Achievement of humidification and dehumidification desalination system by utilizing a hot water sprayer and ultrasound waves techniques

Highlights: • Investigation of a solar desalination humidification and dehumidification system was introduced. • Five modules of ultrasonic humidifier were used to increase the specific humidity of the ambient air. • The maximum achieved daily water productivity was 44.8 kg/day. • The ultrasonic humidifier improves the daily water productivity. -- Abstract: An experimental investigation on the solar system for water desalination was conducted according to the methodology of humidification-dehumidification. Tests have been properly designed and constructed to efficiently assess the productivity of fresh water during the three summer months under local weather conditions of Alexandria, Egypt. The heated air is humidified through two sequent stages, the primary stage is achieved through employing a heated water spatter from the evacuated solar collector. The Further stage is employing an ultrasonic technique for its highly efficient humidification rate. The findings of fresh water output rate is affected by two main parameters; firstly the mass flow rates of both air and water spray, secondly solar radiation. Furthermore, an investigation of heated water spray flow rate over the total flow rate at four values of 0.175, 0.2, 0.25 and 0.3were done respectively. The maximum amount of daily productivity reaches to 44.8 kg/day with mass flow rate of 0.46 kg/s for air, while hot water spray ratio of 0.3. The ultrasonic humidifier improves the daily productivity by 9.3% at 0.24 kg/s and 14.6% at the maximum value of the air mass flow rate 0.46 kg/s. Economic analysis showed that the fresh water cost is about 0.0144 USD/L.