基于燃油经济性的发动机关键技术评估

Evaluation of Key Engine Technology Based on Fuel Economy

以1台3缸直喷汽油发动机为研究对象,建立了GT-Power仿真模型,并根据台架试验数据对仿真模型进行了标定,在发动机高效率工况点(负荷为1.4MPa,转速为3000r/min),针对燃油经济性利用仿真模型对发动机的各项关键技术进行了评估研究。结果表明:不同关键技术参数对燃油消耗率的敏感度不同,其中压缩比的敏感度最大,米勒度的敏感度最小;得到了关键技术参数对燃油经济性的影响权重,高压缩比技术占70%,VVT技术占20%,米勒循环技术占7%,EGR技术占3%;明晰了关键技术之间的交互作用及具体表现情况。

The GT-Power simulation model was established thereby using a 3-cylinder direct-injection gasoline engine as the research object and the simulation model was further calibrated according to the bench test data. Based on the fuel economy, the evaluating and research for the engine key technologies were conducted under the high efficiency conditions of 1.4 MPa and 3 000 r/min by using the simulation model. The results showed that different key parameters had different sensitivities to brake specific fuel consumption, among which the sensitivity of compression ratio was the largest and the sensitivity of Miller degree was the smallest. The weight of key technology on fuel economy was obtained, in which the high compression ratio technology took 70%, VVT technology took 20%, Miller cycle technology took 7% and EGR technology took 3%. The interaction between key technologies and the specific performance were clarified.