燃料设计策略对低温燃烧负荷拓展和热效率改善  

Low Temperature Combustion Load Region Extension and Thermal Efficiency Improvement by Fuel Design

作　　者：方强[1] 黄震[1] 方俊华[1] 庄健[1] 

机构地区：[1]上海交通大学动力机械与工程教育部重点实验室,上海200240

出　　处：《内燃机工程》2013年第S1期14-18,共5页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金重点项目(50936004)

摘　　要：在一台高压共轨直喷式柴油机上进行了低温燃烧的研究,并采用燃料设计的理念研究了不同燃料特性对低温燃烧的负荷范围和热效率的影响规律。研究表明:生物柴油为含氧燃料可降低局部当量比,促进和改善缸内燃烧过程,烟度大幅下降,从而拓展了低温燃烧负荷范围。乙醇柴油混合燃料具有较低的十六烷值和较高的含氧量,雾化效果较好,这些特性都有利于降低烟度,拓展低温燃烧的负荷范围。由于低十六烷值燃料较长的滞燃期,允许采用较早的喷射时刻,从而提高了低温燃烧的热效率,尤其是含20%乙醇的混合燃料。低十六烷值含氧燃料(乙醇柴油)在低温燃烧方面具有较大的潜力。In a DI diesel engine with HP common rail system,effects of different fuels based on fuel design concept on operating load region and thermal efficiency of low temperature combustion(LTC)were investigated.Results show that oxygenated biodiesels decrease local equivalent ratio and improve in-cylinder combustion so that smoke emission is reduced greatly,thus low temperature combustion load region being extended.Lower cetane number,higher oxygen content and better atomization property for ethanol-diesel blends lead to lower smoke emission and extended LTC load limit.And owing to longer ignition delay of lower cetane number blended fuels,advanced injection timing can be adopted and the LTC thermal efficiency is improved,especially for the fuel BDE20.It is thus evident that low cetane number oxygenated blends(ethanol-diesel)possesses great potential in extending load region for LTC.

关 键 词：内燃机 柴油机 低温燃烧 燃料设计 生物柴油 乙醇 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]