柴油引燃乙醇均质混合气的二元燃料燃烧特性  

Combustion Characteristics of Dual Fuel-Homogenous Ethanol Charge Ignited by Diesel Fuel

作　　者：姚春德[1] 魏立江[1] 阳向兰[1] 刘军恒[1] 陈绪平[1] 夏琦[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《内燃机学报》2012年第3期207-213,共7页Transactions of Csice

基　　金：国家自然科学基金资助项目(50876075);教育部博士点基金资助项目(200800560040)

摘　　要：在一台单缸增压中冷试验柴油发动机上,研究了不同转速和负荷下乙醇在进气道形成均质混合气,然后在气缸内由柴油引燃的二元燃料燃烧特性.结果发现:采用柴油引燃乙醇混合气的二元燃料燃烧方式,在高负荷时预混燃烧量明显增加,扩散燃烧大幅度减少;在低负荷以及整个低速工况下都实现了单峰快速放热.另外,采用这种燃烧模式能够降低绝大部分工况的最高燃烧温度,并缩短高温持续时间.研究还发现,这种二元燃料燃烧大部分工况的最高爆发压力和压力升高率都比原机高,燃烧持续期短于原机,在中高负荷时能大幅度地减少柴油消耗并提高发动机热效率.与原柴油机相比,采用二元燃料燃烧的指示热效率最高提高了11.09%.Dual fuel combustion was realized by homogenous ethanol charge which formed in the intake manifold and direct injection diesel spray, and engine combustion at different speeds and loads was con- ducted. Results show that the premixed combustion increases and the diffusive combustion decreases re- markably at heavy load, while at low load of all speeds and all low speed conditions it gives single peak and rapid heat release. The combustion mode can decrease the peak combustion temperature of most oper- ating conditions and shorten the residence time at high temperature. The peak cylinder pressure and the rate of pressure rise of dual fuel combustion at most conditions are higher than those of the baseline engine while combustion duration is shortened. Diesel fuel consumption is greatly reduced and thermal efficiency is improved at middle and heavy loads. The indicated thermal efficiency of the dual fuel combustion mode increases by 11.09%.

关 键 词：柴油 二元燃料燃烧 乙醇 燃烧特性 放热率 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]