Jintae Kim

Study on Optimization of Operating Conditions for High Temperature PEM Fuel Cells Using Design of Experiments

Abstract >> High temperature proton exchange membrane fuel cells (PEMFCs) using phosphoric acid (PA) doped polybenzimidazole (PBI) membranes have been concentrated as one of solutions to the limits with traditional lowtemperature PEMFCs. However, the amount of reported experimental data is not enough to catch the operationalcharacteristics correlated with cell performance and durability. In this study, design of experiments (DOE) based operational optimization method for high temperature PEMFCs has been proposed. Response surface method (RSM)is very useful to effectively analyze target system’s characteristics and to optimize operating conditions for a shorttime. Thus RSM using central composite design (CCD) as one of methodologies for design of experiments (DOE)was adopted. For this work, the statistic models which predict the performance and degradation rate with respectto the operating conditions have been developed. The developed performance and degradation models exhibit a goodagreement with experimental data. Compared to the existing arbitrary operation, the expected cell lifetime and averagecell performance during whole operation could be improved by optimizing operating conditions. Furthermore, the proposed optimization method could find different new optimal solutions for operating conditions if the target lifetimeof the fuel cell system is changed. It is expected that the proposed method is very useful to find optimal operatingconditions and enhance performance and durability for many other types of fuel cell systems.