Numerical Simulation And Efficiency Optimization Of Vehicle Fuel Cell For Fuel Reforming System

Fuel cell has become one of the main research directions of automobile fuel system in the future because of its good environmental protection and high energy conversion efficiency.For its good physical and chemical properties,dimethyl ether can be used as an ideal hydrogen source for fuel cell vehicles.As one of the main technologies of fuel cell vehicles,hydrogen production by on-board fuel cell reforming has attracted the attention of many scholars at home and abroad.In this paper,the numerical simulation and experimental study of dimethyl ether reforming system for hydrogen production were set up,and the performance optimization test of the reactor was carried out.Based on the theory of catalytic reaction kinetics and thermodynamics,reaction kinetic model was established for hydrogen production by dimethyl ether reforming.Then,a numerical model was established for dimethyl ether reforming system.The experimental study on reforming process was carried out.The simulation results were compared with the experimental results,and the correctness of the numerical model was verified.Finally,the dimethyl ether hydrogen production reforming system was optimized by the established numerical model.Firstly,based on the basic theory of catalytic chemical reaction,according to the principle of adsorption and desorption in the process of catalytic reaction,the kinetic equation of hydrogen production by dimethyl ether autothermal reforming was established.Based on the kinetic equation,using computational fluid dynamics software COMSOL,numerical model was established for dimethyl ether reforming system.Dimethyl ether conversion and hydrogen yield for different reaction conditions such as ratio of steam to DME?0?4.0?,ratio of O₂to DME?0.1?0.5?,and gas inlet temperature?200??500??.With the increase of molar ratio of oxygen to dimethyl ether,the conversion of dimethyl ether and hydrogen yield showed an upward trend.With the increase of steam to dimethyl ether ratio,the hydrogen yield increased first and then decreased.The increasing of the inlet temperature of the reaction gas can obviously promote the conversion of dimethyl ether and increase the hydrogen content at the outlet of the reaction gas.Secondly,the experimental platform of dimethyl ether reforming system for hydrogen production was set up,and the experimental study on the hydrogen production by dimethyl ether reforming was carried out.By changing the reaction conditions,the effects of different reaction parameters on the conversion of dimethyl ether,hydrogen production yield and temperature distribution in the reactor were studied.The experimental results were compared with the simulation results,and the correctness of the numerical model was verified.Finally,based on the established numerical model of dimethyl ether reforming system for hydrogen production,the performance optimization of dimethyl ether reforming system was studied from two aspects of operation parameters and structural parameters.The purpose of this paper was to investigate the reaction system of dimethyl ether reforming for hydrogen production.The research results can provide a theoretical reference for the optimization of hydrogen production system of dimethyl ether,which was practical significant.