A New Approach to Modelling Water Flooding in a Polymer Electrolyte Fuel Cell

Abstract:

The distribution and migration of liquids in various layers of a PEFC is commonly modelled by the 3D flow equations. Given the fact these layers are very thin, there are major problems with such models, including heavy computational efforts and doubts in their applicability to the fibrous gas diffusion layer (GDL). Recently, a new approach for modelling multiphase flow through a stack of thin porous layers has been developed [Qin and Hassanizadeh, Int. J. Heat Mass Transfer 70 (2014) 693-708]. In this approach, which is called “reduced continua model”, each layer is modelled as a 2D domain with governing equations in terms of thickness-averaged properties. This work is aimed to illustrating the advantages of the reduced continua model in modelling liquid water dynamics in a PEFC. In comparison to the Richards model, the reduced continua model predicts quite similar water dynamics in the micro porous layer (MPL), but lower steady-state water saturation in the GDL, particularly under the channel area. This is qualitatively in agreement with experimental observations in the literature. Finally, sensitivity studies of a few material parameters by the reduced continua model have been provided.