A high-performance solar driven multistage desalination system by structural modification

The solar-driven multistage desalination (SMD), with its characteristics of a high vapor generation rate, has emerged as a green and effective solution to replenish the demand of freshwater. However, the integral design principle of a high-performance SMD system remains a challenge. Here, a design strategy to improve the water production performance of the SMD system through the synergistic effects of multifaceted structural optimizations is clarified. By constructing a thermal insulation chamber at the first stage to reduce convective heat loss and combining the evaporative cooling effect at the final stage to enhance thermal dissipation capability, the overall temperature gradient as the evaporation driving force of the SMD system is enhanced. Simultaneously, the vapor diffusion resistance is reduced by utilizing 3D printing technology to optimize the interstage air gap. An excellent water collection rate (WCR) of 2.71 kg m –2 h –1 is obtained through a 6-stage SMD device under one sun. Furthermore, the 6-stage device exhibits good practical application potential by achieving a substantial WCR of 12.28 kg m –2 day –1 in an actual outdoor deployment. The design strategy proposed in this work is expected to provide effective guidance for further structural optimization of the SMD system.