Simulating the effects of flow configurations on auxiliary power requirement and net power output of High-Temperature Proton Exchange Membrane Fuel Cell

Abstract

High-temperature proton exchange membrane fuel cells have garnered huge attention in the recent past because of faster electrode kinetics, high CO tolerance, and possible waste heat recovery. The flow channel is a crucial component of the fuel cell, which helps to improve its performance by facilitating uniform distribution of the reactant species, current density, and temperature. Conversely, the pressure drop imposed by various flow channel configurations increases the auxiliary power requirement of the fuel cell, which is a critical issue. Here, the main objectives are to enhance the electrochemical performance and reduce the auxiliary power loss of the high-temperature proton exchange membrane fuel cell by selecting a proper flow configuration. This work compares the parallel, serpentine, and hybrid flow configurations using a physics-based fuel cell model. It involves the mass, momentum, energy, species, and current conservation equations. The simulation results show that the shape and size of the common channel width in the parallel flow configuration have a noticeable influence on the cell performance. The thermal analysis demonstrates that the temperature gradients of the serpentine and hybrid configurations are two times lower than the parallel configuration due to uniform current density distribution and heat dissipation. This study illustrates that the hybrid configuration with the net power output of 0.383 W/cm2 provides the best performance with an auxiliary power loss of 3.6% compared to the serpentine configuration with an 11% loss. The net power output of the hybrid configuration remains superior under various stoichiometric conditions, including cell starvation. The outcome of this work provides a helpful insight into the flow configuration design for maximizing the net available power from the cell.