二次燃油喷射对摩托车汽油机性能影响的试验研究

利用发动机台架试验,对二次燃油喷射技术在摩托车汽油机上的应用进行了研究。结果表明:进气道喷射式摩托车汽油机存在附壁油膜以液体形式进入气缸的现象。发动机性能与附壁油膜挥发量有直接关系,节气门开度较小时,喷油时刻推迟将导致附壁油膜挥发时间变短,从而减少附壁油膜挥发量,使发动机的功率下降、排放恶化;节气门开度较大时,机体温度较高、进气流速较大,改变喷油时刻对发动机动力及排放性能基本无影响;膨胀冲程喷射燃油所占比例较大时,附壁油膜挥发量较大,发动机动力性能较好。

Effects of Twice Fuel Injection on Performance of Motorcycle Gasoline Engine

The application of twice fuel injection(TFI) to motorcycle gasoline engine was studied on a test bed.The experiment results show that for the motorcycle gasoline engine there is wall-film entering cylinder in liquid phase,so its evaporated amount directly affects the engine performance.At small throttle opening,retard of the injection timing will decrease the wall-film evaporation time and amount,causing engine power dropping and emission deterioration,and at wide throttle opening,the engine performance does not change basically with the injection timing because of higher engine temperature and intake air velocity.The larger the fraction injected in expansion stroke,the more the wall-film amount evaporated,thus the more the engine power performance.