Comprehensive Mathematical Model and Optimum Process Parameters of Nitrogen Free Blast Furnace简

According to different energy utilization in different regions, blast furnace is divided into raceway zone, bottom heat exchange zone （BHZ）, thermal reserve zone （TRZ）, and top heat exchange zone （THZ）, and a mathe- matical model of nitrogen free blast furnace （NF-BF） is established. The optimum process parameters of two kinds of nitrogen free blast furnaces are calculated by the new mathematical model. The results show that for the nitrogen free blast furnace with a single row of tuyeres, the optimum process parameters are coke ratio of 220 kg/t, coal ratio of 193 kg/t, and volume of recycling top gas of 577 m3/t; for two rows of tuyeres, the process parameters are coke ratio of 202 kg/t, coal ratio of 211 kg/t, volume of recycling top gas in upper area of 296 m3/t, and volume of recy- cling top gas in lower area of 295 ma/t. Energy balances are reached in different regions. Theoretical combustion temperature （TCT） in raceway zone is largely affected by different processes, and a lower TCT should be adopted for the single row of tuyeres, but for two rows of tuyeres, a higher TCT should be maintained. Compared with tradi- tional blast furnace, in NF-BF, the emission of CO2 would be reduced by 45.91% and 49.02G for a single row of tuyeres and two rows of tuyeres, respectively, and combined with CO2 sequestration technology, zero emission of CO2 could be realized.     

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The tuyere-damaged phenomenon of COREX-3000 was investigated, and the conclusion was found that the combined effect of both melting loss under high temperature and scouring abrasion by high speed air flow led to the damage of tuyeres. The methods from five aspects were proposed to reduce the dilapidation of turyere through analyzing thermal distribution of COREX tuyere combustion zone. Based on that above, the measures that small coke was chosen as substitutes for part of Shanxi coke and oxygen-nitrogen blending injection replaced the oxygen injection were taken by Baosteel, which effectively prolonged the working life of tuyere.Besides, the effects of the measures above on COREX were analyzed in detail, and the following results show:Using Baosteel small coke improved the burden permeability to avoid that heat is gathered in tuyere combustion zone; Oxygen-nitrogen blending injection reduces heat production in tuyere combustion zone, lowers the heat conduction ability of air flow, and forms one thin carbon-nitride protective layer on tuyere surface to prolong the working life of tuyere.     

Uniformity of Blast-Furnace Parameters over the Perimeter

Operational experience with the 5000-m³ blast furnace 9 at the Krivorozhstal plant shows that nonuniform blast distribution over the tuyeres results in very nonuniform distribution of the theoretical combustion temperature, the yield of blast-furnace gas, and the total energy of the blast flux and flux of blast-furnace gas over the hearth perimeter. That, in turn, significantly affects the smoothness of furnace operation, its productivity, the coke consumption, and the quality of the hot metal produced. The influence of 1% change in the variation coefficients of the input blast parameters on the productivity and coke consumption is taken into account. The results may be used in factorial analysis of periods of blast-furnace operation with different parameters. The nonuniform distribution of the blast flow rate over the tuyeres has the greatest influence on furnace performance. Therefore, it is necessary to find means of ensuring uniform distribution of blast at constant temperature over the tuyeres.     

基于T-S模型的高炉喷煤协同优化控制策略研究

高炉炼铁过程通过增煤减焦实现节能减排目标,针对人工操作模式存在主观性、粗糙性和滞后性难以实现增煤减焦的问题,采用上下协同优化控制方法,一方面通过上部提前匹配减焦方式维持高温区热平衡,另一方面通过富氧鼓风保证下部喷入煤粉的高消化率,使煤粉在风口回旋区充分燃烧.进而从控制角度解析描述增煤减焦过程,将铁水温度的稳定控制问题转...     

Influence of phosphorus on the reduction of silicon in regions characterized by droplet flow of the smelting products

The influence of phosphorus on the thermodynamics of silicon reduction in Fe-Si-C melts is considered. The influence of the theoretical combustion temperature of coke in the tuyeres on the silicon content is studied in the blast-furnace smelting of low-phosphorus hot metal at AO Arcelor Mittal Temirtau.     

氧气高炉工业化试验研究

在8m2氧气高炉上进行了工业化试验,试验氧气高炉炉缸和炉身各设1排风口,炉缸风口喷吹氧气和煤粉,炉身风口喷吹预热的焦炉煤气.试验结果表明:氧气高炉可以实现全氧大喷煤炼铁生产,吨铁喷煤量可以达到450kg,生产效率大幅度提高;炉身吨铁喷吹180ms预热焦炉煤气以后,焦比降低90kg,煤比降低50kg,生产效率提高约20%...     

循环流化床的燃烧数学模型

在循环流化床内物料浓度模型的基础上，重点进行了循环内煤的燃烧数学模型的研究，并借助模型考察了几个重要因素对循环床燃烧过程的影响。模型对煤在循环床的密相区和稀相区的燃烧过程采用了不同的处理方法。模型计算结果与实验结果基本吻合，证明了模型的可靠性。     

炉缸煤气流分布的影响因素

 高炉大型化是炼铁发展的趋势,随着高炉炉缸直径的不断变大,中心不活跃区域越来越大,如何引导煤气到达炉缸中心已成为炼铁工作者关注的焦点。为了解决上述难题,通过建立炉缸煤气流动三维模型,应用CFX数值模拟软件计算煤气流速,分别研究了炉缸直径、焦炭粒径、空隙度以及鼓风动能对炉缸煤气流分布的影响。结果表明：即使炉缸内焦炭粒径及空隙度分布均匀,边缘煤气流速依然大于中心煤气流速,并且炉缸直径越大,中心煤气流越弱。炉缸内焦炭粒径和空隙度分布影响煤气流分布,提高炉缸中心焦炭粒径和空隙度有利于引导煤气到达炉缸中心。同时,为了保障高炉稳定顺行,鼓风参数必须和炉缸透气性协调一致,不能过于依靠提高鼓风动能吹透中心。     

氧气高炉风口前燃烧带数值模拟

根据气膜传质控制理论,在物料平衡和能量平衡的基础上,建立了O2高炉风口前燃烧带数学模型,模拟了不同鼓风速度和O2湿度条件下风口前燃烧带内气体各组分浓度场和温度场分布情况。模拟结果表明：改变鼓风速度可以调节风口前燃烧带气体温度和浓度分布,从而调节O2高炉软熔带形状及煤气流分布;增加鼓风湿度可以降低风口理论燃烧温度,增大还原煤气中H2含量。     

唐钢4~#高炉风口破损原因分析及对策

对唐钢4#高炉近期风口大量破损的原因进行分析,发现风口破损的主要原因是焦炭质量波动、炉缸不活、热制度及造渣制度波动以及送风后慢风时间较长所致。通过提高焦炭质量改善炉缸工作状态、改变出铁制度等措施均可预防休风时的风口大量破损,从而为后续炉况恢复奠定基础。     

Modelling and visual verification of combustion zone transfer in ultra-thick bed sintering process

The propagation of the combustion zone is of great importance to the ultra-thick bed iron ore sintering process. A two-dimensional unsteady level modelling of the combustion zone propagation was developed. Influences of sintering bed height and coke content on the combustion zone propagation characteristics were analysed and discussed. Simulation results were compared with the results of visual sintering pot test which was straightforward and distinct to clarify the combustion zone propagation. Calculation of this numerical simulation was performed for various sintering bed height and coke contents. Both the increase of sintering bed height and coke fraction in raw mix resulted in the improvement of thickness and maximum temperature of the combustion zone. Simulation results were consistent with the measured data.     

冶金焦炭质量的评价

通过高炉入炉焦和风口焦的性质测试,揭示了入炉焦和风口焦的质量差异及其评价方法。     

2号高炉技术进步

2号高炉于1997年3月底停炉大修，这次大修采用了无料钟炉顶，霍戈文内燃式高温热风炉等新技术，强化进程较快，通过技术攻关，实现了单铁口不放上渣冶炼，风口损坏较少，利用系数达到2．0，煤比100kg/t,入炉焦比410kg/t，技术经济指标水平比上一代显著提高。     

炼铁过程使用木炭和生物质以及废塑料减少CO2的排放

根据实验室研究,提出了两种可应用于钢铁行业降低CO2排放的方法:利用可再生的生物质或木炭以及利用可回收的含氢废旧塑料。该方法可通过以下两个途径实现:①风口喷吹;②混入入炉炉料,例如:通过混入炼焦煤而进入焦炭,在生产用于高炉或直接还原的球团原料中添加含碳原料和塑料。为考察现代高炉风口喷吹木炭的益处,重点研究了木炭在风口回旋区的气化行为和在风口回旋区外的二次反应。采用实验室装置及其相应的检测设备,研究了几种木头在不同炭化条件下所得到的木炭的转化效率。研究结果表明,对于风口喷吹,所测试木炭的燃烧行为都不逊于矿物质煤;在模拟的高炉炉身条件下,木炭的熔损反应速率高于试验所用的矿物质煤。使用塔姆曼炉试验装置及检测仪研究了可用于直接还原和高炉的冷固结含碳、废塑料和木炭球团的还原和体积变化行为。使用该种球团可抑制和减小还原膨胀,甚至出现体积收缩。球团的自还原行为受还原气的量、气氛和操作条件的影响。采用电阻炉进一步研究了固结废塑料(聚乙烯和垃圾衍生燃料)的氧化铁的还原行为。     

熔融气化炉风口回旋区冶炼特征的数值模拟研究

相比于高炉风口喷吹富氧热风,熔融气化炉风口采用常温纯氧,使得炉内质量、动量、热量的传输以及煤气流分布等冶炼特征与高炉存在较大差异.通过建立熔融气化炉风口回旋区二维数学模型,系统考察熔融气化炉风口回旋区内速度分布、温度分布及气体组分分布的冶炼特征.结果表明:在气固相热交换及焦炭 (或块煤形成的半焦) 燃烧反应的综合作用下,熔融气化炉风口回旋区内气体温度迅速升高至3 500 K以上;此外,风口前端存在小规模的气体循环流动现象,故风口前端扩孔破损现象严重,进而导致非计划休风率较高;为减少此类休风现象,可适当额外喷吹富氢燃料性气体 (天然气、焦炉煤气),不仅能降低风口回旋区内气体温度,更可替代部分固体燃料,并充分发挥其中H₂的高温还原优势,提升熔融气化炉冶炼效率.      

3D model study of coal/coke combustion in a blast furnace effects of coal properties

A three-dimensional mathematical model of the combustion of pulverized coal and coke has been developed.The model is applied to the blowpipe-tuyere-raceway-coke bed region in an ironmaking blast furnace in one computational domain,which includes two parts:pulverized coal combustion model in the blowpipe-tuyere-raceway cavity and the coal/coke combustion model in the surrounding coke bed.The effects of coal properties are examined comprehensively,in terms of coal burnout and gas species distributions.The ...     

应用非高炉炼铁技术处理固体废弃物

先进国家利用熔融还原技术开发了高温焚烧炉，这种带有焦炭床，富氧和双排风口的高温炉，可以达到对固体废弃物进行无害化和资源化的处理，由于我国的资源条件有限和国内高炉喷煤量的迅速提高，应用非高炉炼铁技术在国内形成规模产业是非常困难的，不过利用非高炉炼铁技术，特别是其中的熔融气化炉技术，开发适合处理我国固体废弃物的工艺，可以使我国环境保护方面赶上世界先进水平，这也为非高炉炼铁技术在国内应用提供了一个新的领域。     

鞍钢2580m3高炉降低综合焦比生产实践

鞍钢股份有限公司炼铁总厂为了降低2580m^3高炉综合焦比。通过采用精料方针、调整布料制度、控制冶炼强度、调整送风风口面积等措施。综合焦比由530kg／t下降至500ke4t水平,实现了经济化生产。     

Maintaining the working profile of blast furnaces during service

This article looks at the current working profile of blast furnaces at the Krivorozhstal’ combine. The profiles were formed during a period in which the operation of the furnaces was not forced, the supply of raw materials was inconsistent, and furnace output was irregular. The results of studies show a need for closer monitoring of the cooling system and the parameters of the profile of furnaces in the period before a scheduled maintenance. Timely action needs to be taken to eliminate problems in furnace operation caused by the presence of thick slag crusts. It is shown that the variable slag-formation conditions about the furnace circumference are due mainly to factors that affect the smelting operation from below — nonuniform blast delivery and a nonuniform distribution of the blast among the tuyeres, as well as local differences in drainage and the movement of coke in the hearth. These differences depend on the location of the iron notches. It is noted that the aggressiveness of alkalis and zinc in blast-furnace shafts has increased. An efficient furnace profile can be maintained by limiting the entry of aggressive compounds into the furnace and washing its interior to remove such compounds from the circulation loop.     

高炉理论燃烧温度计算的研究

 理论燃烧温度是判断高炉炉缸热状态的重要参数之一。 在深入分析现有理论燃烧温度计算模型存在问题的基础上,提出修正建议 ：绝热系统内除煤气之外还应包括燃料燃烧后的残留物及未燃煤粉;所有物质的比热容应是温度的函数;焦炭的温度应为高温区热平衡计算所得;同时,考察了这些修正因素对理论燃烧温度计算值的影响。