ABSTRACT

In this study, a high fuel utilization approach for polymer electrolyte fuel cells (PEFC) is proposed and studied experimentally. This approach uses an ultra-low hydrogen stoichiometry supply (i.e., ξ_a = 1.02) meanwhile sustaining stable cell performance. Systematic experiments showed the feasibility of high fuel utilization approach under different pressures and hydrogen/air inlet humidification conditions. It is indicated that the fuel cell is able to provide stable performance at a real fuel stoichiometry ξ_a = 1.02 under high-current density operation. For all the tests at ξ_a/ξ_c = 1.5/2.0 or 1.02/2.0, there exist unstable operation regimes typically in low power conditions. The instability as a result of flooding is affected mainly by air stoichiometry and less by fuel stoichiometry.

摘要

在这项研究中，提出并通过实验研究了一种用于聚合物电解质燃料电池 (PEFC) 的高燃料利用率方法。这种方法使用超低的氢化学计量供应（即ξ _a  = 1.02），同时保持稳定的电池性能。系统实验表明，在不同压力和氢气/空气入口加湿条件下，高燃料利用率方法的可行性。结果表明，在高电流密度操作下，燃料电池能够在实际燃料化学计量ξ _a  =  1.02 下提供稳定的性能。对于ξ _a /ξ _c  = 处的所有测试1.5/2.0 或 1.02/2.0，通常在低功率条件下存在不稳定的操作制度。溢流导致的不稳定性主要受空气化学计量比影响，较少受燃料化学计量比影响。