ZHANG Wu-neng1, WANG Yi-hua2, WANG Yi1, et al. THERMAL FATIGUE OF REHEAT PIPES IN A POWER PLANT[J]. Thermal power generation, 2009, 38(4): 87-88.DOI:
某电厂再热管道的热疲劳原因分析
摘要
对某电厂125MW机组再热管道开裂原因进行了分析。结果表明
再热管道开裂泄漏的主要原因是再热管道上的放空气管、取样管内冷凝水回流引起的热疲劳所致。对此
建议将取样管上移
减小再热管道上放空气管的垂直段长度并改为水平方向排气
以避免冷凝水回流而造成热疲劳
保证再热热段的安全运行。
Abstract
Fatigue
a material destructive phenomenon by the act of cyclic load
is regarded as the main format of hardware's failure gradually by the developing of fracture mechanics.For several reheat pipe leakage accidents happened in a power-plant
the cause of the reheat pipe crack is investigated.The result shows that the backflow of condensed water in gas-venting pipe and sampling pipe over the reheat pipe results in thermal fatigue
leading to a crack on reheat pipe.It is therefore suggested that the sampling pipe be lifted
the vertical length of the gas-venting pipe be shortened and its venting direction be changed to horizontal
in order to prevent condensed water from back-flowing and ensure safe operation of reheat section of the pipe.