摘要
针对天然气、柴油双燃料发动机,研究了不同引燃油提前角下双燃料发动机的燃烧和循环变动特性。结果表明:给定引燃油量,喷油提前角提前,缸内最大压力增大,缸内最大压力出现时刻提前;双燃料发动机的放热率特性曲线存在2个波峰,喷油提前角提前有助于引燃柴油完全燃烧,使得引燃能量更大,整体混合气燃烧更充分,放热持续时间缩短,放热速度加快;随着喷油提前角的提前,缸内最大压力和最大压升率显著增大,缸内最大压力的循环变动的变化不明显,最大压升率的循环变动的变化显著;缸内最大压力和平均指示压力与缸内最大压力对应的曲轴转角密切相关且随喷油提前角的提前向上止点移动,缸内最大压升率与其对应曲轴转角的相关性随着喷油提前角的提前而削弱;随着喷油提前角的提前,最大压力和平均指示压力的循环变动系数减小,喷油提前角为20°时最大压力循环变动系数最大,为5.4%,给定喷油提前角下平均指示压力的循环变动系数均小于4%。
The combustion performance and stability of a dual fuel engine fueled with diesel and natural gas at different pilot diesel injection timings are investigated.The results show that the profile of in-cylinder pressure is advanced,the peak pressure gets greater and appears earlier,and there exist two peaks of heat release rate in dual fuel engine;the advanced pilot diesel injection timing facilitates complete combustion of pilot diesel to supply more ignition power;the whole heat release rate is elevated with earlier pilot diesel injection timing;the peak pressure and the maximum rate of pressure rise increase dramatically with the earlier pilot diesel injection timing,the change of the cyclic variation of peak pressure is unconspicuous,while the change of the cyclic variation of the maximum rate of pressure rise increases with earlier injection timing.The peak pressure and indicated mean effective pressure show a correlation with the crank angle corresponding to peak pressure,the distribution moves towards the top dead center with earlier pilot diesel injection timing,and the interdependence of maximum rate of pressure rise and its correspondingcrank angle is weakened.The cyclic variations get the maximum（5.4%）at 20°before top dead center.The cyclic variations of indicated mean effective pressure are all bellow 4%.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2014年第7期29-33,130,共6页
Journal of Xi'an Jiaotong University
基金
国家重点基础研究计划资助项目(2011CB707200)
