电喷汽油机燃用甲醇-汽油混合燃料的性能

为了研究不同体积分数的甲醇-汽油混合燃料对多点电喷汽油机性能和排放的影响,通过发动机台架试验,对比分析了发动机的动力性、经济性及排放特性,并用气相色谱分析仪测量了目前法规尚未限制的甲醇和甲醛排放,探讨其排放特性及生成机理。实验结果表明:在外特性工况运行时,甲醇-汽油混合燃料发动机的输出功率在高转速时略高于汽油机,有效燃料消耗率比汽油机低,有效热效率比汽油机高;在负荷特性工况运行时,混合燃料发动机的有效燃料消耗率和有效热效率与汽油机基本相当;随着混合燃料中甲醇体积分数的增加,CO排放有所降低,NOx排放几乎保持不变,THC排放在大负荷时略有升高;混合燃料发动机的甲醛排放明显高于汽油机,并且随甲醇体积分数的增加而增大,而甲醇排放低于汽油机。

Performances of electronic fuel injection engine fueled with methanol-gasoline blended fuel

In order to study the effects of methanol-gasoline blended fuels with different methanol volume fractions on the performances and exhaust emissions of multi-point EFI gasoline engine,the power performance,fuel economy and emission characteristic of the engine were analyzed through engine test,the non-regulated pollutant emissions,such as methanol and formaldehyde,were measured by using gas chromatography(GC),their emission characteristics and formation mechanisms were studied.The result shows that under the speed characteristic of full load,the power output of blended fuel engine is slightly higher at high engine speed,the brake specific fuel consumption is lower,and the effective thermal efficiency is higher compared with gasoline engine.Under the load characteristic of operation,the brake specific fuel consumption and effective thermal efficiency is almost similar to that of gasoline engine.With the increase of methanol volume fraction in the blended fuel,CO emission decreases,NO_x emission varies little,and THC emission slightly increases at high engine loads.Formaldehyde emission of blended fuel engine is evidently higher than that of gasoline engine,and increases with the increase of methanol volume fraction,but the methanol emission of blended fuel engine is lower.1 tab,8 figs,8 refs.