一起非典型超临界机组低温过热器吊挂管爆管原因分析

Cause Analysis of a Tube Explosion of the Hanging Tube of a Low-temperature Superheater of an Atypical Supercritical Unit

通过现场调查、宏观检查、微观组织分析、合金成分分析、拉伸试验,分析了2070t/h超临界锅炉低温过热器吊挂管在不超温下运行3.85万小时产生爆管的原因。结果表明,15CrMoG低温过热器吊挂管发生爆管通过现场观察系非典型案例,外观检查爆口附近形貌呈长时过热状态、材质分析合格、金相组织珠光体球化严重,在烟气温度不高的情况下产生长时过热,管道堵塞是爆管的主要原因。

Through on-site investigation,macro inspection,microstructure analysis,alloy composition analysis,and tensile test,the causes of the tube explosion of the 2070t/h supercritical boiler low-temperature superheater hanging tube running for 38,500 hours without overtemperature were analyzed.The results show that the 15CrMoG low-temperature superheater hanging tube explosion occurred through the on-site observation is an atypical case.The appearance near the burst shows a long-term overheating state,the material analysis is qualified,the metallographic pearlite spheroidization is serious,and the long-term overheating occurs when the flue gas temperature is not high.Pipe blockage is the main reason for the explosion.