共查询到19条相似文献,搜索用时 104 毫秒
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质子交换膜燃料电池动态特性实验研究 总被引:2,自引:0,他引:2
质子交换膜燃料电池动态特性的研究对于实际应用来说非常重要,实验研究了质子交换膜单体燃料电池在负载动态变化及启动过程中性能的响应.基于计算机控制的负载变化,得到了在不同进气加湿程度下电池性能在负载突变时的响应和在启动工况中的变化,结果表明电池电流对电压动态变换的响应很迅速,突变工况下电流密度出现了过增现象,高加湿程度的电池在设计启动过程中获得了更好的性能. 相似文献
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质子交换膜是质子交换膜(PEM)燃料电池的核心,对电池的性能起到了至关重要的作用。论文配制了以磷酸为基础并加入硫酸的掺杂剂,制备了掺杂的高温PBI膜,通过电镜照片对比了掺杂膜表面的差异,测试了高温PBI燃料电池的Ⅰ-V特性和交流阻抗特性,分析了高温PBI膜掺杂硫酸的含量和电池温度对其特性的影响。研究发现:在加热条件下掺杂硫酸酸化膜时,对膜的微观结构有一定程度上的破坏,高温PBI燃料电池的特性也随之降低。研究结果对高温PEM燃料电池的PBI膜的性能的深度探索,推动高温燃料电池的普及化应用具有重要意义。 相似文献
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There is a substantial demand for hydrogen flow rate monitoring devices in applications where hydrogen is utilised or produced and which include oil refineries, ammonia production, food and chemical industries, coal gasification, methane steam reforming and water electrolysis. In this paper, a polymer electrolyte membrane (PEM) fuel cell has been demonstrated for measuring accurate flow rates of hydrogen or hydrogen-containing gases. The concept involves applying a constant voltage to a PEM fuel cell to oxidise the entire hydrogen supplied to the anode compartment of the fuel cell and observing limiting current values attained and relating these to the hydrogen flow rates. PEM fuel cells with an active area of 50 cm2 were constructed and used to accurately measure the flow rates of hydrogen up to 170 mL/min. A device with a capability to monitor significantly higher hydrogen flow rates can be constructed by using several cells in a stacking arrangement or by using electrically isolated cells in a single device. The paper discusses advantages and limitations of the technique and the flow rate-measuring response for gases containing 5–100 % hydrogen. The response time for hydrogen gas was of the order of 1–2 min. However, the fuel cell flow field design can be optimised for faster response times. 相似文献
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Proton exchange membrane fuel cells [PEMFC] have become highly attractive for stationary as well as mobile energy applications due to their good efficiency compact cell design and zero emissions. PEM fuel cells mainly consist of anode and cathode containing platinum/platinum alloy electrocatalysts and Nafion membrane as the electrolyte. They operate on hydrogen fuel, which is generally produced by reforming of hydrocarbons, alcohols such as methanol and may contain large amounts of impurities such as methanol, carbon dioxide, trace amounts of carbon monoxide, etc. The studies on the effect of methanol impurity in hydrogen on fuel cell performance and methods of mitigation of poisoning are very important for the commercialization of fuel cells and are described in a limited number of papers only. In this paper, we present the studies on the influence of methanol impurity in hydrogen for the PEM fuel cells. The effect of various parameters such as methanol concentration, cell voltage, current density, exposure time, reversibility, operating temperature, etc. on the cell performances was investigated using pure hydrogen. Various methods of methanol poisoning mitigation were also investigated. 相似文献
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Polymer electrolyte membrane (PEM) fuel cells are considered to have the highest power density of all the fuel cells. They operate on hydrogen fuel, which is generally produced by reforming of hydrocarbons, and may contain large amounts of impurities such as carbon dioxide, nitrogen, and trace amounts of carbon monoxide. We studied the effect of dilution of hydrogen gas with carbon dioxide on PEM fuel cells by polarization studies. The polarization curves were different when hydrogen gas was diluted with same quantities of carbon dioxide and with nitrogen. It may be due to carbon monoxide formation by reverse shift reaction and poisoning of anode platinum catalyst. Use of Pt–Ru alloy catalyst was found to suppress the poisoning. The effects of hydrogen gas composition, temperature, current density, and anode catalyst on fuel cell performances were examined in this study. 相似文献
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A complete three-dimensional and single phase computational dynamics model for annular proton exchange membrane (PEM) fuel cell is used to investigate the effect of changing gas diffusion layer and membrane properties on the performances, current density and gas concentration. The proposed model is a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations are solved in a single domain; therefore no interfacial boundary condition is required at the internal boundaries between cell components. This computational fluid dynamics code is used as the direct problem solver, which is used to simulate the two-dimensional mass, momentum and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC that cannot be investigated experimentally. The results show that by increasing the thickness and decreasing the porosity of GDL the performance of the cell enhances that it is different with planner PEM fuel cell. Also the results show that by decreasing the thickness of the membrane the performance of the cell increases. 相似文献
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操作参数对PEM燃料电池中水迁移的影响 总被引:4,自引:1,他引:3
质子膜内水分和阴极多孔电极中液态水含量是PEM燃料电池正常运行的控制因素。本文给出了一个用于研究PEM燃料电池内水迁移的稳态、等温、两相流模型。模型耦合了连续方程、动量守恒方程和物质守恒方程,以及水在质子膜中传递方程。运用试验结果验证了模型的有效性。分析模拟结果表明,增大系统操作压力、升高电池操作温度和降低加湿温度将会使质子膜中水的净迁移通量增大;增大操作压力、降低操作温度和升高加湿温度会增加阴极CTL与GDL界面上液态水含量。 相似文献
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A novel design and micro-fabrication were developed for micro-proton exchange membrane (PEM) fuel cell stack bipolar plates with cross section of 5 cm2 and thickness of about 650 μm. Copper metals were used to make bipolar plates (BPs) by using a LIGA-like micro-fabrication process of deep UV lithography in order to obtain SU-8 resist patterns/and SU-8 mould. Through two-sided exposure and development, copper metal bipolar plates with serpentine (meandering) flow field configurations for a micro PEM fuel cell stack, were fabricated and performance tests through polarization characteristics were conducted; this made it possible for the first time to consider copper sheets as suitable for BPs in micro PEM fuel cell stacks. 相似文献
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This paper demonstrates the mathematical and MATLAB simulation model of 1 KW (28.8Vdc) PEM fuel cell system with boost convertor and RL load to analyze the yield behavior in accordance to control the hydrogen fuel utilization. Two cases have been designed to evaluate the performance of this model. In the first case, fuel cell parameters are examined with and without a fuel regulator that controls the hydrogen fuel rate while in the second case, the operating temperature of a fuel cell stack is varied to observe the impact on the system. PEM fuel cell based power systems can become an alternate choice in the transportation sector to overcome contamination concerns, especially in South Asia where the environmental issues are at peak. The purpose of this work is to introduce such environmentally friendly system of transportation in South Asia, especially in Pakistan and this stack model can be used as a prototype for developing FC based motorbike as currently no practical models have been tested in this region. Therefore, this model has unique advantages over the existing in the literature. 相似文献