喷射比对汽-柴油双燃料压燃发动机燃烧及微粒排放特性的影响研究

Effects of Injection Ratio on Combustion and Particulate Emission Characteristics of Gasoline/Diesel Dual-Fuel Compression Ignition Engine

在一台车用高压共轨增压柴油机上,基于均质混合气引燃(HCII)燃烧模式,采用进气道喷射汽油、缸内两段直喷柴油的双燃料部分预混的燃烧策略,探究了喷射比对不同负荷下汽-柴油双燃料发动机的燃烧及排放的影响。结果表明:小负荷时,随着喷射比增加缸内压力和温度下降,燃烧恶化;中高负荷下较高的喷射比可以改善缸内燃烧过程,小幅度提高动力性和经济性;试验负荷下,随着喷射比的增加,NO x排放降低;双燃料发动机较原机拥有更优的微粒排放特性,且随着喷射比的增加效果更加明显。

Based on the homogeneous charge induced ignition combustion mode,a dual-fuel partially premixed combustion strategy with gasoline injection in the intake port and diesel direct injection in two sections of the cylinder was adopted,and the effects of injection ratios on the combustion and emissions of gasoline-diesel dual-fuel engine under different loads were investigated on an automotive high-pressure common-rail supercharged diesel engine.The results show that the pressure and temperature in the cylinder decrease and the combustion deteriorates with the increase of injection ratio under the small load.A higher injection ratio under medium and high loads can improve the combustion process in the cylinder,and slightly improve the power and economy.Under the test load,NO x emissions reduce with the increase of injection ratio.Dual-fuel engines have better particulate emission charateristics than the original engine,and the effect is more pronounced as the injection ratio increases.