稀释剂对氢气层流燃烧速度影响的实验和数值研究

In this paper, the near-limit laminar flame speeds of H₂/air at different N₂and CO₂ dilution ratios were measured on a constant volume combustion bomb. Six H₂ mechanisms were verified against the experimental data using numerical simulation. Finally, the NUIG 2013 mechanism was adopted and the chemical, physical and global effects of four diluents(N₂/AR/HE/CO₂) were investigated by using the pseudo dilution gas method. Furthermore, the chemical reaction kinetics was analyzed. The results indicate that the minimum laminar burning velocity measured for H₂/air/diluent premixed flame is about 2 cm/s. In the near-limit condition, the predicted values of different mechanisms are low, which are significantly lower than the experimental values. Dilution inhibition ability CO₂>N₂>AR>HE, CO₂ dilution gas exists the strongest inhibition effect on the chemical effect, and HE exists the weakest inhibition effect, which is due to its higher thermal diffusivity and lower specific heat capacity than the other three diluents. The analysis of chemical reaction kinetics showed that the sensitivity of reaction H+O₂+M ⇔ HO₂+M increased with the increase of diluent ratio. Diluent, as the third body m of the system, controlled the reaction rate. The difference of reaction rate of this reaction may be the reason for the difference between mechanism prediction and experimental value at the near-limit condition.