Final report on LDRD project : elucidating performance of proton-exchange-membrane fuel cells via computational modeling with experimental discovery and validation.

摘要: In this report, we document the accomplishments in our Laboratory Directed Research and Development project which employed a technical approach of combining experiments with computational modeling analyses to elucidate performance hydrogen-fed proton exchange membrane fuel cells (PEMFCs). first part focused efforts on understanding water transport removal from PEMFC. Using transparent cell, directly visualized evolution growth liquid-water droplets at gas diffusion layer (GDL)/gas flow channel (GFC) interface. We further carried out detailed experimental study observe, via direct visualization, formation, growth, instability GDL/GFC interface using specially-designed apparatus, simulates cathode operation developed simplified model, based observation data, for predicting onset water-droplet state-of-the-art neutron imaging instrument available NIST (National Institute Standard Technology), probed distribution inside an operating PEMFC under variety conditions investigated effects evaporation due local heating by waste heat removal. Moreover, models analyzing micro-porous net across GDL anisotropy temperature distributions two-phase model multiphase mixture formulation liquid saturation, pressure drop, maldistribution channels. second electrochemical PEMFCs. constitutive conductivity polymer electrolyte membranes compared prediction data obtained laboratory literature. one-dimensional analytical idealized small surface over-potentials. Furthermore, multi-dimensional computer is finite-element method fully-coupled implicit solution scheme Newton's technique, simulating demonstrated utility comparing computed current density overall polarization those measured segmented cell. last exploratory MEA (membrane electrode assembly) degradation.