UG-75/5.3-M21锅炉水冷壁上集箱连通管爆管事故分析  

BURSTING ACCIDENT ANALYSIS FOR CONNECTION TUBE BETWEEN WATER-WALL HEADER AND BOILER DRUM OF A UG-75/5.3-M21 BOILER

作　　者：赵建平[1] 缪春生[2] 孙涛[2] 

机构地区：[1]南京工业大学机械与动力工程学院,南京210009 [2]江苏省锅炉压力容器安全检测中心所,南京210002

出　　处：《理化检验（物理分册）》2005年第9期467-470,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：分析了某一锅炉在试运行过程中水冷壁上集箱联通管发生爆管事故的原因。通过力学性能测试和断口分析,发现裂纹起源于管道内壁的一条深达1.3mm的沟槽,裂纹沿沟槽向两侧扩展,其断裂形式为塑性断裂。从结构应力分析和故障树分析看,引起爆管事故的原因是多方面的,如果管道没有缺陷,即使温度升高到500℃,结构仍处于弹性阶段,不会发生塑性变形;若温度保持在280℃,即使存在330mm长、10mm宽、1.3mm深的沟槽,结构也仍处于弹性阶段,不会发生塑性变形。当沟槽和过热现象同时存在时,管道进入塑性变形阶段。因此,管道内壁的局部减薄缺陷(沟槽)和过热的共同作用导致爆管。Bursting accident of connection tube between water-wall header and boiler drum of a UG-75/5.3- M21 boiler was investigated. Based on the methods of tensile test and fracture analysis and metallurgical examination, it is found that the crack is initiated from a rectangular flaw with 1.3mm depth in the inner wall and which is propagated along this flaw to the upside and the downside. The dimples were investigated by the SEM photos, so the fracture is described as ductile fracture. Based on the structural stress analysis and fault tree analysis, there are many causes leading to bursting. If there is no rectangular flaw, the structure were still in the elastic state at 500℃ without any plastic deformation. If the operation temperature controlled within 280℃, the structure were still in the elastic state with a 1.3mm depth flaw without any plastic deformation. When the flaw and overheat phenomena were appearance at the same time, the plastic deformation will be found in this structure. Therefore, the causes leading to bursting of the connection tube were the localized thinning of the inner wall of the tube and the operational temperature being improper.

关 键 词：锅炉 水冷壁 爆管 失效分析 

分 类 号：TK223.3[动力工程及工程热物理—动力机械及工程]