Abstract: In order to compare the differential effects of different carbon‑oxygen bond fuels on combustion and emission characteristics when diesel engines are mixed with different oxygen‑containing fuels, diesel, polymethoxy dimethyl ether (PODE)/Diesel, and dimethyl carbonate (DMC)/Diesel were employed to investigate the combustion and emission characteristics of high‑pressure common rail diesel engines under various pre‑injection ratios and exhaust gas recirculation (EGR) rates. The results demonstrated that carbon‑oxygen single bond oxygen‑containing fuel had a stronger ability to reduce carbon smoke than carbon‑oxygen double bond oxygen‑containing fuel. With an increase in the EGR rate, the peak change in the heat release rate of PODE/Diesel was greater, leading to a significant reduction in NOX emissions. At an EGR rate of 20%, the smoke levels of PODE/Diesel and DMC/Diesel decreased by 78.10% and 40.93%, respectively. Similarly, as the pre‑spray ratio increased, the peak change in heat release rate of DMC/Diesel was greater, and NOX emissions decreased. At a pre‑spray ratio of 20%, the smoke levels of PODE/Diesel and DMC/Diesel decreased by 64.27% and 43.40%, respectively. Among the three fuels, the peak concentration of nuclear particulate matter in the carbon‑oxygen single bond hybrid fuel was the highest, but the geometric average particle size of the particulate matter was the lowest.

Key words:  , oxygenated fuel, exhaust gas recirculation, pilot injection strategy, diesel engines

摘要： 为对比柴油机掺混不同的含氧燃料时，不同碳氧键燃料对燃烧及排放特性的差异性影响,以柴油（Diesel）、聚甲氧基二甲醚（PODE）/柴油、碳酸二甲酯（DMC）/柴油为对象，在高压共轨柴油机上，考察其在不同预喷比例及废气再循环（EGR）率下的燃烧及排放特性规律。结果表明：碳氧单键含氧燃料降低碳烟能力比碳氧双键含氧燃料更强，随着EGR率增加，PODE/Diesel的放热率峰值变化幅度更大，NOX排放大幅下降，EGR率为20%时，PODE/Diesel与DMC/Diesel的烟度分别下降78.10%、40.93%；随着预喷比例增加，DMC/Diesel放热率峰值变化幅度更大，NOX排放有所下降，预喷比例为20%时，PODE/Diesel与DMC/Diesel的烟度下降64.27%、43.40%；3种燃料中，碳氧单键混合燃料的核态颗粒物数量浓度峰值最高，但颗粒物几何平均粒径最低。

关键词: 含氧燃料, 废气再循环, 预喷策略, 柴油机