Effect Of N-Butanol Addition On Premixed Combustion And Emission Characteristics Of Particulate Matter In A Diesel Engine

Facing the he energy crisis and the increasingly stringent emission regulations,finding alternative fuel and clear combustion mode are effective ways to solve those problems?Alcohol and biodiesel as oxygenated fuel cause great attention,their properties are different,so leading to distinct combustion and emission?Now the number of particular is limited in Euro 6,it is important to research the particular number size distribution?In this paper,the effect of oxygenated fuel blended on the emission of PPCI mode?the effect of high proportion butanol blended on the emission of PPCI mode and the particular number size distribution are discussed?The result shows:the combustion and emission in diesel engine both improve with oxygenated fuel Blends?Butanol has a lot of good characteristics:Low cetane,high latent heat of vaporization and better volatility,those are good for promoting the formation of mixture gas,expand the proportion of premixed combustion which are good for the realization of premixed combustion.The emission of soot decreases,peak pressures and peak rise rate of pressures both increases,The emission of NOx increases?Compared with butanol,the SME blended has less effect on the combustion,The emission of soot decreases for the oxygen in biodiesel,the emission of NOx increases?The MPCI mode is realized with the high proportion butanol?Compared with the single injection,the proportion of premixed combustion keeps large,and the emission of Soot and NOx decrease,combustion becomes softer?By researching the particular number size distribution with the butanol blended,the result shows that in PPCI mode with single injection strategy,the particle number-size distribution is single mode,for pure diesel,the peak number of particular in early and late injection is larger than that in normal injection,but the diameter in peak number decreases?With the butanol blended,the diameter in peak number moves toward small,the peak number of particular increases?In MPCI mode with two split injection strategy,MPCI mode is realized with pure diesel and butanol blended,the particle number-size distribution is single mode?With the increasing of the mass of pro-injection,the peak number of particular decreases with pure diesel and butanol blended?The time of pro-injection advanced a certain extent,the combustion and the particulate emissions change little?With high proportion butanol blended,the diameter in peak number and peak number of particular both decrease?The post-injection can improve the particular emission ? With the mass of `post-injection increasing using B00,the particular number first increases then decreases?The diameters of the peak number changes little?But with the mass of post-injection increasing using B50,the particle number-size distribution changes from single mode to double mode.The particular number decreases significantly,but GMD increases.