Study on Gas-Liquid Two Phase Flow in Polymer Electrolyte Fuel Cell

为聚合物电解质燃料电池（PEFC）的技术发展，研究了单电池通道内的流量测量技术，并研究了供气特性与燃料电池性能的关系。首先建立了三种不同展宽比的PEFC流道模型，然后测量了不同进气压力和送风流量下的内部流道压力分布。因此，通过在直线和弯道上获取大量测点的压力数据，很难将通道直线部分的弯曲损失与摩擦损失明确区分开来。然而，通过从位于每条直线中心的几个测点获取压力数据，并使用相对准确的摩擦损失预测公式，可以评估弯曲损失，而不会出现任何严重问题。其次，制造了与上述气流测量中使用的气体通道相似的PEFC单单元，然后在提供空气和氢气（在终端系统中）的情况下测量发生器的性能。不同的参数为空气利用率（20%-80%），加湿/不加湿，供气压力（50kPa, 100kPa）。就实验而言，空气利用率对发电机性能的影响最大。在较高的空气利用率、无加湿和较高的气体压力下，发电机的电压、功率和效率等性能较高。为了进一步的研究，有必要研究其他参数对燃料电池性能的影响，并通过详细的内阻测量来阐明性能的主导机制。另一方面，在发电时测量内部流量也很重要，因为在洪水中看到的通道内的流动行为仍然有很多需要澄清。少

Flow measurement techniques in a single cell channel were examined and the relationship between the supplied gas property and the fuel cell performance was investigated for technology development of Polymer Electrolyte Fuel Cell (PEFC). First, three types of single cell channel models simulating PEFC flow channels with different aspect ratios were manufactured, then pressure distribution along the internal flow channel was measured while inlet pressure and flow rate of supplied air were varied. As a result, it was found difficult to clearly separate the bend loss from the friction loss in the straight part of the channel by acquiring pressure data from a lot of measuring points on a straight line and a bend. However, it was found possible to evaluate the bend loss without any serious problems by acquiring pressure data from several measuring points located in the center of each straight line and by using a relatively accurate prediction formula for friction loss prediction. Second, a s … More ingle cell of PEFC with gas channels similar to those used in the aforementioned air flow measurement was manufactured, then generator performance was measured with air and hydrogen (in dead-end system) supplied. Varied parameters were air utility rate (20%-80%), with/without humidification, supplied gas pressure (50kPa, 100kPa). Air utility rate had the strongest influence on generator performance as far as the experiment was concerned. Generator performance, such as voltage, power and efficiency was higher in higher air utility rate, without humidification and in higher gas pressure. For further study, it will be necessary to investigate influence of other parameters on fuel cell performance as well as to clarify the performance dominating mechanism by measuring internal resistance in detail. On the other hand, it will be also important to measure internal flow while electricity is generated because a lot is still to be clarified in the flow behavior in the channel as seen in flooding. Less