Mathematical simulation and experimental study on coke oven gas injection aimed to low carbon blast furnace ironmaking

Coke oven gas (COG) tuyere injection is recognised as one of effective measures to achieve low carbon blast furnace ironmaking. In this paper, simulation of blast furnace operation with COG injection was investigated by means of multi-fluid blast furnace model, and the softening-melting and dripping behaviours of mixed burden were studied on basis of simulation results. The model simulation shows that, with COG injection rate increasing, the concentration of inner-furnace hydrogen is enhanced obviously. Cohesive zone moves downwards and becomes thinner. The column permeability gets better. Hot metal productivity increases and CO₂ emission reduces. Compared with conventional operation without COG injection, when COG injection rate is 152.34?Nm³/tHM, column pressure drop is decreased by 31.5% and hot metal productivity is increased by 26.36% and CO₂ emission is decreased by 17.54%. Therefore, the simulation and experimental results reveal that it is achievable to improve blast furnace operation performance, such as hydrogen-enriched reduction, better column permeability, high efficiency, low carbon emission and so on.     

高炉喷吹常村贫煤时煤粉的利用率

根据岩相显微分析和化学分析的结果,计算了宝钢1^#高炉在进行常村贫煤工业实验时炉尘中未消耗煤粉中的含碳量,确定了常村煤的加入量在20%～40%的条件下炉尘中的含碳量和未消耗煤粉含碳量.给出了宝钢高炉在不同喷煤条件下煤粉在高炉内的利用率.     

Forecasting and scenario planning in the steel packaging industry: case of tinplate petfood cans

Abstract

Modelling national and global steel markets using macroeconomic variables provides a workable basis for forecasting aggregate steel consumption. At the market sector level, paucity of data and distortion hinder equivalent headway. Neural networks are applied to this problem with results that enhance those of conventional econometric models, but are nevertheless variable. A forecasting and scenario planning methodology is developed to manage the variability in the results of market models, and to manage the uncertainty remaining in the market due to major trends and events that are the realm of judgmental forecasting not statistical models. The result is a scenario planning tool that allows the business decision maker to effectively exploit the information available on the petfood sector of the metal packaging market.     

高炉喷煤的氮气复用技术

伴随着国家经济的起伏,钢铁企业在高速发展十几年后也进入了调整期。调整产品结构、淘汰落后设备、改革细化现有的工艺流程、提高工艺水平、降低能耗、节约成本已成为很多钢铁企业重视的工作。阐述了在高炉喷煤操作系统中,通过改革工艺放散管道的结构,实现氮气重复利用,并将此工艺流程实现全自动化操作的控制过程。     

兰炭对高炉混煤喷吹特性的影响

采用WCT-2C型微机差热天平、灰熔点测定仪、BT-1000粉体综合特性测试仪和可磨性测试仪,研究了兰炭配加质量分数为0、30%、40%、50%和100%时对无烟煤燃烧性、反应性、灰融性、流动性和可磨性的影响。结果表明,兰炭可以改善无烟煤的喷吹特性。随着兰炭含量的增加,煤粉着火温度及燃尽温度降低,燃烧时间缩短,综合燃烧指数明显提高,燃烧特性得到改善,煤粉的反应性增强,灰熔融性温度和可磨性指数均降低。兰炭的加入对煤粉的流动性(混煤流动性指数和喷流性指数)影响不明显。而且兰炭配加质量分数不超过40%时,混煤可以满足高炉喷吹条件。     

Submerged liquid slag injection in steel melt: scaleup study using cold model and dimensional analysis

Abstract

Submerged injection of solid flux powder is used in the steel industry to eliminate impurities in an economical way. The efficiency of such an injection process is limited by the fact that only a fraction of the injected particles penetrate into the liquid melt, while the majority remain as bubble encapsulated solids, causing poor heat and mass transfer. Therefore, liquid slag injection can be considered a potential alternative technique in the refining of steel to improve the efficacy of mass transfer in such a process. In the present work, liquid slag injection in a steel melt has been simulated by means of laboratory scale cold model experiments in which, water, paraffin oil and benzoic acid have been used as low temperature analogues for liquid steel, slag and impurities, respectively. Through dimensional analysis it is observed that the modified Froude number can be considered as a criterion for scaling up such a process from a bench scale to a full scale system. A regression analysis has also been carried out to correlate the dimensionless mass transfer rate constant with the relevant dimensionless numbers, namely, dimensionless gas velocity, Froude number, aspect ratio and non-dimensional lance depth.     

高炉喷煤用立式烟气炉的研制与实践

介绍了立式烟气炉的设计制作与生产应用。     

13m^3高炉喷吹粒煤工业试验研究

１３ｍ＾３小高炉喷吹粒煤（－２ｍｍ）试验目的是考察小高炉喷吹粒煤的可行性及其工艺技术特点。在无富氧和较低风温条件下，喷吹粒煤３３～５６ｋｇ／ｔ，置换比达０．７３～０．６６，取得了与喷吹粉煤相近的效果。喷粒煤期间炉缸活跃，产量提高，炉况顺行，质量改善。     

高、转炉煤气应用于蓄热式轧钢加热炉的特性研究

研究了高炉煤气和转炉煤气的燃烧温度变化规律及应用特点。通过理论计算,分析了炉气成分及燃气种类对炉气发射率和炉内传热过程的影响规律。进行了蓄热式加热炉在蓄热过程中的热量平衡计算,得到了空、煤气在不同预热温度下烟气利用率的变化规律,并进一步分析了烟气利用率对加热炉产生的影响。此外,对比分析了使用两种煤气时对设备投资及现场空间布置的影响。     

武钢高炉喷吹用混合煤粉燃烧试验研究

利用TG-DTG-DSC热分析方法对武钢常用烟煤、无烟煤的混合燃烧特性进行实验研究,根据实验数据评估了不同种类烟煤、无烟煤混合使用的最佳配比,武钢炼铁厂根据实验结果,将某些烟煤、无烟煤混合喷吹时挥发分逐渐由14%提高到16%以上,达到了扩大烟煤用量、维持高炉顺行、降低成本的目的,取得了较好的使用效果。     

Influences of taphole numbers on hot metal circumferential flow in blast furnace hearth

The circumferential flow of hot metal has a significant influence on the hearth erosion. Because the situation of the hearth is ??black box??, there is no direct examine method for the hot metal flow. Based on the computational fluid dynamics, the streamline and velocity were studied with different deadman conditions and different tapholes. The results show that when the hot metal tap with single or double tapholes (with the angle of 40??) and the deadman is at the sitting condition whose center is fine coke, the circulating hot metal is the most serious in the hearth. When the hot metal tap with double tapholes(with the obtuse angle), the circumferential flow of hot metal is weakened. The sitting deadman could strengthen the hot metal circulution. However, the floating deadman could weaken hot metal circulution, but it strengthens the hot metal flow of the bottom.     

高炉喷吹用煤的可磨性研究

在对高炉喷吹用煤和兰炭进行工业分析的基础上,对不同比例兰炭与煤混合试样的可磨性分别进行了测试分析。结果表明,试验用煤和兰炭的水分含量均高于喷吹用煤指标要求,可磨性指数普遍偏低,其中高挥发分烟煤的可磨性最低,不符合喷吹用煤要求。     

大型高炉布料参数对煤气流的影响

高炉装料制度与炉况参数之间存在着内在的紧密联系,高炉布料仿真模型是装料制度与炉况参数的纽带.本文利用高炉布料仿真模型计算出区域焦炭负荷指数和炉料落点,并与煤气流参数K值、热负荷、炉喉钢砖温度建立了回归方程.研究了平台+漏斗和中心加焦两种布料模式下布料参数调整方式与煤气流参数的关系,得出了大型高炉煤气流控制方面的操作要点.     

Influence of conveyance methods for pulverised coal injection in a blast furnace

Pulverised coal injection (PCI) is a widely adopted industry practice for reducing blast furnace coke rates. The conditions under which pulverised coal (PC) is injected and combusted, including the co-injection of natural gas (NG), can lead to complex combustion phenomena inside the blast furnace, which must be understood to provide improved furnace performance. This research examines computational simulations of the co-injection phenomena, as well as the industrial drivers behind the project. A wide-ranging parametric study was conducted utilising numerous variations in furnace operating conditions, as well as a new technique for the conveyance of PC. It was found that utilising NG as the carrier gas for PCI could increase coal burnout across the raceway region from about 71% to approximately 87% without altering the design of the tuyere/blowpipe region, with an increase to 96% possible if a shift to a dual lance design for NG injection is considered.     

Research on main technical parameters of blast furnace with natural gas injection

With the application and popularization of blowing natural gas in blast furnace, it is necessary to study the thermodynamic behavior of natural gas and the variation of operating parameters in blast furnace. By the second law of thermodynamics, the reduction behavior of blowing natural gas in blast furnaces was analyzed. Based on the material balance and heat balance model, the influence of oxygen enrichment, blast temperature and humidity on the blast furnace bosh gas volume and the theoretical combustion temperature in the front of tuyere raceway after natural gas injection were discussed. The quantitative analysis of dynamic coupling effect was realized by linear regression on the effect of key parameters. The results show that natural gas first absorbs heat at high temperature and cracks into CO and H2, which helps to improve the volume fraction and reduction potential of CO and H2 in the gas and promote the indirect reduction reaction. Natural gas injection into blast furnace leads to the rapid increase in the bosh gas volume and the rapid decrease in the theoretical combustion temperature. The change of humidity has a great influence on the bosh gas volume and the theoretical combustion temperature, followed by the oxygen enrichment. However, the blast temperature has a mild influence due to the limited potential to change relatively.     

首钢高炉喷吹煤种的灰熔融特性

为了研究首钢高炉喷吹煤粉在风口前灰渣的熔点和高温黏度特性,采用灰熔点仪和FactSage软件对首钢几种常用喷吹煤种及混煤的灰熔融特性进行了对比分析,发现两种方法得到的结果具有相同的趋势。利用FactSage热力学计算软件,分析了1 600 ℃下京唐、迁钢两地喷吹煤灰在SiO₂-CaO-Al₂O₃-MgO(w(MgO)＝2%)四元相图中的位置,并对灰组分中SiO₂、Al₂O₃、CaO、MgO、Fe₂O₃对液相线温度和对高温下煤灰黏度的影响进行了分析。研究发现,不同灰组分改变对煤灰液相线温度和黏度的影响是不同的,灰组分对液相线温度的影响相对复杂。高温状态下,首钢高炉煤灰下灰组分中Al₂O₃、Fe₂O₃、MgO质量分数增加有降低煤灰黏度的作用,而SiO₂质量分数增加会增加煤灰黏度。混煤时应考虑不同组分对煤灰液相线温度和黏度的影响,通过合理控制灰组分达到控制风口前结渣的目的。     

神东烟煤水分对其高炉喷吹性能的影响

神东烟煤具有水分含量高的特征,这对其生产、运输、储存或用于高炉喷吹都会有影响。针对神东烟煤的这个特性,选用5种不同矿区的具有代表性的高水分神东烟煤,探究不同干燥时间条件下水分对其可磨性的影响,并使用高炉喷煤燃烧模拟试验装置研究其燃烧率随水分含量的变化趋势,将不同条件下的失水质量分数与分析水质量分数的比值定义为失水率,探究可磨性和燃烧率与失水率的变化关系。结果表明,失水率增大时,煤的可磨性和燃烧率均呈上升的趋势,随着干燥时间的延长,可磨性增大的趋势变缓,随着失水的增多,燃烧率和失水率近似呈线性增长的关系。     

喷吹天然气条件下高炉主要工艺参数的研究

摘要：随着高炉喷吹天然气技术的应用推广,需要对天然气在高炉内的热力学行为及其操作参数的变化进行研究。利用热力学第二定律,分析了喷吹天然气在高炉内的热力学还原行为。并以物料平衡和热量平衡模型为基础,探讨了鼓风富氧、鼓风温度、鼓风湿度等工艺参量对喷吹天然气后高炉炉腹煤气量和风口回旋区理论燃烧温度的影响及其变化。利用高炉操作参数对炉腹煤气量和理论燃烧温度影响结果进行线性回归,实现定量分析各因素之间的动态耦合效果。研究结果表明：天然气首先在高温下吸热裂解成CO和H2,有助于提高煤气中CO和H2的体积分数和还原势,促进间接还原反应的进行。高炉喷吹天然气导致炉腹煤气量快速升高,理论燃烧温度快速降低。鼓风湿度的变化对炉腹煤气量和理论燃烧温度影响很大,富氧率其次。而风温变化潜力有限,对炉腹煤气量和理论燃烧温度影响相对较小。     

高炉喷吹用煤粉的可磨性试验研究

对4种高炉喷吹用煤(晋城北、冬田良、青州和邯郸)进行了煤岩显微分析和工业分析,并且对各单煤的可磨性指数进行了测定,研究了磨煤温度对不同煤化程度单煤的哈氏可磨性指数的影响以及不同煤种混合煤的可磨性。试验结果表明,4种煤中冬田良煤含硫量以及青州和邯郸2种煤的灰分略高于指标要求,其他指标均可以满足喷吹用煤的指标要求;不同煤种单煤的可磨性指数相差较大,晋城北无烟煤的可磨性指数最低,不符合喷吹指标,需进行配煤提高其可磨性;随着磨煤温度的升高,不同煤化程度单煤的可磨性指数均有一些增加,对煤化程度较高的无烟煤的影响较小;不同煤种混合后煤样的可磨性指数并不等于各单一煤种的可磨性指数的加权平均值。