过热器集汽集箱管座开裂原因分析

分析了125 MW机组SG-400-50411型锅炉过热器集箱支座和管座开裂以及集箱整体上移的原因,认为其主要因导汽管二次应力超标、导汽管柔性不足、原滑动支架设计结构不合理等所致。对此,提出了改造支架滑动结构,增加导汽管柔性,采用小口径薄壁导汽管等处理措施,其经验可供检修和运行人员借鉴和参考。

CAUSE ANALYSIS OF TUBE SOCKET CRACKING ON THE HEADER OF SUPERHEATER FOR 125 MW UNIT

The causes leading to header's supports and tube socket cracking on superheater,and the entire header shifting upwards,which were discovered in the major repair of 125 MW unit(SG-400-50411 type),have been analysed.It is believed that the main causes are as follows: the secondary stress of steam conduit tube exceeding set standard;insufficient flexibility of the steam conduit tube;unreasonal designed structure of the orginal sliding supports, etc.For these,some remedial measures,such as retrofitling the sliding structure of supports,increasing the flexibility of steam conduit tube,adopting steam conduit tube of small diameter and thin wall etc.,have been put forward.The experiences can be used as reference for repair and operation personnel.