Stretch Extinction Limits of Counterflow Diffusion Flame for Blended Fuels Including Carbon Monoxide

Abstract

Numerical calculation was performed to obtain extinction limits of counterflow diffusion flames for blended fuels of CO/H_2 and CO/CH_4,which are produced by thermal decomposition in incinerators. The computer code PRIMIX was converted into a calculation program for counterflow flames, and GRI-Mech ver.2.11 was used as a chemical scheme, eliminating reactions of N and including the radiation heat loss. The stretch rate at extinction of the blended fuel CO/CH_4 has a maximum at a certain mixture ratio as has been shown in the burning velocity. The effects of diluents such as CO_2 and H_2O were also calculated because blended fuels are always diluted by those inert diluents, showing that the stretch rate at extinction has a maximum at a certain dilution rate as well as the mixture ratio of fuels.