The High Temperature Proton Exchange Membrane Fuel Cells Modeling And Simulating

As a kind of energy conversion device,fuel cell has the characteristics of high efficiency,zero pollution and strong applicability.Widely used in mobile power stations,transportation and fixed power stations,etc.In the energy crisis,environmental pollution,climate warming increasingly serious today,fuel cell is more and more important.The high temperature proton exchange membrane fuel cell not only has the advantages of fuel cell,but also has the advantages of strong carbon monoxide tolerance,gaseous water as the product,and simple water management in the high temperature fuel cell system.Therefore,the high temperature proton exchange membrane fuel cell has become a research hotspot in recent years.In this paper,the basic concept,principle,research background and research status of proton exchange membrane fuel cell are introduced firstly.Then the theoretical calculation of proton exchange membrane fuel cell is described,including theoretical efficiency calculation,electromotive force calculation of fuel cell,the relationship between electromotive force and temperature,and the relationship between electromotive force and pressure.The governing equations of high temperature proton exchange membrane fuel cell simulation are described,including mass conservation equation,momentum conservation equation,energy conservation equation,component conservation equation,charge conservation equation,etc.The function of the flow channel is to guide the reaction gas flow and ensure the uniform distribution of the reaction gas to the catalytic layer,so as to ensure the good performance of the proton exchange fuel cell.The models of flow channel without 3D disturbance structure,flow channel with 3D disturbance structure and flow channel with small size without 3D disturbance structure were established,and the effects of 3D disturbance structure on the polarization curve of fuel cell were studied by using Fluent software in ANSYS.In particular,the influence of the height and length of the three-dimensional perturbation structure on the polarization curve of the fuel cell.The results show that the performance of fuel cells with three-dimensional airflow disturbance structure is improved obviously.In the fuel cell with a three-dimensional disturbance structure(the height of the disturbance structure is 0.2mm),the voltage is increased from 0.71 volts to 0.7105 volts at 0.3 amperes.At 0.6 amperes,the voltage increased from 0.6208 volts to 0.6318 volts.Under the same current condition,the output voltage of the small-size single cell without three-dimensional perturbation structure is relatively small,and the small-size single cell without three-dimensional perturbation structure cannot improve the performance of the fuel cell.The simulation results show that the performance of the fuel cell improves with the increase of the height of the three-dimensional perturbation structure.At 0.6V,the current output of three kinds of three-dimensional perturbed structured fuel cells with different heights(0.2mm,0.3mm and0.4mm)is 0.61 A,0.62 A and 0.63 A,respectively.At 0.7 volt,the current outputs of three fuel cells with different three-dimensional perturbation structure heights are 0.306 amperes,0.315 amperes and 0.326 amperes respectively.When the length of the three-dimensional perturbation structure increases to 10 mm,the polarization curve of the fuel cell is coincident with the polarization curve before the length of the three-dimensional perturbation structure increases,indicating that increasing the length of the three-dimensional perturbation structure cannot improve the performance of the fuel cell.The simulation results also show that the increase of the three-dimensional flow disturbance structure in the flow passage can improve the uniformity of the cathode oxygen concentration,which plays an important role in improving the stability of the battery.In the future research,the quantitative optimization of three-dimensional airflow structure and the overall optimization of the battery will be considered.