共查询到19条相似文献,搜索用时 109 毫秒
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利用落塔开展了不同重力情况下质子交换膜燃料电池性能的实验研究.对常重力和微重力条件下质子交换膜燃料电池发电时其阴极蛇形流场内部的两相流动开展了可视化现场观测.对重力因素对质子交换膜燃料电池内部传质过程的影响进行了分析和讨论.实验结果表明:在常重力环境中,液态水堆积在竖置流道的底部,无法有效排出.聚集在流道内的液态水与反应气体在流道内形成气/液两相流动.在微重力环境中,液态水在气体推动力的作用下从流道的底部上升并沿流道向出口流动.聚集在流道内的液态水排除后,减小了反应气体(氧气)从流道向催化层的传递阻力,从而使质子交换膜燃料电池的性能得到提高. 相似文献
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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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《Current Applied Physics》2020,20(5):686-695
To improve the diffusion performance of reactive gas, a porous copper fiber sintered sheet (PCFSS) was fabricated and used as the flow field for proton exchange membrane fuel cell (PEMFC). The pressure and flow velocity distribution of the reaction gas in the PCFSS was firstly compared with the serpentine flow field by using the Fluent simulation software. Our results showed that the superiority of PCFSS in the uniformity of gas diffusion was observed. The total resistance of PEMFC with PCFSS in different porosities was obtained. And the advantages of PCFSS in electronic transmission were found by comparing with the serpentine flow field. Besides, the influences of different operating conditions and different porosities of porous flow fields on the performance of PEMFC were experimentally investigated. With the cell temperature of 70 °C as well as the humidification temperature of 60 °C, a PEMFC with PCFSS of 70% porosity exhibited better performance. 相似文献
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Recently, the requirements for cellular phones, portable computers, and digital cameras have increased dramatically. A portable electric power supply with long duration and high performance is needed for these products. A proton exchange membrane fuel cell (PEMFC) can meet these requirements and becomes one of the best candidates for a portable power source. It is impossible to install an extra humidifier into small-scale portable electric products for PEMFC water management. This article presents a series of experiments to investigate the performance of a single PEMFC. The effects of different operating conditions on cell performance, including the temperature, pressure, and inlet fuel/oxidant flow rate, are discussed. The test results confirm the positive effect of these parameters on cell performance and power output. The interaction effect of temperature--flow rate is related to the cell humidity, and is important for cell performance. The dry-out problem for a PEMFC is also significantly revealed in the experiments for higher cell temperature and flow rate. Current experimental results can provide useful information for investigating the cell performance and its operating effects under dry fuel/oxidant flow conditions and as a benchmark for simulation work in future studies. 相似文献
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质子交换膜燃料电池及其发电系统模拟 总被引:3,自引:0,他引:3
本文通过质子交换膜燃料电池单电池子模型、布气管子模型、流场子模型相互耦合,对电池堆传热传质过程加以数值模拟,得到单电池及电池堆的流场、温场、当地电流密度分布、过电位分布;给定平均电流密度下单电池及电池堆输出电压等参数;并比较了平均电流密度、布气管尺寸对电池输出电压、堆内反应物分配的影响;在此基础上,对整个PEMFC发电系统进行流程模拟和参数分析,得到平均电流密度、重整器S/C等主要参数对系统性能影响. 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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Effects of flow field design on water management and reactant distribution in PEMFC: a review 总被引:1,自引:0,他引:1
The performance of a proton exchange membrane fuel cell (PEMFC) stack is affected by many factors, including the operating conditions, flow field and manifold design, and membrane performance. To achieve the desired PEMFC performance, the reactant must be uniformly distributed and effectively diffused into the catalyst layer for the electrochemical reaction. Water management and reactant distribution in fuel cells are crucial because they affect the distribution and diffusion rate of the reactant. This paper reviews the important research results reported in recent years related to the effects of water and reactant distribution on the performance and life span of PEMFC stacks. 相似文献
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质子交换膜燃料电池波浪形平行流场研究 总被引:1,自引:0,他引:1
质子交换膜燃料电池的传统平行流场存在着传质不佳,高电流密度下大量的液态水无法及时排出导致性能急剧下降等问题。提出了一种新型的波浪形平行流场并利用数值模拟方法优化了波浪形平行流场的几何结构。结果表明,相比于传统平行流场,波浪形平行流场不仅能够有效促进氧气的传输,还能加快液态水的去除,采用波浪形平行流场的PEMFC最大输出功率相比于传统设计提升了30.7%,当波浪长度和波幅分别为4 mm和0.8 mm时,采用新型流场的PEMFC性能达到最佳。 相似文献
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在质子交换膜燃料电池(PEMFC)的阴极流道中安装阻块可以强化氧气传输,提升电池性能,但不同位置的阻块高度对电池性能的影响程度不同。本文建立了一个三维、两相、稳态的PEMFC数值模型,对阴极流道安装有阻块的PEMFC进行了数值模拟,并结合全因子设计法研究了不同位置的阻块高度对电池性能的影响程度。此外,基于敏度分析结果,采用遗传算法对阻块高度进行了优化。结果表明:越靠近出口位置的阻块,其高度变化对低电压下的电池功率的影响程度越大。增加靠近出口位置的阻块高度可以促进催化层反应物的均匀分布,提高催化剂的利用率,最大程度地提升电池性能。当组块高度H1和高度增量ΔH分别为0.9537 mm和0.009 mm时,PEMFC性能最佳,与未安装阻块相比,电池最大净功率提高了18.45%。 相似文献
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Jae-Dong Kim Yong-Il Park Koichi Kobayashi Masayuki Nagai Masayuki Kunimatsu 《Solid State Ionics》2001,140(3-4):313-325
The CO tolerance of a proton exchange membrane fuel cell (PEMFC) was investigated by ac impedance spectroscopy. The impedance of the fuel cell could be obtained by feeding oxygen into the cathode side and simulated gas into anode side. Furthermore, the anode impedance could be obtained by feeding hydrogen into the cathode side and simulated gas into anode side. The CO gas had a greater effect on the charge transfer reaction (high frequency arc) and hydrogen dissociative chemisorption (medium frequency arc) but little effect on the low frequency arc. Although the cathode impedance is a main part at high temperature, irrespective of CO concentration (≤100 ppm), the impedance of the full cell depends on anode impedance at low temperature and high CO concentration. It was found that CO gas has little effect on cathode impedance. 相似文献