混合燃烧时汽油含量对发动机燃烧和排放的影响

在高压共轨增压中冷压燃式柴油机上加装汽油进气道喷射系统,试验研究汽柴油混合燃烧时汽油的质量分数对发动机燃烧和排放的影响。结果表明:发动机转速为1738r/min时,随着汽油质量分数的增加,不同负荷下发动机的燃烧呈现不同的趋势,滞燃期变长,燃烧持续期变短,发动机燃烧的等容度和最大压升率增加;随着汽油质量分数的增加,碳烟和NOx的排放大幅度减少,但是HC和CO的排放大幅升高,需加装柴油氧化催化(diesel oxidation catalyst,DOC)以降低HC和CO的排放。

Effect of Gasoline Content on the Combustion and Emission of Mixed Combustion Engine

A gasoline intake port injection system is installed on a high pressure common rail turbocharged and intercooled compression ignition diesel engine to study the effect of gasoline ratio on combustion and emission of the engine when gasoline and diesel are mixed. The experimental results show that when the engine speed is 1738 r/min, under different loads, with the increase of the proportion of gasoline, the combustion of the engine presents different trends, the ignition delay becomes longer, and the combustion duration becomes shorter. At this time, the combustion capacity of the engine increases, and the maximum pressure rise rate of the engine increases. With the increase of the proportion of gasoline, the emission of SOOT and NO x decreases. However, the emission of HC and CO increases, and DOC is needed to reduce HC and CO emissions.