Thermo-economic performance enhancement of a solar desalination unit using external condenser, nanofluid, and ultrasonic foggers

This work sought to augment the thermo-economic performance of solar still via different proposed modifications. Firstly, to enhance the condensation process, two condensers were utilized and compared, namely: active water/active vapor (type-A) and passive water/active vapor (type-B). For each, various fan operation times, speeds, and powers were tested to obtain the best operation conditions. The comparison showed that type-B was slightly better as it enhanced the yield, energy efficiency, and exergy efficiency by 31, 30, and 12.56% compared to a conventional solar still. Whereas the modified solar still with condenser type-A augmented them by 21.3, 26.1, and 8.79%, respectively. Then, after selecting the proper condenser (type-B) and fan operation conditions, CuO nanofluid (1 wt%) was added to the solar still basin. Finally, three ultrasonic foggers were integrated into the basin to obtain mist and boost the evaporation rate. The results showed that the nanofluid addition augmented the performance by 42.8% (yield), 46% (energy efficiency), and 54.85% (exergy efficiency) relative to the conventional solar still. Finally, integrating the foggers uplifted these ratios to 59.1, 65.5, and 63.8%, respectively. For the environmental analysis, the proposed additives can participate in CO2 mitigation by up to 23.58-ton (energy-based) and 1.44-ton (exergy-based). In addition, the produced freshwater had acceptable quality with reasonable cost.

Automated summary

This study aimed to enhance the thermo-economic performance of solar still by implementing various modifications, such as improving the condensation process and adding nanofluids. The results showed significant improvements in yield, energy efficiency, and exergy efficiency, as well as potential CO2 mitigation.