【作者】 王立群；

【导师】 闫民；

【作者基本信息】 北京林业大学 ， 车辆工程， 2010， 硕士

【摘要】 本文对柴油机废气再循环(EGR)特性,EGR控制以及柴油机低温预混合燃烧(HCCI)进行了研究。建立了能够反映发动机工作状态的VM R425DOHC柴油机整机GT-POWER仿真模型,获得了EGR率升高使发动机燃烧始点推迟、最高爆发压力降低、EGR温度升高使燃烧始点提前、放热率峰值降低等结论。基于以上研究,首次提出了温度修正进气流量线性计算方法的EGR在线闭环反馈控制策略,实现了EGR精确控制。对柴油机HCCI喷射策略进行的实验研究结果表明,早喷、晚喷和窄角喷油能有效实现低温预混合燃烧、早喷需要控制爆燃和氮氧化物排放、晚喷燃烧负荷的拓展受到微粒排放的限制以及窄角喷油器可以实现宽角度范围喷油,而不出现燃油碰壁现象。以上成果对柴油机HCCI的研究具有一定的参考价值。更多还原

【Abstract】 This paper makes a deep research on Exhaust gas recirculation (EGR) characteristic, EGR control strategy and diesel engine low temperature premixed combustion (HCCI). The paper builds a simulation model of VM R425DOHC using GT-POWER software. The simulation results show that this model can simulate the diesel engine. EGR is investigated using the model. The results show that the start of ignition will delay and the peak pressure will drop with the growing of the EGR rate. The start of ignition will bring forward and the peak heat release rate will descend with the growing of the EGR temperature. Base on the simulation study this paper brings forth the linear computational method for the inlet mass flow based the temperature correction and the EGR closed-loop control strategy for the first time. It helps to realize the diesel engine HCCI that EGR can be precisely controlled; the injection strategy research is carried out by experiments. The results show that early injection, late injection and narrow spray angle injector can effectively be used in the low temperature premixed combustion. The early injection need control the detonation and NOX emissions. The late injection need control the Soot emissions when the engine load spreads. The narrow angle injector can give a wide angle injection without spray impinging on the cylinder wall. This injection strategy has certain reference significance.更多还原