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介绍了应用液化石油气(LPG)和汽油燃料时,微粒排放时效特性的对比研究。试验在一台四冲程、水冷125mL、点燃式单缸电喷发动机上进行。试验结果表明:对于两种燃料,随着沉降时间的增加,微粒排放的粒数不但大幅度下降,其粒度分布规律也发生了明显的变化;LPG和汽油燃料排出的小粒径部分微粒在空气中存在时间短,在排出后15min左右即可大部分挥发或凝聚形成大粒径粒子,而挥发消失的颗粒物比率LPG大于汽油;80%以上的大粒径部分(≥0 237um)粒子是在沉降过程中形成的;在测试条件下,汽油燃料微粒排放的大粒径部分粒子比LPG燃料容易沉降或挥发,随着沉降时间的延长,LPG与汽油微粒排放物的粒度分布特性趋于同一水平。
A comparative study of the aging characteristics of particulate emissions when using liquefied petroleum gas (LPG) and gasoline fuel is presented. Test in a four-stroke, water-cooled 125mL, ignition type single cylinder EFI engine. The experimental results show that with the increase of settling time, the particle number of particle emission not only decreases sharply, but also the particle size distribution law also changes obviously. For LPG and gasoline fuel, In the presence of a short time, about 15min after discharge can be most of the volatile or cohesion to form large particle size, and the volatilization of the particle ratio of LPG gasoline is greater than 80% of the large particle size (≥ 0 237um) particles in the settlement . Under the test conditions, large particle size particles emitted from gasoline fuel particles are easier to settle or volatilize than LPG fuel, and the particle size distribution characteristics of LPG and gasoline particulate emission tend to be the same as the settling time prolongs.