基于一种新型喷油系统的船用柴油机NOx排放试验研究

摘要

为了探索采用改进的机械式喷油系统以较低的成本使大功率船用柴油机的NOx排放满足IMO TierⅡ法规的可能性,在一台6PC2-6/2L型柴油机上开展台架试验,验证了自行研发的新型喷油系统,即交叉喷孔油嘴和调压孔式喷油泵,对于降低船用柴油机NOx排放的效果.试验结果表明：交叉喷孔油嘴所产生的扇形喷雾在柴油机气缸的空间分布范围广,混合气更为稀薄,有利于抑制燃烧温度,从而降低NOx排放;将新型喷油系统应用于该柴油机使NOx排放率降低14.3%,同时制动油耗率降低1.5%.新型供油系统进一步优化有望使该柴油机的NOx排放满足IMO TierⅡ排放法规.%To explore the feasibility of reducing the NOx emission of a large power marine diesel engine to meet IMO Tier Ⅱ regulations with low costs by the improvements of the mechanical fuel injection systems,a novel fuel injection system,including the intersecting hole nozzle and pressure-modulating-hole type fuel pump,is developed.Benchmark experiments were performed on a 6PC2-6/2L type marine diesel engine,to clarify the effects of the novel fuel injection systems on NOx emission.The experiment results show that,the fan-shaped spray produced by the intersecting hole nozzle diffuses to such a large scope in the combustion chamber that the leaner mixtures control the combustion temperature,therefore reduce the NOx emission.And the application of the novel fuel injection system to the diesel engine turns out 14.3% reduction of NOx emission and 1.5% reduction of brake specific fuel comsumption.It is believed that,with further optimization,the novel fuel injection system has the potential to make the diesel engine meet IMO Tier Ⅱ regulations.