700MW机组三级再热器管子泄漏原因分析

Causal Investigation into Tertiary Reheater Tube Leakage of 700MW Unit

介绍了珠海发电厂的三级再热器管子爆管的情况,通过对失效的高温再热器管进行宏观分析、光谱分析、金相分析,论证了爆管的原因是更换管夹或管夹螺栓时进行过焊接或气割作业误伤了管壁。对爆漏管子及有吹损情况的管子进行了更换,同时更换新管夹,未再发现其它异常情况。

The tertiary reheater tube burst in Zhuhai Power Station is described. Through macroscopic, spectral and metallurgical analyses of the failed high-temperature reheater tubes, it is demonstrated that the tube burst was caused by the tube wall damage in the welding or gas cutting operation while replacing tube clamps or tube clamp bolts. No abnormalities have been found since the tubes with bursts and flue-dust-induced damages were replaced along with new tube clamps.