Design and performance of black painted Khes wick modified solar still: An experimental and 5E analysis

Abstract

The present investigation recommends some major modifications for performance improvement in the conventional solar still (CSS). Five different configurations have been analysed viz: (1) still with no wick, (2) still with a wick at 15° (3) still with a wick at 30°, (4) still with a wick at 45°, and (5) blackened basin solar still (BBSS) with a wick at 30°. Experiments were conducted in March because of favourable climatic conditions. The flow rate of water passing through the basin and the wick was kept constant for all the configurations (0.2 gram/m2sec). Experiments were conducted to calculate the distillate yield and to carry out 5E analysis (energy, exergy, energy metrices, exergo-economic analysis, enviro-economic analysis). The results explore that the BBSS had the highest productivity of 4.372 kg/m2 among all configurations. However, the distillate yield obtained in CSS with 30° wick is quite close to the BBSS yield i.e., 4.25 kg/m2. Distillate yield obtained in the remaining case of CSS with 15°, 45° and without wick is about 3.802 kg/m2, 3.925 kg/m2, and 4.102 kg/m2, respectively. Energy output for modified CSS was observed to be highest for BBSS i.e., 2.31 kWh/day. The embodied energy was also found to be highest for BBSS i.e., 457.15 kWh with a minimum energy payback time (EPT) of 1.11 years. In addition, CO2 mitigated/year was found to be highest for the BBSS (energy basis -2.01 tones and exergy basis -0.25 tones) compared with the CSS (energy basis -1.88 tones and exergy basis -0.21 tones). The cost of distillate yield was found to be lowest for BBSS, which is found to be ₹ 1.38/L along with the payback period of 91 days.

Keywords

• Solar still
• Blackened basin
• Wick
• 5E analysis