An experimental investigation on the performance of single slope passive solar still for water desalination

In this study, a passive-type single-slope solar desalination system using solar energy for domestic applications was designed, fabricated, and tested for its performance. The effects of various factors such as ambient conditions, temperatures at various locations on the solar still, and air movement were considered in this study. An average cumulative productivity of 6 liters/m2 was obtained with a maximum of 6 to 7 liters/m2 in a few days. The quality of freshwater yield was good enough, with an average pH of 6 and TDS of 171 ppm. Maximum energy efficiency range between 12 to 14% was reasonably good for a solar still without any solar concentrators or enhancement techniques being incorporated in the still. Exergy efficiency ranged between 0.2% and 0.6% with a steep rise at 13 h and a drastic fall at 14 h. Productivity increased by 75 to 100% during 12 h and 13 h, whereas after 13 h, the rise in productivity was reduced to approximately 30 to 40%, which complemented the results of energy and exergy efficiencies.本研究针对家用场景设计、搭建并测试了一款被动式单坡太阳能海水淡化系统的性能表现。本研究考量了诸多影响因素，包括环境条件、太阳能蒸馏器（solar still）各部位温度以及空气流动情况。系统平均累计产水量为6升/平方米，部分单日最高产水量可达6至7升/平方米。所产淡水的水质表现优良，平均pH值为6，总溶解固体（Total Dissolved Solids, TDS）含量为171 ppm。对于未加装任何太阳能聚光器或强化技术的太阳能蒸馏器而言，其最高能量效率区间为12%至14%，表现较为优异。㶲效率（Exergy efficiency）区间为0.2%至0.6%，在13时出现显著上升，14时则大幅下降。在12时至13时期间，产水量提升幅度达75%至100%；而13时之后，产水量的增幅回落至约30%至40%，这与能量效率和㶲效率的测试结果相契合。