COMPARISON OF MEASUREMENTS AND PREDICTIONS OF FLAME STRUCTURE AND THERMAL NO(X), IN A SWIRLING, NATURAL-GAS DIFFUSION FLAME

A combined thermal and fuel NO(x) submodel has recently been added to a generalized, 2-dimensional pulverized coal gasification and combustion model (PCGC-2). This model is applicable to reacting and non-reacting gaseous and particle-laden flows. The thermal NO model is based on the extended Zel'dovich mechanism. To perform an evaluation of the NO(x) submodel, combustion measurements of gas velocities, temperatures, and species concentrations were made in a laboratory-scale, experimental reactor with a 150 kW natural gas flame at an equivalence ratio of 1.05 and a secondary-air swirl number of 1.5. Combustion measurements of velocities and major species concentrations show generally good agreement with predicted values. Gas temperature measurements closely match predictions in the recovery region but fail to show predicted high temperature in the annular region. This study provides an evaluation of a comprehensive combustion model and the NO(x) submodel which can be useful as a design tool to provide pollutant formation trends in applied systems as combustion parameters are varied.