生物含氧燃料成分对柴油机性能影响的试验研究

Influence of Biology Oxygenated Fuel Component on Diesel Engine Characteristics

将占体积比8000/的柴油分别掺混2000/乙醇、2000/生物柴油以及1000/乙醇和1000/生物柴油的混合物,连同纯柴油组成E20、B20、E10B10和柴油共4种燃料,在一台4缸柴油机上进行燃烧、性能及排放特性试验研究。结果表明:含氧燃料成分的不同对折合油耗率基本不产生影响,但对燃烧和排放特性影响较大。发动机燃用E20的缸内最大爆发压力较柴油要大,B20、E10B10较柴油要小;含氧燃料中生物柴油的加入使最大压力升高率减小,燃烧变得柔和;含氧燃料的放热时刻均落后于柴油的放热时刻。含氧燃料成分在中低负荷下对HC和CO的排放影响较大,随着含氧燃料中乙醇比例的增加HC和CO排放增加,在中高负荷下,3种含氧燃料的HC和CO排放基本相当;除了在2300 r/min的中低负荷下含氧燃料的HC和CO排放较柴油高以外,其它工况下含氧燃料的HC和CO排放较柴油要低。含氧燃料成分不同对NOx排放的影响很小,3种含氧燃料的NOx排放都比柴油低。3种含氧燃料的碳烟排放较柴油要低,而且随含氧燃料中乙醇比例的增加,碳烟排放减小。

An experiment on combustion characteristics, performance and emissions were carried out on a four cylinder diesel. Fuels in the experiment was prepared by separately addition 20% ethanol, 20% biodiesel, 10% ethanol and 10% bio-diesel in diesel fuel, and pure diesel. These fuels were coded by E20, B20, E10B10 and diesel. Results showed that the difference in oxygenated fuel component has little influence on the diesel-equivalent brake specific fuel consumption, but large influence on combustion and emissions was observed. The maximum cylinder pressure of E20 was higher than that of diesel, but those of B20 and E10B10 were lower than that of diesel. The maximum rate of pressure rise was lower when addi- tion Of biodiesel in diesel fuel. The timing of heat release of oxygenated fuels was retarded comparing with that of diesel. Fuel component had great effect on HC and CO emissions under low and middle loads. HC and CO emissions increased with the increase of ethanol percent in oxygenated fuel. HC and CO emissions of oxygenated fuels were lower than those of diesel besides low and middle load in 2 300 r/min. Oxygenated fuel components had little effect on NOx emission. NOx emissions of the three oxygenated fuels were lower than that of diesel. The smoke of the three oxygenated fuels was lower than that of diesel and it decreased with the increase of ethanol percent in oxygenated fuel.