A comprehensive model for enhancing productivity of a decentralized desalination unit
Hebatullah Megahed, Nahed El Mahallawy
Abstract
The presented analyses aim for enhancing a decentralized desalination unit by controlling the following parameters: design parameters, environmental and operating conditions as well as all materials property of the solar still components. The model results predicted a rise within the cumulative productivity by adjusting water depth, front side length, and basin depth to width ratio. Decreasing the front side length at a fixed cover plate inclination angle increased the saturated pressure difference between the water level and the inner cover plate. For a lower cover plate thermal conductivity and better basin absorptivity, the analyses included replacing the tempered glass with plexiglass and coating galvanized steel basin with graphene oxide rather than black paint, as a result, the productivity raised by 109.6% and 14.3%, respectively. Regarding the environmental conditions, the model predicts that the highest productivity can be reached by increasing wind speed to 5 m/s and solar irradiance to 1000W/m2. It had been found that increasing the water conductivity by adding 0.01 volume fraction (vf) Al2O3 nanoparticles increased the productivity by 82.71%. Furthermore, the study included all optimum conditions to increase the daily cumulative productivity of the still from 1.3 l/m2 to reach 10 l/m2.