Numerical Simulation Of Electrochemical Properties Of Plate Solid Oxide Fuel Cell

As global climate change and energy shortage problems become increasingly prominent,the development of new energy technologies is of great practical significance.Solid oxide fuel cells(SOFC)are all-solid high-temperature fuel cells with unique advantages such as high power generation efficiency and wide fuel sources.As new energy conversion technologies,they have gradually attracted global attention.In this study,based on the analysis of the principles of electrochemical kinetics,combined with mass transfer,heat transfer,component transfer,momentum transfer,and charge transfer,etc.,a numerical model of a single-channel three-dimensional multiphysics field with a plate anode supported SOFC was established.Using COMSOL 5.4 to conduct electrochemical research and analysis on the established multiphysics numerical model,With a view of providing a basis for SOFC standard formulation and large-scale commercial development.Solve the mathematical model of SOFC when hydrogen is used as fuel,analyze and study the distribution law of the physical quantities such as internal pressure,Velocity,temperature,component concentration and current density of the battery.The results show that:(1)The gas flow rate,battery temperature,substance concentration distribution,and current density in the battery are unevenly distributed in the battery due to the geometric structure and material characteristics.(2)When flowing in the same direction,the velocity of the fuel gas in the flow path increases sharply at the inlet,then increases slowly,and finally increases suddenly at the outlet.(3)When flowing in the same direction,in the gas flow direction,the temperature of each component of the battery gradually increases,the mole fraction of hydrogen and oxygen gradually decreases,the water vapor content increases,the current density gradually decreases,and the activation overpotential gradually decreases.The SOFC model using hydrogen as fuel under different operating parameters and microstructure parameters is solved,and the battery performance changes arestudied and analyzed.The results show that:(1)The improvement of air intake rate is not as obvious as the improvement of fuel intake rate.(2)The performance of the SOFC battery increases first and then decreases with the increase of the porosity of the electrode.Controlling the porosity in the range of about 0.4 can keep the SOFC excellent performance.Taking methane as the fuel for SOFC,the electrochemical performance of SOFC is analyzed on the basis of the reforming reaction and water-gas exchange reaction taking place.The results show that:(1)Due to the interaction of reforming endotherm and electrochemical exotherm,the battery temperature exhibits different results under different fuel intake rates and different operating voltages.(2)Along the length of the battery,the current density,the molar fraction of hydrogen and CO all increase and then decrease,and the change trend of the three is consistent.(3)As the water-carbon ratio continues to increase,the performance of the battery continues to decline,but the increase in the water-carbon ratio can reduce the occurrence of carbon deposition and reduce the battery failure rate.