甲烷浓度对天然气与煤共热解的影响

天然气与煤共转化技术是一种新的合成气工艺。利用热天平比较研究了在甲烷气氛和氮气气氛下褐煤的热失重规律,研究发现在350℃~650℃之间,甲烷气氛下煤热解的失重速率要高于氮气气氛下的失重速率,表明由于甲烷的存在促进了煤的热解。通过不同甲烷浓度下常压固定床褐煤的热解气相产物分析表明,甲烷的存在不仅使煤的热解发生变化,而且甲烷浓度的变化对碳氢组分的析出规律也有较大影响,C2、C3、C4的析出在400℃~500℃温度区间内最为强烈,而随着甲烷浓度的增大,轻质烃的析出浓度基本呈上升趋势。     

神华煤液化残渣的热解特性

在TGA/SDTA851热重分析仪上,以N_2为载气,在气体流速为20 mL/min,升温速率分别为20℃/min、40℃/min、60℃/min和80℃/min,终温1100℃的条件下,进行了煤液化残渣的热解特性研究实验,得到了不同升温速率下神华煤液化残渣热解的TG和DTG曲线,表明神华煤液化残渣的热解是分两步进行的．在低温段主要是神华煤液化残渣中挥发性的气体溢出引起热解失重,在低温度段180～450℃,挥发分迅速释放；高温段则主要是一些高分子有机质的热解过程．此外,研究了粒径对热解特性的影响．研究发现,随着粒径的增加,残渣的最大挥发分释放速率逐渐减小,而最大挥发分释放速率对应的温度逐渐增加．利用Freeman-Carroll法得到煤液化残渣的动力学参数,为煤液化残渣的有效和经济利用提供理论依据．     

生物质加压热重分析研究

对两种生物质木屑和松针进行了不同压力和升温速率下的热重分析试验,通过生物质热重失重率（TG）和失重速率（DTG）曲线,获得了相关热解特性参数,提出了生物质的挥发分综合释放特性指数D．并通过热分析数学方法求取了生物质热解动力学参数．试验结果表明,氮气气氛中,木屑与松针常压和增压下主要热解阶段可认为两段一级反应;热解压力的提高,将延迟生物质挥发分初析温度和DTG峰值温度,降低最大析出率和DTG峰值,生物质的挥发分综合释放特性指数D也减小,增加了生物质挥发分的析出难度,并改变了热解反应活化能和频率因子．同一压力下,提高热解升温速率,生物质综合特性指数D将增加．     

锡林浩特煤热解特性的TG/DTG分析研究

采用TGA/SDTA85le型热重/同步差热分析仪研究了锡林浩特煤(XLHT)的热解特性,考察了不同的热解温度、升温速率以及颗粒粒度对锡林浩特煤热解特性的影响,研究表明:随热解温度的升高,XLHT挥发分析出增加,当热解温度达到850℃以上时,挥发分析出量基本不变;随煤样颗粒粒度的减小,XLHT热解最大失重率减小;随着升温速率的提高,煤热解的最大失重速率随之提高,但最终失重量主要由热解终温决定,升温速率对其影响不大。     

基于热重法的准东煤热解特性研究

采用热重分析法,研究了不同升温速率下准东煤的热解特性。采用Coats-Redfern积分法对不同反应级数下的准东煤热解动力学特性进行拟合,选取拟合度最高的反应级数建立准东煤热解动力学模型。结果表明,随着升温速率变大,热失重速率曲线朝着高温方向偏移,产生热滞后现象;采用Coats-Redfern法计算频率因子时,如果不加以判断,就将(1-2RT/E)项忽略,将会给计算结果带来较大误差。     

煤与杜氏盐藻共热解过程分析及动力学研究

在氮气气氛中,利用热重分析对煤与杜氏盐藻及其混合物的热解特性进行了研究,考察了煤与杜氏盐藻不同掺混比例对热解过程的影响,并研究了共热解动力学.结果表明,煤与杜氏盐藻共热解特性并不是两者单独热解特性的简单叠加,在200～500℃范围内两者之间存在明显的协同效应,其相对值高达28％.煤和杜氏盐藻单独热解均可分3个阶段,由于固定碳和灰分含量高,煤在相同热解阶段的失重率较杜氏盐藻低.动力学分析结果表明,以峰值温度为分界点,采用2个连续一级反应模型与实验数据拟合效果良好,计算得到共热解过程中的活化能和指前因子分别为16.06～28.20 kJ/mol和0.42～16.82 min-1;活化能与指前因子的对数之间具有良好线性关系.     

油泥-煤混合热解挥发分析出特性

利用热重分析的方法对含油污泥、煤及其混合试样的挥发分析出特性进行研究,分析了含油污泥、煤的混合比例及升温速率对含油污泥-煤混合热解过程的化学动力学参数和挥发分析出特性参数的影响规律.实验结果表明,随着混合试样中含油污泥含量的增加,挥发分析出份额越大,混合试样总失重量增加;混合试样的热解反应整体活化能要小于两种单一组分;煤中加入少量的含油污泥就可以使挥发分初析温度显著降低,挥发分析出的温度区间在含油污泥质量分数为33%左右时达到最大;当混合试样中含油污泥质量分数超过33%时,挥发分析出高峰时的温度接近含油污泥,且挥发分最大析出速度、挥发分析出特性指数随含油污泥含量的增加而增大,增加含油污泥对混合试样挥发分的析出有明显的促进作用;在10～30,℃/min的变化范围内,热解曲线随升温速率的增大向高温方向偏移,挥发分析出特性指数随升温速率的增加略有增大,升温速率的增大对于挥发分的析出略有促进作用.     

各种因素对煤加压热解影响的试验研究

在新研制的双炉膛加压热重分析仪上进行了韩桥烟煤和阳泉无烟煤的加压热解试验,研究了各种因素（如温度,粒径,加热速率等）在压力下对煤热解行为的影响,并对此作出新的合理的解释。     

升温速率对神华煤液化残渣燃烧特性与动力学参数的影响

运用TGA/SDTA851热失重分析仪进行了神华煤液化残渣的燃烧特性试验研究。实验表明:神华煤液化残渣的燃烧是分两步进行的,在低温段主要是神华煤液化残渣中挥发性的气体急剧析出,引起燃烧失重;高温段则主要是一些有机质、固定碳的燃烧失重。低温段神华煤液化残渣挥发分含量很高且具有集中析出的特性,在365℃~545℃区间内可挥发物质迅速燃烧完毕;高温段燃烧速率相对较低,半峰宽较大,燃烧不够集中。随着升温速率的增加低温段和高温段燃烧的区分更加明显,且使神华煤液化残渣的燃烧失重增加。此外分析了神华煤液化残渣在一定升温速率下的燃烧特性,利用Free-Carroll法得到神华煤液化残渣燃烧化学反应的动力学参数。图3表4参6。     

植物化工醇废液热解动力学研究

为了研究植物化工醇废液的热解反应机理,将废液置于氮气气氛下进行加热反应。利用热重分析仪考察了不同升温速率对废液热解反应影响,得到了TG/DTG曲线。实验结果表明废液热解反应有五个波动峰,以及蒸发、热解和无机盐反应三个过程,利用Coats-Redfern法计算了动力学参数,热解过程活化能和频率因子均最小,无机盐反应过程最大,活化能大小与升温速率和反应阶段有关。改变升温速率并不会明显改变热解反应特性,热解过程主要是挥发分析出,失重比和失重速率均最大。     

过热器再热器爆漏事故的原因分析及对策

过热器、再热器爆漏事故严重影响了锅炉机组的安全性和经济性,而造成过热器、再热器爆漏事故的主要因素有超温爆管、磨损、高温腐蚀、热疲劳、质量失控等。通过对这些因素的主要原因和爆口特征的分析,提出了一些过热器、再热器爆漏事故的防治措施。     

具有智能化特征的安全稳定分析与控制决策技术

安全稳定预警与控制辅助决策是智能电网调度技术支持系统不可缺少的应用类功能。在分析安全稳定分析与控制决策计算工作特点的基础上,提出安全稳定分析与控制决策支持智能化的主要特征：自动化和自适应性。介绍了自动化的安全稳定分析计算技术,包括输入数据准备、任务执行和输出结果的自动化处理;阐述了自适应电网运行工况、外部环境和硬件运行状态的安全稳定分析技术,包括调整应用功能的输入数据和妥善处理安全稳定性交互影响,以及根据分析计算任务要求动态优化调度计算资源。这些技术已用于安全稳定综合防御系统,提高了分析结果的适应性和分析计算的效率,在电网运行规划、计划安全校核、超短期安全态势预测、调度操作安全校核和在线分析与控制等电网调度运行管理中发挥作用。     

Hydrophilic and hydrophobic materials and their applications

Wettability of a material’s surface plays a significant role in how fluids interact with such surfaces. Wetting behavior is universal but can vary depending on the chemical nature of the solid and liquid phases. Plants and animals adapt to their environment by having evolved special properties. These properties are such as hydrophilic and hydrophobic. Hydrophilic surface has a strong affinity to water and spreading of water on such surface is preferred. The degree of hydrophilicity of the substance can be measured by measuring the contact angle between the liquid and solid phases. Hydrophobic materials are known as non-polar materials with a low affinity to water, which makes them water repelling. A contact angle of less than 90° indicates hydrophilic interaction where as an angle greater than 90° indicates a hydrophobic interaction. More recently, superwetting such as superhydrophilicity has been receiving an increased focus in the literature due to its potential significance. Superhydrophilic surface has a contact angle of less than 5°.

The fabrication of hydrophilic materials can be carried out in two main ways: depositing molecules on surfaces or modification of surface chemistry. Both methods have been successful historically in achieving their intended purposes. Hydrophobic and superhydrophobic materials can be produced with many fabrication methods such as layer-by-layer assembly, laser process, the solution-immersion method, sol-gen techniques, chemical etching, and Hummer’s method.

The applications of such an important property are significant. For example, hydrophilic surfaces can be used in anti-fogging applications, biomedical, filtration, heat pipes, and many others. Hydrophobic and superhydrophobic materials have been successfully applied in many sectors, such as: (I) the removal of petroleum from aqueous solutions, (II) applied to plastic, ceramics, and mesh to contribute to the oil removal from aqueous solutions, (III) hydrophobic layers have a strong self-cleaning effect on plastics, heat pipes, metals, textiles, glass, paints, and electronics, (IV) hydrophobic layers improve the anti-freezing behavior of heat pipes which prevents unwanted build-up and (V) they function as a water and dust protecting coat on electronics.

The presence of this property is historic but there is still a huge potential for development for its applications in many sectors such as water treatment, heat transfer applications, biomedical devices, and many more.     

Defect and impurity diagnostics and process monitoring

The review focuses on four areas of defect and impurity diagnostics: (i) the determination of parasitic resistances, (ii) quantum efficiency analysis including light-beam-induced current measurement systems which use spectrally resolved currents to determine local recombination in solar cells, (iii) methods to determine the recombination properties in solar cell precursors and (iv) techniques suitable for the recognition of the type of impurity or defect, which is responsible for increased recombination. In general, emphasis is on those methods, which are capable of delivering spatially resolved information. The use of the specific metastability features of a defect for its identification is exemplified. In addition, carrier lifetime spectroscopy methods utilising the temperature or the injection dependence of defect recombination are outlined.     

铁道机车车辆轮轨的摩擦磨损与节能降耗

阐述了铁道机车车辆轮轨摩擦磨损的现状;研究了内燃机车车轮、闸瓦和钢轨的消耗数量及相应的维修费用;指出了采用适当的新技术之后,在节能降耗方面会产生显著的经济效益。     

Hydrogen and electricity from water and light

Four self-driven photoelectrochemical hydrogen producers: n-TiO₂/p-CdTe, n-TiO₂/p-GaP, n-SrTiO₃/p-CdTe and n-SrTiO₃/p-GaP were constructed and examined in 1 M NaOH. the current-potential curves of the individual electrodes and the current-cell voltage relationships were measured. Cell current-density measurements versus time demonstrated that the output of each cell is stable for at least 12 h. the n-SrTiO₃/p-GaP cell under xenon light irradiation was the most efficient at 0·7 per cent. the n-TiO₂/p-GaP cell was estimated as the most efficient under solar light at 0·1 per cent. the stability of p-CdTe and its energy gap of 1·5 eV make it a prospect for use as a photocathode in future photoelectrochemical hydrogen producers.     

能源的开发利用与节能

在节能与环保问题成为当今全球性重要研究课题的情况下,笔者对中国能源的现状、新能源开发问题和在用车辆的环保节能问题进行了研究探讨。认为我国应加大开发可再生能源、核能源的力度,开发城市生活垃圾的新能源,找出在用柴油车实现环保节能的一些新措施。     

国内外能耗监测控制管理理论与实践

能耗监测是能源管理中的重要环节,国外不少国家在这方面都进行了积极的努力,制定了一些相关政策,并取得了一部分研究成果.我国于上世纪90年代初就出台了关于能耗监测的有关规定,2007年颁布的《单位GDP能耗监测体系实施方案》规定了能耗监测的主体、主要内容和指标.工业、交通运输和建筑是我国三大“耗能大户”,因此能耗监测研究和管理实践也主要集中在这三个领域.信息技术的发展为工业企业的能耗监测提供了基础平台,运用计算机信息技术对能耗实行现代化管理,成为企业实现信息化管理、降低成本的一种重要手段.道路交通约占我国交通运输业能耗的75％,因而对道路交通能耗的监测是交通运输业能耗监测的主要任务,而对机车能耗的监测是铁路运输能耗监测的主要内容之一.建筑能耗监测主要针对大型公共建筑,通过信息化手段进行信息采集及能耗监测.目前有关能耗监测的研究还处于起步阶段,尚未全面展开,能耗监测技术还不成熟,监测设备也不齐全.今后除了要继续探索能耗监测技术以外,还应重点加强对主要行业能耗监测控制管理体系的研究.     

The roles of science and technology in energy and environment research and development

Countries are becoming increasingly aware of the importance of science and technology in relation to national development and the necessity of formulating a concise science and technology policy. The need to strengthen and orient the scientific and technological infrastructure in line with national development goals, through more effective use of an available qualified work force and the higher education system, is becoming widely recognized. Consequently, appropriate methods of assessing the impact of science and technology on national development are needed so that efforts are concentrated on areas potentially having substantial impacts. Numerous planning studies have been undertaken to this end, particularly by international organizations such as UNESCO, UNIDO, OECD and IEA. This study examines the inter‐relationships of the disciplines of science and technology with energy and environment research and development (R&D) activities, particularly for developing countries. The connections between these topics are discussed along with some basic methods that can be used to exploit the relations. Some illustrative examples are presented. It is anticipated that the present study will serve as a preliminary step for more comprehensive work by providing an example of the utilization of formal methods in formulating science and technology policy for energy and environment R&D. Copyright © 2001 John Wiley & Sons, Ltd.     

火电厂TSI安装调试及常见故障诊断和处理

火电机组TSI探头的安装与调试是一个较为复杂和精细的工作.是火电厂热控安装不可或缺的最重要的组成部分.文章对各种测量探头的原理进行了分析,理论结合实际,将原理图和现场安装图进行对照,通俗易懂.对这些TSI探头在实际安装时应注意的细节问题做了详尽的阐述,同时对试车过程中出现的问题进行了分析并提出了处理措施.对火电机组汽轮机本体热工仪表安装工作有一定的指导意义.