除氧器喷淋管接管座角焊缝裂纹检测与结构优化-热力发电.PDF

第46 卷 第5 期 热 力 发 电 Vol.46 No.5 2017 年 5 月 THERMAL POWER GENERATION May 2017 除氧器喷淋管接管座 角焊缝裂纹检测与结构优化 马翼超，孟永乐，范志东，张志博，牛 坤，马剑民，姚兵印 （西安热工研究院有限公司，陕西 西安 710054） ［摘 要］某电厂自2007 年投产以来，除氧器喷淋管角焊缝运行中多次发生泄漏，虽多次对该位置进 行补焊修复，但仍无法根除该缺陷，给电厂的安全运行造成了很大的隐患。为了提高缺陷 的检出率、防止此类事故的频繁产生，提出采用磁粉检测与超声爬波检测相结合的方法， 并通过磁记忆检测技术对缺陷的原因进行分析，然后通过加装膨胀节对除氧器喷淋管的结 构进行优化，降低喷淋管支管所承受的应力。采用这2 种检测方法及对除氧器喷淋管结构 进行优化改造后，基本解决了喷淋管管座角焊缝经常泄漏的问题，可为其他电厂同类问题 的解决提供借鉴。 ［关 键 词 ］除氧器；喷淋管；角焊缝；裂纹；磁粉检测；超声爬波检测；膨胀节；结构优化 ［中图分类号］TG115 ［文献标识码］A ［文章编号］1002-3364(2017)05-0127-05 ［DOI 编 号］10.3969/j.issn.1002-3364.2017.05.127 Crack detection and structure optimization for fillet welds in nozzle stubs of deaerator spray pipes MA Yichao, MENG Yongle, FAN Zhidong, ZHANG Zhibo, NIU Kun, MA Jianmin, YAO Bingyin (Xi ’an Thermal Power Research Institute Co., Ltd., Xi ’an 710054, China) Abstract: Multiple leakages were found in fillet welds between the nozzle stubs and deaerator spray pipes in a power unit since the plant was put into operation in 2007. Although weld-repair was carried out many times for this fillet welds, defects cannot be eradicated totally, causing serious hidden trouble to safe operation of the power plant. In order to improve the defect detection rate and prevent this kind of accident from occurring frequently, a combination method was proposed using magnetic particle testing and ultrasonic creeping wave. The reason for this defect was analyzed by magnetic memory testing technology. It proposed installing expansion joint to optimize the structure of the deaerator spray pipe and reduce the stress that the spray pipe branch b