Combustion characteristics of a self-preheating burner with gradually-varied porous media

Abstract

ABSTRACT Porous media combustion technology provides an excellent alternative scheme for the efficient utilization of low concentration coal mine methane and the effective control of emissions. A self-preheating combustion system was built and combined with gradually varied porous media. And the spiral, tubular, and finned heat exchangers were designed to compare the combustion characteristics at different working conditions. Results indicated that the combustion temperature was increased effectively and the emission of pollutants was reduced under the addition of preheater. Moreover, the spiral heat exchanger increased the average temperature of preheating zone by 21%. And the starting time of the burners mainly depended on the pore density of the ceramic foam at the burner exit. With the increasing of velocity and equivalence ratio, the combustion temperatures were significantly increased. Meanwhile, the 3 mm-10-30 PPI burner combined the advantages of large and small pore density to realize the reduction of CO emissions below 20 ppm.