The incorporation of phase change material (PCM) enhances the productivity of the solar still as well as makes it continuously operative during low sunshine/nighttime. This study analyzes the performance of single slope solar still incorporated with paraffin wax as a PCM beneath the basin liner and further integrated with an evacuated tube collector under forced convection. The results have revealed that under similar climatic conditions, PCM-incorporated solar still improves the productivity by 30% compared to the system without PCM, yielding 5.064 kg/day using 15 kg PCM at 0.03 m water depth and a flow rate of 0.06 kg/s. The overall energetic and exergetic efficiencies have been found to be 39.56% and 4.05%. Irreversibility has been seen as a function of the intensity of available radiations during the daytime and is crucial at basin liner and, minimum at PCM. Moreover, at night, basin water has the highest irreversibility of ~78% (~30.0 W/m2), while PCM is at a minimum of ~2.0 W/m2. The effect of wind velocity has revealed an increase in energy efficiency by ~3%, reaching a maximum of 44.03% at an optimal speed of 3.0 m/s, while exergy efficiency decreased by ~11%. The increase in PCM and basin water mass has reduced the performance, reaching a maximum of 15 kg paraffin wax for a given water depth.
Dubey et al. (Tue,) studied this question.