ABSTRACT

This paper describes the role of numerical modeling in the design of a low-NOx burner for utility boilers. Environmental regulations for boiler systems are becoming more stringent. With an increasing emphasis on the use of lower-grade fuels, emission controls, and reliability under more complex operating conditions, conventional, empirically-derived design criteria for fossil fuel boilers cannot be adequately extended. As a result, Babcock & Wilcox has developed mathematical modeling techniques to enhance design capability. The role of numerical modeling in an ongoing burner development program is discussed. A review of pilot-scale studies demonstrates the feasibility of using the novel low-NOx burner in a commercial unit. Recent full-scale modeling of the baseline unit and the retrofit condition demonstrates that unit performance, e.g., combustion efficiency, is not degraded with the new burner. Modeling at the utility scale confirms trends predicted at the pilot scale. Ongoing work will collect data for the retrofit conditions, and models will be compared with data and improved. As feasibility is shown for use of the burner in a utility boiler and experience is gained with the models, they will provide valuable tools for use on other “clean air” projects.