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.     

2016年上半年中国大高炉生产指标浅析

由于大高炉是中国高炉炼铁先进技术的集中代表,大高炉具有单位容积投资经济、能耗低、环境负荷低、劳动生产率高的优点。为了给中国大高炉及其他类型高炉生产提供有效的参考及对比,选取中国21座4 000 m3及以上高炉2016年1—6月部分生产技术指标进行分析,从生产、操作参数及原燃料等方面剖析大高炉生产指标和技术特点。并通过分析2016年上半年的中国大高炉生产指标,针对性地提出一些建议,供各企业参考。     

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。     

Making blast-furnace smelting more efficient through the injection of heated natural gas

Subjecting natural gas to multi-stage heating by passing it through the cooled cavities of certain tuyere elements instead of coolant water is technically simple to accomplish and makes it possible to heat the gas to 300°C or more, the exact temperature depending on the amount of gas used. The cost of instituting this technology is an order of magnitude lower than the savings realized by injecting heated natural gas into blast furnaces. The injection of heated natural gas into a blast furnace introduces additional heat into the furnace and makes it possible to use more natural gas in the smelting process without reducing the theoretical combustion temperature. It also increases the value of the coefficient that characterizes the replacement of coke by natural gas, since the gas undergoes more complete combustion in this case. Finally, the injection of heated natural gas results in a more uniform distribution of hydrogen across the furnace and allows fuller use of this element in the smelting operation.     

Theoretical Approach to Change Blast Furnace Regime With Natural Gas Injection

The operation of blast furnace using natural gas and oxygen enriched blast (composite blast technology) is considered in many countries to be standard operation for a modern blast furnace particularly in certain countries with cheap and stable supply of natural gas. The theoretical flame temperature (TFT) of combustion and the degree of direct reduction of iron oxides (r_d) arc considered as the main controlling parameters of composite blast technology. The calculated values of these parameters are mainly dependent on the amount of air blast consumption. This amount of air blast is measured before entering into blast stoves. Actually, some of air blast is lost through valves of air stoves. Consequently, the real volume of air blast in the furnace is less than the recorded value by amounts of 5% ? 15% which is not considered in the estimation of r_d and TFT. The purpose is to analyze the different methods for estimation of air blast inside the blast furnaces and develop a theoretical model to calculate air blast consumption with high accuracy. Based on the calculation of air blast consumption, a complete roadmap is demonstrated to change the operation regime parameters of blast furnaces working on composite blast technology.     

高炉设计的新体系

由于富氧、喷煤等等炼铁技术的发展,过去采用的炉缸面积燃烧强度、冶炼强度为基础的高炉设计方法已经不适用了。应该建立中国的高炉设计体系。高炉设计必须满足高炉强化生产的要求,笔者使用了近代气体动力学的成果,科学地分析了衡量高炉强化冶炼过程的因素－炉腹煤气量指数,用以指导高炉设计,形成新的高炉设计体系。     

中国高炉炼铁技术装备发展成就与展望

 近40年来，我国钢铁工业取得了巨大进步，钢铁产量连续多年居世界第一。我国高炉炼铁技术装备在大型化、现代化、高效化、长寿化等方面发展成就显著。2000年以来，一批5000m3以上特大型高炉、500m2以上大型烧结机、7.63m超大容积焦炉和年产400万t/a以上大型球团生产线相继建成投产，一系列自主研发、集成创新的炼铁关键技术在生产实践中取得重大应用成效。在技术装备大型化的同时，高炉富氧喷煤、无料钟炉顶、煤气干法除尘、顶燃式热风炉及高风温、高效低耗烧结技术、大型清洁炼焦技术等先进技术及其装备研发与应用成效显著，有力推动了炼铁技术装备进步。到本世纪中叶，我国钢铁工业格局和流程结构将发生重大变革，减量化、绿色化、智能化、高效化将是未来一个时期炼铁技术装备的主要发展趋势。     

山东高炉炼铁技术改造思路

介绍了高炉冶炼设施技术改造先进经验和体会 ,分析了山东高炉炼铁现状 ,提出了扩大高炉容积、改进炉底炉缸结构以及改造热风炉提高高炉入炉风温等山东高炉炼铁技术改造思路     

晋南钢铁高炉喷吹富氢气体工业化实践

 钢铁工业是中国制造业中碳排放量最高的行业,碳排放占全国碳排放总量的15%左右。高炉是钢铁工业碳消耗量最大的工序,碳消耗占钢铁流程总碳消耗的70%以上,减少高炉冶炼碳消耗是降低钢铁工业碳排放的最有效措施。高炉喷吹富氢气体不但可以提高冶炼效率,减少污染物排放,而且可以减少焦炭或煤粉消耗,从源头上降低高炉冶炼碳消耗,从而减少碳排放。以山西晋南钢铁两座1 860 m3高炉风口喷吹富氢气体工业化生产数据为例,详细研究了高炉喷吹富氢气体对燃料比、风口理论燃烧温度、炉腹煤气量、H₂利用率以及CO₂排放量的影响。结果表明,喷吹富氢气体可以显著降低高炉固体燃料消耗,在吨铁富氢气体喷吹量为65 m3条件下,富氢气体与固体燃料的置换比为0.49 kg/m3;风口喷吹富氢气体降低了风口理论燃烧温度,吨铁每喷吹1 m3富氢气体,风口理论燃烧温度降低约1.5 ℃,高炉鼓风量和炉腹煤气量都少量降低;喷吹富氢气体以后,炉内H₂的利用率平均为37.3%,CO的利用率约为43.2%;吨铁CO₂排放量可以降低80 kg左右,高炉CO₂排放降低了5.6%,取得了较好的经济、环境和减污降碳效果。     

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.     

冶金工业中的计算传热问题和计算传热学的应用

简要介绍了冶金工业的范围、主要流程以及传热问题的分布情况。对于计算传热学研究和应用比较集中与活跃的工艺流程及设备，例如铸锭过程、连铸、炉子和电解槽等，介绍了应用实例和主要方法。以连续加热炉为背景，对照介绍了计算传热学与现代控制理论在这类问题中的某些本质联系。     

2250mm 热轧生产线加热炉配置及其生产组织探讨

从精准设计的角度出发,针对2250mm 热轧生产线,通过连铸、热轧和加热炉小时产能的匹配分析初步确定该生产线应配置三座步进式加热炉.通过连铸、热轧和加热炉的生产节奏分析进一步验证了三座加热炉是较为紧凑的配置.最后研究了有利于直接热送热装的连铸-加热炉-热轧区段的平面布置,初步探讨并给出了4种加热炉的生产组织模式.     

高炉使用高比例球团的战略思考与球团生产的试验研究

 从战略发展角度分析了高炉使用高比例球团的优势和存在的问题,指出了高炉使用高比例球团的战略机遇。根据国内高硅铁精粉特点,开展了高硅酸性和熔剂性的镁质球团造球、干燥和焙烧等基础研究,分析了球团抗压强度、高温冶金性能、回转窑生产过程结圈形成机理等基础特性,提出了球团生产的基本操作参数设计特点,实现了链箅机回转窑生产高硅镁质酸性和熔剂性球团的稳定连续生产。完成了高比例球团矿高炉冶炼生产试验。实践证明,高比例球团矿冶炼的高炉生产稳定顺行,各项指标优于高比例烧结矿冶炼的高炉,操作思路可复制、冶炼结果可重现、操作经验可推广,并且环境效益巨大,SO₂、NO_x、PM和CO₂的排放远远优于高比例烧结矿生产的高炉。可以预见,优质冶金球团的制备和高炉高比例球团冶炼将是破解中国钢铁长流程降低污染物排放,实现低碳冶炼和可持续发展的最佳举措。     

空气、高炉煤气双蓄热燃烧技术在沙钢加热炉上的应用

介绍了空气、高炉煤气双蓄热式燃烧技术在沙钢集团润中轧钢步进梁式加热炉上的应用及整个蓄热式燃烧系统,解析了整个系统的优化过程,并列出了最终的优化结果.     

高炉炼铁的脱湿鼓风

从技术和经济角度分析了鼓风湿度对高炉冶炼的影响，阐述了适合脱湿鼓风的高炉生产条件，建议新建高炉均采用脱湿鼓风技术。     

同侧型开铁口机优化设计

开铁口机为高炉出铁场的主要设备之一,其工作性能直接影响高炉生产的稳定运行。为适应新型出铁场的各种需要,对同侧型开铁口机进行优化设计。改进后的设备已解决凿岩机开口困难、车轮跑偏及滑动、链条断裂等问题,同时为了适应近些年高炉工艺的不断优化,设备增加水雾吹扫、深度测量功能。生产实践证明,优化改进后的开铁口机在使用过程中取得了良好的效果。     

Stove with a self-supporting dome and an internal combustion chamber

Conventional stoves with a blast temperature of about 1000°C were previously used to heat the blast for the blast furnaces at the metallurgical plant in Koshitse, Slovakia. An increase in the useful volume of these furnaces made it necessary to heat a larger volume of blast and increase its temperature. A new stove with a self-supporting mushroom-shaped dome was built. The stove was provided with a checkerwork made of high-quality refractories and a lining with keyed joints was installed in the combustion chamber. The combustion products from the combustion chamber are discharged in the vertical direction. The lining of the dome is not connected to the outside lining of the stove. __________ Translated from Metallurg, No. 7, pp. 41–44, July 2006.     

满足高炉强化冶炼的铁口技术研究

根据各高炉实际情况的不同,通过控制合理的铁口深度、出铁间隔时间以及出铁速度,实现降铁次的目标,为高炉强化冶炼创造条件,达到降低生产成本和减轻工人劳动强度的目的。     

混合煤气在脉冲燃烧系统上的应用

介绍了720分厂以高炉煤气和天然气的混合气为燃料,在热处理炉上应用脉冲燃烧控制技术的情况,分析了生产实践中的故障.并提出了解决方法.     

钢铁厂流程结构优化与高炉大型化

高炉是钢厂生产流程中物质、能量最为密集的工艺装置,对钢厂的物质流网络和能量流网络的构建与合理化运行有着重大影响。高炉的功能不仅是通过还原反应过程获得优质的铁水,而且伴随大量的能量转换和信息的输入/输出过程,应当在整个钢铁生产流程结构优化的前提下,综合思考高炉的合理座数、合理容积和合理位置。通过分析国际高炉的发展趋势和首钢京唐钢厂5 576m3高炉与迁安钢厂4 080m3高炉的比较,建设2×5 576m3高炉和3×4 080m3高炉可以得到相近的产量,但前者在节省投资、能源节约和信息控制等方面具有明显优势。由此可以看出,为了优化钢厂生产流程,提高市场竞争力,高炉大型化是一种明显的趋势。但是,并不是追求单座高炉越大越好,更不应盲目追求"最大"。应该在产品结构、物质流结构、能量流结构优化和动态运行优化前提下实施高炉大型化。一般的趋势是一个高效益、低成本生产的钢厂应以2～3座高炉为宜,并由此得到高炉大型化的合理容积、合理座数及其合理位置。这种发展趋势不仅适合于生产薄板的大型联合企业,而且也适合于生产建筑用棒/线材的中、小型钢厂。