Enhancing the solar still performance with nano-coated seashells and surface-modified absorber plates for clean water production

Abstract

The study focuses on enhancing the thermal efficiency and water productivity yield of a double slope solar still (DSSS) by integrating a roughened corrugated copper plate, and nano-coated seashells. The surface-modified absorber plate, combined with small and larger-sized conch shells, intends to enhance thermal absorption, thermal transfer, and water evaporation. Four different SS are considered in this study, namely (i) CSS, (ii) corrugated absorber plate with shot blasting (CSBSS) (iii) corrugated absorber plate with small conch shell (CSBSSS), and (iv) corrugated absorber plate with big conch shell (CSBBSS) incorporated SS. The corrugation process and the conch shells’’ addition enhance the absorption, improving heat transfer, maintaining water temperature, reducing heat loss, promoting efficient water evaporation, and augmentation of durability and adaptability of the solar still system. The increased heat flux was observed in the corrugated copper plate (6400.7 W/m2), compared with the flat plate (4723.8 W/m²), suggests that the corrugated design is more capable of capturing and transmitting solar energy effectively through ANSYS software. The daily productivity of CSS was 1468 ml/m2/day, and CSBSS achieved 1708 ml/m2/day. Promoting the implementation of corrugation and the integration of conch shells, CSBBSS and CSBSSS systems exhibited improved yields, reaching 2002 and 2193 ml/m2/day, respectively. CSBSS, CSBSSS, and CSBBSS showed thermal efficiencies surpassing CSS by 6.41 %, 35.53 %, and 24.48 %, respectively. The average exergy efficiencies attained for CSS, CSBSS, CSBSSS, and CSBBSS were 1.653 %, 2.451 %, 3.91 %, and 3.29 %, respectively at an 8 % interest rate.