Optimization on performance of single-slope solar still linked solar pond via taguchi method

Abstract

The efficiency of the solar still is below optimum. To increase the efficiency and to reach the optimum performance many modifications and improvements in the solar stills were attempted. In this research work, a mini solar pond was linked with the solar still. Further with the help of mirrors, solar radiations were reflected into the solar pond and solar still. Four parameters that were influencing the performance of the solar still and their levels were identified. They were: parameter I – sodium chloride concentration level (1.5, 2.5 and 3.5 kg), parameter II – mini solar pond zone (lower converting zone (LCZ), middle converting zone and upper converting zone), parameter III – angle of the reflecting mirror at the bottom of the still (–15°, 0° and 15°) and parameter IV – angle of the mirror fitted in the pond (90°, 113° and 135°). Taguchi method was used to select the best performing levels. S/N ratios and mean performance of the different levels indicated that level 3 of parameter I, level 1 of parameter II, level 2 of parameter III and level 3 of parameter IV were the best performing levels. The regression analysis also confirmed that the above levels of the four parameters had positive regression coefficient. So optimum distillate yield can be obtained when the sodium chloride concentration level was 3.5 kg, the solar still was linked with LCZ of the pond, the reflecting angle at the bottom of the still was kept at 0° and the mirror at the pond at 135°. Combining the above selected levels of the four parameters, the experiment was conducted, and the distillate output obtained was 3.26 L/d. It was 95.54% higher than the yield of the conventional still. The theoretical values were compared with the experimental results, and there was good agreement between the two.