Desalination of brackish water by means of a parabolic solar concentrator

The thermal conversion of solar energy by means of solar concentrators makes it possible to reach high temperatures able to boil the salted water with pressures higher or equal to the atmospheric one. In order to test these concentrators in the brackish water desalination field, we have designed, dimensioned and built in our laboratory a small solar desalination unit equipped with a paraboloid concentrator. To evaluate the performance of this unit, we developed a theoretical model to calculate the absorber average temperature as well as the distillate flow rate as a function of solar flux. The experimental results were compared with those calculated theoretically. A small difference in the absorber average temperature was found between both results. On the other hand, distillate flow rate reached an average relative error of 42%. These results indicate that the design of our unit needs to be improved with special emphasis on the absorber.

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