摘要
某核电厂1,2,3号机组常规岛给水除氧器系统疏水器下游管道焊缝出现共模开裂缺陷。通过对设计选型、原材料检测、运行工况、失效特征等方面开展原因分析,发现管材P元素含量超标、焊材伸长率低及疏水器间歇性疏水导致管道热膨胀应力超过管材许用应力限值。对疏水器进行换型改造,并对疏水器下游管道进行更换。改造后疏水器下游管道焊缝未再出现开裂,为类似焊缝开裂的原因分析及处理提供借鉴。
A common mode cracking defect occurred in the downstream pipe weld of the steam trap of the conventional island feed water deaerator system of unit 1, 2 and 3 of a nuclear power plant. Through the analysis of design selection, raw material examination, operation conditions and failure characteristics etc., it is found that the thermal expansion stress of pipe exceeds the allowable stress limit due to excessive P element content, low elongation of welding material and intermittent drainage of steam trap. The type of the steam trap is change and downstream pipeline of the steam trap is replaced. After the transformation, no more weld cracks of the downstream pipeline of the steam trap ever occur, which provides a reference for the cause analysis and treatment of similar weld cracking.
作者
张本贺
ZHANG Benhe(Yangjiang Nuclear Power Co.,Ltd.,Yangjiang 529941)
出处
《电力安全技术》
2021年第1期30-33,共4页
Electric Safety Technology
关键词
疏水器
焊缝开裂
改造换型
steam trap
weld crack
transformation and type change
