对冲旋流燃烧锅炉冷灰斗管壁急剧减薄原因分析  

Cause Analysis of Cold Ash Hopper Tube Wall Rapid Thinning of the Opposed Swirl Firing Boiler

作　　者：刘宣义 黄世福 LIU Xuanyi;HUANG Shifu(China Energy Science and Technology Research Institute Co.,Ltd.,Nanjing 210023,China)

机构地区：[1]国家能源集团科学技术研究院有限公司,江苏南京210023

出　　处：《锅炉技术》2023年第3期65-70,共6页Boiler Technology

摘　　要：以某电厂350 MW超临界对冲旋流燃烧锅炉为研究对象,对锅炉冷灰斗区域管壁急剧减薄进行原因分析及调整建议。针对管壁腐蚀垢样的成分,开展了外观分析,X射线荧光光谱(XRF)、X射线衍射(XRD)、扫描电镜和能谱分析,化学定量分析和金相组织分析,得出垢样中S、C含量较高。同时结合冷灰斗区域贴壁气氛及温度测试结果,得出高温腐蚀及煤粉刷墙是造成冷灰斗处管壁急剧减薄的主要原因。通过降低下层燃烧器外二次风旋流强度、开展热态一次风速调平、降低一次风母管压力、调整动态分离器转速来降低煤粉细度、冷灰斗区域加装贴壁风等手段,可改善煤粉燃烧状况,减少煤粉沉积在冷灰斗区域,从而保证锅炉运行的安全,为同类型机组运行提供经验参考。The cause of rapid thinning of cold ash hopper tube wall is analyzes and adjusted by taking a 350 MW opposed swirl firing supercritical boiler as the research object.Firstly,the components of the corrosion scale samples on the tube wall are characterized by various technology methods including appearance analysis,X-ray fluorescence spectrum(XRF),X-ray power diffraction(XRD),scanning electron microscope and energy dispersive system,chemical quantitative analysis and metallographic analysis.The results show that the content of S and C in the scale sample is relatively high.At the same time,combined with the near-wall atmosphere and temperature test results in the cold ash hopper area,it is concluded that high-temperature corrosion and coal powder painting are the main reasons for the rapid thinning of cold ash hopper tube wall.Finally,measures such as reducing the secondary air swirling intensity outside the lower burner,carrying out the hot primary air speed leveling,reducing the primary air duct pressure,adjusting the dynamic separator speed to reduce the fineness of the pulverized coal,and installing wall air in the cold ash hopper area,are put forward for improving the combustion of pulverized coal and reducing the pulverized coal deposition in the cold ash hopper are,so as to ensure the safety of the boiler operation and provides reference for the operation of the same type of units.

关 键 词：对冲旋流燃烧 冷灰斗 高温腐蚀 减薄 

分 类 号：TK223.2[动力工程及工程热物理—动力机械及工程]