风口前端氧煤燃烧NO<i><sub>x</sub></i>生成行为分析及控制

doi:10.13228/j.boyuan.issn0449-749x.20220149

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (2406 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要以高炉风口前端煤粉燃烧过程为研究对象,通过热力学计算系统分析了不同约束条件下煤气成分及NO_x的生成规律,探讨了温度、煤种比例及煤粉成分、富氧、喷煤等不同工况参数对NO_x生成行为的影响,并提出降低NO_x生成的方向性建议。研究结果表明,高炉风口前端煤粉燃烧生成NO_x兼具热力型、快速型、燃料型3种途径。温度是影响热力型NO_x生成的重要因素,温度大于2 000 ℃时,温度每升高100 ℃,高炉风口前端NO_x生成量增幅大于30%以上,计算温度范围内(2 000～2 400 ℃),NO_x生成量由4 056 mg/m³增加到12 942 mg/m³,NO_x生成量远超传统燃煤锅炉;其他工况条件不变,高炉烟煤配比由0提高至50%,NO_x的生成量由4 152 mg/m³增加至7 486 mg/m³,增幅达到80%;高炉煤比为80 kg/t时,即使不富氧,NO_x生成量依然达到了18 006 mg/m³;喷吹煤粉中1 mol碳素供氧量由2.0 mol降至1.2 mol,NO_x生成量显著减少了68%。综上所述,高炉通过采取调整理论燃烧温度、减少烟煤配比、使用低挥发分煤种、合理匹配富氧喷煤水平等措施,可以实现NO_x生成的源头控制。此外,就高炉NO_x排放角度而言,炉顶煤气中NO_x的含量水平亦显著受高炉内部还原作用的影响。正常冶炼条件下,生成的NO_x在炉内能够被充分还原,高炉炉顶煤气NO_x量通常为50 mg/m³以下,但应关注亏尺、悬料、休送风等特殊工况时高炉煤气及下游煤气用户NO_x的排放水平。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	甄常亮
	程翠花
	张巧荣
	赵凯

关键词 ：高炉, 风口, 氧煤燃烧, 氮氧化物, 生成, 还原, 排放

Abstract：Taking pulverized coal combustion process at the front end of blast furnace tuyere as the research object, the formation rules of gas composition and NO_x under different constraints were analyzed by thermodynamic calculation systematically. The effects of different operating parameters such as temperature, ratio of coal species, pulverized coal composition, oxygen-enriched and coal injection on NO_x formation behavior were discussed, and several directional advices to reduce NO_x formation were proposed. The results show that there are three ways to generate NO_x by pulverized coal combustion at the front end of blast furnace tuyere, thermal, prompt and fuel. Temperature is an important factor affecting the formation of thermal NO_x, when the temperature is higher than 2 000 ℃, the NO_x production at the front end of blast furnace tuyere increases by more than 30% for each 100 ℃ increase. Within the calculation temperature range (2 000-2 400 ℃), NO_xproduction increases from 4 056 mg/m³ to 12 942 mg/m³, which is far more than the traditional coal-fired boiler. The ratio of bituminous coal increases from 0 to 50%, NO_x production increases from 4 152 mg/m³ to 7 486 mg/m³, and the production content of NO_x increases by 80%. The ratio of bituminous coal increased from 0 to 50%, and production content of NO_x increased by 80%. When the coal ratio is 80 kg/t, NO_x production still reaches 18 006 mg/m³ even without rich oxygen. NO_x generation is significantly reduced by 68% when the oxygen supply for 1 mol carbon in pulverized coal decreased from 2.0 mol to 1.2 mol. Therefore, source control of NO_x generation can be realized by adjusting the theoretical combustion temperature, reducing the ratio of bituminous coal, using low volatile coal, reasonably matching the level of oxygen-enriched and coal injection. In addition, from the perspective of blast furnace NOx emission, the content level of NO_x in the top gas is also significantly affected by the internal reduction of the blast furnace: under normal smelting conditions, the generated NO_x can be fully reduced in blast furnace, and the NO_x content of the top gas of the blast furnace is usually below 50 mg/m³, but attention should be paid to the NO_x emission level of blast furnace gas and downstream gas users, when it is in the special operating mode such as low stock line, hanging, blowing-off, blowing-in, and so on.

Key words： blast furnace tuyere oxygen coal combustion NO_x formation reduction emission

收稿日期: 2022-03-03

引用本文:

甄常亮, 程翠花, 张巧荣, 赵凯. 风口前端氧煤燃烧NO_x生成行为分析及控制[J]. 钢铁, 2022, 57(10): 55-63. ZHEN Chang-liang, CHENG Cui-hua, ZHANG Qiao-rong, ZHAO Kai. NO_x formation behavior analysis and control of oxygen coal combustion at front end of tuyere[J]. Iron and Steel, 2022, 57(10): 55-63.

链接本文:

http://www.chinamet.cn/Jweb_gt/CN/10.13228/j.boyuan.issn0449-749x.20220149 或 http://www.chinamet.cn/Jweb_gt/CN/Y2022/V57/I10/55

[1] 王军霞,李曼,敬红,等.我国氮氧化物排放治理状况分析及建议[J].环境保护,2020,48(18):24.(WANG Jun-xia,LI Man,JING Hong,et al. Analysis and suggestions on nitrogen oxide emission control in China[J]. Environmental Protection,2020,48(18):24.)
[2] 白涛. 燃煤锅炉低NO_x燃烧系统的数值模拟与试验研究[D].北京:华北电力大学,2014.(BAI Tao. Numerical Simulation and Experimental Investigation on Low-NO_x Combustion System in Pulverized Coal Boiler[D]. Beijing: North China Electric Power University,2014.)
[3] 于勇,朱廷钰,刘霄龙. 中国钢铁行业重点工序烟气超低排放技术进展[J]. 钢铁,2019,54(9):1.(YU Yong,ZHU Ting-yu,LIU Xiao-long. Progress of ultra-low emission technology for key processes of iron and steel industry in China[J]. Iron and Steel,2019,54(9):1.)
[4] Wei Zhou,David Moyeda,Roy Payne,et al. Application of numerical simulation and full scale testing for modeling low NO_x burner emissions[J]. Combustion Theory and Modelling,2009,13(6):1053.
[5] 殷庆栋,魏颖莉,魏刚,等. 国内外低NO_x旋流燃烧器研究进展[J]. 电力科技与环保,2012,28(3):24.(YIN Qing-dong,WEI Ying-li,WEI Gang,et al. Research development of typical low NO_x swirl burners[J]. Electric Power Environmental Protection,2012,28(3):24.)
[6] 白月娟,王永英. 低NO_x煤粉燃烧器技术研究进展[J]. 煤质技术,2018,33(2):42.(BAI Yue-juan,WANG Yong-ying. Research development of typical low NO_x burners for pulverized coal[J]. Goal Quality Technology,2018,33(2):42.)
[7] 陈冬林,叶托,李恒. 低NO_x燃烧技术研究现状及进展[J]. 热力发电,2017,46(3):1.(CHEN Dong-lin,YE Tuo,LI Heng. Review on low NO_x combustion techniques[J]. Thermal Power Generation,2017,46(3):1.)
[8] 陈曦梅. 火力发电厂燃烧中低NO_x控制技术研究[J]. 中国高新技术企业,2010,17(4):47.(CHEN Xi-mei. Research on low NO_x combustion control technology in thermal power plant[J]. China Hi-Tech Enterprises,2010,17(4):47.)
[9] 钟北京,傅维标. 再燃过程中HCN对NO_x还原的重要性[J]. 燃烧科学与技术,2000,6(1):77.(ZHONG Bei-jing,FU Wei-biao. Importance of HCN to NO_x reduction in fuel reburning[J]. Journal of Combustion Science and Technology,2000,6(1):77.)
[10] 贾力,殷龙. 烟气再循环实现低NO_x排放的实验研究[J]. 工业加热,2008,37(6):15.(JIA Li,YIN Long. The experimental research on realizing low NO_x emission with recycle of flue gas[J]. Industrial Heating,2008,37(6):15.)
[11] 付颖,曹丽梅,梁爽. 低NO_x燃烧技术及在钢铁行业的应用[J]. 中国金属通报,2016,24(6):52.(FU Ying,CAO Li-mei,LIANG Shuang. Low NO_x combustion technology and its application in the steel industry[J]. China Metal Bulletin,2016,24(6):52.)
[12] 郝宏飞. 燃煤锅炉脱硝技术的应用[J]. 山西化工,2020,40(5):163.(HAO Hong-fei. Application of denitration technology in coal fired boiler[J]. Shanxi Chemical Industry,2020,40(5):163.)
[14] 刘勇,吴国忠. NO_x的生成机理[J]. 油气田地面工程,2007,30(4):32.(LIU Yong,WU Guo-zhong. Formation mechanism of NO_x[J]. Oil-gasfield Surface Engineering,2007,30(4):32.)
[15] 钟北京,傅维标. 燃烧过程中快速型氧化氮形成机理及其影响因素[J]. 燃烧科学与技术,1997,3(4):57.(ZHONG Bei-jing,FU Wei-biao. Study on mechanism of prompt no formation and its affecting factors in combustion process[J]. Journal of Combustion Science and Technology,1997,3(4):57.)
[16] 吴富贤. 煤的挥发分产物中气体成分的初步研究[J]. 中国煤田地质,1992,4(3):31.(WU Fu-xian. Preliminary study on gas composition in volatile products of coal[J]. Coal Geology of China,1992,4(3):31.)
[17] 詹田友,黄业军,李社芝,等. 烟煤中氢含量的实测值与计算值的比对[J]. 煤质技术,2011,26(6):51.(ZHAN Tian-you,HUANG Ye-jun,LI She-zhi,et al. The comparison of the test between the measured and calculated value of the hydrogen content of bituminous coal[J]. Goal Quality and Technology,2011,26(6):51.)
[18] 韩思奇,王秀英,邵欣,等. 高炉煤粉燃烧氮氧化物减排控制仿真[J]. 环境工程,2018,36(12):188.(HAN Si-qi,WANG Xiu-ying,SHAO Xin,et al. Simulation for emission reduction and control of nitrogen oxide from blast furnace coal powder combustion[J]. Environmental Engineering,2018,36(12):188.)
[19] 甄常亮,程翠花,闫宝忠,等. 喷煤富氧相关工程计算及探讨[C]//第十五届全国大高炉炼铁学术年会论文集. 乌鲁木齐:中国金属学会炼铁分会,2014:818.(ZHEN Chang-liang,CHENG Cui-hua,YAN Bao-zhong,et al. Engineering calculation and discussion on oxygen enrichment of coal injection[C]//The 15th National Annual Conference on Large Blast Furnace Ironmaking. Wulumuqi:The Chinese Society for Metals,2014:818.)
[20] 李宁,丁雪松,徐雨红,等.循环流化床锅炉燃烧中NO_x生成机理与预测研究进展[J].能源与节能,2021,26(8):74.(LI Ning,DING Xue-song,XU Yu-hong,et al. Research progress of formation mechanism and prediction of NO_x in CFB combustion[J]. Energy and Conservation,2021,26(8):74.)
[21] 吴胜利,王筱留,张建良. 钢铁冶金学[M]. 北京:冶金工业出版社,2019.(WU Sheng-li,WANG Xiao-liu,ZHANG Jian-liang. Iron and Steel Metallurgy[M]. Beijing: Metallurgical Industry Press, 2019.)
[22] Hiroshi Nogami,Hideyuki Yamaoka,Kouji Takatani. Raceway design for the innovative blast furnace[J]. ISIJ International,2004,44(12):2150.
[23] Hideyuki Aoki,Hiroshi Nogami,Hideo Tsuge,et al. Simulation of transport phenomena around the raceway zone in the blast furnace with and without pulverized coal injection[J]. ISIJ International,1993,33 (6):646.