ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
MODELING AND NUMERICAL ANALYSIS OF AN S PATTERN SMALL DIAMETER TUBE BUNDLE AMMONIA WATER FALLING FILM ABSORBER
Abstract
Absorption performance is very important in an ammonia water absorption system because of the tough coupled heat and mass transfer. Falling film absorption is advantageous on efficient use of absorption heat which has a large temperature glide. The main drawbacks are large bulk and weak heat and mass transfer performance. In this paper, a novel S pattern small diameter tube bundle falling film absorber is proposed to solve the disadvantages through increasing specific area for heat and mass transfer and improving surface wettability. Moreover, the mixing of the falling films at the contact point of the S tubes improves the mass transfer. A numerical model is developed on the basis of double film theory and the flow characteristics. Simultaneous heat and mass transfer processes are considered in both vapor and liquid phases. Finite-difference method is applied to solve the model through an iterative algorithm. Empirical correlations of heat and mass transfer are employed to indicate the heat and mass transfer resistance. The temperature and mass fraction profiles are obtained along the liquid flow direction, as well as the mass flux across the interface. The analysis provides an insightful comprehension on the mechanism of the novel falling film absorber.