柴油机EGR和微粒过滤器的试验研究

Experimental Investigation of EGR System and Ceramic Filter's Regeneration on Diesel Engine

采用废气再循环(EGR)技术与微粒过滤器(DPF)同时降低了柴油机NOx与PM的排放;基于宽范围氧(UEGO)传感器的闭环反馈控制EGR系统,在不同工况下,通过试验方法确定柴油机的空燃比及其它性能参数与EGR率的关系,寻找最佳EGR率,得出了最佳EGR率与空燃比的关系;对于微粒过滤器主要进行了再生的试验研究,通过对加热器的结构和辐射盘上流通孔分布的优化后,研究了再生所用的废气量对再生温度的影响。试验结果表明,闭环控制的EGR系统标定后,在对柴油机的动力性和经济性影响比较小的前提下,大幅度降低了发动机的NOx排放;微粒过滤器系统经过合理的再生优化,再生温度能控制在900℃左右,再生效率能达到80%以上。

The exhaust gas recirculation（EGR） technology and the infrared regeneration of diesel ceramic filter were used to reduce the emissions of NOx and PM. The relationship between the optimized EGR rate and the air-fuel ratio for different operating conditions was determined by experiments based on close-loop feedback control EGR system with universal exhaust gas oxygen（UEGO） sensor. The effect of exhaust gas used for regeneration on regenerating temperatures was investigated by optimizing the configuration of heater and the distribution of holes at radiation plate. The experimental results indicate that the calibration of close-loop feedback EGR system can reduce the emission of NO, with little effect on dynamic and economics performance of diesel engine. The regenerating temperatures can be controlled to about 900℃ and the efficiency of regeneration can reach to above 80%.