660MW超超临界锅炉低温再热器出口连接管与集箱管座对接焊缝泄漏的研究与治理  

Research and Treatment of Leakage of the Butt Weld between Connecting Pipe and Header Socket of Low Temperature Reheater Outlet in 660MW Ultra-Supercritical Boiler

作　　者：胡再新 张松文 HU Zaixin;ZHANG Songwen(Guangdong Yuedian Dapu Power Generation Co.,Ltd.,Meizhou 514021,China)

机构地区：[1]广东粤电大埔发电有限公司,广东梅州514021

出　　处：《锅炉技术》2022年第5期64-68,共5页Boiler Technology

摘　　要：针对某公司2×660MW超超临界П型锅炉低温再热器出口连接管与集箱管座的现场对接焊缝多次失效问题,通过对失效部位进行宏观形貌检查、位置分布、时间分布等统计分析,采取改进措施。结果表明:炉顶管与低温再热器出口集箱都是刚性吊架,在机组启停过程中,由于温度的不同步,吊杆的膨胀也会出现不同步的情况,导致荷载分配不均,从而导致连接管局部区域应力过大,易在现场对接焊缝的薄弱区发生失效。通过将低温再热器出口集箱的刚性支吊更换为弹簧支吊,这样即使在吊杆膨胀不同步时,弹簧能够补偿此膨胀差,使集箱和连接管的受力得到了有效改善,消除了焊缝失效的情况。The butt weld between the connecting pipe and the header socket of the low temperature reheater outlet of a 2×660MW ultra-supercriticalПtype boiler has failed many times.Improvement measures were taken through the macroscopic morphological inspection,location distribution,time distribution and other statistical analysis of the failed parts.The results show that both the roof tube and the low temperature reheater outlet header are rigid hangers.During the startup and shutdown of the unit,due to the asynchronous temperature,the expansion of the hanger will also be asynchronous,resulting in uneven load distribution.As a result,the stress in the local area of the connecting pipe is too large,and the butt weld failure on site is easy to occur in the weak area.By replacing the rigid hanger of the low temperature reheater outlet header with spring hanger,the spring can compensate for this expansion difference even when the expansion of the hanger is not synchronized,so that the force on the header and the connecting pipe is effectively improved,and the failure of the weld is eliminated.

关 键 词：低温再热器连接管 弯头焊缝 膨胀受阻 应力疲劳 弹簧吊架 

分 类 号：TK223.3[动力工程及工程热物理—动力机械及工程]