超临界热电联产锅炉结焦机理分析与工程调整措施  

Mechanism Analysis and Engineering Adjustment of Coking Problem in Cogeneration Super Critical Boiler

作　　者：王林[1] 王红雨[1] 韩瑞 张亚夫[1] 高景辉[1] 孟颖琪[1] Wang Lin;Wang Hongyu;Han Rui;Zhang Yafu;Gao Jinghui;Meng Yingqi(Xi′an Thermal Power Research Institute Co.,Ltd.,Xi′an 710054,China;School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]西安热工研究院有限公司,西安710054 [2]哈尔滨工业大学能源科学与工程学院,哈尔滨150001

出　　处：《燃烧科学与技术》2019年第1期37-44,共8页Journal of Combustion Science and Technology

摘　　要：为解决350 MW超临界锅炉严重结焦问题,现场采集典型焦块样品,发现其断面有明显分层现象;利用SEM-EDS(扫描电镜及能谱分析)对高温侧与低温侧进行了微观形貌与元素组成测试,确认两层焦块成分存在差异;结合煤灰成分分析与结渣性判别指标计算,得出实际燃用煤种灰熔点较低、结焦性强烈.综合分析认为,煤质恶劣、炉温过高是锅炉燃烧器区域水冷壁严重结焦的主要原因.通过采取增加吹灰频率、优化二次风配风、降低一次风量、调整煤粉细度及控制氧量等措施,大幅削弱炉内燃烧强度,降低炉膛温度,调整燃烧气氛,抑制焦块生成,使得冷灰斗处掉焦量显著减少,熔融状大焦基本消除,锅炉运行安全平稳.燃烧调整取得了较好的效果,相关经验可供同类机组参考.To solve the serious coking problem in a 350 MW supercritical boiler,we collected typical coke-block samples on site,and found obvious stratification in the cross section of coke block.SEM-EDS was used to analyze the morphology and element composition of the high and low temperature sides,and the cost difference between the two sides was confirmed.Our analysis and slagging discriminant index calculations show that the actual coal burning ash had a low melting point and strong coking.Comprehensive analysis revealed that poor coal quality and high furnace temperature were the main reasons for the serious coking of water wall in the boiler burner area.By increasing the soot blowing frequency,optimizing the secondary air distribution,reducing the primary air volume,adjusting the fineness of the pulverized coal,and controlling the oxygen content,we can greatly weaken the combustion intensity in the furnace,lower the furnace temperature,adjust the combustion atmosphere,and restrain the formation of coke block.We significantly reduced the coke drop at the ash hopper and essentially eliminated the generation of large fused coke.This operation was safe and stable.The combustion adjustment achieved good results and these findings can be used as reference for similar units.

关 键 词：结焦 燃烧调整 SEM-EDS 结渣指数 机理分析 

分 类 号：TK16[动力工程及工程热物理—热能工程]