喷油提前角对双燃料柴油机燃烧和排放的影响

为研究喷油提前角对双燃料发动机燃烧和排放特性的影响，以4190ZLC-2型船用中速柴油机为研究对象，运用AVL_FIRE软件构建柴油-甲醇双燃料燃烧室模型。通过仿真实验的方法，研究当甲醇掺混比为20%，喷油提前角分别为 16.6°、18.6°、20.6°、22.6°时，对柴油机燃烧、排放、动力特性的影响。研究结果表明:随着喷油提前角的逐渐增大，缸内混合气质量得到改善，从而优化混合燃料在缸内燃烧的质量，同时还可观察到放热率曲线逐渐前移且峰值增加。分析数据可知，在甲醇掺混比为20%，喷油提前角20.6°时，NO排放较原机排放增加29.83%，Soot排放量降低30.5%，CO排放量降低5.6%，指示功率增为58.75 kW。

Effect of Fuel Injection Advance Angle on Combustions and Emissions of Methanol Dual Powered Fuel Diesel Engines

In order to study the influence of the fuel injection advance angle on the combustion and emission characteristics of dual-fuel engines,the 4190ZLC-2 marine medium speed engine was used as the research object,and the diesel-methanol dual-fuel combustion chamber model was constructed using AVL_FIRE software.Simulation experiments were conducted under the methanol blending ratio 20%,characteristics of combustion and emission from diesel engines were respectively studied at the fuel injection advance angle 16.6°,18.6°,20.6° and 22.6°.Results show that with the gradual increase of the fuel injection advance angle,the quality of the mixture within the cylinder is improved,and the heat releasing rate curve gradually moves forward accompanying with a larger peak value.It also reveals that,when the methanol blending ratio is 20% and the fuel injection advance angle is 20.6°,in comparing with those from the original engine,the NO emissions and the indicated powers have increments respectively about 29.83% and 58.75 kW,which are in correspondence with 30.5% and 5.6% decrement in the soot and the CO emissions.