【摘要】 以一台增压柴油机为研究对象设计了一套带有文曲利管的并联EGR系统,该系统可以在较小地损失充气效率的情况下,将排气较为容易的引入到进气管,并与之混合,使混合气的静压力在扩压管中得到最大程度的恢复,通过试验找出了达到Tier3排放法规要求的各工况下所需的EGR率,以及各工况下EGR率与NOx、烟度、油耗的关系,得到了各工况下兼顾满足NOx、油耗、颗粒排放等指标的EGR率范围,并研究了冷却EGR对NOx排放的影响,EGR经过冷却后降低NOx的效果更加明显,这些研究成果具有重要的工程应用价值。更多还原

【Abstract】 A new EGR system with Venturi pipe has been designed based on a diesel engine.This EGR system can reduce the pressure of intake pipe,and it is easy to introduce the exhaust gas into the intake pipe,and make the pressure of mixture of intake air and EGR gas come back to the original inlet pressure.The flow characteristic of venture pipe has been investigated and the EGR rate has been found out at different operating conditions to suit the Tier 2 emission regulation.This paper also shows the relationships between EGR rate and NOx,smoke and fuel consumption.The EGR rate range in which NOx smoke and fuel consumption can all be accepted has been found out.The effect of cooled EGR is also described in this paper.The result shows that the cooled recalculating exhaust gas can reduce the NOx emission more effectively.This research can be applied widely.更多还原