Effect of oxygen inlet configurations on transport behavior in the porous transport layer of PEM water electrolyzers

Abstract

Oxygen transport in liquid water within the anode porous transport layer (PTL) of proton exchange membrane water electrolyzers is investigated using a multicomponent multiphase lattice Boltzmann model. The evolution of oxygen invasion pathways, breakthrough behavior, and oxygen distribution is analyzed, and the effects of inlet coverage, inlet velocity, inlet location, and multiple-inlet spacing are discussed. The results show that oxygen preferentially invades regions with larger pore throats, consistent with strong capillary control. Breakthrough times are highly nonuniform across the titanium layers. As inlet coverage increases, breakthrough time first decreases and then increases because of the combined effects of inlet velocity and changes in the preferred pathway cross-section. Smaller inlet spacing promotes pathway overlap and shortens breakthrough time, whereas larger spacing weakens pathway interaction and makes transport increasingly dominated by a single preferential pathway.