NUMERICAL SIMULATION OF LEAN PREMIXED STAGNATION FLAMES

摘要

Lean premixed combustion counterflow model coupled with detailed chemical kinetics mechanisms are used to study the effects of methane dilution on syngas mixture numerically. The work critically evaluates and examines the effects of methane additions at various methane/syngas ratios and various equivalence ratios (Φ = 0.6, 0.65, and 0.7) using the CANTERA package. The results of this study increase the feasibility of incorporating syngas mixture diluted with methane based fuel for lean premixed gas turbine engines. This study indicates that the flame velocity of a syngas mixture (H_2:CO-75:25) can be reduced to the flame speed of a methane mixture at an equivalence ratio of 0.6 and standard conditions (1 atm and 298 K) by mixing it with 50% of methane. This could reduce the flashback propensity that syngas mixtures will incur due to the significantly high flame speed. Moreover, this study substantiates that the current detailed mechanism is capable of predicting the one-dimensional reacting flows and it matches remarkably well with experimental data. The approach employed herein can be used to optimize and validate detailed chemical kinetics mechanism without the need to correct the flame speed to zero strain or stretch free from the measured datasets.