Performance analysis of hybrid solar still integrated with phase change material and evacuated tube collector under forced circulation

This study presents a unique hybrid solar desalination system that combines the merits of energy storage materials with efficient heat collection through an evacuated tube collector under a controlled flow rate for maximum energy extraction and better controllability. Numerical modeling and simulation using experimental data has been critical approach to investigate the performance for the New Delhi (India) climatic conditions. Optimized PCM mass for the right balance between energy storage and heat transfer is found using 15 kg paraffin wax and more favourable than other used PCMs. At optimal mass, the yield, energy and exergy efficiencies are estimated as 5.016 kg/m(2), 39.56 % and 4.05 %, respectively, on summer day maintaining 30 kg basin water, 10 evacuated tubes and 0.06 kg/s flow rate. The enhancement in yield, energetic and exergetic efficiencies are found to be 29.88 %, 17.03 % and 35.8 %, respectively, compared to the system without phase change materials. Moreover, during winter, the system is found to be more effective than the summer with enhancement of yield, energy and exergy efficiencies by similar to 70 %, 60 %, and 102 %, respectively. The positive effect of phase change material on the performance is observed on successive days of operation with drastic enhancement in yield, energy, and exergy efficiency as 6.61 kg/m(2), 51.79 %, and 5.36 %, respectively, on the third day of operation. The water production cost as 0.02 $/kg is obtained, comparatively lower than the system operating without phase change material (0.023 $/kg).