A novel humidification and dehumidification desalination system powered by direct solar energy

As the global demand for freshwater continues to increase, the critical need for efficient desalination methods has prevailed. Targeting the arid regions with high solar irradiance, solar-powered thermal desalination techniques have opportunities. This study introduces an innovative approach to improve the performance of Humidification-Dehumidification (HDH) desalination system using direct solar energy and integrating a low-energy ultrasonic atomizer device. In this system, thermal energy is supplied to the humidifier via direct solar energy capturing and the ultrasonic atomizer generates fine droplets suspended within the humidifier, where evaporation occurs. The atomized droplets are subjected to direct solar irradiance and forced convection in a closed-loop operation, facilitating efficient evaporation. Over multiple days, the freshwater production was monitored and an average daily output of 4.6 L with 6 h of operation was achieved with a given direct solar capture area of 1.54 m². The maximum freshwater production rate is 8.92 L per day. The results reveal a notable increase in freshwater production between 11:00 and 14:30, coinciding with a significant rise in the relative humidity difference between the inlet and outlet of the humidifier. The system achieved a maximum water recovery at 14:30, highlighting its efficiency during peak operational hours. Compared to existing studies, these findings demonstrate the effectiveness of ultrasonic atomization in enhancing the humidification process, reinforcing its potential for improving solar-driven HDH desalination systems. This study proposes the potential application of ultrasonic atomization as a viable method to enhance solar desalination performance and encourages its adoption for sustainable water production in regions with abundant solar energy.