Polyoxymethylene dimethyl ethers (PODEs) are an excellent blend for diesel due to their high cetane number, high oxygen content, and low viscosity. Combustion and emission characteristics are investigated based on experimental tests on a turbocharged, in-line 6-cylinder, common rail diesel engine. Results show that combustion starts earlier with PODE blending at low and partial loads. With pilot and main injection, the peak combustion pressures and peak heat release rates of diesel/biodiesel/PODE blend fuels increase due to large amounts of reactive radicals formed in the pilot heat release stage. With an increase in load, a slight decrease in both peak combustion pressure and peak heat release rate is observed. At low loads, the CA10s, CA50s, and CA90s of diesel/biodiesel/PODE blend fuels advance, and both rapid combustion and late combustion phases shorten. At medium and high loads, CA10s advance, CA50s remain unchanged, and CA90s clearly advance. Rapid combustion phases increase very little, whereas the late combustion phases clearly shorten. Combustion durations shorten in each engine operation. It can be concluded that the addition of PODE is helpful for more concentrated heat release. As a result, combustion temperatures increase. The NOx emissions of blend fuels arise with PODE at 1400 and 2000 rpm, whereas soot emissions obviously decrease. In particular, diesel/biodiesel/PODE blends reduce soot emissions significantly at medium and high loads and reduce the number concentrations of ultrafine particles at low and partial loads.

中文翻译：

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柴油/生物柴油/聚甲醛二甲醚共混燃料为燃料的共轨柴油机的燃烧和排放性能研究

聚甲醛二甲醚（PODEs）由于十六烷值高，氧含量高且粘度低，因此是柴油的极佳混合物。基于对涡轮增压直列六缸共轨柴油发动机的实验测试，研究了燃烧和排放特性。结果表明，在低负荷和部分负荷下，PODE混合可以更早地燃烧。在先导喷射和主喷射下，由于在先导放热阶段中形成了大量的反应性自由基，柴油/生物柴油/ PODE混合燃料的峰值燃烧压力和峰值放热速率增加。随着负荷的增加，观察到峰值燃烧压力和峰值放热率均略有下降。在低负荷下，柴油/生物柴油/ PODE混合燃料的CA10，CA50和CA90会前进，快速燃烧阶段和后期燃烧阶段都缩短了。在中等和高负载下，CA10前进，CA50保持不变，而CA90明显前进。快速燃烧阶段增加很少，而后期燃烧阶段明显缩短。每次发动机运转时，燃烧持续时间都会缩短。可以得出结论，PODE的添加有助于更集中地释放热量。结果，燃烧温度升高。PODE在1400和2000 rpm时产生混合燃料的NOx排放，而烟灰排放则明显减少。特别是，柴油/生物柴油/ PODE共混物在中高负荷下显着降低了烟尘排放，并在低负荷和部分负荷下降低了超细颗粒的数量浓度。快速燃烧阶段增加很少，而后期燃烧阶段明显缩短。每次发动机运转时，燃烧持续时间都会缩短。可以得出结论，PODE的添加有助于更集中地释放热量。结果，燃烧温度升高。PODE在1400和2000 rpm时产生混合燃料的NOx排放，而烟灰排放则明显减少。特别是，柴油/生物柴油/ PODE共混物在中高负荷下显着降低了烟尘排放，并在低负荷和部分负荷下降低了超细颗粒的数量浓度。快速燃烧阶段增加很少，而后期燃烧阶段明显缩短。每次发动机运转时，燃烧持续时间都会缩短。可以得出结论，PODE的添加有助于更集中地释放热量。结果，燃烧温度升高。PODE在1400和2000 rpm时产生混合燃料的NOx排放，而烟灰排放则明显减少。特别是，柴油/生物柴油/ PODE共混物在中高负荷下显着降低了烟尘排放，并在低负荷和部分负荷下降低了超细颗粒的数量浓度。燃烧温度升高。PODE在1400和2000 rpm时产生混合燃料的NOx排放，而烟灰排放则明显减少。特别是，柴油/生物柴油/ PODE共混物在中高负荷下显着降低了烟尘排放，并在低负荷和部分负荷下降低了超细颗粒的数量浓度。燃烧温度升高。PODE在1400和2000 rpm时产生混合燃料的NOx排放，而烟灰排放则明显减少。特别是，柴油/生物柴油/ PODE共混物在中高负荷下显着降低了烟尘排放，并在低负荷和部分负荷下降低了超细颗粒的数量浓度。