FBC-DPF在柴油机颗粒物控制中的应用研究

Application of FBC-DPF on PM Emissions Control from Diesel Engine

目前针对加装FBC-DPF(燃油添加剂-柴油机颗粒捕集器)后的柴油机放特性研究较少,并且缺乏FBC-DPF对颗粒物中PAHs排放量的影响效果研究.为全面评估加装FBC-DPF后柴油机颗粒物排放特性和FBC-DPF对柴油机尾气中的颗粒物排放污染控制效果,在发动机台架上对装有FBC-DPF的重型柴油机进行了颗粒物排放特性试验.利用电子低压撞击仪(ELPI)测量加装FBC-DPF前、后柴油机颗粒物的数浓度与粒径分布,用玻璃纤维滤膜采集加装FBC-DPF前、后尾气中的固相PAHs,利用色谱质谱联用仪对加装FBC-DPF前、后尾气中的固相PAHs进行定量分析.结果表明:①加装FBC-DPF后柴油机排放的颗粒物数浓度大幅降低,FBC-DPF对尾气中颗粒物的捕集效率平均值在95%左右;②加装FBC-DPF后柴油机固相PAHs总比排放量有所降低,在大负荷区域降幅在25.0%～88.0%之间;③加装FBC-DPF前的颗粒物中位直径为30～89 nm,而加装FBC-DPF后的颗粒物中位直径为41～98 nm,平均增幅为38.2%.对于国Ⅳ及未来国Ⅴ柴油机排放法规,FBC-DPF是解决柴油机颗粒物排放的有效手段;此外,FBC-DPF可以大幅降低柴油机尾气中的有毒成分,并且能够适应高含硫量的燃油环境.

There were few researches on emission characteristics of diesel engine retrofitted with fuel-borne catalyst diesel particulate filter （FBC-DPF）, especially on effects of DPF on the PAHs emission from the exhaust. To comprehensively evaluate particulate matter （PM） emission characteristics of diesel engine retrofitted with FBC-DPF and PAH emission control performance, PM emissions emitted from a heavy-duty diesel engine loaded FBC-DPF were investigated on the engine test bench. PM number concentration and size distribution were obtained by Electrical Low Pressure Impactor with and without FBC-DPF respectively. Additionally, solid polycyclic aromatic hydrocarbons （PAHs） were sampled by fiberglass film filters and PAHs were quantitatively analyzed by gas chromatogragh-mass spectrometer （GC/MS）. Results showed that, DPF substantially reduced the number concentration of PM, and the average filtering efficiency of particulate matter was approximately 95%. DPF also reduced brake specific emissions of PAHs with a high reduce of 25.0% - 88.0% of PAHs. The number count mean diameter （CMD） of PM emission was 30-89 nm without FBC-DPF, while CMD of PM emission was 41-98 nm after the engine retrofitted FBC-DPF. FBC-DPF approximately increased the number count mean diameter of PM emitted from diesel engine by 38.2%. For China 1V and V stage emission standards, FBC-DPF is an effective method to remove the PM emission from the diesel exhaust, and it can significantly reduce the toxic ingredients in the exhaust. In addition, FBC-DPF can adapt to the fuel with high sulfur content.