【摘要】 为了提高氨柴发动机的燃烧效率与热效率，研究了柴油喷射策略对燃烧与排放特性的影响。在一台6缸、压缩比21的氨柴发动机上，采用了进气道喷射氨并缸内2次喷射柴油的控制方法。用柴油第1次喷射来活化缸内热氛围，用第2次喷射来控制燃烧相位。结果表明：提前柴油第1次喷射时刻，可使氨柴模式的氮氧化物（NO_x）排放减少30%；增加第1次喷射量有助于提高氨燃烧效率，并能减少85%的N₂O和50%的CO排放。随第1次喷射量的增加，有效热效率先升高后降低。相比同压缩比下纯柴油模式，优化的氨柴双燃料模式的柴油喷射策略下，最高有效热效率提高1.2个百分点。因此，该文的优化柴油直喷策略，可节能和降低重型车辆的碳排放。更多还原

【Abstract】 The effects of diesel injection strategy on combustion and emission performance were investigated to improve the ammonia combustion efficiency and thermal efficiency of ammonia-diesel engines. The control method of ammonia intake-port injection and diesel split direct injection was used on a 6-cylinder ammoniadiesel engine with a compression ratio to 21. Diesel first injection was used to activate the thermal atmosphere while the second injection was used to control the combustion phase. The results show that advancing the first injection timing of diesel reduces the nitrogen oxide（NO_x） emissions of ammonia-diesel mode by 30%.Increasing the first injection mass improves the ammonia combustion efficiency and reduces the emissions of nitrous oxide（N₂O） and carbon monoxide（CO） by 85% and 50%, respectively. The effective thermal efficiency first increases and then decreases with the increase of the first injection mass. By optimizing the diesel injection strategy, the maximum effective thermal efficiency of ammonia-diesel mode can be 1.2% higher than that of diesel-only mode under the same compression ratio. Therefore, the diesel direct injection strategy optimized is expected to save energy and reduce the carbon emissions of heavy-duty vehicles.更多还原