Molten Hydroxide Direct Carbon Fuel Cell Simulation

Direct carbon fuel cells are a typical class of research objects that require multi-scale coupling analysis.The macroscopic electrochemical reaction,material diffusion,gas flow and other processes,together with the diffusion and migration of microscopic substances in the interior of the electrode,all require the study of the intrinsic and complex reaction mechanism of the chemical power supply from a multi-scale perspective.The rapid development of new energy technologies and clean energy generation technologies has brought more severe challenges to high-energy battery systems.The tempting development prospects of the MHDCFC system have made it a new research focus for people.This article takes MHDCFC as the research object,adopts finite element method?Finite Element Method?,uses the COMSOL Multiphysics simulation software to carry on the coupling analysis to the numerical model,has considered the electrochemical reaction,the material transmission and the charge transmission and so on process in the battery system.The model studies the discharge characteristics of the power system under different current density conditions,and the influence of related structural parameters and physical and chemical characteristic parameters on its discharge performance.Finally,it provides some suggestions for optimizing the performance of the chemical power supply.Establish a set of mathematical models,compare experimental data and model data,and discuss and compare the authenticity of the model.At a current density of less than 10mA·cm^-1,the model calculates the output current density due to irreversible reaction resulting in a decrease in the calculated value of the calculated activation polarization.As a result,the calculated current density results become larger and the overall consistency of the model is good.Through the 3D model,the temperature distribution,current density distribution and OH^-ion mass fraction distribution of the battery were observed.Comparing the performances of different central thermocouples at temperatures of 723 K,773 K,823K,873 K,and 923 K,it can be seen that as the temperature increases,the performance of the battery also increases,and the gradient of the current density inside the battery becomes larger.The increase in current density between the electrodes is more pronounced,and the consumption of OH^-ions around the anode is also accelerated.The anode radius,cathode center-to-center distance and reaction device inner diameter were changed,showing some regularities.The distribution of the current density,the temperature distribution of the battery,and the distribution of the mass fraction of OH^-ions were discussed.After analysis,the battery performance is best when the battery temperature is 923 K,the anode radius is 0.65 cm,the center-to-center distance between the cathode and the anode is 2 cm,and the inner diameter of the reaction device is 5 cm.The active specific surface area was introduced to predict different anode materials and the specific surface area was used to estimate the active specific surface area.The value of the active specific surface area is not only affected by the specific surface area,but also due to the surface oxygen-containing functional groups and the carbon surface microstructure.Although the overall battery performance cannot be accurately estimated,the overall performance and activity of the battery have the same tendency as the specific surface area.