Efficient PCMs selection to improve the productivity of modified solar distillers using a corrugated absorber, nanoparticle-enhanced PCMs, and a copper heating coil integrated with a cylindrical parabolic concentrator

초록

Freshwater scarcity is one of the most critical global challenges, and solar distillation provides a sustainable alternative to conventional desalination technologies. However, its widespread use is limited by low productivity and dependence on variable solar radiation. This study presents a comparative experimental evaluation of three phase change materials (PCMs)—Soy wax, Paraffin wax, and Vaseline—combined with an innovative set of optimization techniques for solar distillers. The design integrates a corrugated tray-shaped absorber to enlarge the evaporation area, a silver-nanoparticle-enhanced PCM reservoir to improve heat storage and thermal conductivity, and a parabolic cylindrical concentrator (CPC) with a copper coil loop to supply concentrated external heat. Experiments were conducted in three stages, each testing one PCM configuration against a conventional solar distiller (CSD). The findings show that Soy wax delivered the best overall performance, achieving a cumulative yield of 16.68 L·m−2·day−1, corresponding to a 274.83 % increase over the CSD (4.45 L·m−2·day−1). Productivity improvements reached 248.31 % with Paraffin wax and 232.58 % with Vaseline. Energy and exergy efficiencies improved to 47.52 %/174.58 % for Soy wax, 35.92 %/134.58 % for Paraffin wax, and 29.58 %/112.50 % for Vaseline. Economically, the Soy wax design reduced the cost of potable water by 50.20 %, achieving 0.0038 $/L. Environmentally, it also achieved the highest impact with a 268.29 % improvement in CO₂ mitigation and carbon-credit generation compared to the CSD. Future work should explore larger-scale deployment, GIS-based site selection, and machine learning optimization for predictive performance and smart operation. © 2025 Elsevier B.V., All rights reserved.

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