Enhancing solar desalination efficiency through integrated parabolic trough solar collector, porous media, and phase change material: a case study using Middle East weather data

Access to fresh water is a critical global challenge, and improving solar desalination systems is essential for sustainable water production. This study enhances a conventional solar still by integrating a porous medium, a parabolic trough solar collector, and a phase change material (PCM) to improve efficiency and productivity. The novelty of this work lies in the combined use of a parabolic trough solar collector and a porous medium, demonstrating a substantial improvement over conventional solar still designs. The system is modeled using real weather data from Tehran over three consecutive days in both summer and winter. The parabolic trough solar collector operates during the day, transferring heat to the saline water via a heat exchanger, while the PCM stores excess energy. The porous medium reduces temperature gradients and enhances solar energy absorption. Results show that the cumulative water productivity increases from 18.15kg.m^-2 in the base case to 21.04kg.m^-2 with the porous medium and 29.54kg.m^-2 with the solar collector. Additionally, solar still efficiency improves from 45.54 % (base case) to 52.81 % (porous medium) and 74.11 % (solar collector). In the porous medium case, the saline water temperature surpasses the basin bottom temperature, unlike the base case. These findings highlight the potential of integrating advanced thermal management techniques to significantly enhance solar desalination performance.