Improvement of the Performance of Direct-Generation Type Polymer Electrolyte Fuel Cells and Their Systemization

本课题在各种类型的聚合物电解质燃料电池中，以不含转化炉的直接发电型PEFC （Polymer Electrolyte Fuel Cell）为研究对象，尝试以乙醇作为无害液体燃料。在这种情况下，PEFC的发电量很低，因此研究了改善性能的措施。采用铸造法（MEA的原始制备方法）制备了一种自制的MEAs（膜电极组件），通过直接供给乙醇水溶液，对其发电性能进行了测试。结果表明，与其他常规制造方法制备的mea相比，输出功率提高了约两倍。当使用镍制成的多孔金属泡沫板作为扩散层时，即使是无源型PEFC，其输出功率也比无辅助设备的PEFC大1.8倍。对PEFC阳极侧流道的反应产物进行了分析，气相色谱仪检测到较多的C0_2，但未检测到CO。液相色谱法测定了副产物乙酸和乙醛。这些结果表明乙醇被氧化为乙酸和乙醛，部分氧化为co2。为了研究这些副产物的行为，在原有GTT方法的基础上建立了PEFC的三维数值分析模型，并对PEFC内的流动进行了数值分析。在此基础上，利用PIV （Particle Image Velocimetry）方法进行了流场可视化和流场分析。结果发现，蛇形流道可以有效地排出这类副产物。作为氢燃料的小尺寸轻重量PEFC，设计了一种原始的无源型小型圆柱形PEFC（命名为“功率管”），其比功率可达13OmW/g。在氢燃料pefc的情况下，输出能量密度高，但输出功率密度低，作为电动汽车的电源。因此，有必要采用由pefc和储电装置组成的混合系统。本课题针对轻型电动汽车，构建了一种由被动型pefc与双层电电容器组成的混合动力系统。为了控制该混合动力系统，提出了一种新颖的分时控制方法，根据系统的运行状态对电机的供电比进行控制。作为电机的供电方式，分别对串联和并联两种供电方式进行了测试，结果表明TSM在两种供电方式下都可以很容易地控制电机功率。少

In this research project, the direct-generation type PEFC (Polymer Electrolyte Fuel Cell) without a reformer was taken as an object of investigation among various types of PEFCs, and it was attempted to use ethanol as innocuous liquid fuel. In this case, the power generation of the PEFC was low, and therefore measures to improve the performance were examined. The power generation performance of a self-made PEEC with MEAs (Membrane Electrode Assemblies) prepared by means of the Cast Method (original making method of MEA) was measured by supplying the ethanol aqueous solution directly. As a result, an increase of about two times in output power was attained in comparison with MEAs prepared by other conventional making methods. When porous metal foam plates made of nickel were used as diffusion layers, the PEFC output power became 1.8 times larger even in the case of passive-type PEFC without any auxiliary equipment. Reaction products in the anode-side flow passage of the PEFC were analyz … More ed. C0_2 was detected but CO was not detected by gas chromatograph. Acetic acid and acetaldehyde as by-products were detected by liquid chromatograph. These results mean that ethanol is oxidized to acetic acid and acetaldehyde, and partly to C0_2. For investigating the behavior of those by-products, a three-dimensional numerical analysis model for the PEFC was composed on the basis of the original GTT method, and the flow in the PEFC was numerically analyzed. Furthermore, the flow visualization and the flow analysis by the PIV (Particle Image Velocimetry) method were carried out. As a result, it has been found that a serpentine flow passage is effective in discharging such by-products.As a hydrogen-fuelled small-size and light-weight PEFC, an original passive-type small cylindrical PEFC (named "Power Tube") which can generate a specific power of 13OmW/g has been contrived. In the case of hydrogen-fuelled PEFCs, output energy density is high but output power density is low for the power source of an electric vehicle. Therefore, it is necessary to apply a hybrid system composed of PEFCs and electricity storage devices. In this research project, a hybrid system composed of passive-type PEFCs and electric double layer capacitors was constructed for a light-weight electric vehicle. For controlling this hybrid system, an original Time-Splitting Method (TSM) which can control the power supply ratio to the motor according to running states has been contrived. As power supply modes to the motor, series and parallel modes were tested, and it has been shown that TSM can easily control the motor power in both modes. Less