EGR对柴油机超多喷孔预混合燃烧影响的研究(上)

Investigation of EGR Effect on Premixed Combustion in Diesel Engine with Ultramultihole Nozzle(1)

为了在柴油机上实现预混合燃烧同时降低NOx和烟度(soot)排放,本研究采用大量废气再循环(EGR)在一台车用六缸柴油机上进行试验研究。大量EGR可以降低NOx排放,但会引起soot排放的增加,为了消除这一不利后果,采用具有大流通面积的超多喷孔油嘴,并结合使用电控高压共轨燃油喷射系统实现高压喷射,缩短喷射持续期从而实现预混合燃烧,降低soot排放。对EGR如何影响柴油机超多喷孔预混合燃烧性能进行了试验研究,选定4个试验工况,通过改变EGR率来测试柴油机性能。结果显示在高EGR率,并结合超多喷孔油嘴,以及合适的喷射压力、喷油始点下,有利于柴油机实现预混合燃烧,达到同时降低NOx和soot排放的目的。

In order to reach premixed combustion, high levels of exhaust gas recirculation （EGR） were used in a six-cylinder diesel engine for heavy duty trucks in this study. EGR can reduce NOx but increase soot. To remedy this, it is necessary to realize the premixed combustion using an uhramuhihote （UMH） nozzle and a high pressure common-rail fuel injection system, The purpose of this study is mainly to investigate the effect of EGR on premixed combustion. Experimental results showed that heavy EGR benefits to realizing the premixed combustion, and reducing simultaneously NOx and soot emissions.