The Effects of Combustion Parameters on Pollutant Emissions in a Porous Burner

Abstract

This paper reports a two-dimensional numerical prediction of premixed methane/air combustion in inert porous media. The two dimensional Navier-stokes equations, the two separate energy equations for solid and gas and conservation equations for chemical species are solved using finite volume method based on SIMPLE algorithm. The burner under study is a rectangular one with two different regions. First region is a preheating zone (low porosity matrix) that followed by the actual combustion region (high porosity matrix). For simulating the chemical reactions, skeletal mechanism (26 species and 77 reactions) is used. For studying the pollutant emissions in this porous burner, the effects of porous matrix properties, excess air ratio and inlet velocity are studied. The predicted gas temperature contour and pollutant formations are in good agreement with the available experimental data. The results indicate that the downstream of the burner should be constructed from materials with high conductivity, high convective heat transfer coefficient and high porosity in order to decrease the CO and NO emissions. Also, with increasing the inlet velocity of gas mixture and the excess air ratio, the pollutant emissions are decreased.

Effects of H2 Enrichment and Inlet Velocity on Stability Limits and Shape of CH4/H2–O2/CO2 Flames in a Premixed Swirl Combustor

“…Also, the inlet mixture velocity has an impact on pollutant emissions. Khiavi numerically investigated the effects of inlet velocity on pollutant emissions, and it was found that increasing the inlet velocity of the mixture reduces NOx and CO emissions. This was attributed to the decrease in the maximum flame temperature.…”

Effect of filling ratio on premixed methane/air explosion in an open-end pipe

“…4 To prevent losses from the explosions of methaneair mixtures in underground coal mines, experimental, theoretical, and computational methods were extensively adopted by scholars to study the propagation characteristics of gas explosion. [5][6][7][8][9][10][11][12][13] Zipf et al 14 used a long tube (length, 73 m; diameter, 1.05 m) to study the deflagration-to-detonation transition of methaneair mixtures under the blockage ratios of 0.13, 0.25, and 0.50. They found that run-up length to DDT increased with the increasing of blockage ratios.…”