燃油系统参数优化对电控柴油机掺烧丁醇性能的影响

Influence of fuel system parameter optimization on performance of electronically controlled diesel engine with diesel-butanol blended fuel

为研究燃油系统参数优化对船用电控柴油机掺烧丁醇性能的影响,分别利用AMESim和AVL-FIRE软件建立喷油系统模型和双燃料发动机燃烧模型。以喷油压力为目标优化燃油系统参数,得到3组优化参数,将这3组参数以及丁醇与柴油的掺混比0、20%(质量分数)分别代入燃烧模型进行计算。根据结果选出一组最优参数,在这组参数下柴油机的综合性能最优:指示功率最大,在掺混比取0、20%时的指示功率分别比原机增加了29%和35.8%;指示油耗率最小,在掺混比取0、20%时的指示油耗率分别比原机减少了6.4%和6.7%;碳烟排放最少,在掺混比取0、20%时碳烟排放分别比原机减少了46.8%和58.3%;而NO的排放量最大,需要进一步优化。与燃烧B00纯柴油相比,柴油机掺烧丁醇(B20)时,在3组优化参数下其动力性损失不大,指示油耗率略有增加,在改善碳烟排放方面的效果比NO的明显。对NO排放再优化建立的NO排放预测模型较准确。当喷孔数为7、喷孔直径为0.28 mm、凸轮型线速度为0.46 mm/(°)、柱塞直径为15.0 mm、油管长度为900 mm、涡流比为0.436时,NO排放量最小。

In order to study the influence of fuel system parameter optimization on the performance of marine electronically controlled diesel engine with diesel-butanol blended fuel,AMESim and AVL-FIRE softwares are used to establish the injection system model and the dual fuel engine combustion model,respectively.The parameters of the fuel system are optimized with the injection pressure as the objective,and three groups of optimization parameters are obtained;three groups of optimization parameters and the butanol-diesel blending ratio 0 and 20%(mass fraction)are substituted into the combustion model for calculation.A group of optimal parameters is selected according to the results,and under the group of parameters,the comprehensive performance of diesel engine is the best:the indicated power is the largest,which is 29%and 35.8%higher than that of the original engine under the blending ratio 0 and 20%,respectively;the indicated fuel consumption rate is the lowest,which is reduced by 6.4%and 6.7%than that of the original engine under the blending ratio 0 and 20%,respectively;the soot emission is the lowest,which is reduced by 46.8%and 58.3%than that of the original engine under the blending ratio 0 and 20%,respectively;while the NO emission is the largest,and have to be further optimized.Compared with fueling B00 pure diesel,when fueling the diesel-butanol blend(B20),under the three groups of optimization parameters,the power loss is small,the indicated fuel consumption rate increases slightly,and the improvement of soot emission is more obvious than that of NO.The NO emission prediction model established for NO emission re-optimization is accurate.The NO emission is the lowest when the nozzle number is 7,the nozzle diameter is 0.28 mm,the cam profile velocity is 0.46 mm/(°),the plunger diameter is 15.0 mm,and the eddy current ratio is 0.436.