Performance optimization study on an integrated solar desalination system with multi-stage evaporation/heat recovery processes

A novel small-sized integrated solar desalination system with multi-stage evaporation/heat recovery processes is designed and tested. The system consists of four linked collecting units. In each unit, an independent desalination process including solar heat collecting, heat recovery and seawater evaporation can be carried out completely. The system operates under barotropic and atmospheric pressure and adopts a stepwise heat recovery method to recycle the sensible heat and latent heat of the steam generated. A series of experiments were conducted under different operating conditions for investigating the effects of the various influencing parameters, including operating pressure, operating pressure adjusting method, weather condition, season condition and maximum collecting temperature. Through the experiments, the effects of operating parameters on system performance, including freshwater yield, system total efficiency and system thermal efficiency, are investigated and discussed in detail. The experimental results provide a striking demonstration that the designed solar desalination system has an outstanding performance in solar collecting, heat recovery and seawater desalination. The experimental study provides useful guidelines for development of a new type of small-sized solar desalination system.