喷吹循环煤气氧气高炉的静态模型

根据整体及各区域的物理化学约束条件建立了氧气高炉工艺综合数学模型.通过模型的计算结果对能量在不同区域的利用情况进行了分析.得出结论如下:氧气高炉无煤气循环流程的一次能耗很高,燃料比在600 kg/tHM以上,并且无法实现高温区和固体炉料区之间的能量匹配.炉顶煤气循环后,可以实现能量在高温区和固体炉料区的同时平衡;在同时满足全炉热平衡和区域热平衡的条件下,氧气高炉炉身喷吹循环煤气流程的理论燃烧温度过高,而炉缸喷吹循环煤气流程的理论燃烧温度偏低;对于氧气高炉炉身、炉缸同时喷吹循环煤气流程,随着循环煤气量的增大,焦比升高,煤比降低,理论燃烧温度可以维持在合理的范围内.     

氧气高炉喷吹焦炉煤气数学模型

 为降低氧气高炉炼铁流程中循环煤气脱除CO2及煤气预热成本,提出了氧气高炉喷吹焦炉煤气炼铁流程,并建立了新流程能质平衡数学模型,应用该模型分别对传统高炉、传统高炉喷吹焦炉煤气、氧气高炉（鼓风氧体积分数为30%、40%、50%、100%）喷吹焦炉煤气炼铁流程主要技术参数进行计算并对比。结果表明,传统高炉喷吹少量焦炉煤气（30 m3/t）可降低燃料比13 kg/t,焦炉煤气置换焦炭的置换比为0.433 kg/m3,但是对其他参数影响不大。氧气高炉喷吹焦炉煤气流程随着富氧率提高,炉内还原势提高,CO和氢利用率下降,炉内存在还原剂表观过剩,非全氧鼓风条件下炉内没有发生氮气富集。新流程外供煤气总热值为3 000 MJ/t左右,与传统高炉相比变化不大,对现有钢铁联合企业煤气供需平衡影响较小。全氧高炉喷吹焦炉煤气炼铁流程相较于目前的高炉炼铁流程可节焦43%,增煤33%,总燃料比降低20%。     

高炉富氧喷吹还原性气体工艺分析

为降低高炉炼铁中固体碳耗、高效利用冶金高温副产煤气,提出高炉富氧喷吹还原性气体工艺流程,建立基于物料平衡与热平衡的高炉数学模型,并修正了理论燃烧温度计算公式。应用该模型分别对传统高炉、炉缸富氧喷吹还原性气体以及炉身喷吹循环煤气的炼铁流程进行技术参数分析。结果表明,炉缸富氧喷吹还原性气体以及炉身喷吹循环煤气的炼铁流程中,当氧气浓度达到50%、炉缸还原性气体喷吹量为267 m3/t时,焦比为291 kg/t,煤比为150 kg/t,直接还原度为0.195,相比传统高炉,燃料比降低109 kg/t,综合能耗降低4.8%。还原性气体温度每升高100 ℃,可多喷吹5.8 m3左右的还原性气体,降低焦比约5.5 kg/t;还原性气体喷吹量对理论燃烧温度影响较大,炉缸每喷吹1 m3/t、1 000 ℃的还原性气体,理论燃烧温度可降低约1.9 ℃。     

顶煤气循环氧气高炉低碳炼铁技术综合评价

顶煤气循环氧气高炉工艺是一种新型高炉炼铁工艺，具有大幅降低燃料比、减少CO₂排放和提高铁水生产效率等优点。对于氧气高炉的内部生产状态、整体生产指标、能量利用以及经济效益等进行了深入的系统性研究。通过顶煤气循环氧气高炉多流体模型，对风口喷吹循环煤气与风口炉身同时喷吹循环煤气2种路线下不同操作参数对氧气高炉的冶炼状态、生产指标、氧气高炉的能量利用效率以及经济效益的影响进行了研究对比。结果表明，随着理论燃烧温度的增加，氧气高炉焦比上升，产量进一步增大，高炉的热力学完善度和■效率降低，氧气高炉的综合效益增加。在只有风口喷吹循环煤气的条件下，与理论燃烧温度2 000℃的案例相比，理论燃烧温度为2 184℃时，焦比上升至243.9 kg/t,产量增加至5 538.3 t/d,热力学完善度由90.69%降低至88.30%,经济效益由13 540万元/a上升至16 252万元/a。与风口喷吹循环煤气的路线相比，风口和炉身同时喷吹循环煤气的顶煤气循环氧气高炉具有更大的产量、节焦量、热力学完善度、■效率以及更高的综合经济效益。在理论燃烧温度为2 184℃,炉腹煤气流量为3 881 m...     

氧气高炉炼铁技术分析

对氧气高炉进行了数值模拟,数值模拟结果表明氧气高炉炉顶煤气循环利用,可以降低燃料消耗5%左右,炉顶煤气CO2进行储存及资源化利用,可以减少CO2排放56%以上。通过分析氧气高炉的工业化试验情况,说明氧气高炉要实现低成本生产,尚需要解决高效喷吹及全流程优化控制技术,循环煤气加热技术,炉顶煤气CO2脱除技术和CO2储存及资源化利用技术四个关键问题,同时为发展氧气高炉炼铁新工艺提出建议。     

氧气高炉的发展历程及其在北京科技大学的研究进展

首先介绍了氧气高炉的发展历程,早期的研究工作主要着眼于解决由于氧气代替空气鼓风而引起的“上冷下热”问题,并总结了各国研究者提出的氧气高炉流程及其主要特点。随后系统阐述了北京科技大学科研人员在氧气高炉工艺基础研究与工程技术开发方面所取得的主要进展。这些研究包括氧气高炉流程设计,含铁炉料还原与软熔,氧气鼓风及循环煤气喷吹条件下的煤粉燃烧,循环煤气加热过程中的物理化学变化等炉内反应与变化,以及在此基础上开展的回旋区及全炉数值模拟研究,为氧气高炉的工程化实施奠定理论基础。最后对氧气高炉的碳素流及节碳潜力进行了分析,并提出富氢碳氢循环氧气高炉将成为炼铁低碳化的重要发展方向。      

工艺参数对气化炉-氧气高炉炼铁能耗的影响规律

利用气化炉一氧气高炉炼铁流程数学模型分析了工艺参数对高炉焦比、煤耗、总能耗等的影响规律。计算结果表明：随着氧气浓度的提高,高炉焦比逐步降低,当氧气浓度为100％时,流程可节能7．0％;随循环煤气温度的提高,高炉焦比略有减少,当循环煤气温度为1473K时,流程可节能8．5％。     

氧气高炉炉身喷吹煤气在炉内的分布

通过二维冷态物理模型对氧气高炉炉身喷吹煤气在炉内分布进行了实验研究,分别研究了炉身煤气总量、辅助风口直径以及炉身喷吹煤气量与炉身煤气总量之比对炉身喷吹煤气在炉内分布的影响.结果表明,炉身喷吹煤气量与炉身煤气总量之比对炉身喷吹煤气在炉身分布起决定性作用,而炉身煤气总量和辅助风口直径的影响较小.同时,在炉身煤气上升过程中涡流扩散效应的影响也较小.通过对根据实验数据绘制的炉身等浓度分布图进行研究发现,炉身煤气分布主要分为两个不同的区域,一个是炉身喷吹煤气主流区,另一个是从高炉下部产生的上升煤气主流区.在炉身等浓度分布图的基础上通过回归分析的方法推导出炉身喷吹水平喷吹煤气的渗透公式.此外,辅助风口被安装在炉身下部有利于铁矿石在炉身的间接还原.      

全氧高炉风口喷吹烧结烟气的冶炼特征

摘要：建立了高炉或氧气高炉喷吹烧结烟气的数学模型,实现对烧结烟气利用与处理的目的。模拟结果显示：当烧结烟气喷吹温度为1250℃,全氧高炉的炉缸与炉身处各循环200m3/t炉顶煤气时,烧结烟气喷吹量每增加100m3/t,高炉理论燃烧温度降低约134℃,直接还原度增大0.02。随着烧结烟气喷吹量的增加,煤比逐渐增大,炉顶煤气中氮气含量逐渐增大,SO2浓度逐渐降低。当烧结烟气喷吹量达到894m3/t时,炉顶煤气中的SO2质量浓度为214.28mg/m3,与普通高炉相比,降低约1.48mg/m3;氮氧化物质量浓度为45.42mg/m3,低于普通高炉约6.36mg/m3。     

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。     

Mathematical Modeling of the Energy Consumption and Carbon Emission for the Oxygen Blast Furnace with Top Gas Recycling

The ironmaking process is the most significant source of CO₂ emission in the iron and steel industry, which generates large quantities of greenhouse gases. Recently, oxygen blast and top gas recycling have been applied to the blast furnace to improve the energy efficiency and reduce the pollution from the ironmaking process. However, as a new ironmaking technology, the oxygen blast furnace with top gas recycling (TGR‐OBF) is still under development. This paper focuses on the investigation of the energy consumption and carbon emission for the TGR‐OBF process by modeling the stack, the bosh, the combustion zone, and the gas recycling system. Effects of the key parameters in the TGR‐OBF process on the carbon consumption of reactions and the energy consumption of the system are investigated by orthogonal experiments. Our results indicate that the TGR‐OBF process has the advantages of reducing energy consumption and CO₂ emission. The low temperature and high reducing environment in the new furnace is favorable to lower the coke gasification and increase the reaction rate of iron oxide. The recycling of the top gas can significantly reduce CO₂ emission, and the main advantage comes when the stripped CO₂ is stored.     

炉顶煤气循环氧气高炉一维气固换热与反应动力学模型

结合风口回旋区燃烧和炉外煤气预热、脱除和循环的平衡关系,建立了氧气高炉一维气固换热与反应动力学模型,并采用传统高炉的运行和解剖数据对模型进行了验证分析.通过模型研究了氧气含量和上部循环煤气流量对氧气高炉炉内过程变量的影响规律.结果表明:氧气含量偏低和上部循环煤气流量不足时,会降低铁矿石还原效果,炉渣内出现大量未还原铁氧化物;氧气含量和上部循环煤气流量的提高可以有效提高炉内CO含量和铁矿石还原速度,但提高上部循环煤气流量会大幅提升炉顶煤气温度,增大热量损失.与传统高炉相比,氧气高炉内CO含量提高1.0~1.5倍,炉内气体还原性更强;铁矿石还原完成位置提高1.49 m,全炉还原反应速度更快;直接还原度降低55.2%~79.2%,炉内直接还原反应消耗的碳量更少.      

Medium oxygen enriched blast furnace with top gas recycling strategy

Top gas recycling oxygen blast furnace(TGR-OBF)process is a promising ironmaking process.The biggest challenge of the TGR-OBF in operation is the dramatic decrease of top gas volume(per ton hot metal),which once led to hanging-up and shutdowns in practice of the Toulachermet.In order to avoid this weakness,the strategy of medium oxygen blast furnace was presented.The maneuverable zone of the TGR-OBF was determined by the top gas volume,which should not be far from the data of the traditional blast furnace.The deviation of ±12.5% was used,and then the maneuverable blast oxygen content is from 0.30 to 0.47 according to the calculation.The flame temperature and the top gas volume have no much difference compared to those of the traditional blast furnace.The minimum carbon consumption of 357 kg per ton hot metal in the maneuverable zone occurs at the oxygen content of 0.30(fuel saving of 14%).In the unsteady evolution,the N2 accumulation could approach nearly zero after the recycling reached 6 times.Thus far,some TGR-OBF industrial trials have been carried out in different countries,but the method of medium oxygen enriched TGR-OBF has not been implemented,because the accumulation of N2 was worried about.The presented strategy of medium oxygen enriched TGR-OBF is applicable and the strategy with good operational performance is strongly suggested as a forerunner of the full oxygen blast furnace.     

Numerical analysis of carbon saving potential in a top gas recycling oxygen blast furnace

Aiming at the current characteristics of blast furnace(BF)process,carbon saving potential of blast furnace was investigated from the perspective of the relationship between degree of direct reduction and carbon consumption.A new relationship chart between carbon consumption and degree of direct reduction,which can reflect more real situation of blast furnace operation,was established.Furthermore,the carbon saving potential of hydrogen-rich oxygen blast furnace(OBF)process was analyzed.Then,the policy implications based on this relationship chart established were suggested.On this basis,the method of improving the carbon saving potential of blast furnace was recycling the top gas with removal of CO_2 and H_2O or increasing hydrogen in BF gas and full oxygen blast.The results show that the carbon saving potential in traditional blast furnace(TBF)is only 38-56kg·t~(-1) while that in OBF is 138kg·t~(-1).Theoretically,the lowest carbon consumption of OBF is 261kg·t~(-1)and the corresponding degree of direct reduction is 0.04.In addition,the theoretical lowest carbon consumption of hydrogen-rich OBF is 257kg·t~(-1).The modeling analysis can be used to estimate the carbon savings potential in new ironmaking process and its related CO_2 emissions.     

炼铁系统节能减排技术的现状和发展

随着科技手段的进步,现代的高炉炼铁技术已经得到充分的发展。然而从资源、能源及环境的角度看,高炉炼铁系统仍然面临着严峻的压力,烧结、焦化、高炉的能耗及污染不容乐观。从不同方面分别介绍了国内外炼铁系统的节能减排的重要方法,围绕含铁原料、燃料、高炉系统分别介绍了烟气脱硫、干熄焦技术、TRT发电技术、全氧高炉- 煤气自循环技术及炉渣的综合利用等几种典型工艺,以及其对炼铁系统节能减排的主要作用,并通过研究提出了中国高炉节能减排的发展方向。     

氧气高炉工艺对炼铁系统的影响

为分析氧气高炉对炼铁系统的影响,利用氧气高炉综合数学模型,获得了2种典型氧气高炉流程的基本工艺参数,并主要分析了氧气高炉对炼铁系统燃料结构与煤气流平衡的影响。结果表明:氧气高炉降低了吨铁燃耗,同时提高了煤粉在燃料消耗中的比率;随着炉缸循环煤气预热温度升高,氧气高炉煤气供给量与炼铁系统需求量都呈下降趋势,其中单排风口工艺输出煤气量能满足炼铁系统内部需求并有较大剩余,双排风口工艺炉顶煤气供应由盈余转为短缺,但此短缺量较小,可以用少量焦炉煤气补足。在此分析基础上,提出了一种氧气高炉条件下炼铁系统工艺流程,有望为氧气高炉工业化应用提供一定参考。     

中国高炉TRT技术的应用现状和发展趋势

 高炉炼铁作为当代主要的炼铁工艺,其能耗在钢铁生产中占较大比例,必须以降低炼铁能耗作为中国钢铁工业系统节能的重点。高炉炉顶压力能约占高炉二次能源产生量的7%,若扣除高炉煤气化学能,则约占高炉余热余能产生量的33%,可见回收高炉炉顶余压能,对降低高炉炼铁工序能耗具有重要意义。因此,着重介绍了高炉TRT技术的发展历程,并对中国TRT技术应用过程中存在的问题进行了总结。最后,从能源利用的角度,提出TRT技术今后应重视大型高炉配备干式TRT技术、TRT与高炉操作协同优化和提高TRT作业率等方面的研究,以进一步提高TRT技术的节能效果。     

炼铁降低工序能耗的措施

通过对韶钢炼铁工序能耗进行分析和实施精料方针、采取合理操作制度、提高喷煤量、提高入炉风温、加强能源管理、充分回收利用高炉煤气等一系列措施，使韶钢炼铁工序能耗由1998年的505．037k标煤／t下降到2002年的389．872k标煤／t，达到全国同类型企业先进水平．     

Technical analysis on ironmaking process of rotary kiln pre- reduction and smelting by coal and oxygen

The traditional blast furnace ironmaking process has many problems such as long process flow, high dependence on coke and large environmental pollution. In order to solve these problems, the new ironmaking process of rotary kiln pre- reduction and smelting by coal and oxygen was developed. This new process has advantages of wide raw material adaptability, no coke consumption, less pollutant emissions and suitable for special iron ore resources. The mathematical model of the new process was established. Numerical simulation results show that the metallization rate of pre- reduction iron, smelting furnace gas oxidation degree and blast air oxygen content have great influence on coal and oxygen consumption. The coal and oxygen consumption reduces with the increase of pre- reduction iron metallization rate, the rise of oxygen degree of coal gas or the decrease of oxygen content of blast air. This process has a significant advantage in smelting special iron ore resources, which can make up the shortage of blast furnace ironmaking. It is also of great significance to reduce fuel consumption and CO2 emissions.