摘要
采用高温高压定容燃烧弹系统对亚/超临界环境下燃料在纯氧中的喷射燃烧现象进行试验研究,通过高速相机和阴影法进行燃烧图像信息的采集,研究在相同的超临界温度下,正己烷和乙醚两种燃料喷射燃烧火焰特性随环境压力和喷油脉宽的改变而呈现的差异性。试验结果表明:在亚临界压力下,两种燃料在不同喷油脉宽下的燃烧时间均随着环境压力的升高而升高,火焰发展后期基本保持较为稳定的形态和亮度,符合传统的喷射燃烧过程。正己烷在临界压力点下火焰长度最短,形态较为规则;超临界压力下,火焰形态有稳定趋势但仍有轻微波动,且火焰长度略短于亚临界;喷油脉宽改变时,燃烧时间在临界压力附近呈现出不同的趋势。乙醚的燃烧时间随压力的升高而增大,在临界压力处达到最大值,后随着压力的继续升高而下降,不同压力条件下火焰形态略有差别。燃烧现象存在差异性主要是由于亚/超临界坏境下燃料的物性参数和破碎蒸发机理不同。
The combustion phenomena of fuel injection in sub-and super-critical environments was studied by using a constant volume bomb system.The high-speed camera and shadow method were used to collect the combustion image information.The differences in the spray combustion characteristics with the change of ambient pressure and injection pulse width were studied at the same super-critical temperature.The n-hexane and ether were used as fuels in the experiment.Results show that at sub-critical pressure,the combustion time of the two fuels with different injection pulse widths increases with the rise of ambient pressure,while the spray flame maintains a relatively stable morphology and brightness in the later stage of combustion development,which is in line with the traditional spray combustion process.When using n-hexane as fuel,the combustion flame at the critical pressure point has the shortest length and regular morphology.The flame morphology at super-critical pressure trends to be stable with a small fluctuation,and the flame length is slightly shorter than at sub-critical pressure.When the fuel injection pulse width changes,the combustion time will show a different trend near the critical pressure.As for the ether fuel,the combustion time first increases with the rise of ambient pressure,and then decreases after reaching its maximum value at critical pressure.In addition,the flame morphology is slightly different under different pressure conditions.The differences in the combustion phenomena are mainly due to the differences of physical properties and fracture evaporation mechanism of fuels in sub and super-critical environments.
作者
马志豪
李亚楠
杜维新
尹振龙
胡二江
MA Zhihao;LI Yanan;DU Weixin;YIN Zhenlong;HU Erjiang(College of Vehicle&Transportation Engineering,Henan University of Science and Technology,Luoyang 471003,China;School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2020年第1期18-26,共9页
Chinese Internal Combustion Engine Engineering
基金
国家自然科学基金项目（91441118）~~
关键词
亚/超临界环境
燃烧特性
喷射火焰
sub-and super-critical environments
combustion characteristic
injection flame
作者简介
马志豪(1965-),男,教授,博士,主要研究方向为内燃机燃烧及有害排放物控制,E-mail:mazhihao@haust edu.cn。
