车用柴油机冷EGR系统的设计与试验

Design and Experiment of Cooled EGR System on Diesel Engine of Vehicles

为了降低车用柴油机NOx的排放量,设计了一套柴油机的冷EGR系统,通过对再循环的废气进行精确冷却来降低NOx的排放量。该系统可以通过控制电动水泵的转速来调节EGR冷却器冷却水的循环量,确保不同工况下EGR的最佳冷却温度范围。对冷EGR系统的主要部件文丘里管和EGR冷却器等主要部件进行了设计计算,并对冷EGR系统的电控单元ECU进行了设计。将该冷EGR系统在R4105T型柴油机试验台架上进行了试验。结果表明:与热EGR系统相比,在各种工况下冷EGR系统可以有效地降低NOx的排放量,且使得柴油机的燃油消耗率也有所降低。

To reduce the NOx emission quantity of the diesel engine,a cooled EGR system on the diesel engine of vehicles is designed.By using the system, the exhausted recirculation gas is cooled and the emission quantity of NOx is decreased.Through controlling the revolving speed of the electric water pump,the cooled EGR system can regulate the cooled water circulation of the EGR cooler.By adjusting the cooled water circulation,the EGR optimum cooled temperature range is ensured.The main parts of the cooled EGR system including Venturi pipe and EGR cooler are designed and calculated.The ECU of the cooled EGR system is designed.By applying the cooled EGR system in R4105T diesel engine test board shelf,the test result shows that compared with the heated EGR system,the cooled EGR system can reduce the quantity of NOx emission and the fuel consumption rate of the diesel engine is decreased.