润滑油对GPF内灰分演化、沉积及迁移特性影响的机理研究

Gasoline direct injection (GDI) engine has been more and more popular these days due to its high fuel economy and power performance. However, the issue comes along is the particle emission from GDI engine is too high to meet the stringent emission regulations. Therefore, this proposal claims to investigate the GPF performance, especially the effects of lubricating oil on the ash formation and evolution, deposition and mobility characteristics. Generally, three research aspects are included. Firstly, experimental work will be done about the effects of lubricating oils on the ash formation and characteristics, like the oxidation property, composition, and morphology to understand the mechanism underneath. Based on this part of work, the analysis and comparison between the ash distributions at different locations like the deep-bed, wall and end area will be done for different lubricating oil-derived ash particles, so that the deposition characters can be understood well. Lastly, take the high temperature and flow characters inside the GPF, the interaction between the ash and GPF substrate will be analyzed, based on this, the transportation or mobility of the ash will be well studied. Overall, this study can provide research database for the integration of GPF and lubrication oil, and also can help to develop new lubricating oil formulations and GPF design, which indicates great academic and engineering value.

GDI发动机因燃油经济性和动力性突出而受青睐。然而，伴随而来的问题是其较高的颗粒物排放（质量和数量浓度）。因此，采用微粒捕集器（GPF）成为其适应排放法规的关键措施。基于此，本项目拟围绕GDI发动机的GPF系统，开展润滑油对GPF内部灰分生成演化、沉积着床以及迁移流动过程影响的机理研究。主要研究内容包括：润滑油对GPF内灰分理化特征的影响规律，探究其对灰分形成、灰分组分及形貌特征的影响；基于此，对GPF中深床捕集区、壁面及末端等区域灰分的分布特征展开分析对比，研究不同金属灰分在GPF内的沉积特性；进而，考虑GPF通道内流速及温度条件，分析灰分之间及与载体间的相互作用附着力，探索灰分在GPF通道内的流动特性，获得润滑油对GPF系统内灰分演化迁移过程的影响机制。本研究对未来GPF系统与润滑油匹配提供理论依据，为优化GPF系统设计及润滑油配方升级提供数据支持，具有重要的学术意义和工程价值。

本项目旨在探索润滑油与尾气中碳烟和灰分颗粒物的关系以及这些颗粒物在颗粒捕集器中的沉积特性和分布规律。首先，通过设计和搭建快速灰分加载系统，项目组实现了对润滑油中成分迁移和转化过程的追踪，以及润滑油改变颗粒物理化特性的机制。其次，通过更改颗粒物捕集器的载体材料以及结构参数，实现了灰分颗粒物在过滤器中的沉积过程以及分布特征，并对相关颗粒物进行了形貌特征的分析表征。另外，项目组总结归纳了润滑油中金属元素对碳烟颗粒物的氧化活性以及氧化过程的影响机理，进而对理解灰分在颗粒物捕集器再生过程的影响作用提供理论支撑，并引导项目组开展了颗粒物捕集器布置位置的工作性能以及对整机性能的影响的研究。本研究对未来GPF系统与润滑油匹配提供理论依据，为优化GPF系统设计及润滑油配方升级提供数据支持，具有重要的学术意义和工程价值。