Performance Assessment of Single Slope Solar Still Using Sinusoidal‐Shaped Basin Liners With Phase Change Materials

ABSTRACT Single slope solar still was built to study the impact of phase change material (PCM) on water output. Bottom along with four sides of the still are built from an aluminium sheet of 0.79 mm thickness. The base is coupled with a sinusoidal shaped basin liners (SSBL), a layer of aluminium fitted with copper tubes. The unit was fixed in a box of 19 mm thick ply to minimise heat loss from the bottom and side faces to the surroundings and completely sealed to reduce the leakage. Myristic and palmitic acid granules as PCM were filled in the copper tubes of 15 mm outer diameter. PCM changes its phase by absorbing excess energy during sunshine as a result of sensible heating till it hits the melting temperature. During the night, PCM solidifies by losing its heat of fusion to the water. The heat interaction between the glass cover and basin water was examined by the analysis of energy balance and internal heat transfer equations. The experiment was performed in three sets: without PCM, with PCM I, and with PCM II; however, the fixed quantity of 6 litres of tap water was taken to maintain 2 cm of water depth. Results showed that SSBL solar still with PCM I (myristic acid) and PCM II (palmitic acid) enhanced the overall yield by 16% and 9% in comparison to SSBL solar still without PCM, while condensate production in night with PCM I and PCM II increased by 75% and 38%, respectively, compared to the solar still output in night without PCM. Meanwhile, PCM I (myristic acid) showed the best performance, achieving the highest thermal (44.0%) and exergy (6.9%) efficiencies. It also offered the lowest cost per liter ($0.0116) and the highest sustainability index (1.076).