A modified solar desalination system using evacuated tube collector

•A modified desalination uses an evacuated tube collector to directly heat water.•A quasi-steady state theoretical model is presented for this desalination system.•Adding stainless steel wool enhances the heat transfer and increases the yield.•The yield and efficiency reach up to 1.01 kg/(m2·hr) and 65.6%, respectively.

Solar energy is turning to one of the important types of clean energies, due to its availability, and its potential for wide range of applications. In this work, a new passive solar desalination system is introduced, which benefits from excellences of twin-glass evacuated tube collectors. For the first time, the evacuated tube collector is not only used as the solar thermal collector, but also as a basin to heat the water. Hence, the thermal resistance between the collector and basin is virtually eliminated. Results show a considerable increase in the rate of desalinated water production and the maximum production reaches up to 0.83 kg/(m2·h). It was observed that the maximum rate of the production occurs when the tube is in inclination angle of 35°, and filled 80% with water. Moreover, it is seen that filling the tube with a stainless steel wool can enhance the production rate up to 1.01 kg/(m2·h). It was observed that optimum inclination angle is 35°, which is the latitude of location of the experiments. Moreover, a theoretical model is presented in order to evaluate the system's efficiency in quasi-steady state conditions.