Characteristic Analysis of Adiabatic Spray Absorption Process in Aqueous Ammonia Solution

Abstract

An absorber is a key device of absorption refrigeration system, and it directly affects the performance of refrigeration system. As an important absorption type, adiabatic spray absorption process disperses the absorption fluid into fine droplets by nozzles and forms immense surface exposed to the coolant vapor. Therefore, it can improve the absorption performance. In the paper, an improved analytical Newman model is presented which can consider the absorption heat effect on adiabatic spray absorption process. Using the model, the absorption characteristics of the adiabatic spray in aqueous ammonia is studied. The results show that increasing absorption time can increase absorption mass, MA. However, when t/tMax approaches to 0.6, MA has reached to 90% of the maximum absorption mass. In other words, increasing absorption time can hardly improve MA aftert/tMax exceeds 0.6. The maximum absorption time, tMax, is proportional to the square of the droplet radius. Decreasing droplet radius can improve the absorption rate，but this increases the energy consumption of the refrigeration system. The current investigation can result in a better understanding of absorption mechanisms of the adiabatic spray absorption.