Novel architectures of polymer electrolyte membrane fuel cells: Efficiency enhancement and cost reduction

Abstract

Three novel architectures of proton exchange membrane fuel cells (PEMFCs), called circular, square and octagonal duct-shaped architectures, are introduced and analyzed numerically. A three-dimensional computational fluid dynamics (CFD) code is used to solve the equations for a single domain of the cell under steady state and non-isothermal conditions. The numerical results are in reasonable agreement with the experimental data over a wide range of current density. The distributions of oxygen, hydrogen and water mass fraction, current density and temperature are studied for the three introduced configurations. The circular- and square-duct configurations show considerably better performance and offer several advantages over the conventional PEMFC configuration. These advantages are related to the way in which the reactant gases are supplied to the flow field, to the shorter channels used and to the lower cost of the PEMFC due to the less bipolar plates needed. Among the three configurations having the same active area and the same inlet area, the square-duct geometry shows considerably higher current density and more uniform water and temperature distributions. The square-duct configuration is, therefore, the best candidate to enhance the PEMFC efficiency while reducing its size and cost, and can be considered for the design of new generation of PEMFCs.