摘要
针对汽油压燃(GCI)在不同负荷存在的问题,将具有高含氧量、高十六烷值的燃料聚甲氧基二甲醚(PODE_n)与汽油掺混,其中PODE_n体积分数为20%,以优化汽油的燃料特性,掺混燃料简称为G80P20.在转速为1660,r/min、平均有效压力(BMEP)分别为1.43、0.95和0.48,MPa的3个负荷下,研究了PODE_n对GCI燃烧与排放特性的影响.结果表明:在大负荷工况下,掺混体积分数为20%,的PODE_n能同时显著改善GCI的碳烟(soot)排放和压力升高率,随着喷油压力的增加,两者的改善程度增加;在喷油压力为120,MPa下,两者降低幅度分别达到68%,和51%,,其NOx和soot排放可在无后处理情况下达到国Ⅴ排放水平;在中等负荷工况下,汽油的燃烧可控性随喷油压力的增加而显著降低,而G80P20的燃烧可控性基本不受喷油压力的影响,且达到与柴油基本相当的水平;在小负荷工况下,G80P20能显著改善GCI的燃烧效率,降低HC和CO排放,循环波动率(COV)从5%,降至2%,,提高了燃烧稳定性.
To solve the problems at different loads in gasoline compression ignition （GCI） combustion mode, polyoxymethylene dimethyl ethers （PODEn）with properties of high oxygen content and high cetane number was blended into gasoline by 20% volume fraction to improve the properties of gasoline. The blending fuel is named as G80P20. Experimental study on the effects of PODE, on combustion and emission characteristics in gasoline compres- sion ignition mode was conducted at n = 1 660 r/min with three different loads （break mean effective pressure = 1.43, 0.95 and 0.48 MPa, respectively）. The results show that soot emissions and the pressure rise rate in GCI mode at high load can be simultaneously reduced by blending 20% PODE,, and the improvement degree increases with the in- crease of injection pressure. At an injection pressure of 120 MPa, soot emissions and the pressure rise rate can be reduced by 68% and 51% respectively, and NOx and soot emissions of G80P20 can meet the China stage V emission regulation without aftertreatment. At medium load, the combustion controllability of gasoline notably decreases with the increase of injection pressure, while the combustion controllability of G80P20 not only is almost not affected by the injection pressure but also reaches almost the level of a diesel. At low load, the combustion efficiency of the GCI mode is significantly improved by blending 20% PODEn, which results in the reduction of HC and CO emis- sions. Moreover, the coefficient of variation （COV）is decreased from 5% to 2% and the combustion stability is im- proved.
作者
刘佳林
王浒
郑尊清
邹泽宇
王其平
尧命发
Liu Jialin, Wang Hu, Zheng Zunqing, Zou Zeyu, Wang Qiping, Yao Mingfa(State Key Laboratory of Engines, Tianjin University, Tianjin 300072, Chin)
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2018年第2期97-106,共10页
Transactions of Csice
基金
国家自然科学基金资助项目(51506145
51576138)
关键词
聚甲氧基二甲醚
汽油压燃
含氧燃料
燃烧
排放
polyoxymethylene dimethyl ethers
gasoline compression ignition
oxygenated fuel
combustion
emission
