Effect of Soot on NOx Emissions in an Oil Fired Industrial Glass Melting Furnace

This study examines the effect of soot concentration on NOx emissions in an oil fired industrial glass furnace. The combustion process is modeled using a single mixture-fraction, chemical equilibrium, probability density function (PDF) approach in FLUENT 5.0. The generation of radical nuclei and formation of soot on these nuclei are incorporated using the two-step Tesner model. It is well known that the presence of soot in the flame increases the radiative heat transfer to the glass and furnace walls due to its luminosity, and also results in reduced peak flame temperature. It is estimated from the current simulation that a peak soot concentration of 1 g/m3 decreases the flame temperature from 2094°C (at Og/m3 soot concentration) to 1726°C. A reduction in peak temperature in turn reduces NOx concentration from 3300 ppmdv to 606 ppmdv at the furnace exit. The numerical simulations are also validated with the existing experimental data available in the literature.