WANG Xiaolong;ZHANG Feilong;WANG Li;XU Xinwei;ZHANG Yixiang;WANG Xuebing;TAN Houzhang;

• 1:CHN Energy Shendong Coal Group Co.
• 2:Ltd.
• 3:School of Energy and Power Engineering
• 4:Xi′an Jiaotong University

Abstract：

The high-concentration pulverized coal burner can stabilize the combustion and significantly reduce NO_x emissions, which is a very economical and environmentally friendly combustion technology. Its primary wind speed has a very important impact on the ignition delay in the furnace, the stability of pulverized coal combustion and the NO_x emissions. In order to determine the primary wind speed suitable for the new high-concentration coal pre-combustion low-nitrogen burner, and provide guidance for the on-site experiment and actual operation of the burner, ANSYS Fluent software was used to simulate and calculate the influence of primary wind speed on the combustion stability of pulverized coal and NO_x emissions. In this paper, a grid-independent test was performed first, and a 25 t/h full-scale pulverized coal industrial boiler was tested to verify the accuracy of the model. The numerical simulation results show that the new high-concentration coal pre-combustion low-nitrogen burner can form two recirculation zones in the pre-combustion chamber and the furnace. The recirculation zone in the pre-combustion chamber ensures stable combustion of pulverized coal, and the recirculation zone in the furnace reduces NO_x. When the primary wind speed is too low, the later mixing of primary and secondary air weakens, the combustion of pulverized coal is unstable, and NO_x emission increases slightly. Also, when the primary wind speed is too high, the mixing of the secondary air and the pulverized coal is weakened, and the combustion of pulverized coal is unstable, resulting in a significant decrease in the coke conversion rate and a significant increase in NO_x emissions. The primary wind speed increases from 17 m/s to 20 m/s, and the NO_x concentration in the outlet section increases by about 10%. An appropriate primary wind speed can not only stabilize the ignition and combustion of pulverized coal, but also achieve low NO_x emissions. The best primary wind speed of the burner studied is between 14-17 m/s.

Key Words： primary wind speed;pre-combustion chamber;low-nitrogen burner;NO_x;numerical simulation

Abstract:

Keywords:

Foundation: 国家重点研发计划资助项目(2017YFB0603902)

Authors: WANG Xiaolong;ZHANG Feilong;WANG Li;XU Xinwei;ZHANG Yixiang;WANG Xuebing;TAN Houzhang;

DOI: 10.13226/j.issn.1006-6772.CE21041701

References：

• [1] SUN G G,CHE D F,CHI Z H.Effects of secondary air on flow,combustion,and NOx emission from a novel pulverized coal burner for industrial boilers [J].Energy & Fuels,2012,26(11):6640-6650.
• [2] 刘建航.我国燃煤工业锅炉现状及分析[J].洁净煤技术，2017,23(4):107-113.LIU Jianhang.Progress and situation analysis of coal fired industrial boilers in China [J].Clean Coal Technology,2017,23(4):107-113.
• [3] SONG M,HUANG Q,NIU F,et al.Recirculating structures and combustion characteristics in a reverse-jet swirl pulverized coal burner [J].Fuel,2020,270:117456.
• [4] 程晓磊.低氮燃烧技术在煤粉工业锅炉上的应用[J].洁净煤技术，2018,24(4):109-113.CHEN Xiaolei.Application of low-NOx combustion technology on pulverized coal industrial boiler [J].Clean Coal Technology,2018,24(4):109-113.
• [5] JUN W,ZHU J G,LYU Q G.Experimental study on combustion characteristics and NOx emissions of pulverized anthracite preheated by circulating fluidized bed[J].Journal of Thermal Science,2011,20(4):355-361.
• [6] 白月娟，王永英.低NOx煤粉燃烧器技术研究进展[J].煤质技术，2018(2):42-47.BAI Yuejuan,WANG Yongying.Research development of typical low NOx burners for pulverized coal [J].Coal Quality Technology,2018(2):42-47.
• [7] PERRONE D,CASTIGLIONE T,KLIMANEK A,et al.Numerical simulations on oxy-MILD combustion of pulverized coal in an industrial boiler [J].Fuel Processing Technology,2018,181:361-374.
• [8] 龚彦豪，许鑫玮，王登辉，等.新型低氮旋流燃烧器NOx排放特性[J].洁净煤技术，2019,25(6):118-125.GONG Yanhao,XU Xinwei,WANG Denghui,et al.NOx emissions characteristics of a novel low-NOx swirl burner [J].Clean Coal Technology,2019,25(6):118-125.
• [9] 许鑫玮，谭厚章，王学斌，等.煤粉工业锅炉预燃式低氮燃烧器试验研究与开发[J].洁净煤技术，2020,26(5):36-41.XU Xinwei,TAN Houzhang,WANG Xuebin,et al.Experimental study and development on a pre-burning low-NOx burner for pulverized coal industry boiler [J].Clean Coal Technology,2020,26(5):36-41.
• [10] 李建生，牛蔚然.预燃室型煤粉燃烧器的开发和应用[J].中国电力，2008,41(4):44-47.LI Jiansheng,NIU Weiran.Development and application precombustion chamber burners [J].Electric Power,2008,41(4):44-47.
• [11] 曾瑞良，徐旭常，李自康.带根部二次风的煤粉预燃室燃烧器：CN85100045[P].1986-12-31.ZENG Ruiliang,XU Xuchang,LI Zikang.Pulverized coal pre-combustion chamber burner with root secondary air:CN85100045[P].1986-12-31.
• [12] 王进卿，池作和，孙公钢，等.一种新型燃用煤粉工业锅炉燃烧器流场特性研究[J].中国计量学院学报，2009,20(3):269-273.WANG Jinqing,CHI Zuohe,SUN Gonggang,et al.Study on flow field characteristics of a new burner of industrial pulverized coal fired boiler [J].Journal of China Jiliang University,2009,20(3):269-273.
• [13] 池俊杰，池作和，孙公钢，等.煤粉工业锅炉燃烧器和炉膛数值模拟与试验研究[J].电站系统工程，2013,29(5):1-4.CHI Junjie,CHI Zuohe,SUN Gonggang,et al.Numerical simulation and experimental study of burners and furnaces of pulverized coal-fired industrial boiler [J].Power Station System Engineering,2013,29(5):1-4.
• [14] 陈智超，严蓉，张绍峰，等.一种采用烟气再循环及预燃室的旋流煤粉燃烧装置：CN109654485A[P].2019-04-19.CHEN Zhichao,YAN Rong,ZHANG Shaofeng,et al.A swirling pulverized coal combustion device using flue gas recirculation and pre-combustion chamber:CN109654485A[P].2019-04-19.
• [15] 宋国良，周俊虎，刘建忠，等.高浓度煤粉输送燃烧技术的利弊分析[J].动力工程，2005,25(1):50-54.SONG Guoliang,ZHOU Junhu,LIU Jianzhong,et al.Analysis of advantages and disadvantages of conveying and combustion technology of dense phase pulverized coal [J].Power Engineering,2005,25(1):50-54.
• [16] 刘鹏中，周建明，牛芳，等.我国预燃室旋流煤粉燃烧器研究进展[J].煤质技术，2021,36(1):20-26,35.LIU Pengzhong,ZHOU Jianming,NIU Fang,et al.Research progress of swirl pulverized coal burner with pre-combustion chamber in China [J].Coal Quality Technology,2021,36(1):20-26,35.
• [17] 王占平，杨斌，杨飞，等.电站锅炉直吹式制粉系统一次风速测量与调整[J].锅炉技术，2017,48(3):6-10.WANG Zhanping,YANG Bin,YANG Fei,et al.Measurements andadjustments of primary air velocity for direct-firing pulverizing system of utility boiler [J].Boiler Technology,2017,48(3):6-10.
• [18] 张宿诚.浅析一次风速标定对锅炉运行的重要性[J].中国科技纵横，2012(21):80.ZHANG Sucheng.Analysis on the importance of primary wind speed calibration to boiler operation [J].China Science & Technology Panorama Magazine,2012(21):80.
• [19] 王磊，吴少华，李争起，等.中心风对径向浓淡旋流煤粉燃烧器燃烧的影响[J].动力工程，2000,20(2):30-34.WANG Lei,WU Shaohua,LI Zhengqi,et al.The effects of cenrtal air on combustion of the radial bias combustion swirl burner[J].Journal of Chinese Society of Power Engineering,2000,20(2):30-34.
• [20] 张海，吕俊复，崔凯，等.旋流煤粉燃烧器低NOx排放的设计分析[J].热力发电，2010,39(11):32-36.ZHANG Hai,LYU Junfu,CUI Kai,et al.Analysis of design for swirling pulverized coal burners with low NOx emission [J].Thermal Power Generation,2010,39(11):32-36.
• [21] 米翠丽，樊孝华，魏刚，等.DRB-4Z型双调风旋流燃烧器出口流场的数值仿真研究[J].热力发电，2012,41(11):36-40.MI Cuili,FAN Xiaohua,WEI Gang,et al.Numerical simulation of outlet flow field of DRB-4Z type dual channel swirl burner[J].Thermal Power Generation,2012,41(11):36-40.
• [22] WANG J,ZHANG R,YANG F,et al.Numerical simulation on optimization of structure and operating parameters of a novel lean coal decoupling burner [J].Chinese Journal of Chemical Engineering,2020,28(11):2890-2899.
• [23] 尚天坤.贫煤低NOx旋流燃烧器的试验及模拟研究[D].北京：清华大学，2016.SHANG Tiankun.Test and simulation study of lean coal and low NOx swirl burner [D].Beijing:Tsinghua University,2016.