A numerical study on the flame characteristics and pollutant emissions in a premixed burner: Comparison between porous and solid bluff bodies

Abstract

The effects of porous and solid bluff bodies in the combustion chamber on flame stability limits, gas and solid temperature distributions, pressure drop, methane conversion rate, and CO and NO emissions are examined numerically. The porous and solid bluff bodies are made of SiC with the inner diameter of 50 mm, the outer diameter of 90 mm, and the length of 22 mm. In this study, Renormalization Group k–ε is used for modeling of turbulence. Eddy dissipation concept is selected for modeling of the interaction between turbulence and chemistry. A reduced mechanism based on GRI 3.0 consisting of 16 species and 41 reactions is employed to model methane combustion. The results indicate that the upper flame stability limit can be diminished by adding porous bluff body in the combustion chamber instead of the solid bluff body. Besides, the pressure drop, CO and NO emissions in the combustion chamber with solid bluff body are higher than those of porous bluff body, while the methane conversion rate increases by replacing porous bluff body instead of solid bluff body in the combustion chamber.

Experimental analysis of the effects of porous wall on flame stability and temperature distribution in a premixed natural gas/air combustion

“…One of these methods is the use of efficient burners. In this regard, porous burner has been proposed by many researchers 1‐11 . The porous burner has several advantages compared with conventional burners, such as increasing flame stability, reducing pollutant emissions, uniform heat distribution, and preheating of unburned mixture 12 .…”