300 MW机组后屏过热器失效原因分析

Cause Analysis of Tube-burst on Rear Platen Superheater of 300 MW Unit

对某发电厂300 MW机组后屏过热器失效原因进行了分析,根据宏观检查、壁温曲线分析、金相检验、拉伸试验的结果,推测在锅炉停运冷却或启动过程中发生了水塞,导致后屏过热器短时过热爆管,并提出了预防水塞的措施。

The cause leading to the tube-burst failures on the rear plate-superheater of a 300 MW unit in the power plant has been analysed.According to the results of visual examination,analysis to wall temperature curves,metallographic examination and tensile test,it is speculated that the water plug which leads to tube-burst failures on rear plate-superheater happened in a short period during the cooling down or start-up process.The measures for preventing water plug are proposed and applied.