Three-dimensional Flow Field And Water-thermal Distribution Characteristics Of Proton Exchange Membrane Fuel Cell

The proton exchange membrane fuel cell power is a clean, efficient green power. Protonexchange membrane fuel cell has the following advantages: it can start with low temperaturequickly, strong adaptability to fuel, and its generation process does not involvehydrogen-oxygen combustion, and thus not subject to Carnot cycle limit, the energyconversion rate is high; high reliability and so on. Effective thermal management and watermanagement for the PEMFC is very important. But if there are no effective thermalmanagement and water management, the temperature of the fuel cell will ascend endlessly,water will be flooded, and these will affect the fuel cell. Effective management of water andheat is the key to ensure that battery high performance and high efficiency.This paper first reviews the history of the development and research progress of theproton exchange membrane fuel cell; introduce some common types of flow field, a briefone-dimensional, two-dimensional and three-dimensional simulation method and the statusquo. Then the PEMFC transfer equation and electrochemical equations, and physicalparameters of the model and the electrode process are described. This paper uses the computersimulation methods to analyze the proton exchange membrane fuel cells, water and heatmanagement, to calculate the PEM module in fluid dynamics software Fluent simulation. Aproton exchange membrane fuel cell single cell model of50mm×11mm×3.28mm isestablished and analyzed.The integrated PEMFC was simulated and analyzed. This paper studies the outputcharacteristic of PEMFC in the different wetting conditions, the diffusion layer temperaturedistribution along the direction of the flow channel, the water content distribution in the anodeand cathode diffusion layer and membranes, the influence of the temperature difference in thedifferent humidification between anode and cathode, the influence of the temperature in thedifferent diffusion layer thermal conductivity, the influence of the fuel cell performance in theair excess coefficient. The results show that, in the conditions of the humidification of100%diffusion layer thermal conductivity of0.6W/(m k), the excess hydrogen coefficient of1.5,the excess oxygen coefficient of2, the battery performance is relatively well.Then, this research adds the porous media properties based on the above-mentionedsingle cell model. In the conditions of the different porosity, this paper studies fuel cellperformance, water content in the membrane, the diffusion layer pressure and oxygen ofconcentration of catalytic layer surface. The results show that with the increase of porosity,phase saturation, liquid water flow and oxygen concentration of the catalyst layer surface increases, the proton exchange membrane diffusion layer pressure and water content in themembrane decreased gradually.Finally, in order to study the cooling of the fuel cell problem, a50mm×11mm×4.48mm with a cooling channel of the PEMFC is established, based on the model of the singlecell, to investigate the temperature distribution in the cooling channels. The study analyzedthe cooling water flow rate, temperature distribution within the cooling flow, cooling flowchannel outlet temperature distribution and import and export drop. The study analyzed thetemperature distribution of the cooling channels in different flow velocity of cooling, thetemperature distribution of outlet and the influence of pressure drop between inlet and outlet.