Investigation of the Parameters Influencing the Evaporation Rate of Downward and upward Sprayed Sea Water in Solar Water Desalination

In this study, the evaporation of inlet water as one of the most important parts of the solar desalination system was investigated. Elevating the evaporation rate is one of the important points in increasing the efficiency of solar water desalination systems .The evaporation rate and reduction of the droplets diameter sprayed in the chamber was investigated using the mathematical model. It should be noted that, the effects of different factors namely environmental conditions inside the chamber, including relative humidity and pressure, as well as the initial conditions of the droplet, including temperature, injection pressure and initial diameter were also considered. In this study, the information on a droplet sprayed from the nozzle inside the glass chamber in a downward and upward direction at injection pressures of 1, 3, 5 bar, at temperatures of 60, 65, 70 °C and outlet diameters of 1.1, 1, 0, 9.0 mm of nozzle was used by considering three nozzle types of long cone orifice, drilled steel orifice and sapphire orifice at different relative humidity and pressure values in a glass chamber to determine the favorable conditions for evaporation and fresh water production. The most important goal in solar water desalination systems is increasing the availability of fresh water by producing high-flow rate of vapor. Finally, the best condition for producing fresh water was obtained at the injection pressureof5 bar, the inlet temperature of 70 °C, and the outlet diameter of 0.9 mm of nozzle with a discharge coefficient of 0.9 in upward direction.