摘要
以柴油机颗粒物粒径分布特性为研究重点,在国-Ⅲ高压共轨柴油机上针对不同混合比的生物柴油与柴油混合燃料的颗粒物排放特性进行了研究。试验结果表明,共轨柴油机的颗粒物数量排放一般为双态分布(核态和聚集态),基本以50 nm为分界线。随着负荷的增加,颗粒粒径分布由单态分布转化为双态分布。这是由于排气中的SO2被催化器氧化为SO3后,进一步形成了微小的硫酸颗粒。在2000 r/min的高低负荷,生物柴油混合燃料的颗粒粒径分布存在明显的不同。试验结果表明,燃料硫含量对柴油机核态颗粒的形成具有直接的影响。而生物柴油混合燃料内部含氧,可明显降低聚集态颗粒排放数量。聚集态计算颗粒质量可有效反映含氧燃料对碳烟的氧化作用,也间接表明了柴油机聚集态颗粒以碳烟为主。
Particle size.distributions （PSD） of PM emissions were investigated in a China-Ⅲ diesel engine employed with common rail fuel injection system when the engine was fueled with biodiesel blends. The results show that PSD of the modern diesel engine composes of two modes： nucleation mode and accumulation mode. The division between two modes is 50 rim. With increase of the engine load, the size distributions of particle emissions transform from log-modal to bimodal. The reason is that the SOa, oxidized from the SO2 in the exhaust gas through the catalyst, results in ultra-fine sulphate particulates. The PSD at lower load obviously differs from the PSD at higher load, which indicates that the sulfur content in fuel has a direct influence on the formation of the nucleation mode particle in the diesel engine. Since oxygen i^s involved in biodiesel blends, particles of accumulation mode are reduced. Calculated mass of accumulation mode particulates can effectively reflect the oxidization of soot in oxygenated fuel engine. And it is confirmed that the main composition of the accumulation mode particulate is soot.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2009年第1期23-26,共4页
Chinese Internal Combustion Engine Engineering
基金
“863”计划-生物柴油组分及汽车匹配技术研发(2006AA11A1A2)
上海市重点学科建设项目(B303)
关键词
内燃机
生物柴油
共轨
颗粒粒径分布
核态颗粒
IC engine
biodiesel
common rail
particle size distributionnucleation mode particle
