Studies on the influence of diesel engine operating parameters on the properties of emitted soot particles

柴油机的进一步发展对燃烧产生的碳烟颗粒的数量、大小、形态和化学成分都有影响。最近的研究表明，排放的烟尘颗粒的性质发生变化，可能会增加对人类健康和环境的危害。以前的大部分研究都是为了了解气缸内碳烟的形成过程、气缸内碳烟颗粒的减少、废气的后处理以及在生物科学领域中不同的碳烟颗粒对人类健康和环境的影响。在本项目的前两年，为了选择与燃烧和碳烟形成特别相关的固定发动机参数，对混合气形成和燃烧的分析与排放的碳烟颗粒的物理化学性质联系在一起。该项目的结果表明，发动机参数，如增压和喷射压力，在固定工作点对排放的碳烟颗粒的物理化学性质有显著影响。通过对混合气的形成、燃烧和排放的碳烟颗粒的分析，可以确定排放的碳烟颗粒的物理化学性质变化的来源。在本项目的继续中，对发动机静态工作点的研究将扩展到发动机的瞬时运行状态。最近的研究表明，在发动机的瞬时运行条件下，与固定的运行点相比，烟尘排放明显不同。

The further development of diesel engines influences combustion-generated soot particles with respect to their number, size, morphology and chemical composition. Recent studies suggest that the changed properties of emitted soot particles may increase hazards for human health and for the environment. The majority of previous research is aimed at the understanding of the in-cylinder soot formation process, the reduction of in-cylinder soot particles, the exhaust aftertreatment and, in the field of biosciences, the impact of different soot particles on human health and the environment.In the first two years of this project analyses of mixture formation and combustion were linked to the physicochemical properties of the emitted soot particles for a selection of stationary engine parameters which are particularly relevant for combustion and soot formation.The results of the project show that engine parameters, e.g. boost and injection pressure, have significant influence on the physicochemical properties of emitted soot particles at stationary operating points. By connecting analyses of mixture formation, combustion and emitted soot particles, sources for changes in physicochemical properties of the emitted soot particles can be identified.In the continuation of this project the research of stationary engine operating points shall be extended to transient engine operating conditions. Recent studies show that at transient engine operating conditions, typical for real traffic scenarios, soot emission is clearly different compared to stationary operating points.