Experimental investigation on the performance improvement of double-slope solar still by different shapes of the channel integration

An experimental investigation has been done for the performance enhancement of double-slope solar still (DSSS) by incorporating channels of different shapes. There are five solar stills including one conventional solar still, and four others modified with square (Sq), rectangular (Rect), triangular (Tri), and trapezoidal (Trap) channel are used. The temperature difference between the channel inlet and outlet, basin, and glass cover was measured at an optimum basin water depth of 2 cm. It is found that incorporating the channels inside the still enhances the basin water surface temperature. Results demonstrate that the best yield rate was achieved from the trapezoidal shape channel inserted in double-slope solar still (DSSS + Trap). DSSS + Sq, DSSS + Rect, DSSS + Tri, and DSSS + Trap channels increased the yield rate by 4.35%, 13.04%, 20.28%, and 30.43% compared to conventional double-slope solar still. Energy and exergy analysis was calculated for different days in the modified solar still. The cost per liter of distillate water was least ($0.034) for DSSS + Trap system with a payback period of 6.5 months. Moreover, it is observed that the modified double-slope solar still with trapezoidal channel attachment has reduced 5.33 tons CO2 for its life cycle. Furthermore, water samples collected during experimental have a drinking quality as per requirements of the World Health Organization standards.