Analysis and Suggestions on Leakage of Boiler Low Temperature Reheater

Abstract:

Leakage causes of boiler low temperature reheater were discussed by means of macroscopic inspection, chemical composition analysis, metallurgical microstructure examination, SEM and EDS fracture analysis. Results showed that the reheater leakage occurred for cracks originating from the fillet seam of ear plate. The main causes lie in improper structural design of the ear plate welding directly on the reheater elbow where suffered from complicated stress condition, wall thinning and out-of-round. In addition, as a weak zone, heat effect zone of the fillet welding seam was more likely to crack under fatigue stress for frequent unit start and stop and pipeline vibration. Installation stress existed between the ear plate and support block also contributed to the cracking. Suggestions were provided to avoid similar accident based on the comprehensive analysis of leakage causes.

• Periodical: Applied Mechanics and Materials (Volumes 341-342)
• Pages: 341-344
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.341-342.341
• Online since: July 2013
• Authors: Xue Xia Xu, Yan Ting Feng, Hao Ke, Xiao Guang Niu, Qing Wang
• Keywords: Boiler, Leakage, Low Temperature Reheater

References

[1] A.K. Ray, Y.N. Tiwari. Engineering Failure Analysis, 2000, 7: 359-376.

[2] Yingting Dou, Jun Li, Zheng Zhang. Materials Engineering, 2012, (4): 12-16.

[3] Pavlovsky J, Million B, Ciha K, et al. Materials Science and Engineering, 1991, A149: 105-110.

[4] Lundin C D, Khan K K, Yang D. WRC Buletin, 1995(407): 1.

[5] Davis C L, King J E. Metallurgical Transactions A, 1994, 25( 3) : 563－573.