混煤氮的热解析出特性及燃料NO_x的形成规律

混煤氮的热解析出特性及燃料ＮＯ_ｘ的形成规律邱建荣，马毓义，曾汉才，吕焕尧，喻秋梅（华中理工大学煤燃烧国家重点实验室武汉４３００７４）关键词：混煤，ＮＯ_ｘ，混合比，燃烧。ＥＭＩＳＳＩＯＮＯＦＮＩＴＲＯＧＥＮＣＯＭＰＯＵＮＤＳＡＮＤＮＯ_ｘＦＯＲＭＡＴ?..     

船形体煤粉燃烧器NO_x生成特性的研究

船形体煤粉燃烧器ＮＯ_ｘ生成特性的研究钟北京,徐旭常（清华大学煤的高效低污染燃烧国家重点实验室北京１０００８４）关键词煤粉燃烧器,“三高区”原理,ＮＯ_ｘ１前言我国电力工业的发展主要依赖于以煤为主要燃料,采用粉状燃烧方式的火力发电。１９９２年我国年产煤...     

逆向复式射流预燃室燃烧器

预燃室是一种高效、低ＮＯｘ排放很有发展前途的洁净煤燃烧技术。但是，目前由于其体积过大，使它在实际应用中受到限制。本文叙述的逆向复式射流预燃室燃烧器结构简单、体积小、燃烧效率高、煤种适应性强，可望成为符合洁净煤技术要求的高效、低ＮＯｘ主燃烧器。     

应用预蒸发技术燃烧液体燃料

本文介绍了一种燃烧液体燃料的新技术－预蒸发燃烧技术：通过分离液体燃料的蒸发过程和燃烧过程,实现液体燃料的“气体化”燃烧;重点介绍利用液体燃料着火前存在的冷焰燃烧现象实现燃料预蒸发的技术原理。与传统的燃烧技术相比,液体燃料的预蒸发燃烧具有高效率、低噪音、低有害污染物特别是ＮＯｘ排放、和易调节等优点。     

电子束辐照处理工业废气

介绍电子束射线辐照处理燃烧废气中ＳＯ_２及氮的氧化物ＮＯｘ的新方法，并与传统方法进行了比较． This paper introduces a new method of eletron beam radiation treatment of SO 2 and NO x in stack gases, with which the traditional methods are compared.     

CrOx在ZrO2上的分散状态及其CO还原NO性能的研究

利用ＸＲＤ和ＢＥＴ等物理技术研究了ＣｒＯｘ对ＺｒＯ２的抗烧结性能及Ｃｒ的分散状态ｒＯｘ是良好的ＺｒＯ２抗烧结剂,会抑制ＺｒＯ２晶型从无定形→四方→单斜的相变过程;ＣｒＯｘ与ＺｒＯ２之间的强相互作用还有利用于ＣｒＯｘ在ＺｒＯ２表面的分散,ＺｒＯ２表面的分散,ＮＯ的ＴＰＤ－ＭＳ实验表明,ＮＯ在ＣｒＯｘ／ＺｒＯ２表面存在两种与ＺｒＯ２作用强弱不同的吸附态,在程序升温脱附过程中发生了ＮＯ的离解反应。ＮＯ＋     

水平浓淡与上下浓淡煤粉燃烧方式气固混合特性的实验研究

本文针对四角切向燃烧锅炉燃用劣质煤时的稳燃及水冷壁高温腐蚀等问题,采用ＰＤＡ测量设备,对水平浓淡及上下浓淡两种煤粉燃烧方式下的气固两相混合规律进行了实验研究。实验表明,与上下浓淡煤粉燃烧方式相比,水平浓淡煤粉燃烧方式的气固两相流动特性使燃烧器在稳燃、低ＮＯｘ排放、防结渣、防高温腐蚀等方面具有优良的性能。     

造纸污泥流化床焚烧试验研究

在一座密相床截面积为 ０．２３ ｍ×０．２３ｍ、高度为 ５ｍ的流化床燃烧试验装置上进行了造纸污泥的焚烧试验．探明污泥水分、流化速度、二次风份额和过剩空气系数等参数对污泥燃烧性能的影响规律,为高水分造纸污泥焚烧炉的优化设计提供了依据．测试表明,在不添加脱硫剂情况下焚烧烟气中ＳＯ２、ＮＯｘ和Ｎ２Ｏ的排放浓度完全满足国家排放标准．     

掺铒SiOx1.54μm强的室温光致发光

采用等离子化学汽相溶积方法,改变ＳｉＨ４和Ｎ２Ｏ的流量比制备含有不同氧浓度的ＳｉＯｘ,用离子注入方法将铒掺入ＳｉＯＸ,Ｃ ３００－９３５℃快速热退火。     

低温太阳热能与化学链燃烧相结合控制CO2分离动力系统

本文探索并提出控制CO2分离的低温太阳热能与清洁合成燃料甲醇-三氧化二铁化学链燃烧相结合的新颖能源动力系统。基于图象(?)分析方法,明确地指出甲醇化学链燃烧能量释放过程燃烧堋损失减小和低温太阳热能品位提升的机理。从能源有效利用和环境相容出发,研究和揭示化学链燃烧与太阳能有机整合共同减小CO2分离能耗的特性规律。相比不分离常规联合循环,新系统(?)效率提高约6．2个百分点;与分离CO2的联合循环相比,新系统媚效率提高约14．2个百分点。同时,低温太阳热能热转功效率可达到22．5％。     

煤基化学链燃烧过程中硫的演变

在双阶段流化床反应器内,基于溶胶凝胶法制备的Fe2O3/Al2O3氧载体研究了褐煤化学链燃烧过程中燃料硫的迁移路径及分布特性,并讨论了温度、过氧系数对燃料硫释放分布的影响.结果表明:所有工况下,氧载体均未出现被硫化的现象;在热解气化学链燃烧阶段,气相含硫物质以SO2和H2S为主,煤焦气化气化学链燃烧阶段绝大部分为SO2气体,部分来源于煤焦中CaSO4的分解。另外,部分燃料硫被碱金属固定于煤灰中。同时,提高温度和过氧系数都能导致SO2/H2S值和SO2释放量增大。     

Advances in high throughput screening of gas sensing materials

The workflow of a high throughput screening setup for the rapid identification of new and improved gas sensor materials is presented. The polyol method was applied to prepare nanoparticulate metal oxides as base materials. These materials have been modified by surface and volume doping. Using multielectrode substrates and high throughput impedance spectroscopy (HT-IS) a wide range of materials could be screened on a short time scale. Selected examples reflect the state of the art for applying HT-IS in search of new selective gas sensing materials.     

溶胶凝胶自燃烧法合成金属与合金材料研究进展

本文综述了溶胶凝胶自燃烧法制备金属与合金材料的研究进展, 详细介绍了该方法的实验原理和技术路线, 通过实例介绍了该方法在制备金属和合金材料中的具体应用. 通过这一系列的工作介绍, 我们证实可以把传统的溶胶凝胶法制备氧化物材料的技术拓展到金属与合金材料的制备, 希望能够对材料研究的实验工作有所帮助.     

Filtration combustion of a porous structure in a multicomponent gas environment

A mathematical model for describing the quasi-isobaric filtration combustion of porous materials with the formation of condensed reaction products in a multicomponent gas is developed. Two-stage combustion waves (control modes) at the counter filtration of gas mixture are examined. The effect of inert gas component on the structure of a two-stage filtration combustion wave is studied, and the critical conditions of the changeover between filtration combustion modes caused by inert gas concentration variation are determined. It is demonstrated the characteristics of the two-stage combustion front propagating in the control mode in a multicomponent gas flow depends on the porosity of the heterogeneous system.     

低温太阳热与甲醇化学链整合能量释放机理实验初探

本文在低温太阳热能与CH3OH-Fe2O3化学链燃烧相结合控制CO2分离动力系统的基础上,进一步探讨了低温太阳热能品位提升的内在规律,分别揭示出辐照强度与CH3OH-Fe2O3反应特性、低温太阳热能品位提升的关联关系.本文采用溶胶凝胶法制作了Fe2O3反应颗粒,在热重反应器中进行了模拟太阳热能与甲醇化学链实验的初步研究,通过电镜,分析了反应前后金属氧化物的表面形貌特征.研究成果将为低温太阳热能与化学链燃烧整合能量释放新机理的研究提供理论依据和基础实验数据.     

Oxide Materials for Development of Integrated Gas Sensors—A Comprehensive Review

In the recent past a great deal of research efforts were directed toward the development of miniaturized gas-sensing devices, particularly for toxic gas detection and for pollution monitoring. Though various techniques are available for gas detection, solid state metal oxides offer a wide spectrum of materials and their sensitivities for different gaseous species, making it a better choice over other options. In this article a critical parameter analysis of different metal oxides that are known to be sensitive to various gaseous species are thoroughly examined. This includes phase of the oxide, sensing gaseous species, operating temperature range, and physical form of the material for the development of integrated gas sensors. The oxides that are covered in this study include oxides of aluminum, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, indium, iron, manganese, molybdenum, nickel, niobium, ruthenium, tantalum, tin, titanium, tungsten, vanadium, zinc, zirconium, and the mixed or multi-component metal oxides. They cover gases such as CO, CO₂, CH₄, C₂H₅OH, C₃H₈, H₂, H₂S, NH₃, NO, NO₂, O₂, O₃, SO₂, acetone, dimethylamine (DMA), humidity, liquid petroleum gas (LPG), petrol, trimethylamine (TMA), smoke, and many others. Both doped and undoped oxides are analyzed for the compatibility with silicon processing conditions and hybrid microcircuit fabrication techniques. In silicon processing conditions, they are further analyzed for the suitability for simple silicon surfaces, silicon-on-insulator (SOI) surfaces, and micromachined silicon geometries for different operating temperatures. Discussion on gas-sensing properties of each material and its applications are described in the text in alphabetical order of the elemental oxides. Further, the gas-sensing properties like sensitivity, detection limits, operating temperature, and so on are summarized in tables al ong with relevant references. The figures incorporated in the present review are primarily based on discussions and data in tables. However, these figures provide a qualitative comparison and present a pictorial view to examine suitability of a material for a particular application. From the known parameters, the present study clearly indicates the suitability of certain materials and the gases that they cover for the development of integrated micro gas sensors. A clear picture has been brought out for the development of silicon-based processing technology. Various parameters are discussed for the selection of these materials, to examine their suitability and practical problems that are being associated. Etching of these metal oxides and the reliability of devices are also discussed.     

Metal particle combustion and nanotechnology

Metal combustion has received renewed interest largely as a result of the ability to produce and characterize metallic nanoparticles. Much of the highly desirable traits of nanosized metal powders in combustion systems have been attributed to their high specific surface area (high reactivity) and potential ability to store energy in surfaces. In addition, nanosized powders are known to display increased catalytic activity, superparamagnetic behavior, superplasticity, lower melting temperatures, lower sintering temperatures, and higher theoretical densities compared to micron and larger sized materials. The lower melting temperatures can result in lower ignition temperatures of metals. The combustion rates of materials with nanopowders have been observed to increase significantly over similar materials with micron sized particles. A lower limit in size of nanoenergetic metallic powders in some cases may result from the presence of their passivating oxide coating. Consequently, coatings, self-assembled monolayers (SAMs), and the development of composite materials that limit the volume of non-energetic material in the powders have been under development in recent years. After a brief review of the classifications of metal combustion based on thermodynamic considerations and the different types of combustion regimes of metal particles (diffusion vs. kinetic control), an overview of the combustion of aluminum nanoparticles, their applications, and their synthesis and assembly is presented.     

Characterization of AZ91D Granules Covered with a Flux during In‐Situ Melting

Oxidation and melting behaviors of AZ91D granules throughout the in‐situ melting process using flux were investigated. The granules were heated under unprotected environment at four different temperatures between 650 and 800 °C, for the durations of 30 and 60 min. The products of heating process were characterized macroscopically and the oxides formed on the granules were examined using field emission scanning electron microscope, energy dispersive X‐ray spectroscopy and X‐ray diffraction analysis. Thermal analysis was used to reveal the response of the granules to heating during the in‐situ melting. The results showed that the granules experienced severe oxidation even in the presence of the flux, and significant amount of them changed to a powdered state due to oxidation and combustion, especially at 800 °C. It was discovered that the granules melted during heating; however, oxides formed on their surface encapsulated the molten metal and prevented the liquids from merging. The results also revealed that increasing heating temperature and time enhanced mold‐magnesium reaction resulted in the entrance of mold materials into the oxidation residues.     

Propagation of Cellular Modes of Titanium-Powder Layer Combustion in Air Channels,Allowing for the Effect of Natural Convection of Gas

In this paper, we have studied the effect of impurity and inert gases on the formation and propagation of cellular-combustion regimes for their inhomogeneous distribution above the surface of the reacting metal layer. The gas-dynamic aspects of the formation and steady propagation of inhomogeneous wave structures in the combustion of a titanium powder layer in through and semi-closed inclined air canals and in channels with uneven loading are considered. The gas composition heterogeneity over the reaction zone and the gas stratification, i.e., the stratification of a gas mixture of different densiies above the reacting layer, are shown to lead to the formation of inclined non-uniform and cellular fronts under conditions of a lack of active gas in the reaction zone and the loss of stability of the planar front.