本研究係以金屬發泡材應用在質子交換膜燃料電池之內流道為標的，探討流場的分區數量（單區、三區、五區），以及進氣的方式（單入口、多入口）對電池內傳輸現象及電池性能之影響。使用CFD前處理器GAMBIT建構完整的三維單顆燃料電池模型及格點系統，搭配計算流體力學軟體FLUENT，分析內部流場分布、電質傳現象以及在實際應用上對燃料電池之性能及流道壓損的影響，藉由選用最佳燃料使用率，和相對較小的壓力損失之流道設計，以符合實際應用上的經濟效益。 由本研究中得知，在流場分區的流道設計中，以單入口進氣的情況下，隨分區數量越多，燃料流經過的路徑越長，使得流場中的壓降增加，燃料往側向和徑向的擴散能力增強，促使反應氣體抵達觸媒參與反應，進而提升反應氣體有效使用率。在進氣方式不同的設計中，多入口進氣設計之性能較單入口略差，且多入口之設計有流量分配不均的問題，但流場壓降較單入口之設計小。考慮加濕程度、發泡材尺寸、鎖模時壓縮程度對燃料電池性能的影響，隨加濕程度越高、發泡材孔徑越小、壓縮程度越大，電池性能也隨之提升，但增加的幅度有限。而單入口設計之性能皆較多入口設計佳。 The main purposes of this study are to investigate the use of metal foam as the flow distributor of proton exchange membrane fuel cells (PEMFCs) and the effects of flow field design on the transport phenomena and the performance of the fuel cells. A three-dimensional mesh system was built by using the GAMBIT and the discredited equations were solved by the CFD software FLUENT. Results of flow, mass, pressure, and electric distributions under real operating conditions are presented and discussed. Based on the results, for single entrance designs, the pressure drop increases as the number of partitions increases. This increase in pressure drop results in enhanced transport of reactants in the through-plane direction. Therefore, reaction rate as well as cell performance increase. As for the comparison between single inlet and multiple inlets, although multiple inlet design has lower pressure drop, it causes lower cell performance due to uneven flow distribution among different partitions. In addition, cell performance was found to increase slightly if the reactant gas was humidified, the pore size of the metal foam was reduced, or the foam/carbon paper was slightly compressed.
