3D CFD Analysis on Flow and Thermal Dynamics of PEM Water Electrolyzer

The proton exchange membrane (PEM) water electrolyzer is an emerging technology to produce green hydrogen due to its compactness and producing high purity hydrogen. This study presents a numerical investigation of multiphase flow dynamics and heat transfer within the anode side of a PEM water electrolyzer, focusing on the anode plate and porous transport layer (PTL). Different channel configurations, i.e., rectangular, semicircular, and wavy channels are considered while varying the PTL thickness within the commercially available ranges. Simulations are conducted under varying oxygen generation rates (corresponding to different current densities) and different inlet water flow rates. The effects of channel configuration and PTL thickness on pressure drop, flow uniformity, and temperature distribution within the cell are illustrated pictorially and graphically. Additionally, impact of PTL thickness on crucial cell performance parameters are reported. The impact of varying water flow rates and oxygen generation rates on phase distribution, pressure drop, and temperature profiles, particularly focusing on hot spot regions and oxygen starvation regions are investigated thoroughly. Detailed oxygen concentration distributions and temperature contours at various locations are depicted for different geometrical and operating condition that are crucial for effective functioning of the membrane. This study brings out the importance of channel configurations and PTL thickness to enhance PEM water electrolyzer performance. The insights gained are expected to guide the design of new anode plates, aiming to mitigate issues such as hot spots and oxygen starvation, ultimately leading to improved efficiency and reliability of PEM water electrolyzer in sustainable hydrogen production.