PEMFC新型流场的设计与数值模拟

Design and numerical simulation of the flow field with a novel structure for PEMFC

质子交换膜燃料电池流场的主要功能是为燃料电池提供反应物和生成物流动的场所。流场决定着质子交换膜燃料电池内部的物料分布。流场设计的优劣直接影响着电池的性能。利用FLUENT12.0进行了模拟,针对在反应中形成的气泡流,提出一种能够有效排除第二相的方案,即加入了副流道的设计。新型流场保留了传统流场的流道,并在脊上打出副流道入口通道。该种新型流场能较高地提高电池的性能,其原因为具有主副双流道的新型流场能够更有效地促进反应物氧气的排除和生成物水的排除。较传统流场相比,新型流场的流道截面上氧气的平均摩尔分数提高了16.4%,水的平均摩尔分数降低了66%,电流密度提高了20%。

The main function of the flow field of PEMFC is to provide the fuel cell reactants and products flowing spaces. The flow field determines the inside material distribution of PEMFC. The flow field design will directly affect the performance of the battery. Aiming at the stream of bubbles formed in the reaction, we propose a way to effectively rule out the second phase, name- ly, the vice channel design. New flow field retains the flow channel of the traditional flow field, and a inlet passage of the vice flow channel is dug at the ridge. The new flow field can improve the performance of the battery, because the new primary and vice double channel flow field can be more effective to promote the exclusion of the reactant oxygen and resultant water. Compared with the traditional flow field, the average mole fraction of oxygen in the flow channel cross-sec- tion of the new flow field increases by 16.4% ,and the average mole fraction of water reduces by66~. The current density increases by20%.