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     

复杂组分燃料的热重分析方法

城市生活垃圾MSW是典型的复杂组分燃料，为研究MSW典型有机组分混合热解时的交互影响及其混合热解特性，设计了一种能够进行较大量物料(10g左右)热重分析实验的实验系统，并采用最小二乘法计算得到由若干平行反应组成的反应．动力学模型。文中列出了在此实验系统上进行的6种MSW典型有机组分的热解实验结果及模型计算结果，两者吻合较好，说明该方法是可行的，为进一步进行MSW典型有机组分混合热解实验研究奠定了基础。图3表2参10     

Fuel gas production from dusty tar pyrolysis

Dusty tar is an undesired product obtained from a coal pyrolysis/combustion system. Thermal conversion of dusty tar into fuel gas was studied with a fixed-bed reactor. It is found that C₂-C₅ hydrocarbons are mainly derived from the cracking of long-chain aliphatics, while CH₄ from the decomposition of long-chain aliphatics and alkyl-substituted aromatic chemicals. The yield of the gas product increases monotonously, but the heating value of gas gradually decreases as temperature increases from 400 to 950°C. Decomposition of chemicals with a boiling point over 360°C contributes to 50–90% C₁-C₅ hydrocarbons and CO_x when pyrolysis temperature is lower than 600°C.     

燃料热解制氢在柴油机上的节油研究

用ZS1100型柴油机进行了台架试验,将几种不同燃料（二甲醚、乙醇、甲醇、氨）热解后通入进气道,就节油效果进行了对比,并与直接向进气道通氢气作了比较。对较低热值的燃料二甲醚、乙醇和甲醇,配合燃用乳化油,能够明显提高能量利用率达10％,同时柴油消耗可减少约15％～18％,经济上可节钱8％～10％。高节油率是燃料热解产生氢气和乳化油共同作用的结果。热解供氢将柴油机排烟热能转化为热解气中的化学能,从而实现了柴油机尾气能量的循环再利用。     

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。     

基于卡尔曼滤波算法的固体氧化物燃料电池的状态预估研究

固体氧化物燃料电池（SOFC）是一种多输入多输出、强耦合和强非线性的新型发电装置,对其内部状态变量的预估将有助于了解实际SOFC的运行过程和实现高效控制器的设计。本文采用卡尔曼滤波算法对SOFC的状态进行预估。通过对SOFC发电原理的深入分析,建立其离散时间的状态空间模型;采用卡尔曼滤波算法对SOFC的各气体进气侧压力值进行预估,并将预估值带入输出电压方程,对SOFC下一时刻的电压进行预估。MATLAB/Simulink仿真结果表明,氢气、氧气和水蒸气压力的估计值与真实值的误差分别为0.425×10⁵,0.141×10⁵和0.364×10⁵ Pa,远小于各气体压力测量值与真实值的误差1.479×10⁵,1.165×10⁵和1.155×10⁵ Pa,同时SOFC输出电压的估计值较为符合真实值的变化,验证了卡尔曼滤波算法在SOFC状态预估中的有效性和实时性。     

固体氧化物燃料电池／燃气轮机混合模式的统计综述

固态氧化物燃料电池（SOFC）作为高效低排放的一种先进发电方式,尤其是其与燃气轮机（GT）组成的混合系统,在未来能源的可持续发展过程中,对于提高化石能源的利用效率和可再生能源的应用将发挥重要作用。本文就目前的SOFC／GT混合模式（包括示范性项目和概念性设计）进行统计分析,在此基础上将SOFC／GT混合模式分为三种基本类型,并对相关典型混合模式进行综述和比较。本文最后对SOFC／GT混合系统目前的研究进展和面临的挑战进行讨论。     

Yields of pyrolysis products from refuse-derived fuel

Pyrolysis yields and gas characteristics must be studied to control pollution caused by waste-energy recycling and to develop a refuse-derived fuel technology. In this study, refuse-derived fuel pyrolysis experiments were performed in a high-temperature tube furnace. The effects of the final pyrolysis temperature, material mixture ratio, and pyrolysis rate on the yields of pyrolysis products, including gas, tar, and semi-coke, were studied. The volume fractions of the pyrolysis gas components (H₂, CO, CH₄, and CO₂) of the samples were also detected. Results showed that with increased final temperature, the tar and gas yields increased but the semi-coke yield decreased. The volume fractions of the components had the following trends: H₂ increased, CO initially decreased and then increased, CH₄ initially increased and then decreased, and CO₂ decreased. With decreased biomass, the tar yield decreased and then increased, whereas the semi-coke and gas yields increased and then decreased. Compared with slow pyrolysis, fast pyrolysis decreased the tar yield by 9.13%, increased the gas yield by 7.45%, increased the CO and CH₄ volume fractions, and decreased the CO₂ volume fraction.     

Single chamber Solid Oxide Fuel Cells selective electrodes: A real chance with brownmillerite-based nanocomposites

In this contribution brownmillerite-based nanocomposite cathode for Single-Chamber Solid Oxide Fuel Cells is developed. These cells can be very attractive especially for small and cheap devices because of the absence of seals. The efficiency of SC-SOFCs is strictly connected to the selectivity of anode and cathode, the bottleneck for this technology. The development of a cathode inert in fuel oxidation is particularly challenging. Our strategy is to start from a catalytically un-active support (CFA = Ca₂FeAl_0.95Mg_0.05O₅) and induce the formation of iron oxide based nanoparticles, expected to activate oxygen. Symmetric (CFA + FeO_x/CGO/CFA + FeO_x) and complete cells (CFA + FeO_x/CGO/Ni-CGO) are studied in air and methane/oxygen 2:1 mixture. The Area Specific Resistance of CFA + FeO_x is less than 1/3 that of CFA. The high selectivity allows to reach an efficiency of 25%; power still needs to be increased but we demonstrated the possibility to develop selective low cost electrodes. The effect of air, methane/oxygen exposure and the heat treatments were carefully investigated.     

固、液混合燃料状态及和持性研究

给出固体金属粉末燃料颗粒尺寸随机分布的分形表示,建立了组分比例,固体燃烧颗粒尺度的特性与固液混合燃料细胞结构的相关性,通过实验分析,论述了由固液料组分比例关系确定固液混合燃料达到饱和状态的临界条件。为揭示燃料组分比例,混合燃料物理特性和化学特性影响燃料空气炸药爆聂交条的本质特征奠定基础。     

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%。     

燃料油的新型替代品——生物质裂解油

从化石能源为主向可再生能源为主过渡,是我国能源发展战略的一项重要任务,其中,燃料油将是可再生能源服务的重要对象之一。生物质裂解油以秸秆等农林废弃物为原料,其特质适于替代燃料油。国际上生物质裂解油已经迈入产业化发展的门槛,我国亦具有广阔的市场前景。当前应该抓住国际技术发展的机遇,推动该技术的研发、示范和产业化。     

运行和设计参数对生物质热解制取燃料气的影响

传统的用来生产工业和民用中等热值气体的生物质热解过程面临着两个缺点，即产气率低和高含量的气相焦油蒸汽引起的下游设备的腐蚀．为克服这些缺点，在保证热解气热值几乎不变的条件下，在实验室内的一套热解系统中研究了运行和设计参数对生物质热解过程的影响．研究的参数包括反应温度、挥发相在热解炉中的停留时间、生物质原料颗粒的预处理、外部加热炉的加热速率和热解炉的热质传递能力．此外，本文还研究了一个独立的裂解炉的运行温度和热解炉的几何形状对燃料气生产的影响．结果表明，上述参数对生物质热解气的产率是敏感的，而且热解气的热值始终在13～15MJ／m^3之间变化．这一热值确保热解气可以较好地用作燃气轮机的动力燃料或炊事燃料．     

Biogas Production from the Organic Fraction of Municipal Solid Waste

This article discusses the potential use of biogas from municipal landfills to fuel urban heat space in Turkey. Biogas can be obtained from digesting the organic material of municipal solid wastes (MSW). The composition of MSW varies by the source of waste; however, in all cases the major constituents of MSW are organic in nature and the organics account for more than 50% of MSW. The main constituents of landfill gas are methane and carbon dioxide, both of which are major contributors to global warming. The generation of methane is worthwhile after one year from the start of the landfill operation. The compositional characteristics of MSW vary considerably from the large cities to the small towns and regions in Turkey. The social and demographic factors for each region are very different.     

燃料电池研究进展及发展探析

燃料电池是一种清洁、高效的能源利用方式。发展燃料电池对于改善环境,实施能源可持续发展具有重要意义。本文介绍了燃料电池的工作原理、分类及优点,详细阐述了目前燃料电池的应用和研究进展。指出随着电池材料的发展、制备技术的提高及生产成本的降低,燃料电池具有广阔的市场前景。     

Photobiological Production of Hydrogen from Spirulina for Fueling Fuel Cells

Abstract

Natural resources of the world are shrinking day by day with ever increasing population and man's growing need for commercialization of petroleum, natural gas, coal, etc. Therefore, there is a need for finding an alternative fuel that could replace these conventional fuels. Hydrogen seems to be an ideal candidate, since hydrogen is a cleaner source of energy. Fuel cell is a good device that converts hydrogen directly into electrical energy efficiently. However, availability of hydrogen is a problem. There are many conventional methods for producing hydrogen, like thermochemical process, catalytic reforming of hydrocarbons, and electrolysis of water, but these methods are not economical and are mostly non-renewable. Biological means of producing hydrogen offers a renewable source of hydrogen production. Cyanobacteria can split water into hydrogen. Anabaena sp. is found to produce more hydrogen than other species of cyanobacteria; however, if this has to be cultured only for hydrogen production, it may not be commercially viable. Spirulina sp. has a good food value and can produce hydrogen as a byproduct. In order to reduce the cost of the fuel cell, the platinum anode may be replaced by a carbon electrode impregnated with suitable inexpensive metal that may have good catalytic activity such as Co-Al oxide spinel and nickel. Studies towards the photobiological production of hydrogen were undertaken. Hydrogen based fuel cell was assembled and fabricated and these studies are being reported.     

Low‐temperature pyrolysis of municipal solid waste: influence of pyrolysis temperature on the characteristics of solid fuel

This paper presents the results of pyrolysis experiments of the mixtures of nine different combustibles municipal solid wastes (MSW's main composition: rice 24.33% and fruits 14.60%). The experiments were carried out in a laboratory‐scale reactor under nitrogen atmosphere at temperature of 300–700°C. The study concentrates on low‐temperature pyrolysis of MSWs and the effect of the pyrolysis temperature on the characteristics of the products (solid fuels) including proximate analysis, volatile content, heating value, ignition temperature and density of the solid fuel. The results indicate that the pyrolysis temperature plays an important role on the characteristics of the solid fuels. The volatile content of the solid fuels decreases with the pyrolysis temperature so that the low‐pyrolysis MSW treating process has advantage for higher heating value of the solid fuel for energy recovery purpose. The heating value is in the range of 23–27 MJ kg^?1, equivalent to the heating value of low‐rank coals. Copyright © 2005 John Wiley & Sons, Ltd.     

生物质成型燃料热解特性及动力学研究

利用NETZSCH STA409PC型热重-差热分析仪对生物质成型燃料在以10℃/min、20℃/min及30℃/min升温速率下的热解过程进行了热重分析。对TG-T、DTG-T曲线分析,结果表明生物质成型燃料热解过程分为干燥、热解预热、热解与炭化4个阶段,热解过程随着升温速率升高出现热滞后现象。对剧烈失重区间建立了反应动力学模型,求解出此温度区间的表观活化能、频率因子等动力学参数。     

可燃固废焦油处理的研究进展

热解气化技术是实现可燃固废资源化利用的主流技术,有必要对热解气化过程中的副产物焦油进行有效处理。本文介绍了可燃固废焦油的组成、危害及处理方法,对原位处理法、物理法和热化学法等焦油处理技术进行了总结。提出一种将焦油与聚乙烯混合进行加氢处理的方法,利用聚乙烯中富含的氢元素,有望提高焦油利用的经济性。