柴油机双卷流燃烧室内外室燃油匹配分析  

Matching analysis of fuel in inner chamber and outer chamber of double swirl combustion system in diesel engine

作　　者：李向荣[1] 周海琴[1] 万远亮 苏立旺[3] 刘福水[1] 

机构地区：[1]北京理工大学机械与车辆工程学院,北京100081 [2]东风商用车有限公司技术中心公司,武汉430056 [3]中国北方发动机研究所,天津300400

出　　处：《农业工程学报》2016年第20期70-76,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：装备预研项目(104010204)

摘　　要：为了分析双卷流燃烧室内室燃油质量分数对发动机性能的影响,研究了双卷流燃烧室最佳的内室燃油质量分数范围。首先利用AVL Fire软件仿真计算不同油束夹角下双卷流燃烧室内室燃油质量分数变化,分析内室燃油质量分数变化对发动机的动力性和排放性能的影响,发现内室燃油质量分数约为10%~20%时,发动机指示功率较高,碳烟排放较低。然后总结归纳了内室燃油质量分数随喷油提前角和转速变化的规律。转速增大,内室燃油质量分数减小;喷油提前角增大,内室燃油质量分数增大。研究表明转速提高时,适当增加喷油提前角可以保证内室燃油质量分数处于较优值,使柴油机取得较佳性能。该研究可为双卷流燃烧系统的燃油匹配提供参考。Direct injection（DI） diesel engines are used in the field of transportation and engineering machinery due to their excellent thermal efficiency and practical economic value. In order to reduce air pollution, diesel engines are continuously forced to improve the combustion processes, especially to reduce emitted particulate matter（PM） and nitrogen oxidants（NOx）. Fuel-air mixing and fuel-air distribution play a vital role to reduce harmful emissions. Therefore, a homogeneous fuel/air mixture in the combustion chamber and an increase of the fuel/air mixture area can significantly improve the utilization of air and restrict the soot formation in diesel engines. Double swirl combustion system（DSCS） has excellent thermal efficiency in practical application, but its mass fraction of fuel in inner chamber has not been studied yet. It is hypothesized that mass fraction of the fuel in inner chamber is 10%. To verify the hypothesis, the best range of mass fraction in inner chamber and the effect of dynamic performance and the emission were researched in present paper. First, we analyzed the changes of mass fraction of fuel in inner chamber under different spray angles. Spray angle was conducted at 140°, 145°, 150°, 155° and 160°, and at this time, the injection advance angle was 12° and the speed was 2 500 r/min. Meanwhile, the power characteristics and emission characteristics were analyzed with CFD（computational fluid dynamics） simulation. We researched the soot and NOx at different spray angles. We then analyzed the effect of injection advance angles on the mass fraction of fuel in inner chamber. Injection advance angle was conducted at 10°（corresponding to crank angle of 350°）, 12°, 14°, 16°, 18° and 20°, and at this time, the spray angle was 145° and the speed was 2 500 r/min. Meanwhile, the mass fraction of fuel on TDC（top dead center） in inner chamber and mass fractions of NOx and soot were analyzed. We also researched the soot and NOx at different injection advance angles. T

关 键 词：柴油机 燃油 匹配 双卷流燃烧室 内室燃油质量分数 排放 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]