Flammability Limits and Dilution Effects Analysis of Opposed-Jet Syngas Diffusion Flames

Due to the shortage of hydrocarbon fuels and the increasing concerns of greenhouse gas emissions, this research aims to investigate the combustion and extinction of opposed-jet syngas diffusion flames. The flammability limits and critical conditions for flame extinction are computed, and the dilution effects on the syngas combustion are analyzed. This two-year project provides the fundamental knowledge of syngas combustion and fire safety for the applications of syngas fuels. The details are described as follows: 1. Flammability limits of opposed-jet syngas diffusion flames: By using the configurations of counter-flow diffusion flames, the characteristics of combustion and extinction of syngas flames are investigated. The effects of strain rate (or stretch rate), syngas composition, atmospheric conditions on the flame structures, chemical reactions and flammability limits are studied. The extinction boundaries of diffusion flames are constructed with the strain rates, hydrogen content or atmospheric conditions as variables. The model predictions of the flammability provide the combustion applications and fire safety for utilizations of syngas fuels. 2. Dilution effects analysis of opposed-jet syngas diffusion flames: The characteristics of combustion and extinction of the opposed-jet syngas diffusion flames with dilution gases are investigated. The extinction boundaries are constructed with strain rate and diluents percentage as the parameters. The dilution effects on the flame structures, chemical reactions, and flammability limits are studied. The roles of individual dilution effects, such as the inert effect, thermal effect, chemical effect, and radiation effect of diluents on the combustion and extinction of syngas diffusion flames are then analyzed.

Project ID:PB10207-1918
External Project ID:NSC102-2221-E182-026