Summary of workshop on materials issues associated with low-NO{sub x} combustion conditions in fossil-fired boilers
It was anticipated by some members of the high-temperature corrosion community that the fitting of low-NO{sub x} burners to coal-fired power plants would lead to an increase in furnace wall corrosion, as a result of the relatively substoichiometric conditions created by the staged combustion process. These expectations were not borne out by initial experience. Recently, however, cases of severe furnace wall corrosion have been reported by some U.S. utility boilers retrofitted with modern low-NO{sub x} burners. There is extensive experience of furnace wall corrosion in utility boilers in the U.K., which indicates that excessive fireside corrosion rates (>200 nm/hr; 34 mil/yr) are experienced when tubes are exposed simultaneously to substoichiometric gaseous environments (CO>3.0 percent) and high radiant heat fluxes. Such conditions may be generated when flame impingement occurs. Where such conditions persist, increases in fuel chlorine content will exacerbate the rate of metal loss. In the absence of either circumstances, corrosion rates are much reduced and little influence of coal chlorine content is anticipated. Although the corrosion is essentially sulfidation caused by H{sub 2}S in the flue gas, the contribution of fuel sulfur in the corrosion experience by U.K. boilers is unresolved, partly because of the relatively small range in sulfur content of coals burned in U.K. utility boilers. The intent of this workshop was three-fold: to better define the problem in terms of the form and rate of attack; to examine what is known about its root causes; and to review the potential for using corrosion-resistant materials as part of the solution.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 458971
- Report Number(s):
- ORNL/FMP-96/1; CONF-9605167-; ON: DE97050349; TRN: 97:001933-0040
- Resource Relation:
- Conference: 10. annual conference on fossil energy materials, Knoxville, TN (United States), 14-16 May 1996; Other Information: PBD: Aug 1996; Related Information: Is Part Of Proceedings of the tenth annual conference on fossil energy materials; Cole, N.C.; Judkins, R.R. [comps.]; PB: 551 p.
- Country of Publication:
- United States
- Language:
- English
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