| dc.description.abstract | This study utilizes COMSOL Multiphysics to construct a three-dimensional, non-isothermal model to investigate an anion exchange membrane water electrolysis unit, wherein both the anode and cathode utilize porous transport layers as flow channels. The model integrates two-phase flow, species transport, electrochemical reactions, ion and electron transfer as well as heat transfer. Initially, an analysis of transport phenomena within the electrolysis unit is performed, including the distribution of two-phase volume fractions in the cathode flow field and thermal analysis. Subsequently, a parametric analysis of various factors affecting the performance of water electrolysis is conducted. This includes geometric parameters, material properties, and operational parameters, examining their impact on current density and liquid consumption, as well as comparing gas distribution results at 2V, and elucidating the reasons for these parameter effects on electrolysis performance.
From the transport phenomena analysis, it was found that as the voltage increases, the average H₂ volume fraction in the flow channels gradually rises, increasing approximately 2.8 times from 1.4V to 2V at the channel exit cross-section. Additionally, it is observed at the cathode flow field exit cross-section that H₂ tends to accumulate at the edges of the catalyst layer beneath the ribs. From the temperature distribution results, it is evident that the anode temperature increases more significantly than the cathode due to a higher density of O₂ bubbles and a higher overpotential of the oxygen evolution reaction. Moreover, the parametric analysis indicates that enhancing the porosity of the flow channels, membrane water content, operational temperature, and KOH inlet flow rate can all improve the performance of water electrolysis. | en_US |