600MW亚临界锅炉屏式再热器失效分析

Failure Analysis of the Platen Reheater ina 600 MW Subcritical Boiler

针对某600 MW亚临界锅炉屏式再热器爆管的问题,通过对管样进行试验和对比,并结合管子的壁温估算和强度校核,分析了爆管原因。结果表明:12Cr1MoVG钢管子在长期超温运行状态下,力学性能下降;而在运行过程中,管子存在短时超温,其高温强度不满足要求;同时,管子有效承载厚度降低。以上综合作用导致屏式再热器爆管。

To solve the problem of the tube explosion of the platen reheater in a 600 MW subcritical boiler, analyses were conducted on the tube explosion through experiments and comparisons for the tube samples, combined with the estimation of wall temperature and the strength check for the tube. Results show that the mechanical property of the 12Cr1MoVG steel tube is decreased due to the long-term over-temperature operation, and the high-temperature strength of the tube cannot meet the requirement due to the short-term over-temperature during operation. Meanwhile, the effective bearing thickness is reduced. The tube explosion of the platen reheater is resulted from the combined effect of above aspects.