Polyoxymethylene dimethyl ethers (PODE) are newly appeared promising oxygenated additive which can significantly reduce soot emissions of diesel engines. In this study, the spray and combustion characteristics of the blends of diesel with different PODE blending ratio of 0%, 20%, 50% and 100% by volume are investigated in a constant volume chamber (CVC) under 100 MPa, 120 MPa and 140 MPa injection pressures. The spray results show that liquid spray tip penetration (STP), average spray angle (ASA) and spray projected area (SPA) all decrease with PODE blending ratio under 4 MPa ambient pressure and 573 K ambient temperature. The addition of PODE in diesel can significantly reduce the soot formation and the integrated natural flame luminosity (INFL). Under 100 MPa injection pressure, the time integral sum KL in whole combustion duration of D100, P20, P50 and P100 are namely 107.35, 2.66, 0.27 and 0.08. When the PODE blending ratio are 50% and 100%, nearly no yellow flame can be observed in the combustion duration. The chemical structure of PODE plays an important role in reducing soot formation.

中文翻译：

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定容室中聚甲醛二甲醚和柴油混合物的喷雾和燃烧特性

聚甲醛二甲醚（PODE）是新近出现的一种有前景的含氧添加剂，可以显着减少柴油发动机的碳烟排放。本研究在定容室(CVC)中研究了不同PODE混合比例0%、20%、50%和100%混合柴油在100 MPa、120 MPa和140 MPa 注射压力。喷雾结果表明，在4 MPa环境压力和573 K环境温度下，液体喷雾尖端穿透度（STP）、平均喷雾角度（ASA）和喷雾投影面积（SPA）均随PODE混合比例的增加而减小。在柴油中添加PODE可以显着减少碳烟的形成和综合自然火焰光度（INFL）。在100 MPa喷射压力下，D100、P20、P50和P100整个燃烧持续时间的时间积分和KL分别为107.35、2.66、0.27和0.08。当PODE混合比例为50%和100%时，在燃烧过程中几乎观察不到黄色火焰。 PODE 的化学结构在减少烟灰形成方面发挥着重要作用。