Performance analysis of evaporation-freezing desalination system by humidity differences

Facing severer global shortage of fresh water and finite energy resource, it is of paramount importance to develop the new energy-efficient desalination methods to solve those problems. A new freezing seawater desalination is proposed in this study that sea water can be frozen driven by humidity difference (humidity difference denotes absolute humidity difference) between air and liquid surface in a 0 °С environment, which utilizes latent heat of vaporization to freeze seawater and thereafter produces fresh water. Based on heat and mass balance equations, the theoretical model of this desalination process was built and it was verified through experimental results obtained from our experimental unit. The effects of humidity difference and airflow rate on fresh water production were studied and they were confirmed to be the key factors for the water production of evaporation-freezing desalination. The theoretical data was consistent with experimental data, and the water production characteristic of this desalination approach was well illustrated by the theoretical model. The results in this research would be in favor of further studies and engineering applications for the evaporation-freezing desalination driven by humidity difference.