Investigation of laminar flame speeds of typical syngas using laser based Bunsen method and kinetic simulation

Synthetic gas (syngas) fuels are promising energy sources in the future. In the current work, laminar flame speeds of typical syngas with different H2 contents were studied using both experimental measurements and kinetic simulations. Measurements were carried out using the Bunsen method with the flame area derived from the OH planar laser-induced fluorescence (OH-PLIF) images; while kinetic simulations were made using CHEMKIN with two mechanisms: GRI-Mech 3.0 and USC-Mech II. The OH-PLIF based Bunsen method was validated with previous results. Both the experimental and simulated results indicated that the flame speed of syngas increased with H2 concentration, which, based on the simulation, is attributed to the rapid production of highly reactive radicals and the acceleration of chain-branching reactions by these radicals. In general, predictions with both mechanisms agreed well with measurements, especially for fuel-lean conditions; simulations with USC-Mech II gave better agreement with experimental results at Φ = 0.8 and 0.9 (discrepancy <5%).