Full-scale Modeling of PEM Water Electrolyzer: Effect of Geometrical Parameters

Abstract

The transition to a low-carbon energy system has intensified interest in green hydrogen as a clean energy carrier. Proton Exchange Membrane Water Electrolyzers (PEMWE), powered by renewable electricity, offer a promising pathway for hydrogen production. The performance of PEMWE is essentially affected by operating conditions and geometrical parameters. However, a full-scale model is seldomly considered for numerical simulations, which requires investigation for better performance of PEMWE. This study develops a 3D full-scale model of A numerical simulation that has been conducted in this study to analyze the effects of PEMWE geometrical parameters, including porous transport layer (PTL) thickness, channel width and cell length, on hydrogen production rate and temperature distribution. Cell length was analyzed as a sensitive factor for hydrogen production rate while all three parameters were sensitive factors for temperature distribution. The results reveal that longer cell lengths and thinner PTL contribute positively to hydrogen output. The channel width demonstrated parabolic trend across different ranges and can be optimized for maximum efficiency. Additionally, both the average temperature and the temperature variance within the catalyst layer rise with increasing PTL thickness, channel width and cell length. The model was further optimized with respect to three geometrical parameters, aiming to maximize the hydrogen production rate while minimizing the operating temperature. This study provides an evaluation of geometrical design of PEMWE in a full-scale numerical model, offering practical guidance for the design of advanced electrolyzer systems with improved performance.