Numerical Simulation Of Air-cooled Metal Bipolar Plate Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cell(PEMFC)has a good development prospect because of its clean,efficiency,long service life.Among them,the air-cooled metal bipolar plate PEMFC has the advantages of good mechanical properties,light weight,simple structure and so on,which is an important development trend of PEMFC.However,due to the limitation of multiple polarization,the actual energy conversion efficiency of the aircooled metal bipolar plate PEMFC is far lower than the theoretical conversion efficiency.Therefore,it is of great significance to study the structure of the metal bipolar plate and the operating conditions of the fuel cell to improve its performance.In this paper,the air-cooled metal bipolar plate PEMFC is taken as the research object.Based on its working principle and structure characteristics,the energy conversion and material transmission characteristics in the working process are analyzed.Then,the PEMFC simulation model was built using Fluent,and the accuracy of the model was verified through experiments.On this basis,the influence of the structural parameters such as the depth of the flow channel and the thickness of the metal bipolar plate,as well as the working parameters such as the operating pressure and the oxygen excess coefficient on the heat and mass transfer and the output electrical performance of the fuel cell were studied by numerical simulation.Based on the above research,the main conclusions of this paper are as follows:In terms of the structural parameters of the metal bipolar plate,the flow-channel depth has a great impact on the output performance and the heat and mass transfer characteristics of the battery.Within the research range,the smaller the flow channel depth is,the better the battery output performance will be.but the greater the pressure dorp in the flowchannel will be at this time.After comprehensive evaluation,the best flow-channel depth should be 0.6 mm.The thickness of the metal plate mainly affects the temperature distribution in the fuel cell by affecting the heat dissipation performance of the fuel cell,but has little effect on the output electrical performance of the fuel cell.Considering the factors such as cost and mechanical strength,the optimal thickness of the metal plate is determined to be 0.1 mm.In terms of the fuel cell operating conditions,both the operating temperature and the oxygen excess coefficient have a great influence on the heat and mass transfer characteristics of the fuel cell.In the range of operating temperature 313 K～353K,the performance of the fuel cell firstly increases and then decreases,and the optimal operating temperature range is 323 K～333 K.The Oxygen Excess Coefficient has an important effect on the heat dissipation of fuel cell,so it is necessary to select the actual optimal excess coefficient according to the operating temperature and ambient temperature.In this study,the numerical simulation method is adopted to obtain some data results which are difficult to obtain in the experiment,and a lot of cost is saved,which provides a certain reference basis for the optimization design and operation of the air-cooled metal plate PEMFC.