特种车辆柴油机喷气燃料燃烧节能设计研究

摘要

针对特种车辆可能出现的燃料短缺问题,为了快速有效预测车辆柴油机燃用喷气燃料后缸内喷雾、燃烧及发动机性能的变化,建立了特种车辆柴油机燃用柴油和航空煤油的缸内燃烧模型.上述模型针对喷气燃料与柴油之间理化性质的差别,利用喷雾试验结果对KH-RT破碎子模型进行了标定,同时耦合了针对不同燃料的不同化学反应动力学机理,具有较高的仿真精度.计算结果表明,相比柴油,柴油机燃用航空煤油喷雾破碎过程中雾化质量提高;燃烧过程中缸内滞燃期缩短,放热率峰值下降;柴油机燃用航空煤油相比燃用柴油功率略有下降,油耗率相当.综合考虑发动机的动力性、经济性、机械负荷及热负荷,喷气燃料在燃料短缺的紧急情况下可替代柴油作为特种车辆的应急代用燃料使用.%Aiming at solving the problem of possible fuel shortages for special vehicles,and in order to quickly and effectively predict spray,combustion and engine performances of vehicle diesel engine fueled with jet fuel,a combustion model was established for special vehicle diesel engine fuelled with diesel and jet fuel.In this combustion model,the differences of physical and chemical properties between diesel and jet fuel were considered,and the KHRT breakup model was calibrated with fuel spray test results,while the mechanism different kinetics of chemical reactions for different fuels were coupled for a better accuracy.The result shows that compared with diesel,a better atomization quality is obtained for jet fuel;ignition delay is shortened and peak of heat release rate is decreased in the cylinder combustion process.The engine power decreases when fuelled with jet fuel and specific fuel consumption is basically the same for both fuels.Considering the power performance,economy performance,mechanical load and thermal load of diesel engine,jet fuel can be an emergency alternative fuel for special vehicles in case of fuel shortage oc