氢气对正己烷-空气燃爆性能的影响

关键词:燃爆；爆炸压力；最大爆炸压力上升速率；层流燃烧速度

关键词:  燃爆  爆炸压力  最大爆炸压力上升速率  层流燃烧速度

Key words:  Deflagration  Explosion pressure  Maximum rate of explosion pressure rise  Laminar burning velocity

摘要:

为了研究氢气对正己烷燃爆性能的影响，在定容燃烧室内实验测量了初始温度为353K，初始压力为100kPa，当量比0.7～1.7，掺氢比0%～80%时，正己烷-氢气-空气混合气的爆炸过程，得到了氢气对火焰传播规律、层流燃烧速率及爆炸压力的影响。研究结果表明，当量比从0.7增加到1.7，无拉伸火焰传播速率和层流燃烧速率呈先增大后减小的趋势，在当量比1.0附近达到最大；随着掺氢比的提高，混合气的燃烧速率明显增大，有利于提高燃料的燃烧效率，当量比为1.0时，掺氢比80%的混合气层流燃烧速率比正己烷-空气混合气提高了2.5倍；同时，掺氢比对混合气的爆炸压力与最大爆炸压力上升速率有明显的影响，对过稀或过浓燃料的影响尤为显著。

Abstract:

To study the effects of hydrogen addition on the deflagration characteristics of n-hexane/air mixture，the explosion process was investigated in a constant volume combustion chamber. Experiments were carried out at initial temperature of 353K，initial pressures of 100kPa，equivalence ratios range of 0.7～1.7 and hydrogen blended ratios of 0%～80%. The effects of hydrogen addition on the flame propagation process，laminar burning velocity and the explosion pressure were obtained. The results show that the unstretched flame propagation speed and laminar burning velocity increase at first and then decrease gradually with the increase of equivalence ratio from 0.7 to 1.7. The highest values are measured near the equivalence ratio of 1.0. Furthermore，the flame laminar burning velocity of n-hexane/air/hydrogen mixture substantially increases with hydrogen addition，showing the development of combustion capacity and thermal efficiency. For stoichiometric mixtures，the laminar burning velocity at the hydrogen fraction of 80% is 2.5 times higher than that of n-hexane/air mixtures. At the same time，the hydrogen addition has a significant influence on the explosion pressure and rate of maximum pressure rise，especially for the over lean or overrich mixture.