氨柴当量比燃烧的发动机性能研究OA北大核心

By employing a dual-fuel combustion system utilizing zero-carbon ammonia and diesel,the combustion and emission characteristics of ammonia-diesel dual-fuel engine were investigated under various stoichiometric ratios.The characteristics of the condition of stoichiometric and lean burn combustion were compared.The results indicate that under the stoichiometric ratio conditions,the combustion speed of ammonia-diesel dual-fuel is faster than that of pure diesel,with significantly shorter combustion duration.Compared with non-stoichiometric conditions,when the excess air coefficient is closer to the stoichiometric ratio and the ammonia energy replacement rate is larger,the combustion duration is shortened more obviously.Additionally,the ammonia-diesel dual-fuel combustion enhances engine power density and exhibits higher indicated thermal efficiency compared to pure diesel mode.Regarding emissions,NOx emissions from ammonia-diesel blended fuel are below 3.4 g/(kW·h),with emissions under low ammonia energy substitution rate being lower than pure diesel mode.However,the overall efficiency of ammonia combustion is lower,necessitating control of unburned ammonia emissions.Compared to pure diesel,condensed particulate matter emissions from ammonia-diesel blended fuel can be reduced by over 97%at an ammonia energy substitution rate of 70%.