Impact of water depth on thermal efficiency, exergy efficiency, and exergy losses of finned acrylic solar still: an experimental study

Abstract

This paper presents a complete exergy analysis and exergy destruction of a finned acrylic solar still (SS) at 1, 2, and 3 cm salt water depth (W_d). The coefficients of heat transfer of salt water-glass have been computed for evaporative, convective, and radiant heat transfer. Also, thermal efficiency, exergy loss of basin, saltwater, and glass was determined. The maximum hourly output of a finned acrylic SS at 1, 2, and 3 cm W_d was1.23, 0.93, and 0.81 kg, respectively. The daily yield of 5.67, 5.16, and 4.41 kg was collected from the finned acrylic SS at 1, 2, and 3 cm salt W_d, respectively. For the finned acrylic SS at 1 cm W_d, the maximal exergy loss of the basin, saltwater, and glass was 604.3, 92.8, and 141.8 W/m², respectively. The thermal and exergy efficiency of the finned acrylic SS at 1 cm W_d is 42.54 and 3.83%, respectively, while at 2 cm salt W_d, it is 37.92 and 3.22% and for 3 cm W_d is 31.2 and 2.7%. According to the findings, the exergy loss of saltwater in finned acrylic SS at 1 cm W_d is minimal when compared to the exergy loss of saltwater in finned acrylic SS at 2 and 3 cm W_d.

Keywords: Exergy analysis; Finned acrylic solar still; Solar energy, desalination.