喷油器参数对直喷柴油机喷油及燃烧过程的影响研究  

Effect of Injector Specifications on Combustion Process of DI Diesel Engines

作　　者：吕峰[1] 蔡忆昔[1] 李小华[1] 李晓明[1] 

机构地区：[1]江苏大学汽车与交通工程学院,江苏镇江212013

出　　处：《拖拉机与农用运输车》2009年第6期82-85,共4页Tractor & Farm Transporter

基　　金：江苏省高校自然科学重大基础研究项目(06KJA47004);镇江市科技攻关项目(DTKJ200613)

摘　　要：利用CFD软件对1115型柴油机在采用不同喷油器参数时的喷油及燃烧过程进行数值模拟,并分析了不同情况下的柴油机缸内燃油浓度场、示功图,排放等。结果表明:随着喷油器孔数增加、孔径减小,油柱破碎时间缩短,燃油蒸发雾化速度加快,空气利用率提高;油束贯穿距离下降,燃油碰壁现象减弱,燃烧室壁面附近的燃油量减少;油气混合速度提高,滞燃期内形成的可燃混合气量增加,燃油燃烧速率和压力升高率上升,碳烟排放量下降,但发动机零部件机械负荷和燃烧噪声增加、NOx排放量上升。By using Computational. Fluid Dynamics（CFD） software, the injection and combustion process of 1115 diesel engine equipped different injectors were simulated, fuel concentration field, indicator diagram and emissions were analyzed under various conditions. The results showed that with the increase of inject orifices in the number and its diameter reduction, the break duration of fuel column is shortened, fuel atomization speed is enhanced and the air efficiency becomes higher. Because the penetration distance is shortened, the fuel has less probability to reach cylinder wall and which leads to less fuel to accumulate around cylinder wall. The mixture rate of fuel and air is increased, as a result, more inflammable mixture is formed during ignition delay and the gradient of combustion rate and in-cylinder pressure increase. Although the soot emission decreases, the mechanical load of engine components and combustion noise increase, so does the NOx emission.

关 键 词：喷油器参数 燃油分布 燃烧 数值模拟 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]