R&D AND PERFORMANCE ANALYSIS OF A PHOTOTHERMAL AND PHOTOELECTRIC SOLAR DESALINATION DEVICE FOR ISLANDS

Given the shortage of freshwater resources and conventional energy resources in remote islands, it is practical to research and develop a solar desalination device for islands. In this paper, a new seawater desalination device was developed through a procedure of technical design, mathematical calculation, heat and mass transfer, simulation test and performance analysis, etc. And its performance was tested under three working modes, photothermal mode, photothermal photovoltaic mode, and electric heating mode. The experimental results showed that:1) the water production rate of the desalination device was 225 mL/h in photothermal mode, 332 mL/h in photothermal photovoltaic mode (47.6% higher than that of photothermal mode), and 1910 mL/h in electric heating mode, reflecting the importance of medium and high temperature solar collector; 2) the optimal experimental conditions of desalination device were as follows:the temperature of evaporation chamber was 103℃, the temperature of cooling water was 41℃, and the ambient temperature was 30℃, then the instantaneous water yield was as high as 2389 mL/h, and the influence degree of various factors were in the sequence of evaporation chamber temperature>cooling water temperature>ambient temperature; 3) the water yield per unit area of the desalination device under the photothermal mode and photothermal photovoltaic mode was 2172, 1167 mL/(m²·d), when the minimum heat consumption of the solar distillation process was 2.03 kW·h/m³.