共查询到19条相似文献,搜索用时 85 毫秒
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质子交换膜燃料电池(PEMFC)引射器设计通常需经过结构参数计算、计算域建模、网格划分和数值模拟等步骤,并经过多轮迭代得到一个性能较优的设计方案,所需时间成本较高。针对PEMFC引射器,通过Python编程语言将以上功能进行集成,自动计算引射器结构参数,并调用OpenFOAM软件中的blockMesh工具进行计算域建模、网格划分,以及rhoSimpleFoam求解器进行数值仿真验证,形成一套参数化的自动仿真设计工具。研究表明,该工具可显著提高PEMFC引射器设计开发的速度,从而促进汽车工业的发展。 相似文献
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质子交换膜燃料电池(PEMFC)的散热对其性能有很大影响。文章利用Gambit软件建立带冷却通道的PEMFC模型,使用计算流体力学软件Fluent中的PEM模块进行数值模拟计算。通过改变冷却通道进口处冷却水的流速和温度,对质子交换膜内温度和冷却水出口处温度进行了分析。数据表明,冷却水的流速和温度对PEM内温度分布都有一定影响。为使PEMFC正常稳定工作,冷却水流速不宜过小、温度不宜过低。 相似文献
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本文利用Gambit软件建立了带冷却通道的质子交换膜燃料电池(PEMFC)模型,使用计算流体力学软件Fluent中的PEM模块进行数值模拟计算。改变冷却通道进口处冷却水的流速和温度,对质子交换膜内温度和冷却水出口处温度进行了分析,其结果为PEMFC优化提供依据。 相似文献
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该文模拟常规矩形平行流场、正六边形平行流场和正六边形蜂窝状仿生学流场对质子交换膜燃料电池(PEMFC)性能的影响。通过对极化曲线、氧气和水分布、膜电流密度以及压降和寄生功率密度进行分析,结果表明:正六边形流场表现出良好的输出性能,且正六边形蜂窝状流场的电流密度比常规矩形平行流场和正六边形平行流场分别提升11.28%和4.95%。此外,常规矩形平行流场、正六边形平行流场和正六边形蜂窝状流场的氧气不均匀度分别为0.64、0.53和0.41,正六边形蜂窝状流场展现出更好的水和膜电流密度分布能力,进一步说明正六边形流场缓解了氧气、水和膜电流密度分布不均匀的问题。正六边形蜂窝状流场压降虽比常规矩形平行流场和正六边形平行流场分别增加40.0%和27.7%,有较高的寄生功率密度,但仍获得了最大的净输出功率密度。 相似文献
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为研究流道结构对质子交换膜燃料电池(PEMFC)反应气体质量传输及输出性能的影响,建立翅脉流道、叶脉流道及蛇形流道的三维PEMFC几何模型,并对比3种流道的反应气体浓度分布、压力分布及电流密度分布,最后对翅脉流道结构参数进行优化。结果表明,与蛇形流道、叶脉流道相比,翅脉流道能明显改善流道和扩散层内反应气体浓度分布的均匀性,有利于强化反应气体向催化层的质量传递;翅脉流道能减小气体压力分布梯度,使反应气体扩散更加充分;翅脉流道的平均膜电流密度更大,有利于促进电化学反应稳定进行;翅脉流道能改善PEMFC的输出性能,翅脉流道峰值功率密度比蛇形流道、叶脉流道分别提高7.72%和6.25%;减小翅脉流道的直流道长度或圆弧流道圆心角,可提升翅脉流道输出性能。 相似文献
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质子交换膜燃料电池的流道结构对反应气体的流动和压降等具有重要影响。受神经元结构启发,提出一种兼顾径向流道和仿生流道在压降和气体分布均匀性优点的新型仿生流道结构。通过COMSOL软件模拟研究该新型流道的分支数(2~9)对质子交换膜燃料电池的性能曲线、阴极氧浓度分布、水浓度分布及压降的影响。结果表明:增加流道分支数可提高质子交换膜燃料电池的输出性能,其中9分支流道的峰值功率密度最大,为0.32 W/cm2,相比于2分支流道增加了的146.15%;分支数的增加也会提高氧浓度分布的均匀性,阴极气体扩散层与催化层交界面处的平均氧浓度从0.44 mol/m3提高到1.42 mol/m3,氧气不均匀度从2.13降低至0.90;分支数的增加也明显改善了弧形流道内的水浓度分布。此外,随着流道分支数从2增加到9,流道压降从38.57 Pa递减至4.47 Pa,质子交换膜燃料电池的输出功率从0.40 W递增到1.56 W。 相似文献
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为了改善质子交换膜燃料电池(PEMFC)的性能,采用流道内使用挡板堵塞的方法,以增强反应气体向催化层的传质。建立了一个三维、两相、稳态的PEMFC数值模型,研究了凸字排布、顺排和逆排这3种不同阴极流道挡板的排布方式对PEMFC性能的影响,并与无挡板常规流场进行对比,然后在最佳排布方式的基础上研究了挡板形状(矩形、梯形和半圆形)对PEMFC性能的影响。结果表明:PEMFC阴极流道挡板顺排性能最好,相较于无挡板常规流道,净功率提升了14.3%;使用梯形挡板的PEMFC性能最好,相较于无挡板常规流道,净功率提高了16.4%。 相似文献
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为深入研究质子交换膜燃料电池内电荷传递的规律,发展了一个三维的单相流、非等温数学模型,模型考虑了电子在催化层和扩散层、质子在催化层和质子交换膜中的传递。通过计算得到了电池内电位和电流密度的空间分布,分析了不同电极结构参数下电流密度的分布和最终造成的性能差异。结果表明,欧姆电位的下降主要发生在膜相电位,而碳相电位的下降几乎可以忽略不计;电流密度在流道与集电极交界处出现"火焰形"累积效应;改变电池的结构对电池性能影响不大,应结合加工成本和电流密度分布综合考虑。 相似文献
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利用CFD方法对采用交指型流道质子交换膜燃料电池阴极的传质过程进行数值模拟,得到了阴极扩散层内氧气和水蒸汽质量浓度的分布特性,探讨了电池结构参数和操作条件对电池性能的影响。 相似文献
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A validated 3 dimensional (3D) computational fluid dynamics model of a single cell proton exchange membrane fuel cell (PEMFC) was used for investigating convergence criteria. The simulation study was carried out using the commercial PEMFC simulation module built in to ANSYS FLUENT 12.1 software package and compared with published experimental data. Convergence data up to 19,000 iterations were collected in order to establish expectations for convergence errors and differences in convergence rates for different boundary conditions. Species mass fluxes and current density were used to perform a dual verification of experimentally verifiable simulation predictions. The results of the simulation showed that convergence trends were consistent for different boundary conditions and that the solution trends asymptotically to a final value with species mass flux errors approaching to constant values. The data were used to establish convergence criteria for future 3D PEMFC simulations where residual monitoring alone is insufficient to ensure convergence. 相似文献
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Proton exchange membrane fuel cell (PEMFC) performance degrades when carbon monoxide (CO) is present in the fuel gas; this is referred to as CO poisoning. This paper investigates CO poisoning of PEMFCs by reviewing work on the electrochemistry of CO and hydrogen, the experimental performance of PEMFCs exhibiting CO poisoning, methods to mitigate CO poisoning and theoretical models of CO poisoning. It is found that CO poisons the anode reaction through preferentially adsorbing to the platinum surface and blocking active sites, and that the CO poisoning effect is slow and reversible. There exist three methods to mitigate the effect of CO poisoning: (i) the use of a platinum alloy catalyst, (ii) higher cell operating temperature and (iii) introduction of oxygen into the fuel gas flow. Of these three methods, the third is the most practical. There are several models available in the literature for the effect of CO poisoning on a PEMFC and from the modeling efforts, it is clear that small CO oxidation rates can result in much increased performance of the anode. However, none of the existing models have considered the effect of transport phenomena in a cell, nor the effect of oxygen crossover from the cathode, which may be a significant contributor to CO tolerance in a PEMFC. In addition, there is a lack of data for CO oxidation and adsorption at low temperatures, which is needed for detailed modeling of CO poisoning in PEMFCs. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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A proton exchange membrane fuel cell (PEMFC) cogeneration system that provides high-quality electricity and hot water has been developed. A specially designed thermal management system together with a microcontroller embedded with appropriate control algorithm is integrated into a PEM fuel cell system. The thermal management system does not only control the fuel cell operation temperature but also recover the heat dissipated by FC stack. The dynamic behaviors of thermal and electrical characteristics are presented to verify the stability of the fuel cell cogeneration system. In addition, the reliability of the fuel cell cogeneration system is proved by one-day demonstration that deals with the daily power demand in a typical family. Finally, the effects of external loads on the efficiencies of the fuel cell cogeneration system are examined. Results reveal that the maximum system efficiency was as high as 81% when combining heat and power. 相似文献