燃油喷射参数对共轨柴油机性能的影响规律

利用 INCA 标定系统工具,在一台 CA6DL2-35E3 高压共轨重型柴油机原预、主喷欧 3 喷油 MAP 上进行了基于单次喷射(去除预喷)及三段喷射(增设后喷)两种模式的喷油参数对发动机性能影响规律试验研究.单喷试验结果表明,提高喷油压力可以改善除 NOx 外其余发动机性能参数,结合喷油正时的延迟可确定一个优化整机性能的折衷点.增设后喷后,改变主后喷间隔(主喷结束到后喷开始)NOx 及碳烟排放均存在拐点,而随着后喷油量的增加(从主喷油量给出)碳烟及 NOx 排放均降低;根据对动力性/经济性影响小及尾气排放降低或不恶化为优化原则对工况点进行优化后,可以认为优化后喷参数能够较好地改善发动机各项性能.

INFLUENCE LAW OF FUEL INJECTION PARAMETERS ON PERFORMANCE OF A COMMON RAIL DIESEL ENGINE

The experiment of injection parameters on performance of a CA6DL2-35E3 common rail HD diesel engine with the basic Euro-3 maps of main injection (MII) and pilot injection (PII) is conducted based on two kinds of injection pattern: single-injection (removing PII) and multiple-injection (adding post injection (POI)) by means of the INCA calibration tool. The results of single-injection test show that boosting injection pressure improves all performances except NOx emission. Combined with delay of injection timing, an optimal trade-off point is determined. After POI is added, the inflexions of both NOx and soot emission curves exist when changing the time interval from MII ending to POI beginning. With an increase of POI oil quality obtained from MII, both NOx and soot emission gets decreased. Optimizing the operation point according to the principle of little influence on economy and power performances and emission without deterioration, we consider that optimizing POI parameters satisfactorily improves the engine properties.