Structural Optimization And Innovation Of Flow Field In PEM Fuel Cell

Proton exchange membrane fuel cell (PEMFC) has a lot of virtues, such as high power density, high-energy efficiency, low-temperature operation, fast start-up and zero-emission, so it is the most probable to apply in automobile, bus, electrical equipment, portable power and stationary product, and it has a very good foreground. But the actual fuel cell is in the research stage, and some of critical questions aren't dissolved. The gas flow field is one of them, and this paper will aim at the gas flow field of the fuel cell.The three-dimensional model of fuel cell was studied in this dissertation, including the fluid flowing, gas diffusion, electrochemistry reaction, water transferred, and so on. It will be helpful to the later simulation.Five PEMFC models with different flow field depth are set up and modeled in the PEMFC module of the Fluent software. The pressure distribution, concentration and batteries performance of the fuel cells are studied and the results show that 0.4mm is the best channel depth.By fixing the channel depth, and changing the width of the channel and shoulder, the geometry models with different ratios are established and simulated. And the results show that width of the shoulder must not exceed that of the channel; when channel depth and shoulder width of flow field are fixed, and shoulder width is less than channel width, changing channel width has no much influence to the battery performance; when channel depth and channel width of flow field are fixed, and channel width is bigger than shoulder width, changing shoulder width has also no much influence to the battery performance; considering the battery performance, pressure drop and some other factors, the optimal ratio is 1:1.Then by fixing the depth and width of the channel, the PEMFC with different kind of cross-section channels is modeled and optimized design by the PEM module of the Fluent software. And the results show that the performance of the PEMFC with rectangle, semicircle, triangle or trapezoid cross-section is not too much difference, but the performance of the PEMFC with changing cross-section channel is much better than that of the above mentioned ones.