Performance Enhancement of a Conventional Solar Still Using a Cylindrical Solar Water Heater and Cu/Al₂O₃ Hybrid Nanofluid: A Sustainable Approach to Water Purification

This study investigates a novel approach to enhancing still solar desalination technology by modifying a conventional solar still unit (SSU) with a cylindrical solar water heater (CSWH) and utilizing Cu/Al₂O₃ hybrid nanofluid as the working fluid. The addition of hybrid nanoparticles significantly improves the heat transfer performance of the system, particularly in the evaporative heat transfer process. This enhancement is achieved by increasing the thermal conductivity of the base fluid, thereby boosting the overall heat transfer coefficient. A comprehensive numerical analysis, conducted using Matlab software, evaluates the impact of these modifications on the performance of the solar desalination system. The results show that the integration of the CSWH and Cu/Al₂O₃ hybrid nanofluid increases both the productivity and energy efficiency of the solar still system. Specifically, the modified system with a nanofluid volume fraction of 0.05 and a mass flow rate of 5 kg/h demonstrates a 77.38% increase in productivity and a 76.64% improvement in energy efficiency compared with the conventional SSU. These findings indicate significant potential for reducing the size, cost, and energy consumption of solar desalination systems. This work provides valuable insights for advancing the development of efficient and cost-effective solar desalination technologies for sustainable water production.