Performance Investigation of a Novel Portable Bio-Inspired Solar Direct-Drive Membrane Distillation System

Solar membrane distillation is a promising solution to overcome water shortage. However, developing a portable and highly efficient solar membrane distillation system is still a complex task. This work proposes a novel portable bio-inspired solar direct-drive membrane distillation system for families in rural areas. For achieving high efficiency and portability of the system, the sweeping gas membrane distillation and the evacuated solar tube with an optimized multi-surface concentrator were skillfully integrated together. Based on the optical simulation, a high optical efficiency optimized concentrator (over 70% within the incident angle of 20°) was designed to improve the feed temperature. By conducting outdoor experiments and mathematical simulation, the effects of operating parameters and the concentrator on the system’s performance were investigated. The experimental results indicate that the highest energy efficiency and the water production per collector area of the system with the concentrator reach 0.68 and 5.1 kg/m 2 /d. Simulation results show that the water yield increases with the increase of the irradiance and inlet air temperature and decreases with the seawater salinity increasing. The economic analysis suggests that the levelized cost of water and the payback period are $5.9/ton and 3.4 years respectively