Black glass balls as thermal enhancers in conical solar distillation: performance optimization and comparative insights

In this study, the main aim is to determine the most effective spacing for 1.6 cm-diameter black glass balls, utilized as a cost-efficient energy storage solution to enhance the performance of a conical solar distillation system. Three identical conical stills were utilized over a two-day experimental period to evaluate various setups. The first distiller, denoted as the conventional conical solar distiller (CCSD), operated without black glass balls on the initial day and served as the reference for comparison on the second day. The second and third distillers, labeled CSD-BGB3 and CSD-BGB4, featured black glass balls spaced 3 cm and 4 cm apart, respectively, while another set of experiments on the subsequent day involved CSD-BGB5 and CSD-BGB6, with black glass balls spaced 5 cm and 6 cm apart. The brine depth in the basins remained constant at 1.6 cm throughout the experiments. The study revealed that CSD-BGB3 achieved the highest yield from the distillation process, reaching 8250 g/m2, while the maximum yields for CSD-BGB4, CSD-BGB5, CSD-BGB6, and CCSD were 7600, 7100, 6600, and 5750 g/m², respectively. The optimal spacing of 3 cm between the black glass balls led to a significant improvement in accumulated yield and daily efficiency by 43.48% and 42.59%, respectively, compared to conical solar stills without black glass balls. The findings suggest that a conical solar distiller equipped with 1.6 cm-diameter black glass balls spaced 3 cm apart offers the most efficient and cost-effective energy storage solution among the configurations examined.