扩散过滤燃烧火焰特性

扩散过滤燃烧是新的燃烧技术,具有扩散燃烧和预混过滤燃烧的某些特性。通过二维双温模型,使用单步总包反应,数值研究氮气稀释的甲烷和氧气同轴同平板扩散过滤燃烧特性。模型中考虑热弥散和组分弥散效应。研究小球直径、气体混合物速度和甲烷质量分数对火焰高度和火焰形态的影响。结果表明,与预混过滤燃烧不同,气体和固体高温区存在于燃烧器的不同位置;而在高温区域之外,气体和多孔介质固体的温差很小。当填充床小球直径从6.66 mm减小到2.02 mm,火焰高度从0.048 m增大到0.12 m。增大混合物速度,甲烷的质量分数导致火焰变宽,火焰高度增大。数值模型的有效性得到了实验验证。     

炭化室高7.63m焦炉高向加热的控制

分析了兖矿7.63m焦炉的炉体结构特点,重点介绍了加热系统高向加热控制的情况。从炉体调节、设备加热、日常维护等方面,介绍了高向加热的各项控制手段:通过调节煤气喷嘴大小、调整喷射板等,逐步调整煤气及空气流量,得出各项适合7.63m焦炉高向加热控制的数据。通过高向加热控制,在保证焦炭均匀成熟的前提下,使焦炉达到最高的热工效率,提高焦炭质量和产量,提高焦炉生产率,最大程度地延长焦炉使用寿命。     

预混富氧燃烧火焰特性的实验研究

对预混富氧燃烧的火焰特性进行实验研究,结果表明:富氧浓度在21%～30%的范围内变化时,随着氧含量的增加,燃烧反应速率和火焰传播速度逐渐增加,进而引起燃烧区的缩小和温度梯度的增加。并且火焰高温区逐渐缩小,最高火焰温度逐渐增高,并且最高温度点向烧嘴口方向移动。     

7.63 m焦炉高向加热的调节

针对目前7.63m焦炉高向加热不均的情况,根据传统理论并结合焦炉的结构特点,以缩短立火道煤气燃烧火焰为目的,做了调节试验,均未达到良好效果。通过使用“低标准温度、低加热煤气压力”的炉温控制方法,焦炉高向加热均匀性得到一定改善。     

纯氧燃烧火焰玻璃抛光法及其工艺研究

纯氧天然气燃烧的火焰抛光方式由于抛光质量好,成品良率高,在现今玻璃制品行业得到广泛应用,然而由于纯氧天然气燃烧当暴露于空气时,实际火焰温度还不能满足玻璃表面质量的抛光温度要求。为此,本工艺将开发一种热氧火焰玻璃制品表面抛光方法,实际火焰温度最高可达2500℃,能够达到更好的抛光效果,且得到的副产物仅为二氧化碳和水,产品的良率更高,并且依照此方法制作出一套玻璃制品生产工艺,易于实现玻璃制品生产的自动化。     

富氧燃烧的火焰特性

燃料燃烧时必须有氧参与，自然状态下空气中氧含量是20．95％。所谓富氧燃烧就是增加空气中的氧浓度并使之燃烧。具许多优点的富氧燃烧，作为节能的新的燃烧技术，正在日益引人注目。但是从设计喷嘴的角度出发探讨富氧燃烧的节能特性的例子，为数不多。本文介绍了助燃空气中氧浓度增加到12－28％时火焰特性的变化，并对综合设计中各种通用喷嘴对富氧燃烧的适应性进行了实验研究，介绍了研究结果。     

92号汽油燃烧初期火焰光谱特征研究

为丰富油料火灾探测机理研究,自主搭建油料燃烧模拟实验台架,排除自然光线背景光谱等的影响后,使用光谱测量装置对油池中92号汽油燃烧火焰发射光谱数据进行采集,得到92号汽油燃烧初期火焰光谱。对92号汽油燃烧发射光谱进行频域分析、时域分析以及特征参数分析,得出其燃烧火焰发射光谱的相关性质:在380～780nm可见光波段,光谱强度较强,随反应的进行强度逐渐增大,随波长增大强度呈上升趋势,存在较多明显的特征谱峰,可以作为粗略检测92号汽油燃烧火焰辐射强度的特征区域。200～1 100 nm的整个波段内,初步可将光谱强度相对较大、特征峰值较易辨识的431、512、516、547、589、766、769、928、933 nm作为92号汽油燃烧火焰识别的标志波长。     

用照度计测定固体推进剂燃烧的火焰温度分布

本文介绍了用照度计测定固体推进剂燃烧火焰温度分布的原理、方法和装置。用标准温度灯验证了该测试系统。在常压、室温下测定了两种双基推进剂和一种复合推进剂的燃烧火焰温度分布。实验指出:双基推进剂的燃烧火焰温度分布符合稳态的燃烧模型,而复合推进剂燃烧的多次实验证明:在火焰相对长度20％和80％附近分别存在两个高温燃烧区;在火焰相对长度40％附近,存在着低温燃烧区。     

不同可燃液体层高度下浸润多孔介质砂床组合燃烧特性实验研究

为探究不同可燃液体层高度下浸润多孔介质砂床组合燃烧特性，开展了一系列不同粒径和液体层高度的燃烧测试，测量了燃料（乙醇）质量损失速率、火焰高度、多孔介质砂床（石英砂）温度和羽流温度等特征参数，分析研究了液体层高度的影响机制。结果表明：可燃液体层的存在对浸润石英砂层燃烧特性具有一定的影响。当砂层上方存在液体层时（h=20～60 mm），浸润石英砂层燃料质量损失速率明显增大，这可归因于液体层燃烧的预热作用。火焰高度随液体层高度增加而先增加随后几乎不变，表现为与质量损失速率相似趋势。浸润石英砂层内部在78.7～79.0℃（接近燃料沸点）出现温度增长迟滞，据此可对砂层内部蒸气区移动速率进行评估。随着液体层高度增加及石英砂粒径减小，砂层内蒸气区移动速率逐渐增大。此外，基于前人推荐的羽流关系和当前实验数据，获得了描述可燃液体浸润多孔介质砂床燃烧火焰羽流轴向温度经验公式。     

不同可燃液体层高度下浸润多孔介质砂床组合燃烧特性实验研究

为探究不同可燃液体层高度下浸润多孔介质砂床组合燃烧特性，开展了一系列不同粒径和液体层高度的燃烧测试，测量了燃料（乙醇）质量损失速率、火焰高度、多孔介质砂床（石英砂）温度和羽流温度等特征参数，分析研究了液体层高度的影响机制。结果表明：可燃液体层的存在对浸润石英砂层燃烧特性具有一定的影响。当砂层上方存在液体层时（h=20～60 mm），浸润石英砂层燃料质量损失速率明显增大，这可归因于液体层燃烧的预热作用。火焰高度随液体层高度增加而先增加随后几乎不变，表现为与质量损失速率相似趋势。浸润石英砂层内部在78.7～79.0℃（接近燃料沸点）出现温度增长迟滞，据此可对砂层内部蒸气区移动速率进行评估。随着液体层高度增加及石英砂粒径减小，砂层内蒸气区移动速率逐渐增大。此外，基于前人推荐的羽流关系和当前实验数据，获得了描述可燃液体浸润多孔介质砂床燃烧火焰羽流轴向温度经验公式。     

Colourless distributed combustion effects on a pre-mixed coke oven gas flame

Fuels consisting of high hydrogen concentration can be consumed under colourless distributed combustion (CDC) to suppress flashback tendency in premixed conditions. Higher NO_X challenges can also be overcome through CDC. For those purposes, coke oven gas was consumed under CDC within the scope of this study. To achieve CDC, ${\mathrm{N}}_2$ or ${\mathrm{CO}}_2$ diluents were introduced into the oxidizer so that oxygen concentration in the oxidizer would be decreased from 21% O₂ to its lean blow-off limits. Excess air ratios were determined as λ = 1.2 and λ = 1.5 along with a thermal power of 10 kW under premixed conditions. A commercial computational fluid dynamics code was used to predict temperature distribution and ${\mathrm{NO}}_X$, CO, and ${\mathrm{CO}}_2$ emissions. 162-step reactions created with GRI-Mech 3.0 chemical kinetics was integrated to the eddy dissipation concept combustion model. The temperature and ${\mathrm{NO}}_X$ profiles predicted were compared with the experimental results. Consistency was achieved at ~95% for temperature profiles, and almost 100% for ${\mathrm{NO}}_X$ profiles between the measured and the predicted ones. According to the results, it is concluded that a more homogeneous temperature distribution with the ~21% decrease in the maximum temperature was observed, and there was about 96% decrease in ${\mathrm{NO}}_X$ level. It was also demonstrated that using ${\mathrm{CO}}_2$ as a diluent is more effective in terms of temperature distribution over the combustor and ${\mathrm{NO}}_X$ reduction, while dilution with ${\mathrm{N}}_2$ is more effective in terms about 70% in decrease on CO.     

焦炉加热燃烧时氮氧化物的形成机理及控制

随着我国经济的快速发展,对焦炉排放氮氧化物的危害也日益重视,并准备制订排放控制标准。文中论述了氮氧化物在焦炉燃烧过程中的形成机理及控制措施。     

煤气质量对甲醇生产的影响及解决措施

由于煤气质量不能满足甲醇生产的要求，我公司焦炉煤气制甲醇装置投产后，甲醇生产不稳定。通过技术改造，增加了电捕焦油器、低温水洗、栲胶脱硫、焦炭过滤器等煤气处理方式，提高了煤气质量，满足了甲醇生产的要求。     

A flame metal combustion method for production of nanoparticles

We propose a flame metal combustion method for continuously synthesizing metal oxide nanoparticles. Micro-sized metal powder precursors were injected into a hydrogen-oxygen flame through a newly designed feeder system in order to be completely converted into metal oxide nanoparticles with good crystallinity. There is no limitation in the selection of precursors including metal, metal chloride and metal organic powders to synthesize nanoparticles. Various oxides such as magnesia, iron oxides and zinc oxide were demonstrated to be successfully generated by using this method. The sizes of oxide nanoparticles were controlled by varying flame temperatures and residence times.     

焦炉煤气低NOx燃烧技术研究进展

介绍了焦炉煤气燃烧NOx排放情况和NOx生成机理,总结了废气循环、空气分级、燃料分级、高温贫氧、浓淡偏差燃烧、低NOx燃烧器、催化燃烧等低NOx燃烧技术的研究进展,指出实现焦炉煤气低NOx排放燃烧是以后的研究重点。低NOx燃烧技术与传统的焦炉、锅炉等燃烧方式相结合,可望实现焦炉煤气的高效、低污染排放燃烧。     

焦炉煤气合成二甲醚关键技术研究

研究了焦炉煤气提氢后经粗甲醇直接合成二甲醚技术,自主研制了醇醚联产二合一生产装置,开发了高活性WD型催化剂和汽化提馏塔等设备。主要技术指标:硫含量≤0.1ppm,二甲醚纯度≥98%,甲醇含量≤1.5%。     

The influence of swirl angles on flame stability in pilot-scale plant

The article presents observations on the behaviour of coal dust-air flames imposed in pilot-scale plant by variations in the angle of swirl of the secondary air stream. It suggests some explanations for the existence of limits of stability, with the most probable for the lower one being the increase in dwell time of mixed eddies in the furnace, mitigating any stochastic increase in delays in mixing or in chemical ignition or, most likely, a combination of both. Two possible interpretations are offered for the occurrence of an upper limit. One is an increase in heat losses from the flame to the cooler furnace walls and the second is based on the concept of flame stretch.Some of the contrasts between the probable behaviour in pilot- and full-scale plant are emphasised and suggestions made, where present results might be applied to the latter.     

智能自适应焦炉加热系统的实施与应用

提出了焦炉智能自适应加热管理的自动控制方案,通过在新余焦化厂2号焦炉上的应用,较好地解决了长期以来由传统控制方案带来的滞后导致焦炉炉温波动大、耗热量高的弊端,取得了较为明显的经济效益和社会效益。     

Determination of reactivity and ignition behaviour of solid fuels based on combustion experiments under static and continuous flow conditions

The reactivity and ignition behaviour of solid fuels is a major parameter for combustion and gasification processes, but also for a safe transport and storage of pyrophoric solids. In this work, seven non-isothermal methods were compared with respect to characterise the ignition behaviour as well as to calculate kinetic parameters; for comparison also ‘classical’ isothermal measurements were done. Different methods and reactors (fixed and fluidised bed, thermogravimetry, oven heating tests) were used and tested under static and continuous flow conditions, taking charcoal, activated carbon and blast furnace coke as model solid fuels. The accuracy of all tested methods to determine kinetic data is reliable within a range of confidence of about ±50 K (with respect to the temperature needed to reach a certain level of reactivity). For a fast and relative simple determination of kinetic data, the ignition test in a small lab-scale fixed bed reactor can be recommended. Additional calculations show that the critical parameters with respect to ignition during transport and storage can also be calculated quite accurately based on this method, i.e. no elaborated basket heating tests are needed.     

Catalytic combustion of methane in the presence of organic and inorganic compounds over La0.9Ce0.1CoO3 catalyst

The catalytic combustion of the emission from coke ovens containing various volatile organic compounds (VOCs) and inorganic species over a La_0.9Ce_0.1CoO₃ catalyst is investigated in an integral fixed reactor through several steps. (1) Combustion of a mixture of VOC reveals that the kinetics of total oxidation of methane determines the total VOC conversion. (2) The conversion of methane, in the case of sulfur-free feed is inhibited by H₂O and CO₂.