掺氢对自由活塞发动机性能及排放的影响研究

Effect of Hydrogen Addition on the Operating and Emission Characteristics of a Free Piston Linear Engine

本文以自由活塞发动机为对象,实验探究了在甲烷燃料中掺加不同体积分数的氢气对自由活塞发动机性能和排放特性的影响。研究结果表明:燃料掺氢后,发动机的性能得到了显著的提升,指示功率最大提升了60.1%,指示热效率最大提升了59.2%。掺氢量达到4%时发动机性能达到最佳,继续增加掺氢量时由于点火定时过于提前,发动机性能下降。掺氢后发动机贫燃运行范围得到了拓宽,发动机运行稳定性得到了提升。掺氢后提高了燃料燃烧速率,减少了碳烟生成。

A miniature free piston linear engine fueled by methane was designed and manufactured.Effects of hydrogen addition on the performance and emission characteristics of the FPLE were studied.The experimental results showed that the FPLE performance is improved significantly with the hydrogen addition.Compared with that of pure fuel condition,the indicated power and indicated thermal efficiency are increased by 60.1%and 59.2%respectively.The optimal performance is achieved with the hydrogen volume concentration of 4%.However,the engine performance cannot be further improved when the hydrogen volume concentration further increases since more hydrogen addition can cause advanced combustion to occur.Moreover,the lean operating range of the engine is significantly extended and the engine operating stability is also improved.The high-speed color images showed the flame is lighter and less yellow compared with that of pure methane addition,indicating that the hydrogen addition to the main fuel have significant impacts on suppressing the soot formation.