Hydrogen emission characterization for proton exchange membrane fuel cell during oxygen starvation - Part 1: Low oxygen concentration

Hydrogen emissions during low oxygen concentration appear in the cathode exhaust of a PEM fuel cell stack. In this paper, the hydrogen emission rates for a stack containing cells without hydrogen crossover leaks are characterized. A Ballard 9-cell Mk1100 stack under standard FCvelocity((R) 1)-HD6 bus module operating conditions is employed, and extensive experiments are conducted under current demand to evaluate individual cell voltages and quantify hydrogen emissions. The results indicate that the emission rates are a strong function of current demands.In parallel, a model is developed to estimate the amount of hydrogen in the cathode outlet. To illustrate the accuracy of the developed model, the simulation results and the measured hydrogen emission rates in the cathode exhaust are compared for two current demands. It is acknowledged that the proposed model can be a reliable emulator for the hydrogen sensor in the cathode exhaust, where catalytic sensors cannot perform correctly because of the lack of proper oxygen concentrations, or other types of sensor may fail due to wetting or sensor degradation. Moreover, the proposed model provides a user-friendly tool for systems engineers to design reliable start-up procedures for the control of hydrogen emissions. Copyright (c) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

质子交换膜燃料电池堆的阴极排气中会在低氧浓度时出现氢气排放。在本文中，对一个无氢气穿透泄漏的电池堆的氢气排放率进行了表征。采用了一个在标准FCvelocity((R)1)-HD6公交模块运行条件下的巴拉德9电池Mk1100电池堆，并在电流需求下进行了大量实验，以评估单个电池电压并量化氢气排放。结果表明，排放率是电流需求的强函数。同时，开发了一个模型来估算阴极出口处的氢气量。为了说明所开发模型的准确性，针对两种电流需求，对模拟结果和阴极排气中测量到的氢气排放率进行了比较。人们认识到，所提出的模型可以作为阴极排气中氢气传感器的可靠模拟器，在阴极排气中，由于缺乏合适的氧浓度，催化传感器无法正确工作，或者其他类型的传感器可能由于受潮或传感器退化而失效。此外，所提出的模型为系统工程师提供了一个用户友好的工具，用于设计可靠的启动程序以控制氢气排放。版权所有(c) 2016，氢能出版有限责任公司。由爱思唯尔有限公司出版。保留所有权利。