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

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 (Wd). 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 Wd 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 Wd, respectively. For the finned acrylic SS at 1 cm Wd, 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 Wd is 42.54 and 3.83%, respectively, while at 2 cm salt Wd, it is 37.92 and 3.22% and for 3 cm Wd is 31.2 and 2.7%. According to the findings, the exergy loss of saltwater in finned acrylic SS at 1 cm Wd is minimal when compared to the exergy loss of saltwater in finned acrylic SS at 2 and 3 cm Wd.