基于混合试验设计生物柴油发动机比油耗优化

Brake Specific Fuel Consumption Optimization of Biodieseldiesel Blends Engine Based on Hybrid Design of Experiment

摘要:

在一台国V排放高压共轨柴油机上燃用20%生物柴油混合燃料，通过调节共轨压力、主喷定时、预喷定时、预喷油量、后喷定时和后喷油量等6个喷油控制参数，优化标定生物柴油专用发动机的性能.选择混合试验设计方法制定了6因素同时调节的全局优化试验方案.分别针对低、中、高转速下的低、中、高负荷9个工况点进行试验.通过该方法拟合的发动机油耗数学模型需要的数据样本容量较小且精度更高.以油耗最小为单目标，通过混合优化算法求解各工况下的全局最优喷油参数组合.优化后发动机比油耗（BSFC）相比原机各工况点平均降幅2.71%.混合试验设计标定方法弥补了传统发动机优化标定方法单因素逐一优化所导致的局部最优特性.

关键词:混合试验设计; 喷油参数; 多因素; 全局优化; 柴油机

Abstract:

A national V emission high pressure commonrail diesel engine filled with 20% biodieseldiesel blends was optimized by adjusting the 6 injection parameters(Pfin， Tfin， Tint， Qpre， Tinta， Qafter). A multifactor global optimization plan was designed by using hybrid Design of Experiment (DoE). 9 different operating points with different speeds and torques were tested. Less data of the sample sizes were in need for a better accuracy to fit a engine Brake Specific Fuel Consumption (BSFC) model by this method. With the goal of minimum BSFC, the global best combination of injection parameters was calculated with the hybrid optimization algorithm. After the optimization， the BSFC of the biodiesel engine was lessened than before by an average of 2.71%. The hybrid Design of Experiment(DoE) method could cover the shortage of the single factor method of calibration which might cause the local optimum.

Key words:hybrid Design of Experiment (DoE); injection parameters; multifactor; global optimization; diesel engine