Effect of Surface Catalytic Reaction on Homogeneous Premixed Combustion

摘要

Surface catalytic reaction is an important way to organize effective and stable combustion inside micro or mini-scale combustor. In this paper, the surface catalytic kinetics theory was used to study the effect of Pt-surface catalytic reaction on homogeneous lean fuel premixed combustion of CH_4/Air in a 2-D mini-scale expanding channel. Using the CHEMKIN surface catalytic kinetics model, a numerical method was presented, which is based on the commercial code, FLUENT. The performance of our numerical procedure was validated by comparison of the results with those obtained from DETCHEM (Redenius, 2001) and the experimental data. Our studies found, compared with homogeneous combustion, the catalytic reaction produces a reduced extinction distance, a thicker flame, and a lower maximum temperature inside the flow field. Worthwhile, the temperature gradient on the unburned side of the flame is decreased. The effects of the surface catalytic reaction on the gas phase combustion are very sensitive to the equivalence ratio. The leaner the mixture is, the stronger the catalytic effects are.