Dimensionless parameter for assessing a solar still's production

Dimensionless analysis is employed in order to group together those variables involved in solar water distillation, based on evapotranspiration. These include the evaporation surface area and the concentration of water in the solution. A dimensionless parameter is devised to correlate their functional relationship. An experimental model has been operated and results are consistent with the model developed. A dimensionless parameter NVS (the Vega-Silva number) will find numerous applications in the handling of brine in evaporative ponds and facilitates the separation of the two main participating areas: land surface and evaporation surface. The experimental model was tested to identify an extended evaporative surface employing several porous media with a constant land surface, which allowed distillate production to increase by a factor of 2.5 when compared with the standard evaporative surface, by making the evaporative surface 4 times as large as the land surface. This is made possible with industrial fabrics as well as with plants and trees.

► Evapotranspiration (ET) increases evaporative surface by means of porous materials.
► Dimensionless parameter NVS groups variables of solar distillation based ET.
► NVS includes evaporation surface area and concentration of water in the solution.
► Distilled water production increased by a factor up to 2.5 within the same land area.