Comprehensive study on vacuum humidification-dehumidification (VHDH) desalination

In this work, a solar-assisted pilot-scale vacuum humidification-dehumidification (VHDH) desalination plant is investigated experimentally as well as thermodynamically. In this process, the humidification performs at subatmospheric pressure, while the dehumidification occurs at over-atmospheric pressure. The annual experimental results show that the maximum desalination rate is obtained as 1200 mL L-1 m(-2) during summer days at the best value of water to air mass flow rate ratio (w/a) and minimum humidifier pressure. It is resulted that despite achieving a high desalination rate at low pressure, the exergy efficiency decreases. This result reveals that the obtained value of humidifier pressure from energy-exergy analyses differs from the experimental one that is obtained regarding the desalination rate.