Modelling and Optimization of a Two-Bed Silica Gel–Water Adsorption Desalination System Using CFD and Genetic Algorithms

The operational dynamics of a silica gel–water system with two beds in a single-stage adsorption desalination system were analysed using an enhanced model based on mass and energy conservation principles, incorporating adsorption and desorption kinetics. Computational Fluid Dynamics (CFD) and mathematical modelling were both employed to simulate the processes occurring within a rectangular finned tube bed packed with absorbent materials, such as silica gel. The adsorbent was modelled as a porous solid medium using the Darcy equation, and a lumped-parameter approach was applied to describe heat and mass transfer during the cycle. Simulations were conducted for both adsorption and desorption phases. Model validation showed maximum deviations of ۹.۳% for water uptake and ۴% for bed temperature. To improve system performance, a Genetic Algorithm (GA) was integrated with the mathematical model to optimize key parameters, including cycle time, bed geometry, and fin configuration. The effects of fin pitch and height were specifically investigated, resulting in an optimized water uptake of ۱.۹۸ kg/kg—representing a ۱۲% improvement in adsorption performance and a ۵% increase in the average bed temperature.

کلیدواژه ها:

Adsorbed system ، mathematical modelling ، Genetic algorithm (GA) ، Fin pitch optimization.