焦炉燃烧室氮氧化物形成的数值模拟

摘要

氮氧化物是一种严重的大气污染物,对生态系统有严重的危害。利用数值模拟方法模拟焦炉燃烧室以获得燃烧室中氮氧化物形成的详细信息,并预测废气循环与空气预热温度对氮氧化物形成的影响。对废气中氮氧化物浓度的预测值与实测值进行了比较。结果发现由于同时具备高温度与高氧气浓度,绝大多数氮氧化物在上升立火道高度方向的中间位置形成,而在立火道的其他位置,或者被低温影响,或者受低氧气浓度影响,氮氧化物的形成反应减少;焦炉燃烧室中采用废气循环装置和降低空气预热温度是减少氮氧化物形成的有效方法。此项研究有助于理解焦炉燃烧室中降低氮氧化物形成的方法。

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	张婷
	卫宏远
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关键词：数值模拟；焦炉燃烧室；氮氧化物形成；废气循环；空气预热温度

Abstract：

As one kind of serious atmospheric pollutants, nitrogen oxides (NO_x) present significant harm to ecosystems. In this paper, numerical modelling methods have been employed to simulate a coke oven combustion chamber to obtain detailed information on the formation of NO_x in the combustion chamber and to predict the effects of exhaust gas recirculation process and air preheated temperature on NO_x formation. The predicted data are compared to measurements in terms of NO_x concentration in exhaust gas. It is concluded that most of the NO_x is formed in the middle zone of the upward vertical flue in height direction due to simultaneous high temperature and high O₂ concentration, while in other zones of the flues, the formation reactions of NO_x, influenced either by low temperature or low O₂ concentration, are reduced; employing exhaust gas recirculation process and lowering air preheated temperature are effective ways to reduce NO_x formation in coke oven combustion chambers. The current work greatly helps to understand the ways used to reduce NO_x formation in coke oven combustion chambers.

Keywords： numerical simulation； coke oven combustion chamber； NO_x formation； exhaust gas recirculation； air preheated temperature

Received 2013-09-05;

Corresponding Authors: Wei Hongyuan, E-mail: crystallization.wei@hotmail.com. Email: crystallization.wei@hotmail.com

About author: Zhang Ting (1988-), female, research interest: Chemical Process Modeling and Simulation.

引用本文:

张婷, 卫宏远, 郑倩倩.焦炉燃烧室氮氧化物形成的数值模拟[J]. 化学工业与工程, 2016,33(1): 82-89,95

Zhang Ting, Wei Hongyuan, Zheng Qianqian.Numerical Simulation of NO_x Formation in the Combustion Chamber of a Coke Oven[J]. Chemcial Industry and Engineering, 2016,33(1): 82-89,95

[1] Hao Dandan. Numerical simulation of carbonization process and macro-scale operations technology for coke oven[D]. Tianjin: Tianjin University, 2012(in Chinese)
[2] Zhang Xinxin, Zhang Anqiang, Feng Yanhui, et al. Energy consumption analysis and technologies of waste heat utilization for coke oven[J]. Iron and Steel, 2012, 47(8): 1-12(in Chinese)
[3] Zhong Yingfei. Formation mechanism and control of NO_x during coke oven heating and combustion[J]. Fuel & Chemical Processes, 2009, 40(6): 5-12 (in Chinese)
[4] Rowland F S. Stratospheric ozone depletion[J]. Philosophical Transactions of The Royal Society B-Biological Science, 2006, 361(1469): 769-790
[5] Jin Y M, Veiga M C, Kennes C. Bioprocesses for the removal of nitrogen oxides from polluted air[J]. Journal of Chemical Technology and Biotechnology, 2005, 80(5): 483-494
[6] Naeher L P, Brauer M, Lipsett M, et al. Woodsmoke health effects: A review[J]. Inhalation Toxicology, 2007, 19(1): 67-106
[7] Ding Weixia. Study of numerical simulation of staged combustion reducing NO_x emission of 300 MW boiler[D]. Beijing: North China Electric Power University, 2006
[8] Fu G. NO_x formation mechanism and control technology in the process of coal combustion[J]. Energy Environmental Protection, 2005, 19(3): 1-8 (in Chinese)
[9] Jin J, Fan J, Sha Y, et al. Experimental research and numerical simulation on NO_x release characteristics along the boiler during pulverized coal combustion[J]. Energy & Fuel, 2010, 24: 940-944
[10] Choi C R, Kim C N. Numerical investigation on the flow, combustion and NO_x emission characteristics in a 500 MW tangentially fired pulverized-coal boiler[J]. Fuel, 2009, 88: 1 720-1 731
[11] Liu B, Yang X, Song W, et al. Process simulation of formation and emission of NO and N₂O during coal decoupling combustion in a circulating fluidized bed combustor using Aspen Plus[J]. Chemical Engineering Science, 2012, 71: 375-391
[12] Cao H, Sun S, Liu Y, et al. Computational fluid dynamics modeling of NO_x reduction mechanism in oxy-fuel combustion[J]. Energy & Fuel, 2010, 24: 131-135
[13] Zhou H, Mo G, Si D, et al. Numerical simulation of the NO_x emission in a 1 000 MW tangentially fired pulverized-coal boiler: Influence of the multi-group arrangement of the separated over fire air[J]. Energy & Fuel, 2011, 25: 2 004-2 012
[14] Li Xiaolei, Xiong Yangheng, Mo Chongjun. Numerical simulation on air-staged low NO_x combustion system in a 1 000 MW-class ultra-supercritical boiler[C]//IEEE. Asia-Pacific Power and Energy Engineering Conference.

Wuhan, China: 2012(in Chinese)
[15] Li Z, Wei F, Jin Y. Numerical simulation of pulverized coal combustion and NO_x formation[J]. Chemical Engineering Science, 2003, 58: 5 161-5 171
[16] Hao D, Liu W, Dang L, et al. Numerical simulation of a coke oven[J]. Advanced Materials Research, 2012: 586-589
[17] Wang Fujun. Computational fluid dynamics: CFD principles and applications[M]. Beijing: Tsinghua University Press, 2004 (in Chinese)
[18] Hellberg P, Jonsson T L I, Jonsson P G. Mathematical modeling of the injection of coke oven gas into a blast furnace tuyere[J]. Scandinavian Journal of Metallurgy, 2005, 34: 269-275
[19] Liu Daifei, Ding Fengqi, Zhang Hongliang, et al. Numerical simulation of high temperature air combustion in aluminum hydroxide gas suspension calcinations[J]. Transactions of Nonferrous Metals Society of China, 2009, 19: 259-266(in Chinese)
[20] Magnussen B F. On the structure of turbulence and a generalized eddy dissipation concept for chemical reaction in turbulent flow[C]//Proceedings of the 19th AIAA Aerospace Science Meeting, St. Louis, United States:1981
[21] Cui K, Liu B, Zhang H, et al. Modeling of pulverized coal combustion in turbulent flow with the consideration of intermediate reactions of volatile matter[J]. Energy & Fuels, 2013, 27: 2 246-2 254
[22] Yao Zhaozhang, Zheng Mingdong. Coking plant science[M]. Beijing: Metallurgical Industry Press, 2008 (in Chinese)
[23] Fiveland W A. Three-Dimensional radiative heat-transfer solutions by the discrete-ordinates method[J]. Journal of Thermophysics and Heat Transfer, 1988, 2(4): 309-316
[24] Stamnes K, Tsay S C, Wiscombe W, et al. Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media[J]. Applied Optics, 1988, 27(12): 2 052-2 059
[25] Backreedy R I, Jones J M, Ma L, et al. Prediction of unburned carbon and NO_x in a tangentially fired power station using single coals and blends[J]. Fuel, 2005, 84: 2 196-2 203
[26] Ma L, Gharebaghi M, Porter R, et al. Modelling methods for co-fired pulverised fuel furnaces[J]. Fuel, 2009, 88(12): 2 448-2 454
[27] Huang Zhonglang. Research on engineering application of membrane method oxygen-enrichment local supporting combustion technigue on decreasing NO_x emission of pulverized coal boiler[D]. Changsha: Central South University, 2007 (in Chinese)
[28] Ou Jianping. Study on application of HTAC in Metallurgy and its optimization with numerical simulation[D]. Changsha: Central South University, 2004 (in Chinese)
[29] Zhong Yingfei. Controlling pollutant discharge quantity and improving the present situation of cokemaking environment[J]. Fuel & Chemical Processes, 2000, 31(6): 277-283(in Chinese)