重型柴油机代表性瞬态循环的开发及排放特性研究

Aiming at the problem that the WHTC condition is difficult to accurately reflect the real road operation of heavy-duty diesel engines,which leads to a significant difference between the laboratory emission certification results and the actual driving emissions,a two-step representative transient cycle development process was proposed.Firstly,the actual driving cycle HRDC of heavy-duty diesel vehicle was established,and the actual transient cycle HRTC of heavy-duty diesel engine was developed accordingly.The test results showed that compared with WHTC,the NOx,soot and PN emissions of heavy-duty diesel engines running at HRTC increased by 36.69%,4.57%and 76.28%,respectively.WHTC significantly underestimates the emission level of real roads.The transient soot emission of HRTC increased by 155.74%compared with the steady-state interpolation.Starting with idle or reverse drag conditions,and the sudden torque process with a torque increase of more than 40%/s is the main scenario that causes deterioration of transient soot emission.