Energy and cost analysis of a humidification dehumidification desalination system driven by low grade waste heat. (December 2017) - He, W.F.
Abstract: In the present investigation, a water-heated humidification dehumidification (HDH) desalination system with heat and mass coupled processes both in the humidifier and dehumidifier is proposed to produce freshwater. In view of the mathematical models based on energy equilibrium, characteristics of the desalination system are calculated and analyzed, and heat and mass transfer areas involved in the waste heat collector, recuperator, humidifier and dehumidifier are obtained. The simulation results show that the balance condition of the dehumidifier, which indicates the modified heat capacity (HCRd ), HCRd =1, is available, and it is significant for the performance of the HDH desalination system. Maximum values of mpw, mpw =105.26kgh -1, and GOR, GOR =2.01, are obtained. Furthermore, in consideration of the heat and mass transfer area and the freshwater production, it is acquired that the maximum expense for the whole desalination system arrives at Et, c =3055.23￥while the corresponding unit expense reaches Eu, c =29.02￥t -1 h at the case of mda =0.5kgs -1 .