DNTP对柴油机PM质量粒径分布影响的实验研究

Experimental Investigation of the Influence of DNTP on Mass Size Distribution of Diesel Engine Particulate Matters

利用微孔均匀沉积冲击器研究了直接低温等离子体技术对柴油机PM质量粒径分布的影响。结果表明,DNTP可有效降低柴油机排放的烟度值,对所选工况烟度的平均降幅达65.85%。在0～10μm范围内,中低负荷时PM质量粒径呈双峰分布,峰值分别在0～0.18μm和>0.32～0.56μm范围内;全负荷时,呈单峰分布,峰值出现在>0.32～0.56μm范围内。随着负荷的增加,粒径较大的颗粒在样品中的质量比例增加。DNTP作用后,25%、50%、75%负荷三种工况时,0～0.18μm的PM质量分数大幅下降;此外,DNTP作用后,四种工况下以>0.32～0.56μm区间为中心的相邻区间内PM的质量分数升高,呈现出明显的"聚拢"效应。

The influence of direct non-thermal plasma （DNTP） on mass size distribution of diesel engine particulate matters was investigated using micro orifice uniform deposit impactor. The results show that DNTP can reduce the smoke intensity dramatically with an average 65.85% drop. In the range of 0-10 μm, the PM mass distribution toward size was bimodal at low and medium diesel load with peaks in the range of 0-0.18 μm and 〉0.32-0.56 μm, and unimodal at full diesel load with peak in the range of 〉0.32-0.56 μm. The mass ratios of PM with larger size grew with the increasing of diesel load. After the treatment of DNTP, the mass ratio of the range of 0-0.18 μm dropped substantially at 25%, 50% and 75% diesel load. In addition, the PM mass ration of the adjoining region of 〉0.32-0.56 range ascended at the selected four diesel loads, showing a gathering round-up trend.