可控活化热氛围下柴油喷雾自燃特性的研究

Study on Auto-Ignition Characteristics of Diesel Fuel Spray in Controllable Active Thermo-Atmosphere

利用可控活化热氛围燃烧试验系统,结合连续喷射系统对柴油燃料在高温热氛围下的自燃特性进行了研究,并利用高速摄影技术,得出柴油燃料喷雾在不同协流温度下的滞燃期、自燃点位置以及稳定火焰起升高度。结果表明,随协流温度的升高,柴油喷雾滞燃期减小,自燃点位置至喷嘴口距离减小。协流温度低于1022K时,不能形成稳定的起升火焰；协流温度处于1022～1074K范围内,火焰起升高度随温度升高急剧降低,而起升高度的均方差也较大。温度继续增加时,起升高度变化趋缓,火焰稳定。

Auto-ignition characteristics of diesel spray, such as auto-ignition delay time, auto-ignition position and stable flame liftoff height, were studied in the controllable active thermo-atmosphere combustion system by using high speed video camera and continuous spray. The experimental results show that the auto-ignition delay time of diesel spray decreases with increasing of co-flow temperature and the distance of auto-ignition position to nozzle exit. Stable lifted flame is hard to form when co-flow temperature is less than 1 022 K. Flame liftoff height decreases and its fluctuation increases at co-flow temperature varying from 1 022 K to 1 074 K. Stable Flame is presented near jet outlet when temperature further increases.