臭氧对甲烷/空气层流火焰传播速度影响规律

为提高气体机稀薄燃烧时的燃烧性能,解决天然气发动机在稀薄燃烧情况下点火能量高以及火焰传播速度慢的问题,利用强氧化性的臭氧对燃料进行改质,进而提高天然气燃烧性能。通过Chemkin软件研究臭氧添加对甲烷层流火焰传播速度的影响,并对臭氧助燃的化学机理进行数值分析。试验结果表明:添加臭氧后,层流火焰传播速度增加,在稀薄混合气条件下增加量更明显。在不同温度及压力条件下,掺加臭氧均能增加层流火焰传播速度,最大可增加36%。分析表明:掺加臭氧能明显提升自由基及中间产物的生成量,进而提高甲烷层流火焰传播速度。

Influence of ozone addition on laminar flame speed in methane-air lean mixtures

A new method was proposed to improve lean burn combustion performance of natural gas engine and to solve the problems of high ignition energy and slow flame speed of combustion of natural gas in lean burn condition by using the ozone with strong oxidation. The influence of ozone addition on laminar flame speed was studied and numerical analysis of chemical mechanism was carried out using Chemkin software. Results showed that laminar flame speed increased with ozone addition and improvement was more obvious with lean mixture. Moreover, laminar flame speed could be increased in different temperature and pressure situation with ozone addition and the maximum increment of laminar flame speed could reach 36%.The concentration of free radicals and intermediate products increased obviously with ozone addition and then improved the combustion characteristics of methane.