生活垃圾焚烧炉中二恶英的生成和计算方法

二恶英是一种剧毒物质,应当更好地加以控制.在已有关于二恶英生成研究的基础上阐明了二恶英在垃圾焚烧炉中各区域的生成机理,并给出了各区域二恶英生成的计算方程.针对计算方程中各个变量进行了分析.结果表明:炉膛内合理良好的燃烧是控制二恶英生成的关键;增加尾部烟气的温降速率和降低飞灰中前体物浓度可有效抑制低温表面催化反应区域二恶英的生成;控制飞灰中残碳含量、烟气中氧含量是控制尾部重新合成二恶英的主要途径.     

温度和气氛对PAHs由从头合成反应生成PCDD／Fs的作用

城市生活垃圾焚烧炉产生的多氯二苯并二恶英(PCDDs)和多氯二苯并呋喃(PCDFs),是一类剧毒的持久性有机污染物(POPs).多环芳烃是城市生活垃圾焚烧炉上二恶英生成的一种主要的碳源.在小型试验用固定床反应器上,研究了温度和燃烧气氛中氧对多环芳烃在模拟飞灰(MFA)的催化下,由从头合成反应生成二恶英的作用.烟气样品参照USEPA1613方法收集,并采用高分辨色谱,低分辨质谱仪进行分析.给出了反应中生成的二恶英的分布特征与温度、氧含量的关系,二恶英的分布特征包括二恶英的总排放量、毒性当量(TEQ)和PCDDs/PCDFs的比例.结果显示,PAHs反应生成的PCDFs的量要比PCDDs高出几倍,在二恶英的生成过程中存在一个最优化的温度区间和氧含量范围,二恶英的毒性当量随着氧含量的增加而增大,并讨论了温度和燃烧气氛的作用机制.     

垃圾焚烧飞灰中重金属和二恶英等痕量污染物分析

对国内外垃圾焚烧飞灰进行收集并着重利用GC-MS、原子吸收光谱等手段对二恶英和重金属等痕量污染物进行系统研究，并结合国内外研究成果进行对比分析．结果表明，飞灰中不同种类重金属含量差异很大，Cu、Pb和Zn的含量较多，Cr的含量次之，Ni、Cd的含量较少．垃圾焚烧飞灰中二恶英含量差别很大，总含量在1．36～31.54ng／g，各种飞灰中二恶英的毒性当量更为悬殊．飞灰中二恶英和重金属含量及分布受垃圾成分、焚烧炉型、焚烧温度、停留时间等因素影响．     

垃圾焚烧过程二恶英的生成机理及相关理论模型

介绍了垃圾焚烧过程中二恶英的高温气相生成机理、从头合成机理和前驱物生成机理及相关的理论模型，提出了垃圾焚烧过程中影响二恶英生成的主要因素和应采取控制方法。     

医疗垃圾焚烧炉回转窑转速与灰渣二恶英排放的关系

通过某回转窑-流化床医疗垃圾焚烧炉的燃烧实验,采集了不同回转窑转速条件下的飞灰和底渣样品,测定了其中的二恶英含量,并研究了回转窑转速与灰渣二恶英排放的关联特性.研究发现,随回转窑转速增加,灰渣的二恶英毒性排放总量增加;当转速为0.82 r/min时,飞灰中二恶英总量和毒性当量排放分别为41.05 ng/g和7.58 ng(I-TEQ)/g;流化床底渣样品中的二恶英含量比飞灰小很多.研究还发现,随着焚烧炉尾部烟气中NO<,x>和H<,2>O含量的增加,飞灰中二恶英总量呈现减少的趋势;随着烟气中O<,2>浓度的增加,飞灰中二恶英总量也随之增加,因此,通过关联性较好的常规气体成分(污染物)浓度的检测,可以在一定程度上预测燃烧_T况的好坏及飞灰中二恶英排放的程度.     

肼类物质抑制二恶英排放的机理及应用探析

探讨了肼类物质水合肼和碳酰肼抑制烟气和飞灰中二恶英向环境排放的机理和应用可能性。肼类物质对烟气中二恶英排放的抑制原理预测：在250℃～400℃温度区直接干扰二恶英的合成;在400℃～700℃温度区破坏二恶英的合成先驱物;肼类物质分解焚烧飞灰中的二恶英可在100℃以上的水热条件下进行,并且效果已经被证实。还阐述了肼的泄漏和检测以及肼用于广谱抑制二恶英应该解决的问题。指出肼类物质是极具前景的一类广谱二恶英排放抑制剂,值得探索。     

垃圾焚烧炉烟气中二恶英指示物研究

为研究在线监测二恶英(PCDD/Fs)的指示物,分别检测了生活垃圾焚烧炉(MSWI)和医疗垃圾焚烧炉(HWI)烟气中氯苯(CBz)、多环芳烃(PAHs)和二恶英(PCDD/Fs)的排放浓度.MSWI和HWI烟气中,PAHs六氯苯(HCBz)PCDD/Fs,在HWI烟气中发现,五氯苯(PCBz)、六氯苯(HCBz)和二恶英(PCDD/Fs)毒性当量(TEQ)的排放相关系数分别为0.92和0.95,五、六氯苯之间的排放相关系数为0.99;同时MSWI和HWI烟气中23478-PCDF和二恶英毒性当量的相关系数也达到了0.99.二恶英指示物的研究是实现二恶英在线测量的关键之一.     

垃圾焚烧过程中二恶英的生成机理及控制研究

介绍了垃圾焚烧过程中二恶英的高温合成机理、从头合成机理和前驱物生成机理,分析了影响二恶英生成的各种因素和当前采取的各种控制方法,并指出了未来二恶英控制技术的发展方向。     

氧气和双氧水水热降解飞灰中二恶英的研究

通过水热法研究O2、H2O2降解医疗垃圾焚烧飞灰中二恶英的规律。研究结果表明,2MPa氧气和8.36mL双氧水,其他条件相同时,飞灰中二恶英降解效率基本相同;50℃和通氧条件下,飞灰中二恶英降解效率最高84.2%;在氧化剂存在时,PCDFs的降解效率高于PCDDs的降解效率;除T4CDD-2378的降解效率低于60%外,其余16种有毒二恶英降解效率均高于70%,其中T4CDF-2378在200℃和通氧条件下降解效率最高为94.1%;水热法降解二恶英过程中存在高代二恶英的脱氯反应。     

典型种类活性炭吸附二恶英影响因素实验研究

采用稳定的二恶英发生源系统,对4种典型的商用活性炭进行了二恶英的吸附实验。研究了活性炭的比表面积、孔径分布、碘值、亚甲基蓝值等物化特性对二恶英吸附的影响。结果表明,活性炭的比表面积、碘值、亚甲基蓝值并不能直接反映活性炭对二恶英的吸附能力;活性炭在吸附气相二恶英时并无明显的选择性,选择性吸附与活性炭的吸附方式有关;作为吸附二恶英的活性炭需具备丰富的2～20 nm段的孔径分布,同时需要适量的大孔分布。     

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。     

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。     

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。     

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.     

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.     

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.     

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.     

Exploring electrocatalytic stability and activity of unmodified and platinum-modified tungsten and niobium nitrides

Transition metal nitrides are interesting electrocatalytic support materials that have similar structure to their carbide counterparts while avoiding associated issues with carbonaceous overlayers resulting from carbide synthesis. This may allow for more intimate contact between the nitride substrate and metal-modifier to promote synergistic effects. In this work, tungsten nitride (WN) and niobium nitride (NbN) thin films were synthesized and evaluated for their stability across a wide range of potential-pH values. Low loadings of Pt were deposited on the nitride thin films and were evaluated for the hydrogen evolution reaction (HER) activity in acid and alkaline electrolytes. The observed activity trends correlate well with the hydrogen binding energies obtained from density functional theory (DFT) calculations. Pseudo-Pourbaix diagrams were generated for WN and NbN to aid in catalyst selection for other electrocatalytic reactions.