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。     

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。     

平板式固体氧化物燃料电池的初步研究

研制出平板式Ni-YSZ|YSZ|LSM单体电池 ,电池以H2 为燃料 ,O2 为氧化剂气体。设计组装了电池性能测试系统 ,在 4 0 0～ 10 0 0℃的温度范围内 ,测试了电池开路电压与温度变化的关系 ,分析了变化的原因 ;考察了单体电池的电流电压特性和电流功率特性 ,计算了电池的效率     

一种新的生物质气发电装置--固体氧化物燃料电池

利用固体氧化物燃料电池将生物质气直接转化为电能是一种新型的生物质气发电技术，这项技术与传统的发电技术相比具有很多优点。文章阐述了固体氧化物燃料电池的发电原理、特点、研究进展以及发展前景。     

固体氧化物燃料电池与燃气轮机混合发电系统

基于固体氧化物燃料电池系统的高效率、环保性以及排气废热的巨大利用潜能,将其与燃气轮机组成混合发电装置,是一种极有前景的分布式发电方案.文章以SWP公司的加压型SOFC-小型燃气轮机混合循环系统为例,对固体氧化物燃料电池及燃气轮机混合循环系统的原理及发展现状作了分析,为我国固体氧化物燃料电池-燃气轮机混合循环系统的研制提供参考.     

固体氧化物燃料电池与燃汽轮机混合系统技术现状

固体氧化物燃料电池具有高能量密度、适用多种不同燃料、结构简单等优点,与燃气轮机结合后能达到近80%的能量利用效率,具有良好的市场前景.本文介绍了固体氧化物燃料电池与燃汽轮机混合系统的结构,应用现状,给出了未来发展的一些方向,并提出了固体氧化物燃料电池与燃气轮机混合系统发展需要解决的一些问题.     

管式固体氧化物燃料电池单体欧姆极化分析

结合管式固体氧化物燃料电池结构特征和性能特征，建立了电池单体电压、电流和功率与电池长度、各级材料性质关系的数学模型。计算结果表明，减少电解质厚度和提高电池电流收集器的导电性可以减少电池的欧姆极化，提高电池的输出能力。     

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...     

管式固体氧化物燃料电池的数值模拟

通过耦合速度场、温度场、电势场和组分浓度场，建立了以纯氢气为燃料的管式固体氧化物燃料电池（SOFC）数学模型，并对西门子．西屋公司阴极支撑型（AES）管式SOFC进行了轴向二维模拟。模拟结果表明，组分浓度和电流密度的分布与SOFC的运行工况密切相关。在所模拟的电压范围内，欧姆极化起主要作用，提高固体氧化物燃料电池的平均工作温度、改善多孔电极的微观结构、使用纯氧代替空气作为氧化剂可改善电池性能。图8参10     

A Distributed Resistance Analogy for Solid Oxide Fuel Cells

The method of distributed resistances is outlined for performance calculations in solid oxide fuel cells. The domain is discretized using a multiply shared space method. Both potentiostatic and galvanostatic conditions are considered. Mass transfer effects on the heat transfer coefficients and the Nernst potential are taken into consideration. Calculations, for one cell and for a 10-cell stack, are compared to those obtained using a detailed numerical method. Agreement is very good. It is concluded that the distributed resistance analogy may be used to predict transport phenomena in fuel cell stacks at a fraction of the computational cost required for conventional means.     

平板状固体氧化物燃料电池的数值模拟

利用流体力学计算软件FLUENT建立平板状固体氧化物燃料电池（SOFC）三维数值模型，研究在不同操作条件和支撑形式下，活化极化、欧姆极化、浓度极化对SOFC性能的影响。在多孔电极中的气体流动符合达西定律的前提下，为满足不同的多孔电极设计，综合考虑了摩尔扩散和Knudsen扩散。另外还考虑了电池电化学反应热对欧姆极化的影响。分析结果表明，阴极和阳极支撑固体氧化物燃料电池具有较低的操作温度和较好的输出特性。     

固体氧化物燃料电池的神经模糊控制策略研究

固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)具有多输入多输出、强耦合的特点,为了使其输出电压稳定设计了高效控制器,采用神经模糊控制方法对其输出电压进行控制。通过机理分析和实验数据拟合方法分别建立SOFC的机理模型和神经网络模型,在此基础上采用模糊控制策略对SOFC的输出电压进行控制,并应用神经模糊控制方法进一步提高了控制精度。通过MATLAB/Simulink仿真实验发现,SOFC神经网络模型得到的预测电压与实际电压之间的误差小于0.008 V,较其机理模型更加准确,所提出的控制策略能有效控制SOFC的输出电压。     

A discussion on mathematical models of proton conducting Solid Oxide Fuel Cells

The paper presents a comparison of the models currently used in relation to the available experimental data. The review highlights the main causes of discrepancies between the results of modeling and experimental data. The models are based on factors that have no physical interpretation and are used only as “fitting parameters”. This hampers use of these models in simulations on states other than those that prevailed during the experiments for which the coefficients were determined.     

Air side contamination in Solid Oxide Fuel Cell stack testing

This work aimed to quantify air side contaminants during Solid Oxide Fuel Cell (SOFC) testing in stack configuration. Post-analyses of a long-term test have shown that performance degradation was mainly due to cathode pollutants originated upstream of the cell, therefore their source identification is crucial. The compressed air system, feeding the airflow to the cathode, was investigated by filtering and subsequent chemical analysis of the filters. Hot-air-sampling was redone in situ at the cathode air entry during a new test run to assess the contaminant concentrations in air in SOFC test conditions. In addition, the behavior of SOFC proximal system components, i.e. alloy oxidation, was characterized separately.Besides the investigation of silicon and sulfur contamination, the present work focused on chromium from high-temperature alloys used in Balance-of-Plant (BoP) components in direct contact with the airflow. Concentrations of volatile Cr-species under SOFC testing conditions were compared to Cr-accumulation on the tested cell as well as to Cr-evaporation rates from BoP alloys, which were individually characterized regarding oxidation behavior. Evaporated Cr quantities were found to saturate the air with Cr-vapors at the cathode air-inlet, as confirmed by the in-situ measurement of volatile species in the hot airflow, and correlate well to accumulated Cr in the cell after long term testing.The results of this study suggest guidelines to reduce air side contamination from exogenous sources in SOFC stacks.     

Evaluation of fuel diversity in Solid Oxide Fuel Cell system

Operability of Solid Oxide Fuel Cell (SOFC) on numerous fuels has been widely counted as a leading advantage in literature. In a designed system, however, switching from a fuel to another is not practically a straightforward task as this causes several system performance issues in both dynamic and steady-state modes. In order to demonstrate the system fuel diversity capabilities, these consequences must be well-evaluated by quantifying the characteristic measures for numerous fuel cases and also potential combinations. From this viewpoint, the numerical predictive models play a critical role. This paper aims to investigate the performance of a SOFC system fed by various fuels using a demonstrated system level model. Process configuration and streams results of a real-life SOFC system rig published in literature are used to validate the model. The presented model is capable not only of capturing the system performance measures but also the SOFC internal variable distributions, allowing the multiscale study of fuel switching scenarios. The fuel change impacts on the system are simulated by considering various fuel sources, i.e., natural gas, biogas, and syngas. Moreover, applications of simulated fuel mixtures are assessed. The modelling results show significant concerns about fuel switching in a system in terms of variation of efficiencies, stack internal temperature and current density homogeneity, and environmental issues. Moreover, the results reveal opportunities for multi-fuel design to address the operation and application requirements such as optimisation of the anode off-gas recycling rate and the thermal-to-electrical ratio as well as the system specific greenhouse gases, i.e., g-CO_x/Wh release.     

A Physically Based Dynamic Model for Solid Oxide Fuel Cells

This paper presents a physically based dynamic model for tubular solid oxide fuel cells (SOFCs) based on the electrochemical and thermodynamic characteristics inside SOFC. The diffusion, material conservation, electrochemical, and thermodynamic equations are used to develop the SOFC model. The effect of temperature on the steady-state (V-I and P-I) characteristics of the SOFC model has been studied, and the model responses have been obtained for constant fuel flow as well as for constant fuel utilization operating modes. The dynamic characteristics of the model are investigated in small, medium, and large timescales, from milliseconds to minutes. The model has been implemented in MATLAB/Simulink and used to investigate the distributed generation applications of SOFCs.     

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%。