Experimental analysis of solar driven bubble column humidifier for humidification-dehumidification (HDH) water desalination system

Humidification-dehumidification (HDH) is a carrier gas based thermal technique, which is ideal as a small scale decentralized water desalination system. An innovative design approach is to use the bubble column humidifier to enhance the performance of the HDH water desalination system. Therefore, a novel bubble column humidifier is proposed which is operated through solar thermal energy as the main source of energy input. The overall objective of this work is to develop and test the novel bubble column humidifier to identify the optimum performance operating conditions for its possible integration with a dehumidifier. The design of the bubble column humidifier is optimized in terms of perforated plate geometric features to reduce the overall pressure drop in the system. The study addresses the relation between the air pressure variation with water column height and air superficial velocity varies. The proposed bubble column humidifier is integrated with Fresnel lens to increase the water temperature as it enters the humidifier. The influence of water temperature on the vapor density is investigated at different air superficial velocities. Results indicate that the vapor density in the bubble column humidifier is significantly increased with the increase in the water temperature and air superficial velocity. One major advantages of this proposed humidifier is its ability to have a direct solar thermal heating. Subsequently, it can be located in remote areas.