乙醇/柴油混合燃料燃烧过程与排放试验研究

在YZ4DB3柴油机上,通过测量燃用乙醇/柴油混合燃料的示功图和排放污染物,分析了燃烧过程与排放污染物的变化规律。结果表明,随着乙醇掺混比例的增加,乙醇/柴油混合燃料的滞燃期延长,燃烧终点提前,燃烧持续期缩短。小负荷时,与柴油相比,E10和E20的最大爆发压力分别下降了0.2、0.4MPa,扩散燃烧放热率峰值升高;全负荷时,与柴油相比,乙醇/柴油混合燃料的最大爆发压力变化不大,预混燃烧放热率峰值升高。与燃用柴油相比,掺混乙醇能明显降低烟度,NOx排放变化不大;HC和CO排放随着乙醇掺混比例的增加而升高,小负荷时较明显。乙醇/柴油混合燃料的燃料消耗率与燃用柴油的燃油消耗率基本相同。

Experimental investigation on combustion and emission characteristics of diesel engine fueled with ethanol/diesel blends

Experiments were carried out on YZ4DB3 diesel engine. The indicator diagram and emission of diesel engine fueled with ethanol/diesel blends were measured. The combustion process and emission of ethanol/diesel blends were analyzed. The results showed that with the increase of ethanol ratios, the ignition delay periods were delayed, the combustion endings were advanced and the combustion durations were shortened. At low load, the peak in-cylinder pressure of E10 and E20 were 0.2 and 0.4 MPa lower than that of diesel, the peak heat release rate of diffusion combustion increased. At full load, the peak in-cylinder pressure of ethanol/diesel blends were almost the same as that of diesel, the peak heat release rate of premixed combustion increased. Compared with diesel, smoke of ethanol/diesel blends reduced significantly. Ethanol ratios had little effect on NOx emission. With the increase of ethanol ratios HC and CO emission increased, especially at low load. The fuel consumption of ethanol/diesel blends and diesel were almost the same.