Efficiency and flexibility enhancement of nanofluid-based hybrid solar desalination system equipped with thermoelectric generator for eco-friendly freshwater and power cogeneration

This study presents an innovative hybrid system aimed at concurrently producing freshwater and power. This system combines a humidification-dehumidification desalination method with a thermoelectric generator, leveraging solar energy transmitted to the cogeneration system through a nanofluid, employing Syltherm 800 as the primary fluid with Cu nanoparticles infused within. Results indicate that the cycle can achieve a simultaneous output of 0.1 kg/s of freshwater and approximately 1.78 kW of power, with 1.384 % and 1.581 % cycle energy and exergy efficiencies under optimal operational conditions, respectively. Furthermore, a parametric exploration demonstrates that adjusting the solar irradiation angle and the mass flow rate ratio of the desalination unit optimizes the hybrid system's performance. Moreover, improvements in the thermoelectric generator coefficient and reductions in inlet saltwater temperature enhance the first law efficiency, while augmented thermoelectric generator coefficient and inlet saltwater temperature elevate the exergy efficiency. Additionally, the second law scanning shows that the parabolic collector predominantly contributes to exergy destruction, with minimal contributions from the Syltherm base fluid with Cu nanoparticles, and the most significant contribution arising from Syltherm 800. In the best scenario (Syltherm 800 + Cu nanoparticles), the exergy destruction ratio of the solar collector and thermoelectric generator are calculated 71.39 % and 1.72 % as the worst and best components from exergy standpoint. Also, the whole exergy destruction in this state is reported 163.615 kW.