Numerical analysis of the enhancement of ammonia-water falling film absorption process by atomized equipment

•Novel falling film absorber with the atomizer installed at the bottom is proposed.•The absorption effect is enhanced by 10.5% after the installing of atomizer.•The improvement is affected by the inlet conditions of absorber.•The droplets parameters optimization can further increase the enhancement effect. As a typical absorption device, falling film absorber has a significant effect on the performance of the ammonia water absorption refrigeration system. In this paper, a novel absorber with atomizer installed at the bottom of the absorber is proposed. The atomizer is introduced to increase the effective mass transfer area between ammonia vapor and the solution. A theoretical model in established and simulation investigation is carried out to obtain the absorption enhancement by the atomizer. The result indicates that the enhancement is 10.5% with the 1 mm initial droplet diameter in the design point of this paper, and it can reach 34.2% when the initial droplet diameter is reduced to 0.2 mm. Furthermore, the optimization of enhancement effect by other droplet parameters has been analyzed.