Experimental and theoretical investigation to optimize the performance of solar still

Abstract

The cheapest and pollution-free method of producing drinkable water is solar distillation utilizing solar stills. However, the solar stills operate at lower-than-optimal efficiency, presenting significant room for improvement. Researchers have identified various techniques, modifications, and improvements to enhance efficiency in solar distillation. Notably, a solar pond is integrated with the solar still to boost performance, with the solar pond dramatically enhancing solar efficiency. In this research, four factors were identified as significantly influencing the performance of the solar stills: the concentration of sodium chloride (NaCl) in the solar pond, mini solar pond zones connected to the solar still, and the angles of internal and external reflecting mirrors. Three levels for each parameter were chosen for our study. The Taguchi method was utilized to identify the optimum level of these four parameters that maximizes performance. The best combination for maximizing efficiency was identified as connecting the solar still to the lower converting zone of the mini solar pond, using water containing 4 kg of NaCl, setting the internal reflecting mirror at 0⁰, and fitting the external reflecting mirror above the solar pond at 140⁰. This combination achieved a daily efficiency increase to 57.14%. Theoretical values were compared with experimental outcomes, showing that the solar still operated most efficiently between 12:00 and 14:00 h. The findings suggest not only immediate applications for improving solar still designs but also a pathway for future research into cost-effective desalination processes.