质子交换膜燃料电池

因其具有独特的优点，质子交换膜燃料电池（PEMFC）的市场前景很好，国际上已经形成了一股研究开发热潮。电催化剂、质子交换膜、双极板、燃料、水管理、热管理是质子交换膜燃料电池的关键技术。文章介绍了PEMFC的特点及开发应用状况，综述了PEMFC的研究进展。     

质子交换膜燃料电池膜电极组件温度分布的神经网络预测模型

质子交换膜燃料电池膜电极组件表面的温度分布会影响质子交换膜燃料电池的性能、寿命和可靠性.为探究质子交换膜燃料电池传热规律,本文提出了一种基于神经网络的质子交换膜燃料电池膜电极组件温度分布的预测模型.本研究选取径向基函数神经网络(RBF)和广义回归神经网络(GRNN)两种神经网络,以电流密度、温度点的位置作为网络输入,不同位置的温度作为网络输出,对平行流道质子交换膜燃料电池、蛇形流道质子交换膜燃料电池分别建立了神经网络预测模型.结果显示,RBF神经网络预测的均方根误差平均为0.464、平均绝对百分误差为1.179％,GRNN神经网络预测的均方根误差平均为0.7155、平均绝对百分误差为2.27％;相较于GRNN神经网络,RBF神经网络精度更高;基于RBF神经网络的平行流道质子交换膜燃料电池膜电极组件温度分布预测模型预测值与96％的实验值的相对误差在5％以内.基于RBF神经网络的蛇形流道质子交换膜燃料电池膜电极组件温度分布预测模型预测值与95％的实验值的相对误差在5％以内.     

基于GT_COOL的质子交换膜燃料电池发动机冷却系统仿真

运用GT-COOL软件建立了30 kW质子交换膜燃料电池发动机冷却系统的一维仿真模型,该模型主要由电堆、水泵、风扇和散热器子模型组成。利用该模型对燃料电池在各工况点的冷却系统散热特性进行仿真,并将仿真结果与实验数据进行比较分析,仿真结果与实验值的相对误差在5%以内,表明所建模型是合理的。     

四流道蛇形结构质子交换膜燃料电池温度分布数值模拟

为研究温度对质子交换膜燃料电池性能的影响,运用多物理场直接耦合分析软件COMSOL Multiphysics,对不同电池温度的四流道蛇形流场质子交换膜燃料电池进行了数值模拟。模拟得到了不同电池温度下垂直膜电极平面以及电池中心处从阳极流道到膜,再到到阴极流道的温度变化情况;还得到了电池温度为353K时,电池入口处、中心处和出口处从阳极流道到阴极流道相应位置点的温差变化。对模拟结果进行分析和比较后发现:电池内部温度的升高与电池本身的原始温度存在线性变化关系;电池入口处、中心处和出口处的温度变化趋势存在差异,且电池入口处温升最大,中心处次之,出口处温升最小;随着电池温度的升高,电池因内部反应所产生的热量减少。模拟结果对质子交换膜燃料电池的性能优化有重要意义。     

质子交换膜燃料电池的开发应用

质子交换膜燃料电池（PEMFC）作为一种新一代的发电技术,已成为世界各国特别是发达国家的研发重点被纳入发展规划,应用领域从特殊应用到商品化、产业化不断开拓.但PEMFC的产业化和推广应用受关键材料和工艺技术的制约,为了加速我国PEMFC的发展,今后必须投入足够的财力,组织相关学科的人才,制定可行的规划,加大科研力度.     

质子交换膜燃料电池可靠性分析

可靠性是质子交换膜燃料电池(PEMFC)的重要指标，文中定性分析了PEMFC组成元件、装配工艺和工作过程的可靠性。提出了提高PEMFC可靠性的措施和可靠性的设计原则。     

质子交换膜燃料电池自增湿研究进展

概述了质子交换膜燃料电池自增湿研究状况，指出自增湿的出发点是有效利用电池阴极过程生成水。综述了薄电解质膜、新型自增湿膜、自增湿流场结构三种方法的研究进展及适用空间。对自增湿技术发展前景进行了探讨。     

质子交换膜燃料电池的研发动态

质子交换膜燃料电池(PEMFC)因其独特的优点具有很好的市场前景,国际上已经形成了一种研究热潮.电催化剂、质子交换膜、双极板、燃料、水管理、热管理是其关键技术.文章介绍了PEMFC的特点及开发应用状况,综述了PEMFC的研究进展.     

质子交换膜燃料电池的应用研究

质子交换膜燃料电池（PEMFC）与其它燃料电池一样，是利用氧化、还原反应产生电子流的装置。它以氢为燃料、以氧为氧化剂，把化学能直接转化为电能。由于该电池以氢气为燃料，生成的产物是水，对环境造成的污染少。在化石燃料日益短缺及环境污染日益严峻的条件下，燃料电池倍受关注。而近几年发展起来的质子交换膜燃料电池（PEMFC）由于其无污染、发电效率高等特点正受到各国各部门的重视。主要评述了PEMFC的主要用途、工作原理及其实现商业化所面临的几个主要问题。     

质子交换膜燃料电池经验模型

分析并总结现有PEMFC经验模型相互之间的关系,并运用Saber仿真软件,结合一定的电化学原理和热动力学原理建立一个较为简单的PEMFC经验模型,模拟其稳态和动态特性。结果表明:这些模型能很好地反映实际燃料电池的电气特性,对后级电力电子装置的设计具有重要指导意义。     

质子交换膜燃料电池的稳态分析

通过建立质子交换膜燃料电池稳态模型,考察了电堆温度和反应压力对电堆性能的影响。仿真结果表明,升高电堆温度使得氢气分压和氧气分压下降,但氢气分压下降的更快;在电堆工作温度范围内,电堆温度升高,热动力电势、欧姆极化电势和活化极化电势均下降,但电堆总输出电压上升;提高阴极侧压力有利于提高热动力电势,同时使得活化极化电势降低,有利于电堆整体性能的改善;提高阳极侧压力对电堆性能改善影响不大。     

The effect of materials on proton exchange membrane fuel cell electrode performance

This paper describes the optimisation in the fabrication materials and techniques used in proton exchange membrane fuel cell (PEMFC) electrodes. The effect on the performance of membrane electrode assemblies (MEAs) from the solvents used in producing catalyst inks is reported. Comparison in MEA performances between various gas diffusion layers (GDLs) and the importance of microporous layers (MPLs) in gas diffusion electrodes (GDEs) are also shown. It was found that the best performances were achieved for GDEs using tetrahydrofuran (THF) as the solvent in the catalyst ink formulation and Sigracet 10BC as the GDL. The results also showed that our in-house painted GDEs were comparable to commercial ones (using Johnson Matthey HiSpec™ and E-TEK catalysts).     

Semi-analytical proton exchange membrane fuel cell modeling

Mathematical techniques are presented which allow for analytical solutions of the catalyst layer transport and electrochemical problem in PEM fuel cells. These techniques transform the volumetric reaction terms to boundary flux terms, thereby eliminating the need for computational solving of the catalyst layer problem. The result is a semi-analytical fuel cell model—a computational model that entails analytical rather than computational catalyst layer solutions. This helps to alleviate the meshing difficulties inherent in the catalyst layers caused by large geometric aspect ratios, and hence reduce the computational requirements for fuel cell models.     

Sliding-mode-based temperature regulation of a proton exchange membrane fuel cell test bench

The temperature regulation of a cooling system of a PEMFC (Proton Exchange Membrane Fuel Cell) test bench is studied in this paper. Because of the unique configuration which is dedicated for cold start experiments, the operation at nominal temperature is unstable with a simple PI controller. A sliding-based control strategy is applied to suppress the temperature fluctuation. Firstly the structure of the cooling system is demonstrated and the cause of temperature fluctuation is analyzed. Then, a physics-based model of the cooling system is proposed on the Matlab/Simulink platform and validated with experimental data. Based on the model, a Sliding-mode controller with Extended Kalman Filter (EKF) is designed to regulate the temperature. The simulation results showed that the controlled system performed satisfactorily. Furthermore, when applied to the real system, the controller's real-time performance fulfills the test bench criterion. Experimental data show that the coolant temperature at the outlet of the fuel cell stack is kept in a range within ±1 °C, disregarding the heat generated at various working condition.     

A cell voltage equation for an intermediate temperature proton exchange membrane fuel cell

A zero dimensional isothermal model equation for a single Intermediate Temperature Fuel Cell is developed and expressed as a semi-empirical relationship for cell potential as a function of current density. The model is applicable to fuel cells in which reactants and water product are in the gaseous or vapour phase. The model considers the influence of electrode kinetics using the Butler Volmer equation, over the complete voltage range, Ohmic potential losses and the effect of mass transport through electrolyte films covering catalyst layers on kinetics and thermodynamics. The model is used to simulate the variation in polarisation behaviour of a hydrogen fuel cell using a phosphoric acid doped PBI membrane. Performance predictions using published parameters for electrode kinetics, thermodynamics, conductivity and mass transport are compared with data from a laboratory fuel cell. Agreement between the model predictions and experimental data are good and indicate the relatively simple cell voltage model equation is suitable for estimating fuel cell voltage and power performance.     

Applications of proton exchange membrane fuel cell systems

Proton exchange membrane fuel cells (PEMFCs) have recently passed the test or demonstration phase and have partially reached the commercialization stage due to the impressive worldwide research effort. Despite the currently promising achievements and the plausible prospects of PEMFCs, there are many challenges remaining that need to be overcome before PEMFCs can successfully and economically substitute for the various traditional energy systems. With the many promising research efforts in overcoming these challenges, the most important tools for the commercialization of PEMFCs will be the technical data and information from a real PEMFC application test. For these reasons, this paper introduces and discusses the remaining challenges and some of the latest research on the application test of PEMFC to real systems such as transportation, residential power generation and portable computers. In addition, this paper describes and summarizes the relative prospects and the competitive force of PEMFCs in these fields.These prospects primarily depend on stable and economical high-purity hydrogen supplies, the scale of application, the existence of more efficient competitive power sources and the social viewpoints such as the health and environment benefits as well as infrastructural aspects associated with traditional power supply and demand. The review shows that PEMFC have the most promising applications to buses, recreation vehicles, and lightweight vehicles. Without doubt, the technology for a stable supply of high-purity hydrogen along with the corresponding infrastructure is essential for the success of PEMFC in various application fields.     

Cold start of proton exchange membrane fuel cell

In this review, “cold start” is defined as the startup of proton exchange membrane (PEM) fuel cells from subfreezing temperatures. Problems occurring during the cold start pose some of the remaining barriers to commercial applications of PEM fuel cells in transportation, stationary, auxiliary and portable systems. Fundamental studies of transport phenomena are critical to a better understanding of the mechanisms of cold start and offer ultimate solutions to resolving cold-start issues. In this review, experimental studies are discussed, focusing on output performance degradation, water and ice visualization, and component damages during a cold start. Analytical, numerical, and microscopic models and their results are also discussed. One of the emphases is on transport phenomena relevant to cold starts, including supercooling, phase change and transport of water in the membrane, catalyst layer, microporous layer, and gas diffusion layer. Another emphasis is placed on the strategies utilized to optimize cold-start processes for improved performance. The strategies include material designs of the components, cell/stack structures, and startup mode/load controls. It is shown that all of the effective strategies to mitigating cold-start problems derive from a basic understanding of the transport mechanisms during a cold start. It is also suggested that future models for this problem should place a great deal of attention in supercooling phenomena and water phase-change and transport in multilayer porous media. Lastly, more advanced experimental methods, such as real-time water/ice visualization and cryogenic microscopy, are needed to validate emerging theories and models.     

Investigation of mechanical vibration effect on proton exchange membrane fuel cell cold start

A three-axis vibration platform is first constructed and utilized in the investigation of the effects of mechanical vibration on the cold start performance of a proton exchange membrane (PEM) fuel cell. In addition, an intermittent pattern of purging is adopted to improve the purging efficiency. The applied vibrations are found to promote water dispersion, but ultimately do not enhance water removal. Under subzero conditions (−13 °C), the vibration of the fuel cell improves cold start performance via delayed freezing, especially when vibrating at the fuel cell natural frequency (10 Hz). With an increase in vibration amplitude, the freezing rate is found to be slow and eventually plateau. Finally, the vibration in the vertical axis is found to play a positive role in improving cold start performance; the effects of other orientations depend on the startup temperature. The result of cold start under vibration might indirectly prove the existence of super-cooled water.     

Cross-linked PEEK-WC proton exchange membrane for fuel cell

The low cost proton exchange membrane was prepared by cross-linking water soluble sulfonated-sulfinated poly(oxa-p-phenylene-3,3-phthalido-p-phenylene-oxa-p-phenylene-oxy-phenylene) (SsPEEK-WC). The prepared cross-linked membrane became insoluble in water, and exhibited high proton conductivity, 2.9 × 10⁻² S/cm at room temperature. The proton conductivity was comparable with that of Nafion^® 117 membrane (6.2 × 10⁻² S/cm). The methanol permeability of the cross-linked membrane was 1.6 × 10⁻⁷ cm²/s, much lower than that of Nafion^® 117 membrane.     

An improved thermal control of open cathode proton exchange membrane fuel cell

Proton exchange membrane fuel cell is a well-known technology that has shown high efficiency and performance as a power system compared to conventional sources such as internal combustion engines. Especially, open cathode proton exchange membrane is growing more popular thanks to its simple structure, low cost and low parasitic losses. However, the open cathode fuel cell performance is highly related to the operating temperature variation and the airflow rate which is adjusted through the fan voltage. In this regard, the present study investigates the thermal management of an open cathode proton exchange membrane fuel cell. The objectives are the stack performance improvement and the stack degradation prevention. Indeed, a safety and optimal operating zone governed by the load current, the stack temperature and the air stoichiometry, is designed. This optimal operating zone is defined based on the system thermal balance and the operating constraints. Hence, the proposed control strategy deals concurrently with the stack temperature regulation and the air stoichiometry adjustment to guarantee the goals achievement. The performance of the proposed control strategy is verified through experimental studies with different operating conditions and results prove its efficiency. To properly design an appropriate control strategy, a multiphysic fuel cell model is developed based on acausal approach by mean of Matlab/Simscape and experimentally validated.