不同燃料对压燃发动机燃烧及关键组分的影响

Effect of Various Fuels on Combustion and Key Species for Compression Ignition Engines

摘要:

采用计算流体动力学(CFD)模拟技术研究了直喷式柴油机燃用不同燃料(柴油、甲苯、十二烷、十六烷、正庚烷及异庚烷)的燃烧特性以及燃烧过程中关键反应组分的变化历程,分析了不同燃料燃烧反应组分与放热率之间的关系.研究结果表明:缸内压力计算值与参考文献中实验值较吻合,验证了模型的正确性; 燃用甲苯缸内压力、放热率以及累积放热量最大; 燃用甲苯缸内燃烧反应产生的H,N,OH与O活性基量级最大.此外,燃用6种不同燃料,均是OH活性基生成较多.

Abstract:

The combustion characteristics and the variation of incylinder reaction species were investigated for DIdiesel engines with various fuels (diesel,toluene,cetane,dodecane,nheptane and iheptane) using computational fluid dynamics (CFD) technique.Meanwhile,an analysis was made of the correlation between the rate of heat release and reaction species.The results show that,the model is reasonable and the calculated values of incylinder pressure keep in accordance with experimental ones in references.Compared to other fuels,for toluene,four species (H,N,OH and O) generated in combustion process,incylinder pressure,rate of heat release and accumulated heat release are the highest.In addition,as to various fuels,the amount of OH species generated is also the highest.