高炉瓦斯灰燃烧性能研究

对高炉瓦斯灰在空气气氛和富氧气氛下的燃烧性能进行了研究,结果表明在富氧气氛中燃烧,着火温度降低,燃尽温度前移,可燃指数和稳燃判别指数、综合判别指数均提高。通过与其他煤种对比可知,将瓦斯灰与煤粉混合有助于燃烧,将高炉瓦斯灰与煤粉混合后喷入高炉是利用高炉瓦斯灰的一项可行的技术。     

Numerical prediction and practical improvement of pulverized coal combustion in blast furnace

The burning characteristics of pulverized coal in blowpipe and tuyere at two different injection patterns are simulated numerically, to aid improving the practical performance of blast furnace. With the condition of the same fuel and oxidant mass flow rates, the predictions indicate that the combustion efficiency of pulverized coal using double-lance can be substantially enhanced compared with that using single lance. Accordingly, the pulverized coal injection in a practical blast furnace was modified from single lance to double-lance. As a result, the practical injection rate of the pulverized coal in the blast furnace was increased from 110 to 153 kg/tHM, revealing that a profound decrease in operating cost of the blast furnace has been implemented.     

炉内煤粉燃烧一维数学模型及其仿真

为了准确计算炉内煤粉的燃尽率,从研究煤粉粒子的燃烧机理入手,以炉膛内最复杂的燃烧器区域的煤粉燃烧过程为研究对象,通过合理简化煤粉中挥发分和焦炭的燃烧过程,建立了炉内煤粉燃烧沿高度方向上的一维宏观模型,在模型中考虑了煤粉燃烧过程中氧含量的变化,以单个煤粉颗粒燃烧的等密度模型为基础,通过多种煤粉粒径的燃烧过程反映煤粉燃烧的整体过程,推导出计算炉内煤粉燃尽率的显示公式,满足了实时仿真计算的要求。计算结果与实测数据和现有的文献相符,并对结果进行了分析。     

混煤燃烧特性的实验研究

选择武钢高炉混煤喷吹的某种烟煤和某种无烟煤为研究的煤源,对不同混合比例的混煤燃烧进行了实验研究。利用差热天平的TG—DTG—DTA热分析,探讨了烟煤不同掺混比对混煤的燃烧特性的影响规律和合适的烟煤掺混比例,阐明了烟煤掺混高炉喷煤技术经济指标的改善作用。     

循环流化床中石油焦与煤混合燃烧温度场研究

石油焦是炼油工艺的副产品．具有低灰分、一定挥发份和高热值的特性。焦中含有相当多的硫、氮元素和钒、镍等碱金属元素．这些成分在石油焦燃烧时可造成锅炉内腐蚀和沾污。经过技术对比认为：利用循环流化床燃烧技术将石油焦与煤混合燃烧是高效、清洁回收利用石油焦的有效方法。本文在热输入率为0．5MW的循环流化床热态试验装置上进行了石油焦与煤掺混燃烧炉内温度场研究,分析了石油焦与煤不同燃料配比,不同锅炉运行参数,如一次风率、过量空气系数、Ca／S比和给料量等对炉内温度场分布的影响规律。     

Comparison of combustion characteristics of petroleum coke and coal in one-dimensional furnace

The effect of primary air fraction f₁, outer secondary air swirl strength and excess oxygen coefficient on the combustion characteristics of petroleum coke, Hejin lean coal and Shenmu soft coal are researched on a one-dimensional furnace using a dual channel swirl burner. The results show that with the increase in primary air fraction f₁, the NO_x emission concentrations of both Hejin lean coal and petroleum coke increase, and the combustion worsens in the earlier stage, but the burn-out rate of Shenmu soft coal is improved. The NO_x emission concentration obtains a minimum value with an increase in f₁. The ignition and burn-out rate of petroleum coke and Shenmu soft coal are optimal when Ω_dl is minimum and Ω_dl=0.87, respectively. However, both the NO_x emission concentration of petroleum coke and Shenmu soft coal are minimum when Ω_dl=1.08. The increase in excess oxygen coefficient delays the ignition of petroleum coke, worsens the combustion condition and increases the NO_x emission concentration, but it greatly decreases the NO_x emission concentration of Shenmu soft coal.     

Pulverized coal burnout in blast furnace simulated by a drop tube furnace

Reactions of pulverized coal injection (PCI) in a blast furnace were simulated using a drop tube furnace (DTF) to investigate the burnout behavior of a number of coals and coal blends. For the coals with the fuel ratio ranging from 1.36 to 6.22, the experimental results indicated that the burnout increased with decreasing the fuel ratio, except for certain coals departing from the general trend. One of the coals with the fuel ratio of 6.22 has shown its merit in combustion, implying that the blending ratio of the coal in PCI operation can be raised for a higher coke replacement ratio. The experiments also suggested that increasing blast temperature was an efficient countermeasure for promoting the combustibility of the injected coals. Higher fuel burnout could be achieved when the particle size of coal was reduced from 60–100 to 100–200 mesh. However, once the size of the tested coals was in the range of 200 and 325 mesh, the burnout could not be improved further, resulting from the agglomeration of fine particles. Considering coal blend reactions, the blending ratio of coals in PCI may be adjusted by the individual coal burnout rather than by the fuel ratio.     

富氧燃烧条件下煤焦特性研究

以大同烟煤为研究对象,在高温携带流模拟反应器上,利用平流火焰燃烧器制取真实富氧燃烧气氛下的煤焦,对不同停留时间下制取的煤焦进行工业分析,讨论停留时间对煤焦的燃尽率、固定碳和挥发份的含量的影响,当停留时间超过94ms时,煤焦的各种参数保持不变.利用热重分析仪进行煤焦的燃烧实验,讨论不同O2/CO2(20/80、30/70和40/60)气氛对煤焦燃烧特性的影响,并采用Coats - Refern法计算煤焦的活化能和指前因子等动力学参数,460～660℃范围内,背景气氛O2/CO2为30/70时煤焦的活化能和指前因子数值最大,为进一步研究煤焦在富氧燃烧气氛中的燃烧反应提供理论依据.     

Minerals and iron-making reactions in blast furnaces

Coke is central to blast furnace operation, but because it is the most expensive raw material used, there is continuing pressure to minimize its use. Consequently, it has become increasingly pertinent to measure and predict the factors affecting coke performance more accurately. Coke performance is affected both by its properties and blast furnace operation. Recently, the importance of the minerals in coke in determining its performance in the blast furnace has been recognized. Minerals in coke influence its reaction with gas, metal and slag phases. This paper reviews coke behavior in an operating blast furnace with the main emphasis being on the role of its inherent mineral matter. Various techniques including advanced approaches such as scanning electron microscopy (SEM) and quantitative X-ray diffraction (XRD) have been used to identify and quantify coke minerals. Fundamental studies based on bench-scale reactors have highlighted the role of various mineral phases on the kinetics of gasification, hot-metal carburization and slag reactions. Because coke reaction rates are influenced by the constituent mineral phases differently, conventional ash analysis is not sufficient to determine the true impact of coke minerals on coke reactivity. The dominant catalytic phases of coke minerals can be identified and related to coke gasification with CO₂ at low temperatures. The kinetics of hot-metal carburization by coke and its temperature dependence is influenced by the melting behavior of minerals. Coke–slag reaction rates are largely influenced by total mineral matter content as well as composition. Coke changes its properties during descent through an experimental blast furnace (EBF) and some of these changes are presented. The increase in the ordering of the carbon in the coke as it descends the EBF can be related to increases in coke ordering in a bench-scale reactor, indicating that order in a particular coke may serve as a thermometer of its maximum exposure temperature. Moreover, coke fines emissions are influenced by the extent of graphitization in industrial blast furnaces. In contrast, coke reactivity in an operating blast furnace is influenced by recirculating alkalis as well as inherent mineral matter. Mineral phases of industrial cokes were found to be changed after CO₂ gasification with increasing reaction temperatures. Coke quality needs in current and emerging blast furnace process innovations are discussed to highlight that existing tests are not sufficient. A comprehensive coke quality index is required, particularly one that incorporates the heterogeneity of coke minerals, in order to make a reliable assessment of the impact of cokes on iron-making reactions.     

燃尽风喷口位置对NOx排放的影响

针对一台采用旋流式燃烧器的煤粉炉NOx排放质量浓度较高的问题,采用空气分级燃烧方式以降低NOx排放量,基于CFD软件平台,在额定负荷下,分别对3种不同燃尽风喷口位置的改造方案进行了炉内燃烧及污染物生成的数值模拟,并通过综合比较炉内各参数的变化确定了最佳燃尽风喷口位置．结果表明：燃尽风喷口位置的上移降低了主燃区氧气的体积分数,同时使炉膛内的最高温度降低了23～29K．燃尽风喷口位置对NO,的还原效果、出口烟气温度以及煤粉焦炭转化率的影响较大．当燃尽风喷口位置升高时,NOx质量浓度降低,炉膛出口烟气温度升高,煤粉焦炭转化率下降．经综合比较炉膛出口烟气温度、NOx质量浓度以及煤粉焦炭转化率得出,距最上层燃烧器7．7m处为最佳燃尽风喷口位置．     

Influence of blast‐furnace process thermal parameters on energy and exergy characteristics and exergy losses

The technology ‘blast furnace—converter’ dominates at present in the production of steel all over the world. Therefore, the blast‐furnace process is continuously being improved, among others, by raising the thermal parameters, such as temperature and oxygen‐enrichment of the blast, as well as the addition of auxiliary fuels. The changes in the consumption of coke go together with changes in the consumption of blast, the production of top‐gas and its consumption in Cowper stoves, as well as the production of electricity in the recovery turbogenerator utilizing the waste exergy of the top‐gas due to raised pressure. Related to a unit of pig iron production, these values are called energy (exergy) characteristics of the blast‐furnace plant. They serve as a quantity measure of the thermal improvement of the blast‐furnace process. This paper presents an algorithm of the process exergy analysis of simulative investigations of the influence of increased thermal parameters on the thermodynamic perfection of the process and the blast‐furnace plant. This algorithm bases on the theoretical empirical balance method of the ‘input–output’ type. By means of this algorithm the influence of increased thermal parameters of the process not only on the saving of coke but also of the blast can be determined, as well as of the production and composition of top‐gas, the consumption of top‐gas in the Cowper stoves and the production of electric energy in the recovery turbine. The blast‐furnace process displays a high exergy efficiency, whereas the process of compressing and preheating the blast is characterized by rather high exergy losses due to the application of the combustion process. It has been shown that the internal exergy losses in the blast furnace are comparable with the exergy losses in the processes of compressing and preheating of the blast. Calculations were carried out for a modern Polish blast furnace with a volume of 3200 m³. Copyright © 2005 John Wiley & Sons, Ltd.     

高炉脱湿鼓风节能研究及除湿方法的选取

对高炉鼓风除湿进行了节能分析,通过高炉系统的热平衡原理得出了理论燃烧温度,继而得出了鼓风除湿能降低焦煤消耗与提高产量的结论。通过研究得出了最佳除湿剂为LiCl及其最佳除湿浓度为40%,并对除湿剂的除湿原理进行了介绍与说明。     

石灰立窑代焦型煤燃烧特性的实验研究

在SDTQ600差热-热重联用仪上对石灰立窑代焦型煤试样进行了热重分析,研究了不同升温速率对其燃烧特性的影响,并以5℃/min的升温速率将型煤、焦炭和无烟煤块煤试样进行对比。利用马弗炉研究了单颗粒代焦型煤的燃烧速率。结果表明,代焦型煤的燃烧过程经历了干燥预热、挥发份析出、碳粒燃烧和残碳燃尽4个阶段;随着升温速率的增加,代焦型煤燃烧各阶段的反应时间缩短,反应速率加快;当升温速率由5℃/min提高至10和15℃/min时,代焦型煤的着火时间由28.12min下降至14.01和10.13min,其燃尽时间也由36.82min下降至27.59和22.47min。通过对比,型煤在着火、稳燃性能及综合燃烧特性方面最好,而燃尽性能居中;代焦型煤、焦炭与无烟煤块煤3种试样的综合燃烧指数分别为53.25×10-9、30.14×10-9和11.53×10-9。燃烧温度对型煤燃烧速率影响较小,而型煤尺寸对后期燃烧速率影响较明显,减小型煤尺寸可增大燃烧速率;相同条件下,代焦型煤的燃烧速率低于焦炭而高于无烟煤块煤。实验结果可为石灰立窑型煤代焦提供指导。     

延迟焦化装置加热炉炉管在线烧焦技术应用

介绍青岛石化1.6Mt/a延迟焦化装置一炉三燃烧室六管程加热炉在线烧焦技术应用:如何根据焦化装置加热炉的运行参数,判断加热炉炉管的结焦情况,确定是否进行炉管在线烧焦,炉管结焦到在线烧焦前加热炉的操作方法;以其中一个燃烧室为例,详细说明烧焦过程中分燃烧室、炉管在线烧焦、并燃烧室时,根据各种现象对加热炉在线烧焦采取具体的控制方法,温度、压力、流量等相关参数的控制范围和调节速度,各个操作步骤中的注意事项;分析引起加热炉炉管结焦的具体原因,并提出具有针对性的预防措施;通过对焦化炉炉管在线烧焦前后的参数进行对比,得出在线烧焦的实际效果;针对焦化炉炉管在线烧焦遇到的实际问题提出应对建议。加热炉在线烧焦技术能够消除炉管结焦,确保装置长周期、安全、平稳运行。     

钢铁工业的节能新技术

钢铁产量连年大幅攀升,能量消耗约占钢铁生产成本的1/3左右,节约能源是钢铁企业发展的重点,采用震荡燃烧、稀释氧燃烧、直接火焰冲击燃烧、高(焦)炉喷吹废塑料以及微波、电弧和放热加热直接炼钢技术,可以有效地节能降耗,促进钢铁工业可持续发展。     

过剩空气系数对多种燃气燃烧温度影响的分析

钢铁企业炼钢过程中产生数量众多的焦炉煤气、高炉煤气、转炉煤气和COREX煤气等各类燃气,燃气燃烧温度受燃气燃烧的过剩空气系数、空气和燃气的被加热温度等因素影响很大.空气和燃气温度均被加热到400℃时,各种燃气的燃烧温度显著提高,对于低热值高炉煤气燃烧温度提高约200℃,达到1580℃.同一燃烧设备当燃用燃气种类发生变化...     

煤粉与废塑料混合在模拟高炉风温下的燃烧试验研究

为了研究向高炉中混合喷吹废塑料和煤粉的可行性,在模拟高炉喷吹风温条件下改变空气流量、混合试样中的废塑料颗粒粒径和混合掺入废塑料比例进行燃烧性能(平均燃烧速率)研究。结果表明:空气流量对燃烧平均速率的影响最为显著,其次是塑料比例,塑料粒度对混合试样燃烧平均速率的影响最小;在高温燃烧下废塑料所产生的灰烬量低于煤粉。     

Forecasting of the energy effects of injecting plastic wastes into the blast furnace in comparison with other auxiliary fuels

The main aim of rationalizing the energy management of a blast-furnace plant is to save coke. In general practice coke is replaced by injecting cheaper auxiliary fuels (among others hydrocarbon plastic wastes). The paper gives a short account about such attempts carried out so far in some countries. The energy effects of injecting plastic wastes into the blast furnace have been analyzed and compared with the injection of pulverized coal, natural gas and coke-oven gas.     

浅谈变组分燃料燃烧特性研究进展

以沼气为例分析了变组分燃料对发动机性能的影响，论述了国内外变组分燃料沼气、煤层气和高炉煤气的研究进展，介绍了采用定容燃烧装置和发动机研究变组分燃烧特性的方法，并提出了今后的研究方向。     

浅谈变组分燃料燃烧特性研究进展

以沼气为例分析了变组分燃料对发动机性能的影响,论述了国内外变组分燃料沼气、煤层气和高炉煤气的研究进展,介绍了采用定容燃烧装置和发动机研究变组分燃烧特性的方法,并提出了今后的研究方向。