不同富氧含量玻璃熔窑火焰空间温度场的对比

建立了玻璃熔窑火焰空间温度场的三维数学模型，通过对某日产400t燃油浮法玻璃熔窑火焰空间在三种富氧情况(氧含量分别是24％，27％，30％)下用图像模拟直观的表述出计算结果。模型包括气相流动与传热模型，雾化油滴燃烧的轨道模型，和辐射传热模型。程序采用MS-FORTRAN语言，绘图采用Stanfordgraphic软件。对比结果表明，随着富氧含量的增加，各小炉火焰长度明显缩短，温度显著提升，模拟结果对窑炉设计与富氧燃烧组织有一定的参考价值。     

燃天然气浮法玻璃窑炉的三维数值模拟

建立了具有实用意义的浮法玻璃熔窑三维数学模型,将火焰空间燃烧模型、配合料熔化模型、玻璃液流动模型进行耦合计算,求解出玻璃熔窑火焰空间、玻璃液流的温度场、速度场分布及配合料堆的长度分布。以日产400t的燃天然气浮法玻璃熔窑为对象研究了其火焰空间内气体、窑池内玻璃液的流动情况及各自的温度场分布。从模拟结果可以看出,该三维耦合数学模型能够比较客观地反应燃天然气浮法玻璃熔窑的速度场和温度场的分布规律,对燃天然气浮法玻璃熔窑的设计和运行具有一定的实用价值。     

应用图像处理技术进行预混层流火焰传播速度的在线测量

利用图像处理技术，根据层流预混火焰稳定燃烧的条件结合预混火焰燃烧模型，设计了火焰传播速度在线实时测量系统，通过图像采集在线获取火焰的静态图像，然后自动对图像进行滤波，边缘提取，再进行计算得到火焰传播前沿面积，在线算出火焰传播速度，这种方法具有非接触式测量的优点，利用它不仅可以测量层流预混火焰的传播速度，同时还为层流火焰的燃烧机理的研究提供一种直接的手段．     

新型燃烧模型在柴油机燃烧模拟中的应用(上)

将每个计算单元分为燃料区、空气区和混合区3个区域,在火焰传播方向上又将每个区域分为已燃区和未燃区,建立了柴油机的三区相关火焰燃烧模型,利用该模型对超多喷孔柴油机和传统柴油机缸内燃烧过程进行三维数值模拟,不仅得到了与试验值相符的气缸压力、NOx和SOOT排放量等结果,而且获得了柴油机缸内混合气的浓度场、温度场、NOx质量...     

新型燃烧模型在柴油机燃烧模拟中的应用(下)

将每个计算单元分为燃料区、空气区和混合区3个区域,在火焰传播方向上又将每个区域分为已燃区和未燃区,建立了柴油机的三区相关火焰燃烧模型,利用该模型对超多喷孔柴油机和传统柴油机缸内燃烧过程进行三维数值模拟,不仅得到了与试验值相符的气缸压力、NOx和SOOT排放量等结果,而且获得了柴油机缸内混合气的浓度场、温度场、NOx质量...     

基于支持向量机的火焰状态识别方法

电站锅炉燃烧稳定性的定量判别一直是一个难题。作者首先对火焰图像进行特征提取，提取出火焰亮度、火焰高温亮度、火焰面积、火焰高温面积、火焰高温面积率、质心偏移距离和圆形度等7个特征量。然后分别对这个特征空间和原始图像数据使用支持向量机对其进行识别分类，结果表明：两种数据结果相同．能够正确识别燃烧火焰状态．证明特征量的提取是成功的；支持向量机方法用于燃烧火焰的分类识别是可行的。图4表1参8     

湍流预混燃烧的小火焰模型

由Level set方法确定湍流预混燃烧火焰面的位置,考虑CHEMKIN库详细化学反应机理,通过PDF方法建立湍流预混燃烧数学模型,计算组分浓度和温度在火焰内部分布。以矩形突扩燃烧室为例,模拟甲烷/空气预混燃烧的平均火焰位置和火焰内部温度、浓度分布,计算结果与实验结果吻合良好,表明此模型能较好模拟湍流预混燃烧。     

一维湍流预混火焰的数值模拟

建立湍流燃烧的“双流体”数学模型,用于一维湍流预混稳态火焰的描述,假定燃烧火焰由冷的反应物（预混气体）和热的生成物（燃烧产物）组成,它们既有各自的属性,又相互作用,进行热量,质量和动量的交换,采用Patankar和Spalding的Phoenics计算程序来求解该数学模型,成功地模拟了一维湍流参混火焰的压力场,密度场,速度场。     

磁场对油池旋转火焰温度影响的研究

通过磁场对油池旋转火焰燃烧特性影响的理论分析和实验研究，得到不同磁场强度对旋转火焰燃烧温度的影响程度，从而了解实际燃烧过程中旋转火焰在有磁场作用下的燃烧特性。通过理论分析和实验研究可知：在一定的磁场强度下，旋转火焰的温度随磁场强度的增加而增加，但是其增加的幅度是有限的。这对研究实际火灾中火旋风的燃烧特性具有重要意义。     

电站锅炉火焰检测及燃烧诊断技术

电站锅炉的安全运行主要决定于燃烧的稳定性，实时探测燃烧火焰是否稳定，及时作出判断，对电站锅炉安全运行有着重要的实际意义。本文分析了炉膛火焰特征与火焰检测和燃烧诊断的关系，论述了火焰检测的基本原理和方法以及燃烧诊断理论和技术，并对目前火电厂燃煤锅炉应用的各种火焰检测器和燃烧诊断系统进行了分析比较，最后讨论了火焰检测及燃烧诊断技术的进一步研究方向。     

3．0Mt／a重催装置余热锅炉现状及节能技术改造

兰州石化公司炼油厂3．0Mt／a重油催化裂化装置的两台余热锅炉在运行中存在烟气侧运行阻力大、排烟温度高、省煤器给水入口温度低、存在尾燃等问题。采用翅片管结构省煤器、提高助燃空气温度、改造燃烧器、布置正压防爆固定旋转式蒸汽吹灰器对余热锅炉进行节能技术改造。改造后,两台锅炉炉膛压力分别由改造前的2.8kPa和2.7kPa降到1.9kPa和1.8kPa,余热锅炉烟气侧阻力降低;锅炉排烟温度由300℃降到205℃,烟气热量利用率和锅炉热效率得到提高;增设给水预热器后,省煤器给水温度及出水温度分别提高到150℃和240℃,外取热器及油浆蒸汽发生器多产蒸汽10t/h,两台锅炉总产汽量增加了60t/h,产生效益1908.42万元。     

Experimental Studieson Gas－Particle Flows and Coal Combustion in New Generation Spouting－Cyclone Combustor

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A new framework for modeling coal devolatilization and combustion in boiler furnaces

This paper presents a new framework for the modeling of coal‐fired boiler furnaces. The input required for the model is the ultimate analysis of a coal sample. The model accounts for devolatilization followed by gas‐phase combustion. The devolatilization model used in this work is taken from published literature with slight modifications to match the numerical predictions with experimental measurements. This work also develops a reactor network model for simulating the performance of boiler furnaces. For the seamless integration of kinetic models of coal devolatilization and combustion with furnace numerical model, the thermochemistry data of several hypothetical and intermediate species involved in devolatilization chemistry are evaluated in the form of 14 coefficient National Aeronautics and Space Administration polynomials. The capability of the model for predicting the furnace temperature and product composition is demonstrated by simulating a single‐zone model. Copyright © 2017 John Wiley & Sons, Ltd.     

Experimental studies on Gas—Particle Flows and Coal Combustion in New Generation Spouting—Cyclone COmbustor

Based on previous studies, an improved non-slagging spouting-cyclone combustor with two-stage combustion, organized in perpendicularly vortexing flows, is developed for clean coal combustion applied in small-size industrial furnaces and domestic furnaces. The isothermal model test and the combustion test give some encouraging results. In this study, further improvement of the geometrical configuration was made, a visualization method and a LDA system were used to study the gas-particle flow behavior, and the temperature and gas composition in combustion experiments were measured by using thermocouples and a COSA-6000-CD Portable Stack Analyzer. Stronger recirculation in the spouting zone and the strongly swirling effect in the cyclone zone were obtained in the improved combustor. The combustion temperature distribution is uniform. These results indicate that the improved geometrical configuration of the combustor is favorable to the stabilization of coal flame and the intensification of coal combustion, and it provides a basis for the practical application of this technique.     

水热媒技术在连续重整装置加热炉烟气余热回收系统中的应用

为回收加热炉的余热,扬子石化公司在1．39Mt／a连续重整装置应用了水热媒余热回收技术,以中压锅炉给水为热载体,利用从烟气中回收的热量来加热锅炉给水和预热助燃空气,达到降低排烟温度,减少燃料消耗,提高加热炉热效率和高压蒸汽产量的目的。介绍了水热媒技术的原理、特点、工艺流程以及装置实际应用中的运行步骤、注意事项和改进措施。运行结果表明,水热媒余热回收系统能够适应加热炉负荷和燃料性质的变化,排烟温度调节灵活;混合排烟温度和助燃空气温度达到了设计要求,能有效防止低温露点腐蚀,延长了设备使用寿命;加热炉群平均热效率达91．15％．节约能量为5．543MW,全年可节约燃料3812t,每年可产生经济效益1334万元。     

Effect of heat transfer space non-uniformity of combustion chamber components on in-cylinder heat transfer in diesel engine

Combustion chamber components (cylinder head-cylinder liner-piston assembly-oil film) were treated as a coupled body. Based on the three-dimensional numerical simulation of the heat transfer of the coupled body, a coupled three-dimensional calculation model for the in-cylinder working process and the combustion chamber components was built with domain decomposition and boundary coupling method, which adopts the coupled three-dimensional simulation of in-cylinder working process and the combustion chamber components. The model was applied in the investigation of the influence of space non-uniformity in heat transfer among combustion chamber components on in-cylinder heat transfer. The results show that the effect of wall temperature space non-uniform distribution of combustion chamber components on heat transfer happens mainly at the end of the compression stroke and expansion stroke. Therefore, it can be concluded that wall temperature space non-uniform distribution of combustion chamber components would influence heat transfer during the intake and exhaust stroke obviously.     

An investigation of the combustion of pulverized coal-air mixture in different combustor geometries

A two-dimensional theoretical study of the flow and combustion of pulverized coal by diffusion flames is presented. The model predicts gas flows, species concentrations, and temperatures in combustors having specific geometries. The conservation equations are solved utilizing the κ-ε turbulence model. Coal devolatilization is modeled by the two-competing-reactions scheme, which generates two sets of volatiles and char, each by a specific rate constant, described in Arrhenius form. Char combustion from devolatilization occurs by reaction with oxygen, carbon dioxide, water, particle dispersion, and radiative heat transfer between furnace wall and particles. The model is used to investigate the interaction between flow and combustion in flames produced by arranging the locations of the primary inlet and the secondary air inlets in a furnace. The predictions, which could be valuable for designing furnaces, indicate that a centered primary inlet and a minimum recirculation are some of the criteria that could favorable for combustion.     

延迟焦化加热炉存在问题分析与整改

惠州炼油420×104t/a延迟焦化装置加热炉采用美国FW公司双面辐射斜面阶梯炉,每台加热炉由6个辐射室、1个对流室组成。每个辐射管程设置单独的一个炉膛。共用的对流室安装在辐射室上,用于原料预热和蒸汽过热。该加热炉运行16月后,出现对流炉管结焦、排烟温度上升、部分炉管堵塞等问题。造成对流段结焦的主要影响因素,是回炼催化油浆以及注水温度相对偏低,导致渣油中沥青质析出;排烟温度高的主要影响因素是炉管结焦与对流段取热不足。对此,增加两排对流管、一排注水管、一排低低压蒸汽过热管。操作方面,主要优化措施有:停止催化油浆进焦化回炼,提高注水温度,注水方式从单点注水改为两点注水;同时平稳操作,减少焦粉携带。通过技术改造与操作优化,加热炉运行平稳,排烟温度显著降低,基本消除了加热炉对流段的结焦因素,加热炉在线清焦周期明显延长。     

Meeting emission standards with high-sulfur coals

The economics of strategies for meeting sulfur oxides (SO_x) emission standards from furnaces fueled with high-sulfur coals has been assessed based on published data. The strategy of SO_x control depends on how the coal is utilized. For large power plants, flue-gas desulfurization (FGD) is preferable to conversion of coal to clean fuel. In comparison with coal conversion, the total capital and operating costs for FGD are almost an order of magnitude lower, thermal efficiencies are higher, and utility requirements are lower. Even with possible breakthroughs in coal-conversion technologies, it appears that FGD will remain the economically preferred route to desulfurization. FGD has been in commercial operation since 1968, and the reliability of the process has reached an acceptable level. For industrial furnaces, direct combustion is preferred to gasification because gasification is inherently expensive. Fluidized-bed combustion is the only viable option for clean direct combustion of coal in small industrial furnaces. Fluidized-bed combustion has reached commercial status and is economically competitive in many parts of the world. For furnaces requiring gaseous or liquid fuels, gasification to medium-Btu gas is preferred. For domestic and commercial uses, coal can be gasified to clean, low-Btu gas. This is an old process and might be amenable to cost reduction through application of new technologies. The only other economically viable approach involves the production of clean solid fuel by compounding coal with additives such as limestone and manganese nodules.     

Analysis on energy consumption and performance of reheating furnaces in a hot strip mill

Energy consumption and performance of reheating furnaces in a hot strip mill is analyzed by means of both numerical predictions and practical measurements in this study. In the numerical part, three different heating curves representing various heating rates of the furnaces are simulated and compared with each other. The results indicate that increasing production rate of the furnaces is conducive to utilizing fuel more efficiently. In the practical aspect, when the furnaces are treated as a system, the measurements reveal that near 80% of heat in the furnaces is contributed by fuel combustion and 15.7% by hot flue gas. It follows that energy recovery via heat exchanger plays an important role in energy management. Furthermore, the practical measurements suggest that the efficiencies of heat exchange and heat recovery in the recuperating zone are 86.66% and 47.76%, respectively.