An Investigation of Fuel Mixing and Reaction in a CH4/Syngas/Air Premixed Impinging Flame with Varied H2/CO Proportion

Abstract

For industrial applications, we propose a concept of clean and efficient combustion through burning syngas on an impinging burner. We performed experimental measurements of particle image velocimetry, OH radical (OH*) chemiluminescence, flame temperature, and CO emission to examine the fuel mixing and reaction of premixed impinging flames of CH 4 /syngas/air with H 2 /CO in varied proportions. The velocity distribution of the combustion flow field showed that a deceleration area in the main flow formed through the mutual impingement of two jet flows, which enhanced the mixing of fuel and air because of an increased momentum transfer. The deceleration area expanded with an increased CO proportion, which indicated that the mixing of fuel and air also increased with the increased CO proportion. Our examination of the OH* chemiluminescence demonstrated that its intensity increased with increased CO proportion, which showed that the reaction between fuel and air accordingly increased. CO provided in the syngas hence participated readily in the reaction of the CH 4 /syngas/air premixed impinging flames when the syngas contained CO in a large proportion. Although the volume flow rate of the provided CO quadrupled, the CO emission increased by only 12% to 15%. The results of this work are useful to improve the feasibility of fuel-injection systems using syngas as an alternative fuel.

Investigation of Waste Biogas Flame Stability Under Oxygen or Hydrogen-Enriched Conditions

“…Another option to improve flame stability and flammability is to use an addition of hydrogen/syngas or supply of oxygen-enriched air [16][17][18][19][20][21][22]. Chiu et al [23] investigated the effect of H 2 /CO on a premixed methane flame. The research was performed in an impinging burner by changing an H 2 /CO concentration from 20/80 to 80/20 vol% and a methane concentration from 10 to 20 vol%.…”