Numerical Investigation of Pyramid Solar Stills with PCM-Nanoparticles and Absorber Fins: Enhanced Thermal Performance for Sustainable Water Desalination

In arid regions facing challenges of limited access to potable water and electricity, solar desalination stands out as a promising solution for producing clean water from brackish sources. This research intends to examine and enhance an innovative and sustainable solar desalination system. A computational study is conducted on a pyramid solar still (PSS) combined with a phase-change material incorporated with nanoparticles, with a variety of absorber fins. The study investigates three configurations: a traditional pyramid–shaped solar still, one with square absorber fins, and another with circular fins. Paraffin wax mixed with Al₂O₃ nanoparticles is used beneath the absorber fins. Conservation equations are solved using COMSOL Multiphysics. Simulation outcomes demonstrate that the incorporation of finned absorbers, coupled with elevated water temperatures, significantly enhances the yield of the improved PSS compared with its conventional counterpart. The square-finned absorber PSS exhibits a substantial increase in total accumulated productivity over the conventional design. Moreover, the PSS with square-finned absorbers demonstrates an impressive average peak daily thermal efficiency improvement of 49.19% compared with a conventional solar still. This study highlights the effectiveness of the modified PSS as a superior option for household water generation.