柴油机燃用混合含氧燃料的燃烧与排放

Combustion and emission of oxygenated fuel blends used in diesel engine

为协同推广使用不同生物质来源的乙醇和生物柴油,研究了不同混合比下乙醇-柴油-生物柴油混合含氧燃料的经济性、动力性与排放特性,为混合含氧燃料的推广应用提供理论和试验依据。研究结果表明:以柴油为参照,柴油机燃用3种混合燃料时的缸内压力均略有降低,EBD1(80%柴油+20%生物柴油)峰值压力出现位置提前约1°CA,乙醇的加入使EBD2(70%柴油+20%生物柴油+10%乙醇)和EBD3(55%柴油+20%生物柴油+25%乙醇)压力峰值略有滞后;3种混合燃料对应放热率曲线峰值均低于纯柴油。随生物柴油以及乙醇掺混比例的增加,混合燃料的放热率峰值呈现不同程度的下降;随混合燃料含氧量的增加,HC和CO排放均有不同程度的降低,烟度排放下降趋势明显,而NOx排放则略有增加。

In order to synergistically boost applications of ethanol and biodiesel from biomass, the economy, power and emissions of the ethanol-diesel-biodiesel blends in different proportions were investigated to provide theoretical and experimental basis for the promotion and application of mixed oxygenated fuels. The results show that cylinder pressures of three fuel blends are slightly lower than that of neat diesel. The corresponding crank angle of peak pressure in cylinder of EBD1 （80% diesel＋20% biodiesel） is about 1°CA in advance. The addition of ethanol makes the pressure peak of EBD2 （70% diesel＋20% biodiesel＋10% ethanol） and EBD3 （55% diesel＋ 20% biodiesel＋25% ethanol） slightly delayed. The heat release peaks of three fuel blends are lower than that of neat diesel with the increase of biodiesel and ethanol in fuel blends, the heat re- lease heats all decline in different degrees. With the increase of oxygen content in fuel blends, both HC and CO emissions decline in different degrees, and smoke emissions also decrease appar- ently, while NOx emission increase slightly. 3 tabs, 6 figs, 13 refs.