COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF FINNED TUBE DEHUMIDIFIER FOR SOLAR HUMIDIFICATION DEHUMIDIFCATION DESALINATION PLANT

Abstract

Desalination by air Humidification Dehumidification (HDH) is one of the upcoming technologies of converting brackish water into freshwater. It works by evaporating the brackish water and humidifying air passing over it, leaving the salts behind. The humidified air is then passed through the condensers to recover the water it carries by condensation of water vapour. This condensed water is free from salts and can be directly used or can be further treated for use. The use of a compact finned tube heat exchanger for the purpose of the 2nd dehumidifier in a two stage HDH process is carried out by using computational fluid dynamics (CFD) analysis. The boundary condition for the computational work is obtained from experimental setup in a pilot plant. As CFD models can take up very large computational power for solving fin structures, the model is solved by modelling the fins side of the dehumidifier as a porous medium. The water yield obtained from condensation, thermal characteristics of the fluid model are obtained is compared with experimental results. The yield of water obtained is 3848 ml/hour for the first set of experimental observations.