Simulation Analysis Of Mass Transfer On PEM Fuel Cell Flow Field

With the accelerated pace of clean energy development,the industrialization of hydrogen energy is increasingly concerned and regarded as the most promising clean energy in twenty-first Century.Hydrogen and fuel cell technology provides a new way for the application of clean energy system.Hydrogen fuel cell technology unaffected by Kano limit cycle,with the high energy conversion rate,low temperature starting,without noise and many other advantages,can be widely used in transport,stationary power generation and portable standby power supply etc.There are many factors affecting the performance and cost performance of proton exchange membrane(PEM)fuel cell,and the flow field plate has become one of the key factors,and it is also the focus of today's researchers.The reasonable flow field structure can improve the battery flooding and the uneven distribution of reaction gas,and directly affect the performance of PEM fuel cell,therefore,affect its commercial prospects.In order to further study the influence mechanism of flow field on mass transfer and the mechanism of cell performance,the flow field structure was optimized,and the research work was carried out based on multi physical field coupling analysis software.A single cell three-dimensional model with four flow field structures was established by using multi physical field direct coupling analysis software.Under the condition of operating voltage of 0.6 volt,four kinds of flow field PEM fuel cell monomers were numerically simulated.The simulation results gave the results for that the concentration of hydrogen in the anode flow field,the oxygen concentration in the cathode flow field and the concentration of water in the cathode flow field.The results showed that the distribution of the cathode oxygen concentration was the most uniform in the single finger single serpentine flow field,the cathode oxygen concentration distribution in the bilateral interdigital single flow field was the second,followed by the cathode oxygen concentration in the interdigital flow field distributes in the sub single serpentine flow field,and the cathode oxygen concentration distribution is the worst.Three-dimensional steady-state models of three kinds of PEM fuel cell with different flow structure creation were established,and the effects of three kinds of flow structure on the performance of PEM fuel cell output were investigated.The analysis gave the results for the cathode oxygen concentration distribution,cathode water concentration distribution,import and export of oxygen concentration difference,the anode catalyst layer,the membrane interface temperature changes.At the same time,under the same operating conditions,the flow field of PEM fuel cell with different gases diffusion layer thickness were simulated.The results showed that the decreasing gas diffusion layer thickness has little effect on the hydrogen distribution,but a positive effect on the distribution of cathode oxygen concentration and the water concentration and current decreasing distribution of proton exchange membrane.The numerical simulation results show that compared to the single serpentine flow field and interdigitated flow field,the two mixing flow field in the drainage performance,the cathode oxygen concentration distribution and the whole battery output performance has showed better results,at the same time,the reduced gas diffusion layer thickness is beneficed to the transfer of the PEM fuel cell cathode,which provide certain reference significance for design of flow field and mass transfer analysis.