柴油机分段喷射及涡流匹配燃烧和排放特性  

Combustion and Emission of a Diesel Engine with Split Injection and Swirl Matching

作　　者：李向荣[1] 高浩卜[1] 赵陆明[1] 苏立旺[1] 刘福水[1] Li Xiangrong Gao Haobu Zhao Luming Su Liwang Liu Fushui(School of Mechanical and Vehicular Engineering, Beijing Institute of Technology, Beijing 100081, China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《内燃机学报》2017年第1期1-8,共8页Transactions of Csice

摘　　要：为探究柴油机分段喷射及涡流改善燃油经济性的潜力和机理,在单缸机上进行了有、无进气涡流时不同分段喷射策略的试验,5%,预喷比例、10°,CA间隔工况的燃油消耗率比单次喷射降低6.1,g/(k W·h),NO_x排放增加200×10^(-6)(体积分数);有、无涡流对比试验中,在过量空气系数为1.6时,加入涡流比为1.0的涡流,燃油消耗率仍降低2.0,g/(k W·h),NO_x排放增加120×10^(-6).内窥镜试验利用KL因子表征碳烟浓度,上止点后16°,CA,单次喷射工况KL因子为1.22,分段喷射工况KL因子为0.75,有涡流分段喷射工况KL因子为0.21.仿真分析表明,小预喷、短间隔分段喷射和适当进气涡流的加入,均使得主喷油束可以利用预喷产生的热氛围且不被其束缚,从而改善燃油经济性,降低缸内碳烟浓度.In order to explore the potential and mechanism of fuel economy improvement for split injection and intake swirl, a split injection test with and without swirl was performed on a single cylinder diesel engine. Results show that the brake specific fuel consumption （BSFC）at the strategy of 5% pilot injection fraction and 10° CA dwell time be- tween injections has got 6.1 g/（kW · h）less than that at the single injection strategy, while the NOx emission at the split injection strategy is increased by 200 × 10^-6volume fraction compared with that the single injection strategy. In the swirl comparison test, the engine is operated at an excess air coefficient of 1.6 with pilot injection. Results show that the BSFC under the operation with a swirl ratio of 1.0 is cut down by 2.0 g/（kW · h）and NOx emission is in- creased by 120× 10^-6 compared with the operation without swirl. In the endoscope test, KL factor was used to evaluate soot emission. It is found that at the fixed crank angle of 16° CA ATDC, the/（L factor is 1.22 for single injection strat- egy, 0.75 for spilt injection strategy without swirl and 0.21 for split injection with swirl. The simulation analysis re- sults show that a small amount of split injection, a short dwell time between injections and a proper intensity of swirl can make the main injection fuel development to fully utilize, but not to be restricted by the thermo-atmosphere pro- duced by the pilot fuel burn. As a result, fuel economy is improved and in-cylinder soot concentration is decreased.

关 键 词：柴油机 分段喷射 燃烧过程 进气涡流 内窥镜 仿真计算 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]