A new procedure for predicting NOx emissions from furnaces

This paper presents a new method for the determination of NOx formation fro m industrial boilers. The flow and temperature fields within the furnace, o btained through CFD codes, are approximated by a network of ideal reactors. This approach allows using a very detailed and comprehensive kinetic model , without losing the detailed thermal and fluidynamic information. The mean ing of this work is to move a further step in the direction of a better des cription of both kinetic and fluidynamic aspects during combustion. The pre diction of pollutant byproducts, whose amount is in terms of ppms or even p pbs, necessarily requires the use of a detailed description of the process chemistry. Moreover, in the case of NOx formation, the air and fuel staging , as applied to more recent plants, implies the interactions between nitric oxides and hydrocarbon radicals. A detailed description of these reaction paths is extremely important to correctly reproduce the final emissions. Th e comparison of the obtained predictions with the experimental industrial r esults shows a quite satisfactory agreement. qualitatively and quantitative ly, in different operating conditions and plant configurations. (C) 2001 El sevier Science Ltd. All rights reserved.