天然气水蒸气重整与SOFC耦合应用

固体氧化物燃料电池（SOFC）系统具有高能源效率和使用可再生燃料的可能性,将在未来的可持续能源系统中发挥重要作用。过去几年燃料电池的发展很快,但在成本、稳定性和市场份额方面,该技术仍处于早期发展阶段。在以天然气为燃料的SOFC系统中,燃料的重整过程和燃料利用水平都可能影响系统运行的稳定性、热量和能量平衡,从而影响系统的使用寿命、输出功率和效率。因此,对燃料重整过程的设计与控制对有效的SOFC电池运行具有重要意义。对天然气在SOFC系统中的重整器配置方式（包括外重整和内重整）、重整参数和重整燃料利用方式进行了详细的综述分析,并对未来天然气SOFC系统的发展进行了展望。     

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。     

进气管通道直径对直接内部甲烷蒸汽重整性能的影响

蒸汽重整对于固体氧化物燃料电池利用甲烷等燃料具有很明显的优势,基于CFD商业软件及对应燃料电池多孔介质内多组分流动和扩散、传热传质、电化学反应、电流场等复杂的物理过程和电化学反应所开发的程序,对平板式阳极支撑固体氧化物燃料电池(PES-SOFC)甲烷蒸汽重整过程进行数值计算,得到不同排气管通道直径下燃料电池内部各气体组分摩尔分数、温度、温度梯度、输出电压等参数的分布。在通道直径为0.004 5 m时,输出电压最高,达到0.4923 V,同时在通道直径为0.004 5～0.005 m范围,能保证比较优化的温度分布。     

支撑形式及多孔电极结构参数对SOFC性能的影响

研究不同结构设计条件下，活化极化、欧姆极化、浓差极化对SOFC性能的影响。在分析浓差极化时，综合考虑了普通扩散和Knudsen扩散，使模型更接近实际。采用灵敏度分析方法，分析了5个结构参数对SOFC性能的影响。结果表明，在该文的分析条件下，阳极支撑的设计具有较好的输出特性。     

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。     

基于容阻建模技术的SOFC电堆数值模拟

借助MATLAB软件，通过建模对固体氧化物燃料电池堆的运行进行仿真。为了计算的方便，模型采用了容阻建模技术。采用由质量守恒、能量守恒、动量守恒和电化学过程组成的模型，对SOFC电堆通道中的气体组成、温度分布、电压分布和电流密度分布进行了计算分析。这些分析结果可对电堆的设计提供参考。     

管式SOFC热电特性的三维数值研究

1前言固体氧化物燃料电池(SOFC)作为一种高效、低排放的先进发电方式,日益受到了人们的关注。其几何结构主要有板式、管式和单一整体形式。管式SOFC具体结构紧凑、能承受较高的工作压力等特点,目前,美国西屋公司开发的管式SOFC已经有了示范性工程。SOFC的平均工作温度一般在800     

SOFC热电联供系统的设计方法研究

介绍了固体氧化物燃料电池建筑热电联供系统的各种结构流程,提出SOFC系统的设计路线,通过对SOFC系统的建模和模拟,开发出一种用于BCHP中燃料电池系统的设计方法,并利用该方法进行实例设计,结果表明:该方法可以针对用户的能源需求计算所需的燃料电池电堆的容量及系统辅助设备的容量,为电堆规模的确定、系统配套辅助设备的选型提供重要的参考依据,为SOFC在BCHP中的应用提供一个有力的系统设计工具.     

改进炉内燃烧工况在烟气治理中的作用

分析一台锅炉烟尘治理失败的原因,并根据这一典型实例,对同类型问题提出了改进意见.     

低负荷下燃烧器投运方式对锅炉性能的影响

以一台低NOx燃烧改造后的700 MW锅炉为研究对象,在300 MW低负荷下开展了CDEF 4层、DEF上3层和CDE中间3层燃烧器这3种投运方式对锅炉性能和机组煤耗影响的试验和数值模拟研究.结果表明:在300 MW低负荷下,不同燃烧器投运方式对再热蒸汽温度和煤耗的影响明显;采用DEF上3层燃烧器投运方式时,可以明显提高大屏入口炉膛截面平均温度,强化再热器换热,大幅提高再热蒸汽温度,提高汽轮机效率,降低机组的发电和供电煤耗;在300 MW及以下低负荷下,建议优先采用DEF上3层燃烧器投运方式,以提高机组的综合性能.     

Performance enhancement of biodiesel fueled SOFC using paper-structured catalyst

In this study, performance of solid oxide fuel cell (SOFC) connected with paper-structured catalyst (PSC) was evaluated in the direct feed of wet oleic fatty acid methyl ester (oleic-FAME, C₁₉H₃₆O₂), which is a mono-unsaturated component of practical biodiesel fuels (BDFs), in the steam to carbon ratio (S/C) range between 2.0 and 3.5, and high current density of 1 A cm⁻² (at 0.7 V) was recorded at 800 °C. Long term stability of oleic-FAME fueled SOFC was achieved by the incorporation of PSC into SOFC even under severe operating condition prone to coking (direct feed of unsaturated hydrocarbon with carbon number 19 and low S/C ratio of 2.0). After 100 h test, coking was not observed in both SOFC anode and PSC.     

Performance simulation for an anode-supported SOFC using Star-CD code

Experimental activities and computational fluid dynamics (CFD) simulation are presented in this paper for investigating the performance of an anode-supported solid oxide fuel cell (SOFC). The goal of this work is to assess a commercial CFD code, Star-CD with es-sofc module, to simulate the current–voltage (I–V) characteristics with respect to the experimental data. Compiled with the geometry of cell test housing, a 3D numerical model and test conditions were established to analyze the anode-supported cell (ASC) performance including current density and temperature distributions, fuel concentration, and fuel utilization. After adjusting parameters in the electrochemical model, the simulation results showed good agreements with the experimental data. The results also revealed that the power density increased while the fuel utilization decreased as the fuel flow rate increased.     

Performance comparison of two combined SOFC–gas turbine systems

A necessary step in the use of natural gas (methane) in solid oxide fuel cells (SOFCs) is its preliminary conversion to hydrogen and carbon monoxide. To perform methane conversion within fuel cells and avoid catalyst carbonization the molar ratio between methane and steam (or steam with carbon dioxide) should be 1:2 or higher at the SOFC inlet. In this article two possible technological approaches to provide this desirable ratio in a combined SOFC–gas turbine system are compared. The first approach involves generation of the required steam in the coupled gas turbine cycle. The second (which is more traditional) involves recycling some part of the exhaust gases around the anodes of the SOFC stack.     

Performance of a glass-ceramic sealant in a SOFC short stack

The development of sealants for solid oxide fuel cells (SOFCs) is a significant challenge as they must meet very restrictive requirements; they must withstand the severe environment of the SOFC (i.e., be resistant to oxidative and reducing gas environments) and be thermo-chemically and thermo-mechanically compatible with the materials to which they are in contact with. This work discusses the design and the operation of two SOFC short stacks (based on planar anode-supported cells) along with the performance of a glass ceramic sealant inside the stack.     

Performance analysis of a SOFC under direct internal reforming conditions

This paper presents the performance analysis of a planar solid-oxide fuel cell (SOFC) under direct internal reforming conditions. A detailed solid-oxide fuel cell model is used to study the influences of various operating parameters on cell performance. Significant differences in efficiency and power density are observed for isothermal and adiabatic operational regimes. The influence of air number, specific catalyst area, anode thickness, steam to carbon (s/c) ratio of the inlet fuel, and extend of pre-reforming on cell performance is analyzed. In all cases except for the case of pre-reformed fuel, adiabatic operation results in lower performance compared to isothermal operation. It is further discussed that, though direct internal reforming may lead to cost reduction and increased efficiency by effective utilization of waste heat, the efficiency of the fuel cell itself is higher for pre-reformed fuel compared to non-reformed fuel. Furthermore, criteria for the choice of optimal operating conditions for cell stacks operating under direct internal reforming conditions are discussed.