Flow Field Design And Hydrothermal Management Of Proton Exchange Membrane Fuel Cell

With the continuous growth of energy demand,the contradiction between environmental pollution and energy utilization has become increasingly prominent,and the combustion-based utilization has intensified the consumption of primary energy,and the energy consumption revolution is imminent.As an efficient and clean power generation device,fuel cell is considered to be one of the ten revolutionary technologies in the future.It has received close attention from all walks of life,but there is a complicated heat and mass transfer process inside.By studying its internal heat and mass transfer mechanism,optimizing the flow field design and hydrothermal management,the cell performance and reliability can be effectively improved,and the wide application of fuel cells in various fields can be realized.In this paper,a cycle serpentine flow field structure with enhanced convection under the ribs is designed,and its influence on cell performance is explored by a combination of numerical simulation and experiment.And established a fuel cell model with cold plates,and optimized its structure.The specific work is as follows:Through the analysis of the pressure difference between adjacent channels and the local oxygen concentration distribution,it is found that the sub-rib convection promotes the oxygen mass transfer and the concentration distribution,and a cycle serpentine flow field design that strengthens the sub-rib convection is designed.When the voltage is 0.5V,compared with the three-channel serpentine flow field(3SFF),the oxygen concentration at the interface between the diffusion layer and the catalytic layer of the three-channel cycle serpentine flow field(3NFF)increases by 3.72%,and the net power density was increased by 4.35%.At the same time,the distribution uniformity coefficient(DU)is used to analyze the distribution of reactants in different flow field structures,and the cycle serpentine structure obtains the best uniformity performance.Finally,the single cell is assembled according to the fuel cell’s materials and test characteristics,and the performance test is carried out.The results show that at 0.5V,compared with 3SFF,the current density of 3NFF is increased by 5.48%,indicating that the cycle serpentine design has performance advantages and further verifies the correctness of the simulation results.Based on the single cell,a fuel cell model with a cold plate is designed.Based on the field synergy theory,the performance of wave cold plates and parallel cold plates is studied from the temperature and pressure characteristics.When the inlet Reynolds number is 330,the average temperature of the wavy cold plate is reduced by 1.08 K compared with that of the parallel cold plate,and the uniformity is also improved.In addition,the wave cold plate is optimized.The optimized cold plate can effectively control the pressure drop on the basis of improving the convective heat transfer capacity.