Thermal and electrochemical analysis of different flow field patterns in a PEM electrolyzer

This paper presents a comparison between five flow field patterns including parallel, single path serpentine (1-path), dual path serpentine (2-path), triple path serpentine (3-path) and quadruple path serpentine (4-path) with 25 cm2 active area to identify the pattern with the best performance in terms of distribution of molar fraction of produced hydrogen, current density, temperature and pressure drop. This is a three-dimensional (3-D) numerical analysis for different flow fields based on finite volume method at steady state, single phase and non-isothermal conditions. The results of the numerical analysis are in good agreement with experimental data. The results reveal that serpentine flow field provides better distribution of current density and temperature in comparison with parallel configuration. At voltage of 1.6 V, the current density for 1-path, 2-path, 3-path, and 4-path patterns are almost 0.28, 0.19, 0.13, and 0.10 A/cm2 higher than parallel pattern, respectively. Also, for 1-path, 2-path, 3-path, and 4-path patterns, the hydrogen mole fraction at outlet of anode channel are 0.0034, 0.0028, 0.0023 and 0.0021, respectively. The results indicate that the 2-path pattern is relatively advantageous in terms of pressure drop, distribution of current density and hydrogen molar fraction.