Measurements of water distributions in in-plane direction of a PEFC by using neutron radiography and analysis of gas-velocity distributions in the channel and the GDL

Visualization and measurement of water distributions in a polymer electrolyte fuel cell (PEFC) were carried out by means of neutron radiography for clarifying water effects on the performances. The two-dimensional water distributions were applied for a network model. It analyzes the gas-velocity distributions depending on the local pressure drop which is affected by the gas-flow rate and the water accumulation. Formation of the accumulated water in the channel was assumed based on measurement results of water distributions in through-plane direction. Furthermore, it was estimated that maximum water accumulation in the gas diffusion layer (GDL) and mechanism of water discharge from the GDL to the channel. From the analysis results, change of gas-velocity distributions depending on the water accumulation in the PEFC could be obtained. (author)