Abstract The current study focused on the particulate matter emissions of polyoxymethylene dimethyl ethers (PODE)/diesel blends with PODE blending ratios of 0, 10%, 20% and 30% have been experimentally investigated in a common-rail engine. The influences of PODE blending ratio on the smoke emission, particle size distribution and particle oxidation characteristic are discussed. Results show that the addition of PODE in diesel fuel can effectively reduce smoke emission and its decreasing range becomes larger with increasing PODE blending ratio. With the increment in PODE blending ratio, the particle concentration distribution moves towards the direction of small particle size, and the total particle number concentrations decrease. Besides, the peak values of particle number concentration, surface area concentration, and volume concentration are all decreased. Adding PODE in diesel fuel increases the soluble organic fraction (SOF) content of particles, rises maximum weight loss rate of particles, and lower the peak temperature of particles. Also, the activation energy of pyrolysis reaction of particles decreases, which indicates that the oxidation of particles becomes easier as PODE blending ratio increases. The apparent morphology of particles was measured by scanning electron microscope, and the results show that the morphology of particles sample are mostly chain like or flocculent.

中文翻译：

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PODE/柴油混合物对共轨柴油机颗粒物排放和颗粒氧化特性的影响

摘要 目前的研究集中在聚甲醛二甲醚 (PODE)/柴油混合物的颗粒物排放上，PODE 混合比为 0、10%、20% 和 30%，已在共轨发动机中进行了实验研究。讨论了PODE混合比对烟气排放、粒径分布和颗粒氧化特性的影响。结果表明，在柴油中加入PODE可以有效降低烟气排放，并且随着PODE掺混比的增加其降低幅度变大。随着PODE混合比的增加，粒子浓度分布向小粒径方向移动，总粒子数浓度降低。此外，粒子数浓度、表面积浓度、和体积浓度均降低。在柴油中加入PODE，可提高颗粒的可溶性有机物（SOF）含量，提高颗粒的最大失重率，降低颗粒的峰值温度。此外，颗粒热解反应的活化能降低，这表明随着 PODE 混合比例的增加，颗粒的氧化变得更容易。用扫描电镜测量颗粒的表观形貌，结果表明颗粒样品的形貌多呈链状或絮状。这表明随着 PODE 混合比例的增加，颗粒的氧化变得更容易。用扫描电镜测量颗粒的表观形貌，结果表明颗粒样品的形貌多呈链状或絮状。这表明随着 PODE 混合比例的增加，颗粒的氧化变得更容易。用扫描电镜测量颗粒的表观形貌，结果表明颗粒样品的形貌多呈链状或絮状。