Designing an active solar water desalination system by considering weather conditions and economic factors

Abstract

ABSTRACT Water plays a significant role in the daily activities of the human population, and its overall consumption is increasing rapidly, due to the enhancement of living standards. Iran is located in the dry belt of the earth, and 70% of its area is arid and semi-arid. The desalination systems, which use fossil fuels in order to overcome the water crisis in Iran, are not ever sustainable due to available energy depletion and greenhouse gas emissions. This study investigated the design of an active solar water desalination system. Evaporation rate and diameter reduction of sprayed saline water droplets in a glass chamber were calculated by a verified mathematical model. The effect of key parameters, including nozzle type (long cone orifice, drilled steel orifice, sapphire orifice), nozzle size (outlet diameters of 0.9–1.1 mm), injection pressure (1–5 bar), temperature, relative humidity (20–60%) and pressure inside the glass chamber (4500–6500 Pa), on evaporation rates, were investigated by the mathematical model. The flow rates of produced vapor and inlet saline water were calculated as 0.003252 L/s and 0.0181 L/s, respectively, by considering favorable condition, such as injection pressure of 5 bar, nozzle size of 0.9 mm, relative humidity of 20% and pressure of 4500 Pa inside the glass chamber. Radiation intensity was calculated using Meteonorm 7 software for Tehran during a year, which was compared with meteorological data of Mehrabad airport station.