机构地区: 西安交通大学能源与动力工程学院动力工程多相流国家重点实验室
出 处: 《内燃机工程》 2010年第5期1-6,10,共7页
摘 要: 研究了二甲氧基甲烷(DMM)、EGR和排气后处理对于柴油机燃烧排放的影响,并讨论了达到欧-Ⅲ排放标准的途径。研究结果显示:柴油掺混50%体积比的DMM,在中低负荷下采用28%的EGR率,在高负荷下采用7%的EGR率,可以同时显著降低NOx和碳烟排放,使用柴油机氧化催化转化器(DOC)可以大幅度降低HC和CO排放。通过与纯柴油燃烧过程的比较表明:DMM-柴油混合燃料可以同时增加预混燃烧和扩散燃烧速率,导致最高燃烧压力和放热率增大,采用EGR并未使燃烧持续期显著延长。自然吸气式柴油机掺烧大比例的DMM并结合EGR和DOC,有望达到欧-Ⅲ排放标准。 Influence of dimethoxymethane(DMM) addition,exhaust gas recirculation(EGR) and emission aftertreatment system on combustion and emissions of direct-injection(DI) diesel engine was investigated experimentally,and the approaches to meet Euro-III standard were discussed.Results show that,when using diesel fuel blended with 50 % DMM volume fraction and EGR rate of 28 % at low and middle load range and 7 % at high load range,both NOx and soot emissions of the engine reduce markedly;HC and CO emissions can be reduced by the use of diesel oxidation catalyst(DOC).In comparison to pure diesel fuel,application of DMM/diesel blends increases both premixed and diffusion combustion,leading to higher peak cylinder pressure and heat release rate.The combustion duration has not been lengthened evidently by using EGR.It is deducted that the natural aspirated diesel engine operating on high DMM addition rate,combined with EGR and DOC should be able to meet Euro-III emission standard of vehicle diesel engine.
关 键 词: 内燃机 二甲氧基甲烷 废气再循环 柴油机氧化催化转换器 排放
领 域: [动力工程及工程热物理]