Experimental investigation of a desalination system based on evacuated tube collector

In this study, the thermal performance of a solar thermal desalination system has been investigated experimentally. The desalination system consists of an evacuated tube collector (ETC), which acts as a heat source for the desalination process. A storage tank of saline water has been connected to ETC by using connecting pipes. A separate condensing unit has been used to condense water vapor generated by the desalination system. The saline water is circulated naturally throughout the ETC and storage tank. During the experiments, the data for temperature of the saline water at different locations, solar intensity, saline water pressure at inlet & outlet of ETC, and system's productivity in terms of fresh water were recorded. The performance of the present desalination system has been evaluated in terms of exergy & energy efficiency. The mass flow rate of the saline water has been calculated to understand the phenomenon of thermosiphon. The economic analysis has been also done in order to calculate the cost incurred in produced fresh water. The system was able to maintain temperature of saline water about 100 degrees C for 4 h continuously, which results in a good amount of fresh water i.e. 4.8 L. The average energy & exergy efficiency of the desalination system was found 50.67% and 15.61% respectively. The maximum saline water flow rate was 0.0085 kg/s, and the cost incurred to produce fresh water was 0.01902 $/L.