Computed Flammability Limits and Combustion Application of Hydrogen-Enriched Syngas Fuels

Due to the stress from the shortage of hydrocarbon fuels and the reduction of greenhouse gases, this research project is aimed at the combustion characteristics and applications of hydrogen-enriched synthesis gases (syngas or reformer gases). The detailed flame structures and flammability limits of syngas fuels are investigated, and the gas turbine combustion performance and combustor designs are studied. The following contents of the three-year project provide the fundamental knowledge to hydrogen-related energy application and hydrogen safety issues. 1. Combustion and flammability limits of counterflow diffusion flames of syngas fuels: By using the configurations of counterflow diffusion flames, the flame structures and extinction limits of hydrogen-enriched syngas fuels are investigated. The effects of hydrogen contents, strain rates on the diffusion flame structures are studied. The extinction boundaries of diffusion flames are constructed with the strain rates and the percentage of diluents as variables. The model predictions of the flammability provide the combustion applications and fire safety for utilizations of syngas fuels. 2. Combustion and flammability limits of counterflow premixed flames of syngas fuels: By using the configurations of counterflow premixed flames, the flame structures and flammability of hydrogen-enriched syngas fuels are investigated. The effects of hydrogen contents, equivalence ratio on the premixed flame structures are studied. The flammability limits of premixed flames are constructed using equivalence ratio and strain rates as parameters. Besides, the laminar flame speeds of syngas fuels are computed and compared with a model of free-propagation premixed flames. The model predictions of these combustion features provide the fundamentals of utilizations of syngas fuels. 3. Gas turbine combustor design and combustion analysis of syngas fuels: For the syngas combustion applied in gas turbines, the combustor designs and combustion properties are studied with model analysis. The combustor performance including combustion efficiency, flammability, ignitability, pressure loss, flame stabilization, flashback, cooling, pattern factor and emission are examined to evaluate the potential combustion technologies with clean energy.

Project ID:PB9907-10764
External Project ID:NSC99-2628-E182-004