Several important applications of the oxygen-enriched combustion in steam generators include the design of a new generation of advanced boilers and the gain in power resulting from the use of oxygen-enriched air in existing boilers. This paper tackles the first option, namely, the impact of oxygen enrichment on the boiler design. The proposed model consists of the combustion calculus for an existing boiler (the base case), the analysis of the consequences of oxygen enrichment, and the evaluation of the heat transfer surface areas necessary for a new boiler that uses oxygen-enriched combustion. (C) 2003 Elsevier Ltd. All rights reserved.