基于燃烧路径图降低柴油机排放的试验研究

Test Research on Diesel Engine Emission Reduction Based on the Burning Path Graph

基于燃烧路径图,从控制缸内燃烧温度来减少柴油NO_x和碳烟排放出发,采取EGR、推迟喷油和进气节流等措施,研究了同时降低柴油机NO_x和碳烟排放的方法,并对燃烧路径进行定性推测。试验表明:在2 500 r/min、29 N·m工况,采用EGR和推迟喷油后,缸内平均燃烧温度降低明显;并且通过推迟喷油和EGR+推迟喷油的方式实现了同时降低的NO_x和烟度;进气节流后缸内平均燃烧温度升高,虽在一定节流范围内,烟度下降,但NO_x排放升高;采用EGR阀全开+进气节流方式,在提升了缸内平均燃烧温度的同时,实现了NO_x和烟度同时降低的趋势。

Based on combustion path graph,via controlling combustion temperature in cylinder,diesel NOx and soot emissions are reduced.Adopting EGR,delayed injection and inlet throttling,the method of reducing diesel engine NOx and soot emissions at the same time is studied,and the burning path is qualitatively speculaed.Experiments show that：In 2 500 r/min,29 Nm condition,using EGR and delayed injection,the average combustion temperature in cylinder decreased obviously;And by the way of delaying injection and EGR＋delayed injection,NOx and smoke emissions were reduced at the same time.After the intake throt-tling,the average temperature in cylinder rises,although the smoke emission goes down only within a certain range of throttling,but NOx emission rises.By the way of EGR valve fully open＋inlet throttling,the average combustion temperature in cylinder is improved,while the NOx and smoke emissions are reduced.