聚甲氧基二甲醚及其高比例掺混柴油混合燃料发动机燃烧与排放的试验研究

Investigation of Engine Combustion and Emission Performance Fuelled with Neat PODE and PODE/Diesel Blend

为研究聚甲氧基二甲醚(PODE)及其高比例掺混柴油混合燃料对发动机燃烧与排放的影响,在一台高压油泵柱塞直径加大的云内动力2102QB柴油机上开展了柴油、PODE及30%、50%质量比掺混柴油混合燃料的燃烧与排放试验研究。发动机燃用纯PODE时排气无烟,相对于柴油,其有效热效率最高提升9.67%,并使总未燃碳氢(THC)和CO排放分别降低了50%及60%,而NOx排放增加不超过10%,因此PODE可以单独作为柴油的替代燃料。30%、50%掺混时发动机经济性略有提升,同时排气烟度及CO、THC排放均有较大幅度的改善。缸压分析燃烧过程显示,柴油中添加PODE后燃烧性能改善,滞燃期和燃烧持续期略微缩短,发动机的有效热效率提高。研究结果还表明,PODE与柴油按质量比30%掺混,可以显著降低排气烟度和有害气体排放,而不需要改变发动机的燃油供给系统。

To investigate the combustion and emission performance of neat polyoxymethylene dimethyl ethers （PODE） and PODE/diesel blends, experiments are conducted in a modified diesel engine. It is found that compared with diesel, neat PODE leads to a smokeless operation to heightens the thermal efficiency by 9.67% under full-load conditions. NOx emission increases less than 10%, while the emissions of THC and CO are lowered by 50% and 60%, the neat PODE can thus be used alone instead of diesel in modified diesel engines. The engine running on 30% PODE/diesel and 50 % PODE/diesel can obtain better thermal efficiency and lower emissions than pure diesel. Analyzing cylinder pressure, it is found that adding PODE decreases ignition delay and improves combustion processes in the engine cylinder. The results also indicate that low fraction adding of PODE （30%） into diesel can be used directly in diesel engines without modification for the supply system structure.