Improvement of humidification–dehumidification desalination unit using a desiccant wheel

Abstract

In the present work, theoretical performance of humidification–dehumidification desalination unit using a desiccant wheel or heat exchanger in order to increase the thermal performance of the system is investigated. The sensitivity of each parameter including the inlet water and air flow rates ratio, inlet hot water temperature, inlet cooling water temperature, inlet air humidity and regeneration temperature on the fresh water production, Gain output ratio, specific thermal energy, and recovery ratio is studied. Also, the optimum condition of different parameters of desalination units is presented. The results show that the desalination unit with the desiccant wheel is more efficient than the base humidification–dehumidification or use a heat exchanger to provide distillate water. The inlet cooling water temperature and inlet air humidity have a tiny effect on Gain output ratio and specific thermal energy while inlet water and air flow rates ratio, inlet hot water temperature, and regeneration temperature has a measurable effect on Gain output ratio and specific thermal energy. The maximum fresh water production is about 0.4603kgw/kga, Gain output ratio is about 4.515, recovery ratio is about 46.03% and minimum specific thermal energy is about 0.149kWh/kg.