Performance analysis and experimental comparison of three operational modes of a triple-effect vertical concentric tubular solar desalination device

This paper presents an experimental investigation and performance analysis of a novel triple-effect vertical concentric tubular solar desalination unit. The productivity and thermal efficiency of the device for three operational modes (e.g., single-, double- and triple-effect) were tested and compared under the fixed heating power and controlled heating temperature conditions, respectively. The temperature in different measured points in the device was tested. Also, Gain Output Ratio (GOR) of the system was calculated for three operational modes. The experimental results indicate that the fresh water production for the triple-effect mode can reach 1.162 kg/h at the heat input of 400 W. The GOR of the device for the double-effect and triple-effect modes can reach about 1.21 and 1.89 under the condition of fixed heat input. The experimental results are then compared with the numerical results, and it is found that the trend of the experimental results is consistent with the theoretical water production rate. The economic analysis results show that the production cost of water is about 6.6 $/ton, which implies an excellent application prospects of the designed desalination device.