In this study, a comparative study of the combustion characteristics and performances of a dual-fuel engine fueled with diesel/methanol and diesel–polyoxymethylene dimethyl ether blend/methanol was conducted. All the experiments were conducted on a heavy-duty common rail diesel engine at an engine speed of 1800 r/min. The engine loads were fixed at low, medium, and heavy loads, with the brake mean effective pressure at 0.42 MPa, 0.7 MPa and 0.9 MPa, respectively. Methanol substitution ratio (MSR) was defined as the torque output contributed by methanol to the total torque output, and in this study, three MSRs (0%, 20%, and 40%) were defined. Diesel–polyoxymethylene dimethyl ether (PODE) blend was defined as P50 (50% diesel and 50% PODE by volume) to clarify the effect of PODE addition on engine performance. The results showed that the dual-fuel engine fueled with P50/methanol had a higher peak cylinder pressure, lower first peak heat release rate (HRR), and higher second peak HRR than the dual-fuel engine fueled with diesel/methanol. Both the ignition delay and combustion duration of the dual-fuel engine decreased when the pilot fuel injection changed from diesel to P50. Moreover, both NOx emissions and particulate matter produced by the P50/methanol engine were lower than those produced by the diesel/methanol engine for the specific MSR and engine load.

在这项研究中，对柴油/甲醇和柴油-聚甲醛二甲醚共混物/甲醇为燃料的双燃料发动机的燃烧特性和性能进行了比较研究。所有实验都是在重型共轨柴油发动机上以1800 r / min的转速进行的。发动机负载固定为低，中和重负载，制动平均有效压力分别为0.42 MPa，0.7 MPa和0.9 MPa。甲醇替代率（MSR）定义为甲醇对总扭矩输出的贡献扭矩输出，在本研究中，定义了三个MSR（0％，20％和40％）。柴油-聚甲醛二甲醚（PODE）混合物定义为P50（50％柴油和50％PODE，按体积计），以阐明PODE添加对发动机性能的影响。结果表明，与以柴油/甲醇为燃料的双燃料发动机相比，以P50 /甲醇为燃料的双燃料发动机具有更高的峰值气缸压力，更低的第一峰值热释放率（HRR）和更高的第二峰值HRR。当先导燃料喷射从柴油变为P50时，双燃料发动机的点火延迟和燃烧持续时间均减少。此外，对于特定的MSR和发动机负载，P50 /甲醇发动机产生的NOx排放和颗粒物均低于柴油/甲醇发动机产生的NOx和颗粒物。当先导燃料喷射从柴油变为P50时，双燃料发动机的点火延迟和燃烧持续时间均减少。此外，对于特定的MSR和发动机负载，P50 /甲醇发动机产生的NOx排放和颗粒物均低于柴油/甲醇发动机产生的NOx和颗粒物。当先导燃料喷射从柴油变为P50时，双燃料发动机的点火延迟和燃烧持续时间均减少。此外，对于特定的MSR和发动机负载，P50 /甲醇发动机产生的NOx排放和颗粒物均低于柴油/甲醇发动机产生的NOx和颗粒物。