超超临界锅炉水冷壁管的疲劳失效分析

Fatigue Failure Analysis ofWaterWall Tube in Ultra-supercritical Boilers

随着机组参与灵活性调峰日益常态化,设备保持长期安全、稳定的重要性日益凸显。基于燃煤发电机组锅炉基本原理,针对超超临界电站锅炉水冷壁管疲劳失效问题展开试验分析,揭示了水冷壁的损伤机理,阐述了超超临界锅炉传热恶化的随机特征,发现了径向热应力与温升速率具有正相关性,指出主动控制水动力循环是预防传热恶化和热应力集中的良好途径,并提出了重点关注相变点高度附近水冷壁管屏的壁温监测和检修维护等运行调整建议,为燃煤发电企业安全运行提供了参考依据。

With the increasing normalization of unit participation in flexible peaking,the importance of maintaining long-term safety and stability of equipment is becoming increasingly prominent.Based on the basic principles of coal-fired generator set boilers,the fatigue failure problem of water wall tube of ultra-supercritical power plant boiler is analyzed experimentally,the damage mecha-nism of water walls is revealed,the random characteristics of heat transfer deterioration in ultra-supercritical boilers are described and it is found that radial thermal stress has a positive correlation with temperature rise rate.It is pointed out that active control of hy-drodynamic circulation is a good way to prevent heat transfer deterioration and thermal stress concentration and the suggestion that the operation adjustment of the wall temperature monitoring and maintenance of the water-cooled wall tube panel near the height of the phase change point should be emphasized is put forward,which provides reference for the safe operation of coal-fired power genera-tion enterprises.