Elsevier Science Ltd and IIR. All rights reserved.