降低船用柴油机NO_x排放率的研究

在“低温燃烧”的概念下,根据IMO《船用柴油发动机氮氧化物释放控制技术规则》推荐的试验程序,对一台4135G柴油机在推进工况下进行改变喷油正时和压缩比的试验研究。结果表明:延后喷油正时和(或)减少压缩比可以实现柴油机的“低温燃烧”,从而降低柴油机的NO_x排放率,但柴油机的油耗率和烟度将受到影响;若采取喷油正时延后4°和压缩比提高5.5％的组合技术方案时,则可使柴油机在推进工况下的NO_x平均排放率减少16.3％,柴油机的油耗率稍有降低,但烟度在高负荷时稍有增加而低负荷时稍减。

In the concept of low temperature combustion, experimental cycles are made on NOx emission from a 4135G diesel engine by changing injection timing and compression ratio on propeller working condition, according to the IMO Technical Code.Experiment results make it clear achieving low temperature combustion and reducing NOx emission from the diesel engine by reducing injection timing or/ and compression ratio, but increasing fuel com-sumption and smoke; reducing NOx emission by 16.3% and slightly reducing specific fuel cornsump-tion when reducing injection timing by 4?and increasing compression ratio by 5.5%, but slightly increasing smoke when high load and slightly decreasing smoke when low load.