燃油喷射系统优化对柴油机性能的影响及喷油参数再优化

Influence of fuel injection system's optimization on performance of diesel engine and its injection parameter re-optimization

为研究燃油喷射系统参数优化对柴油机性能的影响,利用AMESim仿真软件建立燃油喷射系统模型,运用正交试验设计方法对相关结构参数进行优化;再利用AMESim耦合AVL_FIRE软件将优化得到的喷油规律导入高压循环模型中燃烧计算,并对喷油系统参数再优化.结果表明,15 mm-0.22 mm-0.46 mm·(CaA)^(-1)与14 mm-0.30 mm-0.46 mm·(CaA)^(-1)(柱塞直径×喷孔直径×凸轮型线速度)两组参数组合满足设计压力要求,油耗率相对于原机分别降低约3.8%和5.4%,NO_x排放量分别提高了约98.2%和144.4%.经过再次优化后,以降低油耗率为优化目标的最优参数组合下的油耗率较原机降低了约10.5%;以降低NO_x排放为优化目标的最优参数组合下的NO_x排放量较原机降低了约45.3%.

In order to study the influence of parameter optimization of the fuel injection system on the performance of diesel engine,the fuel injection system＇s model was built by using AMESim code,and the related structural parameters were optimized by using orthogonal experimental design method. The optimized fuel injection law was led into the high pressure cycle model for combustion calculation by coupling AMESim and AVL_FIRE software,then the fuel injection system＇s parameters were optimized. Simulation results show that the designed pressure can be met when the fuel injection parameters are 15mm-0. 22 mm-0. 46 mm ·（CaA）^-1 and 14 mm-0. 30 mm-0. 46 mm·（CaA）^-1（ diameter of plunger-diameter of orificecam velocity）. The fuel consumption rate is reduced by about3. 8% and 5. 4% compared with the original machine respectively,but the NOx emissions are increased by approximately98. 2% and 144. 4% respectively. After re-optimization,the fuel consumption rate is reduced by about 10. 5% compared with the original machine under the optimal combination of parameters to reduce fuel consumption optimization target. The NOx emission is reduced by about 45. 3% to reduce NO_x emission optimization target.