JCCI发动机全工况燃烧和排放特性研究  

Combustion and Emissions Characteristics of JCCI Engine at All Conditions

作　　者：张强[1,2] 隆武强[2] 田江平[2] ZHANG Qiang LONG Wuqiang TIAN Jiangping(PLA 91550, Dalian 116023, China Institute of Internal Combustion Engine, Dalian University of Technology, Dalian 116024,China)

机构地区：[1]中国人民解放军91550部队 [2]大连理工大学内燃机研究所

出　　处：《内燃机工程》2017年第3期34-40,共7页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(51379034)

摘　　要：将一台单缸农用柴油机压缩比降至12,在缸盖上增加一个带液化石油气(LPG)供给通道和火花塞的点火室,将其改造为射流控制压缩着火(jet controlled compression ignition,JCCI)发动机,研究了全工况范围点火正时和负荷对JCCI发动机燃烧可控性的影响。试验结果表明:在大多数工况范围内,柴油预混合气的燃烧始点相位θ_(10)和燃烧中点相位θ_(50)随点火正时单调变化,且滞燃期对负荷不敏感,说明其着火相位可以通过点火正时直接控制;在接近全负荷工况时,滞燃期迅速缩短,部分柴油提前发生自燃,射流对着火相位的影响减弱;在大多数工况范围内,NO_x和碳烟排放均较低,且对点火正时敏感,减小点火提前角可以显著降低NO_x和碳烟排放,但是HC和CO排放较高。An experimental study on jet controlled compression ignition（JCCI） engine was conducted at all conditions on a prototype engine that was modified from a single cylinder diesel engine. The engine compression ratio was reduced to 12 to avoid auto-ignition of premixed diesel, and a small ignition chamber comprising a gas fuel injector and a spark plug was mounted on the cylinder head. Experiments were conducted at all loads to study the influences of ignition timing and load on the combustion controllability of a JCCI engine. The experimental results show that the combustion initial point d10 and middle point θ50 （referring to crank angles that correspond to 10% and 50% of total heat release） of premixed diesel change in one direction at most conditions. Its ignition delay is insensitive to load variation, indicating that a direct control of ignition timing for premixed combustion can be expected. However, the ignition delay starts to be reduced quickly at a point near full load due to an unexpected auto-ignition of premixed diesel. Therefore the effect of jet on the controllability of the ignition timing is weakened. The NOx and smoke are maintained at a low level at most conditions and they can be reduced greatly by advancing the spark timing due to their sensitivity to it. However, HC and CO are higher.

关 键 词：内燃机 射流 预混合 压缩着火 

分 类 号：TK421.24[动力工程及工程热物理—动力机械及工程]