摘要 本文為探討不同的流道設計對氣體在質子交換膜燃料電池流場內造成的影響，模擬三維燃料電池陽極面，在不考慮氫氣加濕以及化學產物產生的條件下，利用米曼方程式，來決定氫氣在觸媒層的反應消耗量。 在此設計蛇型流道、指叉型流道、以及非對稱式指叉型流道三種，並固定流道匝數，改變流道寬、流道深以及肋條寬。三種形式的流道入口皆為相同的質量流率2.5×10-7 kg/s，且出口為固定2大氣壓力。 結果顯示出，本文中的蛇型流道在較高的壓力下能利於氫氣的消耗，但是也會造成流道內的氫氣流動過快，而來不及觸媒層反應；指叉型流道在流道內的流速皆偏低，容易產生死域而不利反應，當流道設計時能造成較高的壓力發生，由於強制對流的效應，亦能提高氫氣的消耗量；本文設計的非對稱式指叉型流道顯示出，在固定流道匝數的條件下，適當地減小出口區域流場的流道寬度時，能對於氫氣的消耗量有一定的幫助。 ABSTRACT In order to discuss the effect of channel dimensions in the flow-field distributor on the performance of PEM fuel cell, this article simulated the three-dimensional fuel cell at anode side without considering the hydrogen humidification and chemical production and used Michaelis-Menten equation to determine the consumption of hydrogen in catalyst. Single-path serpentine flow-field, interdigitated flow-field, and asymmetrical type interdigitated flow-field were used for different channel width, channel depth, and rib width by using the same coils of channels. With the same boundary conditions, the inlet mass-flow-rate was 2.5×10-7 kg/s and outlet was 2 atm. The results demonstrating that serpentine flow-field needs higher pressure to improve consumption of hydrogen, but higher pressure may cause fast speed hydrogen flow pass through the catalyst and wouldn’t have enough time for the reaction. Interdigitated flow-field could easily produce the dead zone which is not good for the reaction of hydrogen, but it would result in higher pressure by decreasing the channel dimension and the higher consumption could be reached. The asymmetrical type interdigitated flow-field in this article showed that if we reduce the channel width of outlet flow-field zone properly, the consumption of hydrogen would be increased.
