Keskinen Jorma, Rönkkö Topi
a Aerosol Physics Laboratory, Department of Physics, Tampere University of Technology , Tampere , Finland.
J Air Waste Manag Assoc. 2010 Oct;60(10):1245-1255. doi: 10.3155/1047-3289.60.10.1245.
Real-world particulate emission measurements usually include a fresh nanoparticle mode called the nucleation mode. The formation of the nucleation mode during mixing, dilution, and cooling of diesel exhaust is discussed based on existing experimental and modeling data. The further evolution of the nucleation mode and the local dilution ratio within the vehicle exhaust is reviewed. The nucleation mode forms at low dilution ratios (≤10) and is fully formed at the dilution ratio of approximately 100. The findings of the studies comparing real-world and dynamometer measurements are reviewed. A qualitative agreement of nucleation mode formation is generally observed. The geometric mean diameter of the nucleation mode, measured on-road, is well reproduced in the laboratory. However, the number concentration of the nucleation mode is too low in the laboratory (by a factor of 2-10). Nevertheless, the trends are reproduced, including those caused by differences in vehicle speed and engine load, engine and aftertreatment technology, as well as fuel and lubricant composition.
实际工况下的颗粒物排放测量通常包括一种新出现的纳米颗粒模态，即成核模态。基于现有的实验和模型数据，讨论了柴油机排气在混合、稀释和冷却过程中成核模态的形成。综述了车辆排气中成核模态的进一步演变以及局部稀释比。成核模态在低稀释比（≤10）时形成，在稀释比约为100时完全形成。综述了比较实际工况测量和底盘测功机测量的研究结果。通常观察到成核模态形成的定性一致性。在道路上测量的成核模态的几何平均直径在实验室中得到了很好的再现。然而，实验室中成核模态的数量浓度过低（低2至10倍）。尽管如此，包括车速和发动机负荷、发动机及后处理技术以及燃料和润滑剂成分差异所导致的趋势仍能再现。
