Coupling of a continuum fuel cell model with a discrete liquid water percolation model

摘要

An iterative algorithm is developed to directly integrate a discrete liquid water percolation model into a 3D continuum fuel cell model. In the continuum model the thermodynamic processes, most relevant for the water management and fuel cell performance, are calculated. For the discrete liquid water distribution in the porous transport layer (PTL), a water path network model is used, calculating the discrete, injection pressure and condensation scenario dependent saturation distribution. The saturation in the PTL is compared to synchrotron visualization data and a good comparison is found. Using the model, the influence of PTFE content, the application of a microporous layer, PTL perforation and ionomer desorption rate on the water configuration and fuel cell performance are analyzed. The interfacial liquid water is identified as an important parameter for the liquid water transport and the oxygen diffusivity to the active areas.