Schiavetti Pierluigi, Del Prete Zaccaria
Department of Mechanics and Aeronautics, La Sapienza University of Rome, via Eudossiana 18, 00184, Rome, Italy.
Rev Sci Instrum. 2007 Aug;78(8):085107. doi: 10.1063/1.2769576.
The efficiency of an automotive engine based on a "self-breathing" and "self-humidified" proton exchange membrane fuel cell stack (PEM FC) connected to a dc brushless electrical motor was measured under variable power load conditions. Experiments have been carried out on a small scale 150 W engine model. After determining the fuel cell static polarization curve and the time response to power steps, the system was driven to copy on the test bench a "standard urban load cycle" and its instantaneous efficiencies were measured at an acquisition rate of 5 Hz. The integral system efficiency over the entire urban load cycle, comprising the losses of the unavoidable auxiliary components of the engine, was then calculated. The fuel cell stack was operated mainly in "partial" dead-end mode, with a periodic anode flow channel purging, and one test was carried out in "pure" dead-end mode, with no anode channel purging. An uncertainty analysis of the efficiencies was carried out, taking into account either type A and type B evaluation methods, strengthening the discussion about the outcomes obtained for a system based on this novel simplified FC type. For our small scale engine we measured over the standard urban cycle, on the basis of the H(2) high heating value (HHV), a tank-to-wheel integral efficiency of (18.2+/-0.8)%, when the fuel cell was operated with periodic flow channel purging, and of (21.5+/-1.3)% in complete dead-end operation mode.
在可变功率负载条件下，对基于连接到直流无刷电动机的“自呼吸”和“自增湿”质子交换膜燃料电池堆（PEM FC）的汽车发动机效率进行了测量。实验在一个小规模的150W发动机模型上进行。在确定燃料电池的静态极化曲线和对功率阶跃的时间响应之后，驱动该系统在试验台上模拟“标准城市负载循环”，并以5Hz的采集速率测量其瞬时效率。然后计算整个城市负载循环中的整体系统效率，其中包括发动机不可避免的辅助部件的损耗。燃料电池堆主要在“部分”死端模式下运行，阳极流道定期吹扫，并且在“纯”死端模式下进行了一次测试，即不进行阳极通道吹扫。考虑到A类和B类评估方法，对效率进行了不确定性分析，加强了对基于这种新型简化燃料电池类型的系统所获得结果的讨论。对于我们的小规模发动机，在标准城市循环中，基于H₂的高热值（HHV），当燃料电池在阳极流道定期吹扫的情况下运行时，从油箱到车轮的整体效率为（18.2±0.8）%，在完全死端运行模式下为（21.5±1.3）%。
