超超临界机组水冷壁管弯曲处失效泄漏原因分析  

Cause Analysis on Leakage Failure at Tube Bends of Water Wall in an Ultra-supercritical Unit

作　　者：吴优福 侯召堂[2] 

机构地区：[1]神华(福建)能源有限责任公司,福州350004 [2]西安热工研究院有限公司,西安710054

出　　处：《发电设备》2017年第3期188-192,共5页Power Equipment

摘　　要：采用化学成分分析、硬度检测、金相观察、扫描电镜断口分析、断口表面腐蚀产物的能谱分析以及有限元数值模拟等手段,对某发电公司的水冷壁管失效泄漏的原因进行了分析。结果表明:水冷壁制作过程冷变形所致的残余应力和运行过程的热应力过大,是导致管子弯曲处过早失效的主要原因,腐蚀烟气对热疲劳裂纹扩展起了促进作用。By means of chemical composition analysis, hardness testing, optical microscopy observation, fracture surface analysis, spectrum analysis and finite element numerical simulation, the causes leading to the leakage failure of water wall tubes in a power generation company were investigated. Results show that the failure was mainly caused by both the too large residual stress from cold deformation of water wall during fabricating process and the too large thermal stress generated during operation period, which led to the premature failure of relevant tube bends. Moreover, the corrosive flue gas also accelerated the propagation of related thermal fatigue cracks.

关 键 词：锅炉 水冷壁管 热疲劳 弯曲工艺 腐蚀烟气 

分 类 号：TK249[动力工程及工程热物理—动力机械及工程]