Study on Performance of Wavy Flow Channel in Proton Exchange Membrane Fuel Cell

• Main Authors: Jia-Hong Lin, 林加弘
• Other Authors: Ji-Jen Lee
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/46650642913849215613

碩士 === 大同大學 === 機械工程學系(所) === 94 === This research is mainly on improving the flow field plate design, using Dupont 5- Layers Reformate MEA, and the active area is 100cm2. This research regards improving the performance of parallel flow channel as main object. The shape of flow channels used in this research is wavy form. The wavy form flow channel is different from tradition parallel flow channel in that prolonged flow channel length, with a lot of turn to make increase of flow resistance. The object is that the fuel gas can react abundantly and the performance of fuel cell is improved. The sample of this experimental is a single cell test. This experiment is divided into two groups according to its assembly way. For the case 1, the flow channel of flow field plate of two electrodes is totally coincided when assembling. For the case 2, the flow field plate of cathode is rotated by 90 degree to enforce the flow channel crisscross each other. And the influence of the overlap percentage of ribs on the performance of fuel cell is discussed. The experimental result shows that rising the humidification temperature gradually, does not improve the performance of fuel cell improve consistantly in case1. The reason is that the electroosmotic force driven by high current density made the air side producing water, and then jammed in the gas diffusion layer which will block the reaction of air side and lead to lower performance. The current density of case 2 is lower than that of case1 so the problem of water does not happen in case 2. In this research, the ribs overlap percentage of case 1 is 100%；the ribs overlap percentage of case 2 is 50%. The experimental results shown that all of fuel cell performances in case 1 are higher than those of case 2 when operated at same humidification temperature. The reason maybe that the ribs overlap percentage decreased from 100% to 50%. It will increase internal resistance and make the fuel cell performance worse.