质子交换膜燃料电池作为军事通信电源的应用前景分析

介绍了军队现有的通信电源装备在未来战争中存在的不足，以及质子交换膜燃料电池的特点．通过对质子交换膜燃料电池和现有通信电源装备的对比，分析了质子交换膜燃料电池作为军事通信电源存在的巨大优势。     

燃料电池用氢气燃料的制备和存储技术的研究现状

质子交换膜燃料电池（PEMFC）进行反应的燃料是高纯度氢气,氢气的制备和存储是质子交换膜燃料电池能否应用和规模化应用的先决条件和关键技术。对燃料电池用氢气的制备、纯化、存储技术的研究现状进行了综合分析。     

甲醇质子交换膜燃料电池的水和热管理

甲醇质了换燃料电是未来最有希望获得工程应用的燃料电池，文章简述了燃料电的发电原理及其分类。对多孔电极，直接甲醇质子交换膜燃料电及甲醇改质质子交换膜燃料电作了分析和讨论，指出了对质子交换膜燃料电池系统进行水管理和热管理的重要性和必要性。     

船用燃料电池动力推进技术应用研究

燃料电池船舶电力推进技术是绿色船舶发展的重要方向,为拓展燃料电池技术在船舶领域内的应用,针对船用燃料电池电力推进系统开展相关研究。介绍了具有应用前景的两种燃料电池(质子交换膜燃料电池和固体氧化物燃料电池)的工作原理,基于船用燃料电池示范工程项目的分析,全面回顾和总结了燃料电池在船舶领域的研究现状和应用前景,并重点分析船用燃料电池电力推进系统的几种供电模式。基于大型远洋船舶的特点和燃料电池技术的现状,探讨了其运用的可行性和未来的突破方向。     

燃料电池发电的新进展

燃料电池是转换效率很高的一次性电能转换装置，早先主要应用于宇宙空间的探索方面，近几十年来随着材料工艺的不断发展，它的应用领域也不断得到了开拓，尤其在发电方面的开发上取得了较大进展。目前开发的燃料电池技术主要有以下类型：碱性燃料电池熔融碳酸盐燃料电池（MCFC）磷酸燃料电池（PAFC）固体聚合物质子交换膜燃料电池（PE）固体氧化物燃料电池（sooc）本文主要介绍后四种类型。1磷酸燃料电池（PAFC）磷酸燃料电池体积小，运行温度在200℃左右，发电效率达40％，工作时无噪声和振动，可动部件少，几乎不排放污染物，是开发…     

主流燃料电池技术发展现状与趋势

简要介绍了燃料电池的工作原理和系统结构,并结合关键技术以及在相关行业中的应用,对当今燃料电池的主流即质子交换膜燃料电池和固体氧化物燃料电池的发展现状进行了系统的介绍。同时,将两种主流燃料电池技术进行了对比分析,最终阐明了燃料电池技术未来的发展方向和应用前景。     

交指状流场质子交换膜燃料电池的流动特性

不同流场构型对质子交换膜燃料电池的流动特性和电池效率有重要的影响,因此流场的设计和理论研究是质子交换膜燃料电池研究的重要课题.发展了一个基于计算流体力学的稳态的三维数学模型,应用建立的模型对一个交指状流场设计的质子交换膜燃料单电池进行了数值研究,电池的电极面积大小为6.4×6.5 cm2,计算得到了电池的流场、局部电流密度和组分浓度等的空间分布,分析了其流动特性和传输机理.     

燃料电池在车辆中应用的技术难关

近年来,人们对能源匮乏和环境污染问题日益重视,使得燃料电池汽车的研究开发成为汽车行业的热点。阐述了燃料电池汽车的结构及质子交换膜燃料电池(PEMFC)是燃料电池汽车动力源的首选;对燃料电池汽车目前存在的技术难关及发展形势进行了综述。最后,预测随着燃料电池技术的进步,燃料电池最终将完全取代内燃机成为车辆动力装置。     

氢能知识系列讲座(9)微型燃料电池

一微型燃料电池电源微型燃料电池定义为功率为几瓦到十几瓦的燃料电池,用于日常微电器(图1)。它可以是直接甲醇燃料电池,也可以是改型的质子交换膜燃料电池。     

燃料电池知识——燃料电池在家庭中的应用

低温质子交换膜燃料电池或磷酸燃料电池几乎可以满足私人居户和小型企业的所有热电需求。目前，这些燃料电池还不能供小型的应用，美国、日本和德国仅有少量的家庭用质子交换膜燃料电池提供能源。质子交换膜燃料电池的能源密度比磷酸燃料电池大，然而后者的效率比前者高，且目前的生产成本也比前者便宜。这些燃料电池应该能够为单个私人居户或几家居户提供能源，[第一段]     

燃料电池技术进展

评价了国际燃料电池技术的发展,总结了燃料电池在工业中特别是汽车中的应用,燃料电池已成为我国能源领域最重要的研究项目之一,AFC,PAFC,MCFC,SOFS和PEMFC燃料电池的制造技术已掌握,但燃料电池的应用程序和技术水平还很低。     

The stability of Pt–M (M = first row transition metal) alloy catalysts and its effect on the activity in low temperature fuel cells: A literature review and tests on a Pt–Co catalyst

Carbon supported platinum metal alloy catalysts (Pt–M/C) are widely used in low temperature fuel cells. Pt alloyed with first-row transition elements is used as improved cathode material for low temperature fuel cells. A major challenge for the application of Pt–transition metal alloys in phosphoric acid (PAFC) and polymer electrolyte membrane (PEMFC) fuel cells is to improve the stability of these binary catalysts. Dissolution of the non-precious metal in the acid environment can give rise to a decrease of the activity of the catalysts and to a worsening of cell performance. The purpose of this paper is to provide a better insight into the stability of these Pt–M alloy catalysts in the PAFC and PEMFC environments and the effect of the dissolution of the non-precious metal on the electrocatalytic activity of these materials, in the light of the latest advances on this field. Additionally, the durability of a PtCo/C cathode catalyst was evaluated by a short test in a single PEM fuel cell.     

MCFC versus other fuel cells—Characteristics, technologies and prospects

Characteristics of molten carbonate fuel cell (MCFC) were critically compared to these of polymer electrolyte membrane fuel cell (PEMFC), alkaline fuel cell (AFC), phosphoric acid fuel cell (PAFC) and solid oxide fuel cell (SOFC). In comparison to the other fuel cells, the MCFC operates with the lowest current densities due to limited zones of effective electrode reactions and low solubilities of oxygen and hydrogen in molten carbonates; also it has a thickest electrodes–electrolyte assembly. In consequence, the applications of MCFC are almost limited to stationary power generators. Although the MCFC stationary power generators have now approached high technological level of precommercialization, in the future they may face a serious contest from SOFC and PEMFC, for which improvement of operational parameters is believed to be achieved easier.     

Issues in fuel cell commercialization

After 25 years of effort, the phosphoric acid fuel cell (PAFC) is approaching commercialization as cell stack assemblies (CAS) show convincingly low degradation and its balance-of-plant (BOP) achieves mature reliability. A high present capital cost resulting from limited cumulative production remains an issue. The primary PAFC developer in the USA (International Fuel Cells, IFC) has only manufactured 40 MW of PAFC components to date, the equivalent of a single large gas turbine aero-engine or 500 compact car engines. The system is therefore still far up the production learning curve. Even so, the next generation of on-site 40% electrical efficiency (LHV) combined heat-and-power (CHP) PAFC system was available for order from IFC in 1995 at US$ 3000/kW (1995). To effectively compete in the marketplace with diesel generators, the dispersed cogeneration PAFC must cost approximately US$ 1550/kW (1995) in the USA and Europe. At somewhat lower costs than this, dispersed cogeneration PAFCs will compete with large combined-cycle generators. However, in Japan, costs greater than US$ 2000/kW will be competitive, based on the late-1995 trade exchange rate of 100–105 Yen/US $). The perceived advantages of fuel cell technologies over developments of more conventional generators (e.g., ultra-low emissions, siting) are not strong selling points in the marketplace. The ultimate criterion is cost. Cost reduction is now the key to market penetration. This must include reduced installation costs, for which the present goal is US$ 385/kW (1995). How further capital cost reductions can be achieved by the year 2000 is discussed. Progress to date is reviewed, and the potential for pressurized electric utility PAFC units is determined. Markets for high-temperature fuel cell system (molten carbonate, MCFC, and solid oxide, SOFC), which many consider to be 20 and 30 years, respectively, behind the PAFC, are discussed. Their high efficiency and high-quality waste heat should make them attractive if technical progress and costs are acceptable. Commercialization of the proton-exchange membrane fuel cell (PEMFC) system is considered for stationary and mobile applications.     

质子交换膜燃料电池的建模与输出特性研究

质子交换膜燃料电池（PEMFC）作为一种重要的燃料电池,对于发展新型清洁能源以及改善环境有着重要的意义。针对其数学模型与仿真方法展开了研究。首先简单介绍了PEMFC的原理与特性,并构建了PEMFC系统的数学模型,模型主要包括燃料电池模型与气体改革者模型。然后以MATLAB的SIMULINK为平台依据上述模型建立了PEMFC的仿真模型,并利用仿真模型分析了PEMFC在负载变化情况下的输出特性以及燃料变化特性,结果表明,PEMFC能够快速地响应负载的变化,输出特性良好。     

Austenitic stainless steels in high temperature phosphoric acid

Austenite 316 L, 317 L, and 904 L stainless steels were investigated in 98% H₃PO₄ at 170 °C and they experienced passivation regardless of the purged gas. When polarized at 0.1 V (hydrogen) and 0.7 V (air) (phosphoric acid fuel cell (PAFC) environments), currents at the level of mA cm⁻² were observed. Compared to carbon composite under identical conditions, 904 L showed lower currents while 316 L and 317 L showed much higher currents.

X-ray photoelectron spectroscopy (XPS) depth profiles indicated that the surface film of the fresh steels consists of a Fe-oxide-rich outer layer and a Cr-oxide-rich inner layer. After being polarized in the PAFC environments, the Fe-oxide layer was selectively dissolved and Cr-oxide dominated the passive film. Phosphorus was incorporated into the film during the process, thus the chemical composition of the passive film differed from those formed in the polymer electrolyte membrane fuel cell (PEMFC) environments. The thicknesses of the stainless steels in the passive films in PAFC environments were estimated.     

Molten carbonate fuel cells in a future United Kingdom context

A 1983 report (Ref. 5 below) concluded that the phosphoric acid fuel cell (PAFC) would not be a likely candidate for electricity production in the U.K. market, except for specialized congeneration applications. We re-examine the potential of future fuel cells (FCs), of a few hundred kW to several MW for dispersed power production. In contrast to the PAFC, a number of variants of the molten carbonate fuel cell (MCFC) could be competitive in the U.K. market. On-going research programs, particularly in the U.S. and Japan, make it likely that the technical goals for the MCFC will be achieved.     

Technology learning for fuel cells: An assessment of past and potential cost reductions

Fuel cells have gained considerable interest as a means to efficiently convert the energy stored in gases like hydrogen and methane into electricity. Further developing fuel cells in order to reach cost, safety and reliability levels at which their widespread use becomes feasible is an essential prerequisite for the potential establishment of a ‘hydrogen economy’. A major factor currently obviating the extensive use of fuel cells is their relatively high costs. At present we estimate these at about 1100 €(2005)/kW for an 80 kW fuel cell system but notice that specific costs vary markedly with fuel cell system power capacity. We analyze past fuel cell cost reductions for both individual manufacturers and the global market. We determine learning curves, with fairly high uncertainty ranges, for three different types of fuel cell technology – AFC, PAFC and PEMFC – each manufactured by a different producer. For PEMFC technology we also calculate a global learning curve, characterised by a learning rate of 21% with an error margin of 4%. Given their respective uncertainties, this global learning rate value is in agreement with those we find for different manufacturers. In contrast to some other new energy technologies, R&D still plays a major role in today’s fuel cell improvement process and hence probably explains a substantial part of our observed cost reductions. The remaining share of these cost reductions derives from learning-by-doing proper. Since learning-by-doing usually involves a learning rate of typically 20%, the residual value for pure learning we find for fuel cells is relatively low. In an ideal scenario for fuel cell technology we estimate a bottom-line for specific (80 kW system) manufacturing costs of 95 €(2005)/kW. Although learning curves observed in the past constitute no guarantee for sustained cost reductions in the future, when we assume global total learning at the pace calculated here as the only cost reduction mechanism, this ultimate cost figure is reached after a large-scale deployment about 10 times doubled with respect to the cumulative installed fuel cell capacity to date.     

Step response analysis of phosphoric acid fuel cell (PAFC) cathode through a transient model

Transient state response analysis of phosphoric acid fuel cell (PAFC) cathode is important to understand various competitive processes like diffusion, reaction and product back diffusion occurring at various layers of the composite cathode. A two-dimensional unsteady state model for simulating PAFC cathode is developed as an extension of the previously developed steady-state model [S. Roy Choudhury, M.B. Deshmukh, R. Rengaswamy, A two-dimensional steady-state model for phosphoric acid fuel cells (PAFC), J. Power sources 112 (2002) 137–152]. The transient model is solved to study the impact of various parameters such as Tafel slope, diffusivity etc on the step response of the fuel cell. The effect of partial pressure variation in bulk gas for large sized PAFC cathode is also analysed. Trend analysis based on the model output is also experimentally verified using a small unit cell setup. The effect of various parameters on the settling time of the cathode, as revealed in this study, suggests possible development of a diagnostic tool employing such transient model.     

Comparison of efficiencies of low, mean and high temperature fuel cell Systems

Fuel cell systems are always said to show high electrical efficiency. The results achieved up to now, however, differ considerably, especially between the various fuel cell types all using natural gas as fuel. With the presented study the reasons for the different results and general potentials for fuel cell systems are highlighted. For that purpose several system lay-out concepts were elaborated for PEFC, PAFC and SOFC.The performed energy balance calculations for eight different plant concepts (three PEFC, two PAFC and three SOFC) for steady state operation with methane revealed that because of external reforming PEFC and PAFC systems are limited to about 67% and 70%, respectively, for the fuel utilisation. High temperature fuel cells can achieve at least 80% because of the possibility of internal reforming, or even over 90% in case of anode off-gas recycling. In combination with a cell voltage which is about 100 mV lower than that of MCFC and planar SOFC, PEFC can only achieve 38% of electrical net efficiency, PAFC 42% and tubular SOFC 54%. The latter is similar to MCFC, which is operated at higher cell voltage but lower fuel utilisation. The highest efficiency with up to 63% can be achieved with planar SOFC systems, because this concept allows high fuel utilisation together with high cell voltages.