为解决电厂燃用准东煤后各级受热面出现的大面积沾污结焦问题,对五彩湾电厂煤样、灰样及焦块样品进行了化学成分与内部结构分析.与神府煤及大同煤对比后发现,准东煤中Na、K等碱金属元素含量较高;焦块内部为多层结构,最底层的碱金属细颗粒强化了煤种的积灰结渣倾向;计算了各煤样的污染指数与结渣指数,佐证了准东煤高含量的Na2O与其强结焦性密切相关.根据分析计算结果,提出控制炉膛温度、调整炉内流场分布、合理选择煤粉细度、提高一次风速、加强炉膛吹灰及掺烧低碱金属含量煤等措施.经调试调整后,锅炉运行平稳,结焦问题得到较好控制,相关经验可为同类机组提供参考.%In order to solve the problem of large area contamination and coking on boiler heating surface by burning Zhundong coal in power plant,samples' chemical composition and internal structure analysis of Wucaiwan coal,coal ash and coke block were carried out.Compared with Shenfu coal and Datong coal,the content of Na,K and other metallic elements in Zhundong coal was very high.Coke block was a multilayer structure,and the fine particles at the very bottom riched in alkali metal strengthen the slagging tendency of coal ash.The calculation of pollution index and slagging index were carried out,which supported the correlation between high content of Na2O in Zhundong coal and strong coking intendency.According to the results of the analysis and calculation,measures including control the furnace temperature,adjusting the furnace flow field distribution,a reasonable choice of pulverized coal fineness and a wind speed,strengthen the furnace soot blowing and blending low alkali metal content in coal were proposed and put into practice.After the implementation of measures,the operation of boiler is stable,and coking was well controlled.Relevant experience can provide reference for similar units.
展开▼
