某DZL型燃煤锅炉锅筒鼓包原因分析和对策

Analysis and Countermeasures of Drum Deformation of a DZL Coal-fired Boiler

某单位燃煤锅炉锅筒底部受热面出现两处鼓包,存在严重安全隐患。为了找出锅筒鼓包原因,并为锅炉使用维修提出应对措施,本文通过壁厚测定、金相分析、硬度测定、计算分析、水质检测等对锅炉鼓包原因进行了分析,结果表明锅炉锅筒鼓包的主要原因为锅筒筒节直接受火焰加热,未按要求采用耐火隔热层进行覆盖;同时,锅炉给水和锅水的浊度、硬度等多项指标不合格,导致锅筒内壁被较厚水垢覆盖、导热性能变差。当锅筒发生过热甚至过烧从而导致金属结构强度降低时,在内部蒸汽压力的作用下发生了鼓包变形。

Two drum deformations were found in the heating surface of the boiler drum bottom of a coal-fired boiler, and there was serious hidden danger. In order to find out the reason of boiler drum deformation, and put forward countermeasures for boiler maintenance, through the wall thickness measure, metallographic analysis, hardness measure, calculation analysis and water quality testing, this paper analyzed the reason of boiler drum deformation. The results showed that the main reason of boiler drum deformation was that the drum section was directly heated by flame. And the inner drum was covered by thick scale that results in bad thermal conductivity. When the shell was overheated which lead to the decrease of strength, drum deformation happened under the action of the inner pressure of the pot.