火力发电厂锅炉受热面管泄漏原因分析

Analysis on the Leakage of Boiler Heating Surface Tube of Thermal Power Plant

一直以来,高温过热器爆管事故都是影响电厂安全运行的主要因素之一,且造成的损失最大。该文结合现场工作的实际对某电厂1号锅炉末级过热器泄漏原因进行了讨论。通过宏观检验、化学成分分析、力学性能试验及显微组织观察等多种试验手段,对该受热面管进行了较为全面的分析,以期对改善锅炉受热面管失效提供帮助。分析得出该末级过热器的泄漏为长时过热所致,泄漏处的显微组织为铁素体加碳化物,珠光体球化达5级,并存在大量蠕变裂纹。

The high-temperature superheater bursting accident is one of the main factors that affect the safe operation of power plants,and causes the greatest loss.Based on the actual work in the field,the reasons for the leakage of final superheater of boiler No.1 in a power plant are discussed.Through a variety of test means such as macroscopic test,chemical composition analysis,mechanical properties test and microstructure observation,the tubes are comprehensively analyzed to improve the failure of the heating surface tube of the boiler.The analysis shows that the leakage of the last stage superheater is caused by long overheating.The microstructure near the leakage position is ferrite plus carbides,pearlite spheroidized up to 5 levels,and there are a lot of creep cracks.