Abstract The late-injection strategy (close after main-injection) of common-rail diesel engine is capable of enhancing combustion turbulence and reducing particulate matter (PM) emissions. In this work, experimental study was performed to investigate the effect of diesel late-injection on combustion and emissions characteristics of diesel/methanol dual fuel (DMDF) engine. The experiments were carried out at a constant engine speed of 1340 rpm and a medium load of 1.0 MPa brake mean effective pressure (BMEP) with various methanol substitution ratio (MSR) on a common rail DMDF engine. The results reveal that higher MSR caused simultaneous decrease of nitric oxides (NOx) and accumulation mode PM emissions in spite of late-injection strategy. In particular, an augment of up to 12.8% in nucleation mode particle number (PN) was observed as MSR increased from 15% to 50%. A small late-injection of diesel ( 1200 μs) induced a simultaneous increase of particles with different size.

中文翻译：

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柴油后喷对柴油/甲醇双燃料发动机燃烧及排放特性的影响

摘要 共轨柴油机晚喷策略（主喷后关闭）能够增强燃烧湍流，减少颗粒物（PM）排放。在这项工作中，进行了实验研究，以研究柴油延迟喷射对柴油/甲醇双燃料 (DMDF) 发动机燃烧和排放特性的影响。实验是在 1340 rpm 的恒定发动机转速和 1.0 MPa 制动平均有效压力 (BMEP) 的中等负载下进行的，并在共轨 DMDF 发动机上进行了不同的甲醇替代比 (MSR)。结果表明，尽管采用了延迟注入策略，但较高的 MSR 导致一氧化氮 (NOx) 和累积模式 PM 排放的同时减少。特别是，最多增加 12 个。随着 MSR 从 15% 增加到 50%，观察到 8% 的成核模式粒子数 (PN)。少量的柴油后期喷射 (1200 μs) 会导致不同尺寸的颗粒同时增加。