本研究目的透過一金屬多孔材陽極封閉燃料電池設計，探討如何有效提升燃料電池系統之氣體管理能力。其中燃料電池利用金屬多孔材之特性與平均等長氣體流道設計，以提升電池性能，並且在燃料電池陽極出口裝置一電磁閥，利用週期排氣施行氫氣的氣體管理，提高燃料利用率。論文中探討各燃料電池操作參數，對燃料電池性能之影響，以及陽極封閉模式中操作參數對排氣週期的特性。 由實驗結果得知利用金屬多孔材與平均進氣流道，有助於反應氣體分佈之均勻性，使氣體以均勻的濃度在質子交換膜反應面積，並且在較低之氣體流量時也能有優異的電池性能。在陽極側的氣體管理方面，得知當電磁閥關閉、氫氣停留在電池內部時，其氣體利用率為100％，而隨氣體壓力增加所產生的背壓，能提高氫氣濃度同時也可強化氣體通過擴散層的能力。此外，電磁閥開啟將反應生成物排除，能夠使電池長時間穩定操作。實驗過程中發現提高增濕溫度、電池溫度都會導致排氣週期的增長，而加大陰極空氣化學計量比則須縮短排氣週期。此排氣週期策略有助於提升電池性能，維持長時間穩定操作，並避免燃料電池在不適當的操作下造成損壞。;The purpose of this study is to find an appropriated solution to enhance the management capacity of the gas fuel cell system based on a design of anode purging of metal foam proton exchange membrane fuel cell, where the properties of metal foam and the average gas flow path of the fuel cell can improve fuel cell performance. After setting up a solenoid valve at the anode outlet of the fuel cell, it is achievable to implement the control of hydrogen by cyclically purging gas management. The effects of purging parameters on fuel cell performance will be discussed in the article. Several phenomena can be observed from the experiments. First, uniform flow distribution can be obtained by using metal foam and the improved inlet design. Secondly, it can increase the utilization rate of reaction area and reactant gas. Even with low gas flow rate, the fuel cell still has excellent performance. Thirdly, for gas management on the anode side, it is known that gas utilization rate is 100% when hydrogen gas stays in the fuel cell and the solenoid valve closed. Fourthly, back pressure generated from the higher gas pressure can rise hydrogen concentration and strengthen gas ability to pass gas diffusion layer. In addition, it can remove the reaction product by opening solenoid valve for keeping fuel cell working stably for a long time. It is found that the increase of humidification and cell temperature are directly proportional to the increase of purging cycle during the experiment. Also, it should shorten purging cycle for increasing the stoichiometric ratio. The strategy of purging cycle helps to improve stable fuel cell performance for a long time, and it prevents the degradation of the fuel cell from unappropriated operating.
