进气压力对汽油低温压燃的影响

在一台装有电液可变气门的单缸柴油机上,通过改变进气压力,研究了不同喷油正时和内部废气再循环(EGR)率下汽油压燃的燃烧特性和排放特性,并对实现汽油燃料高效清洁稳定低温燃烧(如平均指示压力循环波动系数5%,NOx排放低于0.4g/(kW·h),烟度低于0.1FSN,CO和HC排放尽可能低)的控制区间进行了探索研究。内部EGR通过排气门两次开启实现,发动机转速和循环喷油量分别固定为1 500r/min和28mg。研究结果表明,基于燃油早喷、较低内部EGR率和适量进气压力(0.12MPa)的协同控制可以使辛烷值为93的汽油在平均指示压力约为0.47MPa的工况下实现高效清洁燃烧。

Effects of the Intake Pressure on Gasoline Low Temperature Compression Ignition

The gasoline compression ignition combustion and emissions characteristics at different injection timings and internal exhaust gas recirculation(EGR) rates were investigated by changing the intake pressure on a single-cylinder diesel engine equipped with a electrohydraulic variable valve actuator system. The control area for the gasoline engine to achieve high-efficient, clean and stable low temperature combustion (i.e., COVIMEP<5%, NOx <0.4 g/(kW·h), Smoke<0.1FSN, CO and HC as low as possible) was explored and discussed. The internal EGR was achieved by opening the exhaust valve twice during the intake process, where the engine speed and fuel injection were fixed at 1 500 r/min and 28 mg/cycle respectively. Results show that under the synergistic control of early fuel injection timing, low EGR rate and proper intake pressure (0.12 MPa), the engine fueled by RON 93 gasoline can achieve high efficient and clean combustion at the IMEP of about 0.47 MPa.