NOx emissions of an opposed wall-fired pulverized coal utility boiler

The present paper was addressed to the effects of operational variables and coal properties on NOx emission level of a 600-MW opposed wall-fired pulverized coal utility boiler. The in situ experiments were performed to study the effects of operational variables on boiler performance by changing individual variables while the other variables were held nearly constant on the basis of the nominal load operation. It was found that the oxygen level was a significant parameter to affect the NOx emission. The impacts of coal properties on NOx emission indicated that NOx emission level decreased with the increase of the ratio of the nitrogen content to low heating value because the volatile matter content in coal significantly influenced the in-flame NOx formation. Coal volatile content was the dominant parameter to affect fuel NOx formation through affecting the reducing condition in the inner near-burner zone when the low NOx burners were applied in the boiler. (c) 2009 Curtin University of Technology and John Wiley & Sons, Ltd.