NOx Emission Characteristics in a DesiNOx Gned Premixed Burner

Abstract

Nitrogen oxides (NOx) formed in gas instantaneous water heater combustion systems is a significant pollutant source in the domestic environment. Advances in the science of reactions, mathematical modeling, and increased performance of computer systems have made comprehensive modeling of NOx formation and destruction a valuable tool to provide insights and understanding of the NOx reaction processes in combustion systems. In this approach, the chemical combustion reactions are described by nine species and six steps. The predicted NO level is less than 30 ppm when diameter of round fire holes (d) is 0.6 or 0.7mm, and excess air ratio (α) is 1.3. Our results indicates that the vortex produced between a bunch of the round fire holes and another bunch of the round fire holes results in thermal agglomeration and the elevated value of NO. The areas of vortex regions are decreased with the increase of heat load. The lower temperature is produced in the vortex regions. The reduction of NO concentration under higher heat load is attributed to the lower temperature.