Experimental investigation on an enhanced humidification-dehumidification solar desalination system with weakly compressed air and internal heat recovery

摘要

Humidification-dehumidification (HDH) process has proven to be a feasible method to obtain fresh water. Ongoing research on HDH desalination system has been carried out to improve the system performance and maintain steady fresh water production. However, it is difficult to guarantee the efficiency and stability of fresh water production at the same time. In this paper, an enhanced HDH desalination system with weakly compressed air and internal heat recovery is thus proposed, and the experimental setup is then designed and fabricated. Benefiting from a new-design evaporative-condenser, the latent heat released by the process air can be recycled completely, which can provide a continuous and steady heat input for the evaporation of seawater. Therefore, additional heat source and cooling seawater are no need any more during steady running. The experimental results show that when the spraying seawater temperature is heated to 70°C, and both evaporation pressure and condensation pressure are -1444 Pa and 943 Pa, respectively, the fresh water production and specific energy consumption (SEC) are 116 g h~(-1) and 1.01 kg kW~(-1)h~(-1). By experiments, we have confirmed the feasibility of enhanced-HDH desalination. Meanwhile, the theoretical analysis of the system self-sustaining is also verified.