增压直喷汽油机的低速早燃特性研究

对一台增压直喷汽油机进行低速早燃(low-speed pre-ignition,LSPI)试验研究,在转速为1 750r/min和转矩为320N·m这一典型的低速早燃工况下,早燃的着火时刻越早,爆震发生倾向越高,并且强度也越大。试验同时研究了发动机运行参数和机油物理化学性质对早燃的影响,研究结果表明随着中冷温度和冷却液温度的提高,早燃频次增加;高黏度的机油可以抑制超级爆震频次和发生倾向;机油添加剂中钙元素对超级爆震的发生起极大促进作用,磷元素起较大抑制作用,镁元素的抑制作用最小。

Research on Low Speed Preignition Characteristics of a Turbocharged Direct Injection Gasoline Engine

A low speed pre-ignition characteristics was studied on a turbocharged direct injection gasoline engine. Results show that under low speed pre-ignition conditions at the speed of 1750 r/min and with a torque of 320 N·m, the earlier the ignition timing of pre ignition, the greater the knocking tendency and its intensity. Moreover, studying the influence of engine operating parameters and lubricating oil physicochemical properties on pre-ignition also shows that the frequency of pre-ignition increases with the rise of inter-cooler temperature and coolant temperature. High viscosity lubricating oil can suppress the frequency and tendency of superknock. Moreover, calcium element in the oil additive greatly promotes the occurrence of superknock, while phosphorus element plays a greater inhibitory role, and magnesium element has the least inhibitory effect.