Characteristics of different flow patterns for proton exchange membrane water electrolysis with circular geometry

Abstract

This study comprehensively analyzes five circular-shaped flow field configurations (one-path, two-path, two-channel, two-segment, and four-segment serpentine), using membrane electrode assembly (MEA) area of 38.5 cm2. Here, it aims to identify the optimal pattern in terms of velocity, pressure, liquid saturation, temperature, and current density distribution. Further, a comparison is conducted between the uniformity index, polarization curves, and average membrane temperature curves of various cases. Using a finite element method, a three-dimensional, non-isothermal, two-phase model is developed based on the conservation equations of mass, momentum, electric charge, energy, and species. To confirm modelling reliability, the numerical results have been validated and demonstrated a strong match with the experimental data. Findings indicate that the one-path, followed by the two-path serpentine pattern, yield the most favorable flow distribution and temperature uniformity within the PEMWE. Conversely, the four-segment serpentine flow pattern results in the least desirable outcomes. At a cell voltage of 2.1 V, the uniformity index of liquid saturation, temperature and current density and average membrane temperature for one-path and two-path serpentine patterns exhibit reductions of 70 and 29 %, 95.5 and 95.2 %, 33 and 31 %, and 9.1 and 6 K, respectively, compared to four-segment serpentine design. Moreover, the four-segment, two-segment, and two-path serpentine flow patterns exhibit optimal performance in terms of polarization curves.