CH_4在O_2/CO_2气氛下均相着火延迟的模拟研究

Simulation Study on Homogeneous Ignition Delay of CH_4 under O_2/CO_2 Atmosphere

分析在不同燃烧气氛（O_2/CO_2,O_2/N2,O_2/X）下,CH4着火延迟和自动着火温度的规律。结果表明,在相同CO_2体积分数下,O_2/X气氛下着火延迟时间明显比O_2/CO_2气氛下短,下降比为12%~17%,且自动着火温度也明显降低,说明在O_2/CO_2气氛下着火延迟不仅是因为CO_2的高比热容和低扩散性等物理原因,CO_2的化学性质也有很大影响。

This paper analyzed the rule of CH4 ignition delay and automatic ignition temperature in different combustion atmosphere（O_2/CO_2,O_2/N2,O_2/X）. The results showed that, in the same volume fraction of CO_2, ignition delay time in O_2/X atmosphere is obviously shorter than in O_2/CO_2 atmosphere, drop ratio is 12% ~17%, and automatic ignition temperature is also significantly reduced, and it was proved that ignition delay in O_2/CO_2 atmosphere was not only because of the physical causes such as high specific heat of CO_2 and low diffusivity, but also because of the big effect of chemical properties of CO_2.