Abstract
The air heater is a rotary regenerative heat exchanger which recovers heat from the outgoing hot gases of the boiler and transforms it to the incoming air needed for combustion process. This system is composed of large numbers of heat transfer elements made from corrosion-resistant material (Corten) or enamel coated in order to resist acid dew-point corrosion. In this study, a root cause failure analysis of heating elements was carried out. Visual inspection, chemical analysis, and microscopic examinations of the heating elements, enamel coating, and depositions were conducted. Sulfuric acid dew-point temperature (ADPT) was determined to be 138–142 °C based on the sulfur dioxide of the flue gases. Moreover, temperature distribution across the air heater matrix was simulated using Fluent software. The failures of the heating elements were mainly due to sulfuric acid dew-point corrosion and under-deposit pitting corrosion. The corrosion products were mainly iron sulfate, iron oxide, and iron sulfide. In the case of enamel-coated elements, the failure was attributed to the existence of a large number of cracks and big bubbles in the coating, allowing the penetration of corrosive elements into and beneath the surface of coating and thus the detachment of coating.
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References
I. Warren, Ljungstrom heat exchangers for waste heat recovery. J. Heat Recovery Syst. 2(3), 257–271 (1982)
D. Reay, A review of gas-gas heat recovery systems. J. Heat Recovery Syst. 1(1), 3–41 (1981)
J.M. Blanco, F. Peña, Increase in the boiler’s performance in terms of the acid dew point temperature: environmental advantages of replacing fuels. Appl. Therm. Eng. 28(7), 777–784 (2008)
S.C. Hunter, Formation of SO3 in Gas Turbines. J. Eng. Power 104(1), 44–50 (1982)
S. Matsuda, T. Kamo, A. Kato, F. Nakajlma, Deposition of ammonium bisulfate in the selective catalytic reduction of nitrogen oxides with ammonia. Ind. Eng. Chem. Prod. Res. Dev. 21(1), 48–52 (1982)
Y. Wang, Q. Zhao, Z. Zhang, Z. Zhang, W. Tao, Mechanism research on coupling effect between dew point corrosion and ash deposition. Appl. Therm. Eng. 54(1), 102–110 (2013)
B. ZareNezhad, A. Aminian, Accurate prediction of the dew points of acidic combustion gases by using an artificial neural network model. Energy Convers. Manag. 52(2), 911–916 (2011)
A. Bahadori, Estimation of combustion flue gas acid dew point during heat recovery and efficiency gain. Appl. Therm. Eng. 31(8–9), 1457–1462 (2011)
X.Q. Cheng, F.L. Sun, S.J. Lv, X.G. Li, A new steel with good low-temperature sulfuric acid dew point corrosion resistance. Mater. Corros. 63(7), 598–606 (2012)
V. Linsa, E. Guimaraes, Failure of a heat exchanger generated by an axcess of SO2 and H2S in the sulfur recovery unit of a petroleum refinery. J. Loss Prev. Process Ind. 20(1), 91–97 (2007)
F. Barreras, J. Barroso, Behavior of a high-capacity steam boiler using heavy fuel oil, part II: cold-end corrosion. Fuel Process. Technol. 86(2), 107–121 (2004)
F.S. Shieu, K.C. Lin, J.C. Wong, Microstructure and adherence of porcelain enamel to low carbon steel. Ceram. Int. 25(1), 27–34 (1999)
X. Yang, A. Jha, R. Brydson, R. Cochrane, The effects of a nickel oxide precoat on the gas bubble structures and fish-scaling resistance in vitreous enamels. J. Mater. Sci. Eng. A 366(2), 254–261 (2004)
M. Kim, S. Chang, O. Oh, J. Won, H. Park, Failure analysis of enamel-coated carbon steel heating elements of gas-gas heater for flue gas desulfurization system. Eng. Fail. Anal. 14(4), 686–693 (2007)
A. Zhang, S. Jiao, Z. Jiang, D. Wei, Bubble structures, fishscaling resistance and adhesion of vitreous enamel to low carbon steel. Prog. Adv. Mater. Res. 409(1662–8958), 736–742 (2011)
Standard specification for steel, sheet, for porcelain enameling, ASTM-A424-06, ASTM International, 2000, p 1–3
J.H. Cleland, P.G. Morgan, Failure of vitreous enameled coatings. Eng. Fail. Anal. 3(3), 149–155 (1996)
R.A. Eppler, D.A. Eppler, Glazes and glass coatings (American Ceramic Society, Westervill, 2000)
F.H. Verhoff, J.T. Banchero, Predicting dew points of flue gases. Chem. Eng. Prog. 70, 71–72 (1974)
A. Heidari-Kaydan, E. Hajidavalloo, Three-dimensional simulation of rotary air preheater in steam power plant. Appl. Therm. Eng. 73(1), 397–405 (2014)
Y.K. Son, C.J. Lee, J.M. Lee, B.M. Kim, Deformation prediction of porcelain-enameled steels with strain history by press forming and high-temperature behavior of coating layer. Trans. Nonferrous Met. Soc. China 22(1003–6326), 838–844 (2012)
N.T. Shardakov, EKh Kurumchin, G.K. Vdovin, V.A. Deryabin, Effect of the steel substrate on the composition of gases in enameling. Glass Ceram. 53(1–2), 46–47 (1996)
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The authors highly appreciate the financial support provided by Ramin Power Plant, Ahvaz, Iran. The project was also partially supported by the Shahid Chamran University of Ahvaz, Iran.
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Shayan, M.R., Ranjbar, K., Hajidavalloo, E. et al. On the Failure Analysis of an Air Preheater in a Steam Power Plant. J Fail. Anal. and Preven. 15, 941–951 (2015). https://doi.org/10.1007/s11668-015-0041-6
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DOI: https://doi.org/10.1007/s11668-015-0041-6