NOx emission prediction from 3-D complete modelling to reactor network analysis

This paper describes the activities carried out for the development and the use of CRFD codes and related procedures for the design of industrial furn aces. The objective is to predict the emission of pollutants, such as nitro gen oxides, in combustion flue gases. This prediction may be correctly acco mplished using a detailed kinetic mechanism, which cannot be directly imple mented on CRFD codes due to actual computational limits (both in terms of m emory and CPU time consumption). A new approach has been developed: analysi ng the 3D CRFD flow fields, an "equivalent" chemical reactors network model is extracted with corresponding residence time distributions and overall r eactor properties, and the detailed kinetic calculation is performed on thi s simpler scheme. The approach has been successfully applied to different scale of furnaces s uch as pilot plants and industrial boilers, low-NOx burners and glass furna ces. In the papers a description of the CRFD codes is given, and the methodology to extract a chemical ideal reactor network from CFRD fields is presented. Finally, an application of the procedure on the Monfalcone #3 steam genera tor is discussed.