Simulation Study On Water Management Of New Flow Field Structure Of Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cells are widely concerned by research scholars because of their high efficiency,low temperature and zero pollution,and become an important device for the use of clean energy in the future.How to obtain high-performance proton exchange membrane fuel cells has become a hot and difficult issue in this research field.As the only product of the fuel cell electrochemical reaction,good water management capability plays a very important role in fuel cell performance.Based on the synthesis of previous studies,this paper conducts a comparative simulation study on the control methods of the relative humidity of the intake gas during the water management simulation research,specifically analyzes the output capacity of the battery performance under the three control methods.And on this basis the proposed new flow field structure is modeled and analyzed,and analyzed and improved according to its water management capabilities and specific battery performance.Firstly,the calculation model of proton exchange membrane fuel cell was established by using CFD module of ANSYS software,and the different control methods of the relative humidity of the intake gas in the simulation process were simulated and analyzed,and the factors influencing the performance of the proton exchange membrane fuel cell were studied.The study found that,regardless of whether it is a temperature variable,a humidity variable or a pressure variable,the fixed proportional adjustment method can more accurately reflect the real working conditions of the battery than the fixed oxygen adjustment method and the fixed nitrogen adjustment method.Secondly,a new calculation model of cathode variable cross-section flow field structure is established,compared with the traditional linear flow field structure model and cathode diagonal flow field structure model,the battery output performance of the calculation model is simulated to study.We found that the cathode variable cross-section flow field under high humidity conditions.The structure achieves a maximum power density of 1.386 W/cm2at 0.6 V.Compared with the traditional linear flow field structure,the maximum power density is 1.366 W/cm2.The performance is improved,and the battery performance is improved by 2.9%,but it is worse than the 1.415 W/cm2 cathode diagonal field structure.Under low humidity conditions,the maximum power density of the cathode oblique flow field structure and cathode variable cross-sectional structure at 0.6 V is 1.440 W/cm2 and 1.412 W/cm2,respectively,while the maximum power density of the traditional linear flow field structure is at Obtained at 0.5 V,its value is 1.136 W/cm2,and the performance of the cathode variable cross-sectional structure is 24.2%higher than that of the traditional linear flow field structure.Even in the case of high current density,channel 2 has a performance improvement of 7.1%compared to channel 1,and channel 3 has a 4.2%improvement over channel 1.The water management effect is obvious,and the battery performance has been improved and improved.Finally,the flow field structure is improved according to the results obtained from the exploration.The research shows that under high humidity operating conditions,the battery performance of the four flow channel case 1-case 4 has a certain difference under high current density.The battery performance The flow field structure performance of case 4 is the best.The analysis shows that the four flow channels all obtain the maximum power density at 0.6 V.From case 1 to case 4,the order is:1.381 W/cm2,1.424 W/cm2,1.461 W/cm2 and 1.482 W/cm2,case 4 compared to case 1,its battery performance increased by 7.3%.Under low humidity operating conditions,the performance of the four flow channels is basically the same.The four flow channels all obtain the maximum power density at 0.6 V,from case 1 to case 4 in order:1.381 W/cm2,1.382 W/cm2,1.385 W/cm2 and 1.387 W/cm2.In this paper,by using ANSYS simulation,the effects of three control methods in proton exchange membrane fuel cell simulation on battery performance are studied,and a new cathode variable cross-sectional flow field structure is proposed to obtain good water management.capabilities.