在一台重载柴油机上,对柴油/甲醇二元燃料燃烧不同甲醇替代率下发动机的进气成分、气体排放特性和燃料效率进行了研究。结果表明,随着甲醇替代率的增加,发动机进气流量、NO_x排放和折合当量燃油消耗率依次减小,而发动机过量空气系数、HC和CO排放以及有效热效率持续增加。在甲醇替代率达到30%时,NO_x排放和燃料效率同时取得最优效果;NO_x平均下降了34.51%,折合当量燃油消耗率最低仅为181.85 g/(kW·h),整体平均下降了6.03%,有效热效率平均提高了6.40%。 In a heavy-duty diesel engine, the intake composition, gas emission characteristics and fuel efficiency of the engine at different methanol replacement rates for diesel / methanol binary fuel combustion were studied. The results show that as the methanol replacement rate increases, the engine intake flow, NO x emission and equivalent fuel consumption decrease in turn, while the engine excess air ratio, HC and CO emission and effective thermal efficiency increase continuously. When the methanol substitution rate reached 30%, the NO_x emission and fuel efficiency achieved the best results at the same time. The NO_x average decreased by 34.51% and the equivalent fuel consumption was only 181.85 g / (kW · h), with an average decrease of 6.03% , The effective thermal efficiency increased by an average of 6.40%.