Experimental investigation on thermal and exergetic performance improvement of a half-cylindrical solar still using PCM and reflectors

This study explores the potential of enhancing solar still performance by integrating a corrugated absorber with phase change material (PCM) and a reflector. The study aims to improve water yield, extend operation beyond sunset, and boost thermal and exergy efficiencies compared to a conventional flat absorber. Experiments were carried out on flat, corrugated, and corrugated-with-PCM absorbers, both with and without reflectors, to evaluate the effect of each modification. The results show that using a reflector with a flat absorber improved daily productivity by 22%. A corrugated absorber increased accumulated productivity by 38%, and when combined with a reflector, the improvement reached 40%. Incorporating PCM into the corrugated absorber increased productivity by 49%, while the highest gain of 68% was achieved when both PCM and a reflector were applied together. The corrugated absorber with PCM also extended still operation after sunset. Thermal and exergy efficiencies increased by 61% and 92%, respectively, compared to the flat absorber baseline. These findings confirm that coupling corrugation, PCM storage, and reflector-assisted solar input can significantly enhance solar still performance, offering a practical approach for improving freshwater production in sunny regions.