研究了高压共轨增压中冷柴油机燃用天然气转化制成的合成油(Gas to liquid,GTL)不同添加比例的混合燃料在恒转速增转矩瞬态工况下的微粒排放粒度分布特征,分析了工况瞬变率及GTL添加比例对于微粒排放粒度分布的影响。研究结果表明,随着...研究了高压共轨增压中冷柴油机燃用天然气转化制成的合成油(Gas to liquid,GTL)不同添加比例的混合燃料在恒转速增转矩瞬态工况下的微粒排放粒度分布特征,分析了工况瞬变率及GTL添加比例对于微粒排放粒度分布的影响。研究结果表明,随着恒转速增转矩工况瞬变率的减小,各种试验燃料的微粒排放总量及其随时间变化的增长率均有所降低。随着GTL添加比例的增加,微粒生成总量、核态微粒和超细微粒总数均有所下降,积聚态微粒的生成量在大粒径处稍有增加。在5s增转矩工况下,G20和G30的核态微粒数量明显减少,比国IV石化柴油分别降低了42%和20%。与石化柴油相比,不同瞬变率的增负荷工况下发动机排气中超细微粒和核态微粒的比例,G10燃料稍有增加,G20和G30均有显著降低。展开更多
Oxygen fuels have broad application prospects and great potential for realizing efficient and clean combustion,and hence this study applies diesel/n-butanol blends to explore the influence of split-injection strategy ...Oxygen fuels have broad application prospects and great potential for realizing efficient and clean combustion,and hence this study applies diesel/n-butanol blends to explore the influence of split-injection strategy on combustion and emission characteristics.Simultaneously,changing the way of exhaust gas recirculation(EGR)gas introduction forms uneven in-cylinder components distribution,and utilizing EGR stratification optimizes the combustion process and allows better emission results.The results show that the split-injection strategy can reduce the NO_(x)emissions and keep smoke opacity low compared with the single injection,but the rise in accumulation mode particles is noticeable.NO_(x)emissions show an upward trend as the injection interval expands,while soot emissions are significantly reduced.The increase in pre-injection proportion causes the apparent low-temperature heat release,and the two-stage heat release can be observed during the process of main combustion heat release.More pre-injection mass makes NO_(x)gradually increase,but smoke opacity reaches the lowest point at 15%pre-injection proportion.EGR stratification can optimize the emission results under the split injection strategy,especially the considerable suppression of accumulation mode particulate emissions.Above all,fuel stratification coupled with EGR stratification is beneficial for further realizing the in-cylinder purification of pollutants.展开更多
文摘研究了高压共轨增压中冷柴油机燃用天然气转化制成的合成油(Gas to liquid,GTL)不同添加比例的混合燃料在恒转速增转矩瞬态工况下的微粒排放粒度分布特征,分析了工况瞬变率及GTL添加比例对于微粒排放粒度分布的影响。研究结果表明,随着恒转速增转矩工况瞬变率的减小,各种试验燃料的微粒排放总量及其随时间变化的增长率均有所降低。随着GTL添加比例的增加,微粒生成总量、核态微粒和超细微粒总数均有所下降,积聚态微粒的生成量在大粒径处稍有增加。在5s增转矩工况下,G20和G30的核态微粒数量明显减少,比国IV石化柴油分别降低了42%和20%。与石化柴油相比,不同瞬变率的增负荷工况下发动机排气中超细微粒和核态微粒的比例,G10燃料稍有增加,G20和G30均有显著降低。
基金Projects(51476069,51676084)supported by the National Natural Science Foundation of ChinaProject(2019C058-3)supported by the Jilin Provincial Industrial Innovation Special Guidance Fund Project,China+1 种基金Project(20180101059JC)supported by the Jilin Provincial Science and Technology Development Plan Project,ChinaProject(2020C025-2)supported by the Jilin Provincial Specific Project of Industrial Technology Research&Development,China。
文摘Oxygen fuels have broad application prospects and great potential for realizing efficient and clean combustion,and hence this study applies diesel/n-butanol blends to explore the influence of split-injection strategy on combustion and emission characteristics.Simultaneously,changing the way of exhaust gas recirculation(EGR)gas introduction forms uneven in-cylinder components distribution,and utilizing EGR stratification optimizes the combustion process and allows better emission results.The results show that the split-injection strategy can reduce the NO_(x)emissions and keep smoke opacity low compared with the single injection,but the rise in accumulation mode particles is noticeable.NO_(x)emissions show an upward trend as the injection interval expands,while soot emissions are significantly reduced.The increase in pre-injection proportion causes the apparent low-temperature heat release,and the two-stage heat release can be observed during the process of main combustion heat release.More pre-injection mass makes NO_(x)gradually increase,but smoke opacity reaches the lowest point at 15%pre-injection proportion.EGR stratification can optimize the emission results under the split injection strategy,especially the considerable suppression of accumulation mode particulate emissions.Above all,fuel stratification coupled with EGR stratification is beneficial for further realizing the in-cylinder purification of pollutants.
