Research On The Influence Of Operating Parameters And Flow Channel Structure On The Performance Of Hydrogen Fuel Cell

Hydrogen fuel cells have high energy density and conversion efficiency,it is clean and environmentally friendly,and have broad application prospects in many fields such as automobiles and ships,as well as fixed power stations.The bipolar plate is one of the most important parts in the composition of a hydrogen fuel cell,and the design of the flow field largely determines the performance of the bipolar plate,so the design of the flow field is very important.In addition,different operating conditions have different effects on the performance of hydrogen fuel cells.Th e subject conducts experimental and numerical simulation research on the bipolar plate flow channel to obtain a reasonably designed flow field structure and the best operating parameters of the fuel cell.In this study,a single cell with an activation area of 4.84 cm~2 was designed and operated.Independently designed and built a hydrogen fuel cell test bench to obtain the performance of the hydrogen fuel cell under different hydrogen flow,air flow,fuel cell temperature and air humidification.The experiment rec ords the polarization curves of the flow field under different operating conditions to obtain the best operating conditions.In order to verify the stability of the fuel cell,a fuel cell stability experiment was carried out.The fuel cell designed in this study can operate stably.In this study,in order to obtain the performance of the fuel cell under different bipolar plate flow field designs,the computational fluid dynamics(CFD)method was used,and the polarization curve,current density distribution,and the mass distribution of oxygen and water were used as the evaluation criteria.Through the verification of experimental results,the performance of the hydrogen fuel cell obtained through simulation prediction is very consistent with the results obt ained through the experiment.In order to improve the performance of the fuel cell,this research proposes several innovative bipolar plate flow field structures for hydrogen fuel cells,including cross flow channels,trapezoid flow channels,variable cros s-section flow channels.The traditional single-channel serpentine flow field is used as a reference for the new flow field.The numerical calculation results of the bipolar plate flow field show that the cross-shaped flow channel can effectively improve the oxygen distribution in the fuel cell.Change the traditional rectangular cross section to a trapezoidal cross section can optimize oxygen and the distribution of current density enhances the performance of the fuel cell.Compared with the cross-sectional flow channel,the variable cross-section flow channel can increase the current density and power density of the fuel cell,and effectively improve the performance of the fuel cell.The experiments and numerical simulations in this paper can better study the influence of operating parameters and bipolar plate flow channel structure on the performance of hydrogen fuel cells.More reasonable operating parameters and bipolar plate flow channel structure are proposed,which provides a theoretical basis for the realization of higher performance hydrogen fuel cells.