An efficient high-temperature PEMFC/membrane distillation hybrid system for simultaneous production of electricity and freshwater

A new hybrid system model mainly consisting of a high-temperature proton exchange membrane fuel cell and a direct contact membrane distillation is proposed. According to thermodynamics and electrochemistry theories, key performance indicators of the proposed system are formulated, from which feasibilities and effectiveness as well as performance features of the proposed hybrid system are verified. Numerical calculation results indicate that the hybrid system's maximum power density, the according energetic efficiency and exergetic efficiency are, respectively, 5580.3 W m^?2, 49.4% and 23.3%, which are, respectively, 51.8%, 110.9% and 112.0% greater than that of a single fuel cell system. Simultaneously, the corresponding exergy destruction rate density is decreased by 28.1%. Direct contact membrane distillation can be regarded as an efficient waste heat recovery technology. Furthermore, extensive parametric studies show that feed water temperature, flow velocities of both feed water and permeate water, convective heat transfer coefficients of both feed side and permeate side as well as porosity of hydrophobic membrane have positive effects on the hybrid system performance, while hydrophobic membrane thickness and permeate water temperature have negative effects on the hybrid system performance. The results obtained may be beneficial to design and run such a real hybrid system.