预喷射控制柴油机NO_x和烟度排放作用的试验研究

以某四缸电控高压共轨柴油机为对象,试验研究了预喷射在控制柴油机NOx和烟度排放中的作用。通过优化预喷射量、预喷与主喷间隔,寻求最佳的控制NOx和烟度的预喷参数。试验结果表明,预喷射在全工况范围内都能降低NOx的排放,但对降低NOx有力的措施却无法有效降低烟度;较大的主预喷间隔、较大的预喷量,NOx排放较低;适当的主预喷间隔、较大的预喷量有利于降低烟度;预喷射虽不能从根本上解决NOx和炭烟排放中的矛盾,但适当的主预喷间隔和预喷量可在烟度基本不变的情况下,大幅度降低NOx排放量。

Experimental Investigation on Effect of Pilot Injection on NOx and Smoke Emissions of Diesel Engine

An experiment was taken to investigate the role of pilot injection to control NOx and smoke emissions through a four-cylinder electronically controlled high pressure common rail diesel engine.Optimal parameters of pilot injection to control NOx and smoke were sought by optimized pilot quantities and the intervals between pilot and main injection.The results show that pilot injection can reduce NOx emissions in all operating conditions,however,some methods are good for NOx reduction,can not effectively decrease smoke.The research also shows that NOx emissions are lower under the condition that the intervals between pilot and main injection as well as pilot quantity are bigger.The proper main and pilot injection intervals,the larger pilot injection quantity are beneficial to reduce the smoke.Though the contradiction between NOx and smoke emission can not be completely resolved by pilot injection,NOx emissions can be significantly reduced under the condition of the intervals and the amount carefully controlled while smoke emissions remain stable.