汽油理化特性对整车经济和排放性能影响

Effects of Physical and Chemical Properties of Gasoline on Economy and Emission Performance of a Vehicle

采用主成分分析法,研究了汽油12种理化特性对整车新欧洲驾驶循环(NEDC)下经济和排放性能的影响,发动机为气道喷射汽油机.结果表明:汽油12种理化特性可降维为3个主成分,第一主成分得分与蒸气压呈负相关,与密度、初馏点、5%蒸发温度(T_(5))、10%蒸发温度(T_(10))、终馏点、芳烃含量和研究辛烷值(RON)呈正相关.第二主成分得分与重芳烃含量和90%蒸发温度(T90)呈负相关.第三主成分得分与烯烃含量呈正相关.提高燃油的蒸气压,降低燃油的密度、初馏点、T_(5)、T_(10)、芳烃含量、终馏点和RON,可以降低车辆在市区驾驶循环(UDC)和NEDC下的CO_(2)排放(最高降幅为18.14%)以及车辆在UDC下的百公里油耗(最高降幅为14.80%).降低燃油的烯烃含量可以降低车辆在UDC、市郊驾驶循环和NEDC下的NOx排放,最高降幅为32.61%.

The principal component analysis method was used to study the comprehensive effects of 12 physical and chemical properties of gasoline on economy and emission performance of a vehicle under new European driving cycle(NEDC).The vehicle has a port-injected gasoline engine.The results show that the 12 physical and chemical properties of gasoline can be reduced to 3 principal components.The score of the first principal component is negatively correlated with vapor pressure,and positively correlated with density,initial boiling point,5%evaporation temperature(T_(5)),10% evaporation temperature(T_(10)),final boiling point,aromatics content and research octane number(RON).The score of second principal component is negatively correlated with heavy aromatics content and 90%evaporation temperature(T_(90)).The score of third principal component is positively correlated with olefin content.Increasing the vapor pressure and reducing the density,initial boiling point,T_(5),T_(10),aromatics content,final boiling point and RON of fuel can reduce carbon dioxide emissions(with a maximum percentage of 18.14%)of the vehicle under both urban driving cycle(UDC)and NEDC,while reduce fuel consumption per 100 kilometers(with a maximum percentage of 14.80%)under UDC.Reducing the olefin content of fuel can reduce nitrogen oxides emissions(with a maximum percentage of 32.61%)of the vehicle under both UDC and NEDC and extra UDC as well.