重整条件对SOFC电池堆性能影响的实验研究

以天然气为燃料,建立了外部重整固体氧化物燃料电池(SOFC)系统的实验平台,在不同重整工艺参数条件下,对电池堆的性能进行了测试,得到了电池堆性能参数的变化趋势,分析了水碳物质的量比(即水碳比)、重整温度、重整方式以及天然气体积流量对SOFC电池堆性能的影响.结果表明:在不同的电流密度下,采用水蒸气重整方式电池堆的输出功率高于自热重整方式电池堆的输出功率;当电池堆工作温度设定恒值为1 023K时,随着水碳比的增大,电池堆的输出功率逐渐提高,随着天然气体积流量的增加,电池堆的输出功率显著提高.     

天然气重整SOFC/MGT混合分布式供能系统性能分析

针对固体氧化物燃料电池(SOFC)与微型燃气轮机(MGT)构成的混合分布式供能系统,首先建立了一种管式SOFC准二维数值模型,优化了辐射计算,提高了热传递模型的准确性;考虑了CO及H2同时作为燃料参加电化学反应,并完善了损失计算模型;最后采用所发展的系统性能预测模型,分别在内部重整和外部重整情况下,预测比较了两种SOFC/MGT混合系统的性能,结果表明外部重整系统在系统输出功率、CO2排放以及热应力分布方面都比内部重整系统具有优势,然而这种轻微的优势是需要额外增加外部重整器的设备投资换取的。     

住宅用固体氧化物燃料电池热电联供系统的设计与分析

固体氧化物燃料电池(SOFC)发电技术是一种能够直接将燃料中的化学能转化电能的绿色高效的新能源技术。将SOFC作为分布式能源的发电装置运用在家用热电联供系统,具有综合效率高、无污染、无噪声等优点。文章搭建了天然气重整制氢-SOFC热电联供系统,完成了基于SOFC的家用热电联供系统的设计与分析。文章根据用户夏冬季热电消耗数据,提出了一种以用户电消耗为核心的家用热电联供系统的运行方案,同时给出了蓄电池容量和水箱容积的推荐参数。与传统火力发电系统相比,采用天然气的SOFC热电联供系统更加节能。     

基于固体氧化物燃料电池的高效清洁发电系统

  目的  固体氧化物燃料电池（SOFC）是一种尖端技术,可通过电化学反应将碳氢燃料中的化学能转化为电和热,具有燃料来源广、发电效率高、余热品质高、运行安静、排放低、可模块化安装等优点,是实现化石能源高效清洁利用的有效途径之一。  方法  文章阐释了SOFC发电原理,介绍了国内外SOFC技术和产业化现状,分析了基于SOFC的分布式热电联供、联合循环发电以及煤气化燃料电池发电技术（IGFC）新一代发电系统应用场景。  结果  通过燃料电池发电技术路线和产业化现状研究,浅析了目前存在的问题,并结合我国资源禀赋和对高效清洁发电装置的市场需求,对该领域的未来发展趋势进行了展望。  结论  对比国内外在SOFC领域的技术差距,基于国内在SOFC电堆核心材料方面的优势,加大对SOFC系统集成技术攻关,为新一代以高温燃料电池为核心的清洁高效发电产业奠定基础。     

固体氧化物燃料电池直接内重整的模型研究进展

固体氧化物燃料电池（SOFCs）是一种通过电化学氧化反应直接将化学能高效率地转化为电能的装置,在大规模发电、联产以及一体化燃料升级等可再生能源系统领域具有广阔的市场前景。为进一步拓宽SOFCs的应用场景,降低运行成本,直接内重整（DIR）技术可将CH4等烷烃类物质在阳极催化生成H2,减少了燃料预处理要求且提高了转化效率,是目前SOFCs研究领域的热点之一。为了优化该技术的系统设计和操作条件,模型模拟的研究可显著减少实验工作量,并为其提供理论支撑和指导性建议。通过DIR-SOFC系统的模型模拟,结合场分布、动力学参数等,可以量化评估系统内的反应,从而了解其物理、化学过程的复杂性。本文总结了DIR-SOFC建模工作的现状,介绍了体积平均模型和针对微观结构的模型;重点讨论多尺度数学模型,对现有研究中的反应动力学过程描述、“能量-质量-动量”平衡方程、“1D-2D-3D”DIR-SOFC单元描述等进行了综述,能更好地评估变量对DIR的影响;对DIR-SOFC模型中不同液体燃料的重整反应及相关的反应动力学参数进行总结;指出现有模型的不足,并对DIR-SOFC系统模型的未来发展进行展望,使模型更加...     

固体氧化物燃料电池与燃气轮机联合发电系统模拟研究

固体氧化物燃料电池(SOFC)是一种高效低污染的新型能源。建立了以天然气为燃料的固体氧化物燃料电池和燃气轮机(GT)联合发电系统的计算模型,并对具体系统进行计算。结果表明：SOFC与GT组戍的联合发电系统,发电效率可达68％(LHV);加上利用的余热,整个系统的能量利用率可以超过80％。文中还分析了SOFC的工作压力、电流密度等参数对系统性能的影响,提高工作压力,可以增加电池发电量,提高系统的发电效率;而电流密度的增大将使SOFC及整个系统的发电量降低。     

固体氧化物燃料电池镍基阳极积碳机理及性能提升策略研究进展

固体氧化物燃料电池(solid oxide fuel cell,SOFC)是一种高效清洁的能量转化装置,具有效率高、环境友好、燃料适用灵活等突出优势,有望成为新一代清洁能源.当前,SOFC阳极使用最广的是镍基材料,这得益于其低成本、优异的化学稳定性和催化效果等优点.但是,当SOFC以碳氢化合物为燃料时,镍基阳极上会产生大量积碳,严重破坏阳极结构,进而影响电池性能和运行稳定性.因此,探究固体氧化物燃料电池镍基阳极积碳机理与改善方法具有重要的科学意义.基于近年来SOFC镍基阳极积碳过程的前沿研究,本文综述了SOFC镍基阳极积碳机理及各种积碳改善策略的最新研究进展,并从优化阳极材料组成和操作条件等方面归纳总结了几种SOFC阳极材料的研究现状和未来发展方向,以期为高性能SOFC阳极材料的开发提供有价值的参考.     

燃料重整固体氧化物燃料电池发电系统性能分析及多变量参数优化

以燃料重整的固体氧化物燃料电池发电系统为研究对象,通过数值模拟方法对固体氧化物燃料电池发电系统的性能、(火用)损、(火用)效率以及多变量运行参数优化进行了分析。研究结果表明：重整反应中燃料利用系数、电池工作温度、水碳比、电堆电流密度等参数对系统性能影响显著;电堆工作在不同电流密度下都有其对应的最佳工作温度、最佳燃料利用系数工况点;水碳比会改变重整反应产氢量,从而影响电化学反应速率,空气加热器的(火用)损所占份额最大;优化后的系统效率及(火用)效率为0.480 9和0.462 6,效率提升约4%。     

基于甲醇重整的燃料电池与有机朗肯循环耦合热电联产系统性能分析

为了解决氢能储运困难问题,实现甲醇燃料的高效和清洁利用,提出一种基于甲醇重整的燃料电池与有机朗肯循环耦合热电联产系统。在所提出系统中,甲醇与水在中低温条件下发生重整反应生成富氢合成气。在燃料电池中,合成气的化学能转化为电能,燃料电池的高温废气不仅用于加热空气也可作为有机朗肯循环的热源,实现了能量的梯级利用。在系统稳定运行的条件下,对新系统进行能量分析、■分析和经济性分析。结果表明：系统输出电力为147.372 kW,系统总效率为51.29%,系统■效率为40.56%;新系统的动态回收周期为4.97 a;在15年的运营周期内,净现值为127.94万元。     

固体氧化物燃料电池技术进展及其在汽车上的应用

固体氧化物燃料电池（SOFC）采用的是全固体的电池结构,可进行甲烷、燃料油（汽油、柴油）的内部重整、适用于多种燃料气,从而解决了燃料的供应问题？固体氧化物燃料电池不但可以应用于固定电站。在电动车方面也有很好的发展前景。较详细地介绍了SOFC在汽车方面的应用以及为了实现这一技术的产业化所必须解决的关键问题。     

Comparative study of fuel gas production for SOFC from steam and supercritical-water reforming of bioethanol

Theoretical study of fuel gas (H₂ + CO) production for SOFC from bioethanol was carried out to compare performances between two reforming technologies, including steam reforming (SR) and supercritical-water reforming (SCWR). It demonstrates that the fuel gas productions are comparable among the two reforming systems; however, SCWR requires the operation at much higher temperature and pressure than SR. The maximum hydrogen yield can be obtained at 850 K, atmospheric pressure, ethanol to water molar feed ratio of 1:20 for SR system and at 1300 K, 22.1 MPa, and ethanol to water feed ratio of 1:20 for SCWR. The use of a distillation column to purify the bioethanol feed was proven to improve the fuel conversion efficiency of both systems. The analysis reveals that SCWR is a promising system for fuel production for SOFC when a gas turbine is incorporated to the system for energy recovery. Further, it is not necessary to distil bioethanol to obtain too high ethanol recovery (i.e. >90%) as higher energy consumption at the distillation column could lead to lower overall thermal efficiency.     

固体氧化物燃料电池与燃气轮机混合发电的发展及甲烷蒸汽重整的研究

燃料电池与燃气轮机混合发电系统有着很高的能量利用效率,是能量转换的重要研究方向。而固体氧化物燃料电池的蒸汽重整技术为该联合提供了重要的技术支持。本文设计了固体氧化物燃料电池的结构,并进行甲烷蒸汽重整的模拟计算,计算结果显示燃料电池排气温度达到1380K左右时,有很高的能量利用价值。     

Thermodynamic modeling of direct internal reforming solid oxide fuel cells operating with syngas

In this paper a direct internal reforming solid oxide fuel cell (DIR-SOFC) is modeled thermodynamically from the energy point of view. Syngas produced from a gasification process is selected as a fuel for the SOFC. The modeling consists of several steps. First, equilibrium gas composition at the fuel channel exit is derived in terms mass flow rate of fuel inlet, fuel utilization ratio, recirculation ratio and extents of steam reforming and water–gas shift reaction. Second, air utilization ratio is determined according to the cooling necessity of the cell. Finally, terminal voltage, power output and electrical efficiency of the cell are calculated. Then, the model is validated with experimental data taken from the literature. The methodology proposed is applied to an intermediate temperature, anode-supported planar SOFC operating with a typical gas produced from a pyrolysis process. For parametric analysis, the effects of recirculation ratio and fuel utilization ratio are investigated. The results show that recirculation ratio does not have a significant effect for low current density conditions. At higher current densities, increasing the recirculation ratio decreases the power output and electrical efficiency of the cell. The results also show that the selection of the fuel utilization ratio is very critical. High fuel utilization ratio conditions result in low power output and air utilization ratio but higher electrical efficiency of the cell.     

Development of a fuel feeder for a solid oxide fuel cell test station

Solid oxide fuel cells (SOFC) can utilize various fuels, such as natural gas, hydrogen and biogas, but often, it is sensible to use a pre‐reformer that converts the fuel into a hydrogen‐rich gas stream. Relevant testing conditions, including the fuel to be used in SOFC systems, are important because cell performance depends on test conditions, such as fuel composition. Still, a majority of the reported single‐cell and short stack tests are performed with pure hydrogen or synthetic reformate mixed from gas bottles. In this article, the development of a fuel feeder used to pre‐reform natural gas for a single cell SOFC test station is presented. To mimic SOFC system conditions, natural gas is taken from the grid, desulfurized with commercial sulfur sorbent and reformed with a commercial precious metal catalyst. The fuel feeder is designed to be a versatile and efficient research tool, capable to be used in a wide temperature and gas flow range and with different reforming techniques, such as steam reforming, catalytic partial oxidation and simulated anode off‐gas recycling. The construction, operation and characterization of the fuel feeder as well as methods of avoiding carbon formation are discussed. The performance is evaluated by comparing measured outlet temperatures and compositions against equilibrium values. All measured gas compositions matched closely with the calculated equilibrium values, and the identified deviations were small and to no harm in practical use. The operator can control the product gas composition by setting the fuel feeder heater to the temperature corresponding to the targeted composition. Results show that the fuel feeder design can be used as such for single‐cell testing or scaled to fit larger stack test stations. Copyright © 2015 John Wiley & Sons, Ltd.     

Thermodynamic performance comparison of SOFC-MGT-CCHP systems coupled with two different solar methane steam reforming processes

Multi-energy complementary distributed energy system integrated with renewable energy is at the forefront of energy sustainable development and is an important way to achieve energy conservation and emission reduction. A comparative analysis of solid oxide fuel cell (SOFC)-micro gas turbine (MGT)-combined cooling, heating and power (CCHP) systems coupled with two solar methane steam reforming processes is presented in terms of energy, exergy, environmental and economic performances in this paper. The first is to couple with the traditional solar methane steam reforming process. Then the produced hydrogen-rich syngas is directly sent into the SOFC anode to produce electricity. The second is to couple with the medium-temperature solar methane membrane separation and reforming process. The produced pure hydrogen enters the SOFC anode to generate electricity, and the remaining small amount of fuel gas enters the afterburner to increase the exhaust gas enthalpy. Both systems transfer the low-grade solar energy to high-grade hydrogen, and then orderly release energy in the systems. The research results show that the solar thermochemical efficiency, energy efficiency and exergy efficiency of the second system reach 52.20%, 77.97% and 57.29%, respectively, 19.05%, 7.51% and 3.63% higher than those of the first system, respectively. Exergy analysis results indicate that both the solar heat collection process and the SOFC electrochemical process have larger exergy destruction. The levelized cost of products of the first system is about 0.0735$/h that is lower than that of the second system. And these two new systems have less environmental impact, with specific CO₂ emissions of 236.98 g/kWh and 249.89 g/kWh, respectively.     

Thermodynamic model and parametric analysis of a tubular SOFC module

Solid oxide fuel cells (SOFCs) have been considered in the last years as one of the most promising technologies for very high-efficiency electric energy generation from natural gas, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. Among the SOFC technologies, tubular SOFC stacks with internal reforming have emerged as one of the most mature technology, with a serious potential for a future commercialization. In this paper, a thermodynamic model of a tubular SOFC stack, with natural gas feeding, internal reforming of hydrocarbons and internal air preheating is proposed. In the first section of the paper, the model is discussed in detail, analyzing its calculating equations and tracing its logical steps; the model is then calibrated on the available data for a recently demonstrated tubular SOFC prototype plant. In the second section of the paper, it is carried out a detailed parametric analysis of the stack working conditions, as a function of the main operating parameters. The discussion of the results of the thermodynamic and parametric analysis yields interesting considerations about partial load SOFC operation and load regulation, and about system design and integration with gas turbine cycles.     

A novel combined cycle with synthetic utilization of coal and natural gas

 In this paper, a novel combined cycle with synthetic utilization of coal and natural gas is proposed, in which the burning of coal provides thermal energy to the methane/steam reforming reaction. The syngas fuel, generated by the reforming reaction, is directly provided to the gas turbine as fuel. The reforming process with coal firing has been investigated based on the concept of energy level, and the equations has been derived to disclosing the mechanism of the cascade utilization of chemical energy of natural gas and coal in the reforming process with coal firing. Through the synthetic utilization of natural gas and coal, the exergy destruction of the combustion of syngas is decreased obviously compared with the direct combustion of natural gas and coal. As a result, the overall thermal efficiency of the new cycle reaches 52.9%, as energy supply by methane is about twice as much as these of coal. With the same consumption of natural gas and coal the new cycle can generate about 6% more power than the reference cycles (the combined cycle and the steam power plant). The promising results obtained here provide a new way to utilize natural gas and coal more efficiently and economically by synthetic utilization.     

Internal reforming of hydrocarbon fuels in tubular solid oxide fuel cells

The application of heterogeneous catalysis has an important role to play in the successful commercial development of solid oxide fuel cell (SOFC) technology. In this paper, we present an SOFC that combines a catalyst layer with a conventional anode, allowing internal reforming via partial oxidation (POX) of fuels such as methane, propane, butane, biomass gas, etc., without coking and yielding stable power output. The catalyst layer is fabricated on the anode simply by catalyst support coating and reforming catalyst impregnation. The composition and microstructure of catalyst support layer as well as the catalyst composition was easily tailored to meet the demand of in situ reforming. The usage of catalyst layer as an integrated part of the traditional SOFC will provide a simple low-cost power-generating system at substantially higher fuel efficiency and faster start-ups, and may accelerate the application of SOFCs through the direct use of hydrocarbon fuels.     

An alternative process for gasoline fuel processors

The article explores the thermodynamics of an alternate hydrogen generation process - dry autothermal reforming and its comparison to autothermal reforming process of isooctane for use in gasoline fuel processors for SOFC. A thermodynamic analysis of isooctane as feed hydrocarbon for autothermal reforming and dry autothermal reforming processes for feed OCIR (oxygen to carbon in isooctane ratio) from 0.5 to 0.7 at 1 bar pressure under analogous thermoneutral operating conditions was done using Gibbs free energy minimization algorithm in HSC Chemistry. The trends in thermoneutral points (TNP), important product gas compositions at TNPs and fuel processor energy requirements were compared and analyzed. Dry autothermal reforming was identified as a less energy consuming alternative to autothermal reforming as the syngas can be produced with lower energy requirements at thermoneutral temperatures, making it a promising candidate for use in gasoline fuel processors to power the solid oxide fuel cells. The dry autothermal reforming process for syngas production can also be used for different fuels.