基于正交—主元分析对柴油机燃烧参数匹配优化

基于电控化改造后的4190柴油机，利用AVL—FIRE软件建立天然气—柴油双燃料发动机燃烧室高压循环模型，并与原机进行验证。采用正交试验法以指示功率和NOX生成量为优化目标，并对燃烧参数进行匹配，进行仿真试验。利用主成分分析法对仿真结果进行优化分析，将优化结果与正交试验结果对比并最终代入模型进行检验。通过正交—主成分分析得出：柴油机运行参数对低温燃烧影响的主次顺序与正交试验设计基本一致，且具有更高的可靠性和准确度。优化后的参数为：天然气替代率45%，进气压力0.224MPa，EGR率12.5%，进气温度335.15K，喷油提前角22.7°对应的指示功率为37.83kW，NOX生成质量分数比原机降低78.73%，比极差分析最优组合降低10.92%。该优化方案在保证动力性的前提下可以有效地降低NOX排放。

Optimization of Diesel Engine Combustion Parameters Matching Based on Orthogonal-Principal Component Analysis

Based on the electronically modified 4190 diesel engine, the high pressure circulation model of the natural gas-diesel dual fuel engine combustion chamber was established by AVL-FIRE software, and verified with the original machine. The orthogonal test method was used to optimize the power and NOx production, matching the combustion parameters for simulation. The principal component analysis method is used to optimize the simulation results. The optimization results compared with the orthogonal test results and finally substituted into the model for testing. Through orthogonal-principal component analysis, the primary sequence of diesel engine operating parameters which affecting low-temperature combustion is basically consistent with the orthogonal test design, and it has higher reliability and accuracy. The optimized parameters are as follows: the natural gas replacement rate is 45%, the intake pressure is 0.224MPa, the EGR rate is 12.5%, the intake temperature is 335.15K, and the injection advance angle is 22.7°. corresponding indicating power is 37.83kW.The mass fraction of NOX was lower than the original machine 78.73%and lower than the optimal combination of range analysis 10.92%. It shows that the optimization scheme can effectively reduce NOX emissions under the premise of ensuring dynamic performance.