基于活化热氛围控制的直喷汽油机颗粒物生成机理及碳烟形貌与纳观结构特性研究

Gasoline direct injection (GDI) engine can significantly reduce fuel consumption and CO2 emission compared to port fuel injection (PFI) engine. However, particulate matter (PM) emission of GDI engine is higher than PFI engine. In this proposal based on control of activity thermo-atmosphere in cylinder, the law of particle number and size distribution emissions from a GDI engine will be investigated under different homogeneous and stratified charge combustion mode. The varying law of fuel oxygenation and exhaust gas recirculation (EGR) et al. combustion control parameters on formation of PM from a GDI engine will be explored. The morphology and nanostructure of PM and soot from a GDI engine will be investigated using an advanced measurement and diagnosis technology under different activity and thermo-atmosphere. The varying law of fuel oxygenation and EGR on generated and spatial distribution of PM and soot from a GDI engine will further be clarified. The generation mechanism of PM and soot from a GDI engine will be explored. The difference of effect of activity and thermo-atmosphere control parameters on the graphitization degree and nanostructure of primary particles will be revealed. The control strategy of reduction PM emission from a GDI engine will be determined. The model of chemistry dynamic for describing formation and oxidation of soot will be established. The effects of fuel oxygenation and EGR on generated of soot will be explored. This study will be provided a theory and an engineering value for realizing an efficient and clean combustion of GDI engine.

缸内直喷汽油机（GDI）比气道喷射汽油机(PFI)有更大的节能和降低CO2排放潜力，但它比PFI汽油机有更高的颗粒物排放。本项目围绕缸内活化热氛围控制，研究GDI汽油机在均质和分层不同燃烧模式下颗粒物排放数量和粒径分布规律，揭示燃料中氧含量和EGR等燃烧控制参数对GDI汽油机颗粒物生成的影响规律；采用先进的测量诊断技术研究不同活化热氛围下GDI汽油机颗粒物和碳烟颗粒的形貌与纳米结构特征，进一步阐明燃料中氧含量和EGR等对GDI汽油机颗粒物和碳烟生成及空间分布的影响规律，揭示GDI汽油机中碳烟和颗粒物生成机理；研究活化热氛围控制参数对颗粒物石墨化程度和基本碳粒子微观结构的影响差异，以确定降低GDI汽油机颗粒物排放控制策略；建立描述碳烟生成和氧化的化学反应动力学模型，探讨燃料中氧含量和EGR对碳烟排放生成的影响。这些研究将对实现GDI汽油机高效清洁燃烧具有重要理论意义和工程应用价值。

随着车用发动机排放和油耗法规的不断加严，汽油缸内直喷技术由于其在动力性、燃油经济性和排放性能等方面出色的表现和潜力，缸内直喷汽油机已经成为车用汽油机的主流动力。但缸内直喷汽油机颗粒物排放明显高于气道喷射汽油机，是制约缸内直喷汽油机使用的重要因素之一。因此对缸内直喷汽油机颗粒物的质量和数量浓度排放特性及粒径分布特性、生成机理等进行更加深入细致的研究，有效抑制缸内直喷汽油机颗粒物生成具有重要意义。.本项目主要以试验和仿真模拟为研究手段，围绕缸内活化热氛围控制研究了缸内直喷汽油机在均质和分层不同燃烧模式下颗粒物排放数量和粒径分布规律，揭示了燃料中氧含量和废气再循环等燃烧控制参数对缸内直喷汽油机颗粒物生成的影响规律；进一步阐明了燃料中氧含量和废气再循环等对缸内直喷汽油机颗粒物和碳烟生成及空间分布的影响规律，揭示了缸内直喷汽油机中碳烟和颗粒物生成机理；研究了活化热氛围控制参数对碳烟排放和颗粒物的影响差异，以确定降低缸内直喷汽油机颗粒物排放控制策略；建立了描述碳烟生成氧化的化学反应动力学模型，探讨了燃料中氧和废气再循环对碳烟排放生成的影响。提出了控制直喷汽油机颗粒物排放的策略，这些研究对实现缸内直喷汽油机高效清洁燃烧具有重要理论意义和工程应用价值。在项目执行期间完成了项目计划主要研究内容，还增加了多助燃方式下改善缸内直喷发动机燃烧和排放控制的相关研究内容。本项研究运行期间共发表了24篇国际期刊SCI检索研究论文，培养了1名博士毕业生和3名硕士毕业生。