缸内直喷式汽油机燃用当量空燃比混合气的试验研究

摘要

缸内直接喷射式汽油机,要求部分负荷时在压缩过程后期喷入燃油,实现混合气分层燃烧,以获得好的经济性;在全负荷时,燃油在进气过程中喷入,采用化学计量比混合气,实现均质预混合燃烧,以保持汽油机升功率高和排放低的优点.本文将一台柴油机改装为缸内直接喷射汽油机,在试验台架上进行了高负荷时燃用当量空燃比混合气的试验研究,结果表明,与化油器式汽油机相比,高负荷时油耗降低了6%,未燃碳氢降低了31%,Nox排放降低了10%,取得了较为满意的结果.%For gasoline direct injernction(GDI) engines,the fuel is required to be injected into the cylinder near the end of the compression stroke to realize the stratified charge combustion at part load.However at full load,the fuel is required to be injected into the cylinder during the intake stroke to realize the homogeneous stoichiometric charge combustion to achieve the high specific power output and low emissions by threeway catalyst converter.In this paper,the experimental studies were carried out on a gasoline direct injection engine operating on stoichiometric mixture to study the performances of GDI engine is decreased by 6% and UBHC is decreased by 31%and Nox is decreased by 10% at full load.