中国电力 ›› 2018, Vol. 51 ›› Issue (9): 83-87,150.DOI: 10.11930/j.issn.1004-9649.201707073

• 发电 • 上一篇    下一篇

超超临界机组疏水罐罐体泄漏原因分析及防治

俞葆青1,2, 彭杏娜1, 丛相州1, 彭先宽1, 杜占江1, 高志1   

  1. 1. 北京国电富通科技发展有限责任公司, 北京 102401;
    2. 南瑞集团(国网电力科学研究院)有限公司, 江苏 南京 211000
  • 收稿日期:2017-07-10 修回日期:2018-07-03 出版日期:2018-09-05 发布日期:2018-09-20
  • 通讯作者: 彭杏娜(1983-),女,通信作者,博士,工程师,从事高温压力管件成形及焊接研究,E-mail:pengxingna2325@163.com
  • 作者简介:俞葆青(1969-),男,工程师,从事压力容器管道管件设计,E-mail:yubaoqing@sgepri.sgcc.com.cn

Cause Analysis and Prevention of Drainage-Tank Leakage in Ultra-supercritical Power Plant

YU Baoqing1,2, PENG Xingna1, CONG Xiangzhou1, PENG Xiankuan1, DU Zhanjiang1, GAO Zhi1   

  1. 1. Beijing Guodian Futong Science and Technology Development Co., Ltd., Beijing 102401, China;
    2. NARI Group Corporation(State Grid Electric Power Research Institute), Nanjing 211000, China
  • Received:2017-07-10 Revised:2018-07-03 Online:2018-09-05 Published:2018-09-20

摘要: 对运行不到2年的某电厂1 000 MW超超临界火电机组再热热段管道疏水罐罐体开裂的原因进行了分析。首先对罐体进行超声检测、然后对裂纹进行解剖,对裂纹周围微观组织、裂纹断口形貌进行观察分析。结果表明,再热热段管道疏水罐开裂的主要原因是再热管道上的冷凝水反复回流,造成罐体上下部分温差较大,从而产生热疲劳裂纹,最终热疲劳裂纹扩展导致泄漏。对此,建议改进疏水罐结构并采用过热度控制方式,且定期对疏水罐进行超声检测。

关键词: 1 000 MW超超临界机组, 火电厂, 再热热段管道, 疏水罐, 热疲劳, 裂纹

Abstract: The cause of drainage-tank leakage of the reheat steam pipe is analyzed in a 1000MW ultra-supercritical power plant which has been operated for less than two years. Firstly, the tank is examined using ultrasonic, then the crack is dissected, and finally the microstructure and fracture morphology of the crack are inspected carefully and analyzed. The results show that, the cracking of the pipeline hydrophobic tank in the reheating section can largely be attributed to the repeated reflux of the condensate water on the reheat pipe, which causes significant temperature difference between the upper and lower parts of the pipe, and hence the thermal fatigue cracks are generated. Eventually the thermal fatigue crack propagation leads to the leakage. Therefore, it is suggested that the structure of the drain tank should be improved and the superheat control mode should be adopted. Additionally the ultrasonic inspection for the tank should be carried out regularly.

Key words: 1 000 MW ultra-supercritical unit, thermal power plant, the reheat steam pipe, drainage-tank, thermal fatigue, crack

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