Performance improvement of desiccant air conditioner coupled with humidification-dehumidification desalination unit using solar reheating of regeneration air

Abstract

The present experimental study aims to enhance a performance of hybrid system of desiccant air conditioner coupled humidification-dehumidification desalination unit using solar reheating technology. To investigate this idea, the regeneration air leaving from desiccant air conditioner was reheated using the solar energy before entering the humidifier of desalination unit. The solar reheating technology aims to increase the ability of the regeneration air to carry the water vapor inside the humidifier and thus increase the freshwater productivity of humidification-dehumidification desalination unit. To obtain the effect of solar reheating technology on the performance of hybrid system, two configurations of the present hybrid system was designed, formed and tested under the weather conditions of Egypt. The first configuration is the desiccant air conditioner coupled with humidification-dehumidification desalination unit; the second configuration is the desiccant air conditioner coupled with humidification-dehumidification desalination unit with solar-reheating technology. The experimental results show that; (i) the coefficient of performance of the air conditioner varying between 0.48–1.11, 0.33–0.61, 0.23–0.42, and 0.18–0.31, for the rate of regeneration air 60, 120, 180, and 240 m3/h, respectively; (ii) the enhancement in accumulated freshwater production for using solar reheating technology in the second configuration reached 26.5, 38.96, 13.16, and 11.31%, as compared to the first configuration for the rate of regeneration air 60, 120, 180, and 240 m3/h, respectively; (iii) the improvement in gain output ratio for using solar reheating technology in the second configuration reached 42.5, 50.35, 22.1, and 18.85%, as compared to the first configuration for the rate of regeneration air 60, 120, 180, and 240 m3/h, respectively.