CFD Modelling and Simulation of the Thermal Management in a Polymer Electrolyte Membrane (PEM) Fuel Cell Stack

Abstract

Polymer Electrolyte Membrane fuel cells are a promising technology for clean energy conversion due to their high efficiency and low emissions. However, one of the critical challenges in the operation of fuel cells is the effective management of temperature and humidity within the fuel cell stack. Uneven temperature distribution can cause uneven water vapor condensation, leading to performance inconsistencies among individual cells in the stack. This necessitates a comprehensive understanding and control of the thermal and humidity dynamics within the fuel cell stack to ensure optimal performance and longevity. In this study, with the use of COMSOL Multiphysics, a mathematical polymer exchange membrane fuel cell stack model is designed and is applied to assess the thermal control of a stack of polymer exchange membrane fuel cell made up of two end plates, five membranes electrode assembly, and five cells. The boundary conditions are established and the mathematical equations are numerically solved. The obtained results indicate that that the thermal and electrochemical performance within the fuel cell stack is significantly influenced by the distribution of cooling flow and gas reactants. Higher temperatures near the outlet highlight the importance of optimizing cooling strategies to prevent overheating and ensure uniform temperature distribution. Moreover, the observed variations in relative humidity suggest that water management is crucial for avoiding flooding, particularly in the first and last cells. This study also reveals the intricate relationship between temperature, humidity, and gas flow, which must be carefully balanced to prevent performance degradation. These insights suggest that optimizing the thermal and humidity management strategies is crucial for improving the durability and reliability of polymer exchange membrane fuel cell stacks.