Solar Desalination System – HDH

The desalination process is based on the humidification-dehumidification, aka HDH, concept, in the closed air-open water (CAOW) version of the cycle.

A seawater flow is pre-heated in the dehumidifier that consists of a finned tube heat exchanger. The seawater is further heated using PV/T collectors, and then is sprayed in the humidifier. The humidifier is a direct-contact column where the seawater is counterflow to air stream where a simultaneous heat and mass transfer occurs. The seawater cools down and evaporates, with the concentrated seawater is discharged from the humidifier, whereas the air is heated and humidified.

Afterwards, the air flows inside the dehumidifier, where it is cooled below its dew-point temperature and the pure water is produced. Finally, the air stream flows back to the humidifier, closing the loop.

For relatively small-decentralized community, this process is a promising technology thanks to a low environmental and social impact through the possible integration with a renewable energy source.

A small prototype at SolarTechLab will be build in order to analyze the performance of this system and maximize the pure water production in different working conditions.