喷油正时对氨/柴油双燃料发动机燃烧放热规律和部分排放的影响  

Effects of injection timing on combustion exothermic pattern and partial emissions of ammonia/diesel dual-fuel engine

作　　者：桑浩 梁俊杰[1] 吕林[1] 祝能 SANG Hao;LIANG Junjie;LYU Lin;ZHU Neng(School of Naval Architecture,Ocean and Energy Power Engineering,Wuhan University of Technology,Wuhan 430063,China;College of Automobile and Traffic Engineering,Wuhan University of Science and Technology,Wuhan 430065,China)

机构地区：[1]武汉理工大学船海与能源动力工程学院,湖北武汉430063 [2]武汉科技大学汽车与交通工程学院,湖北武汉430065

出　　处：《武汉科技大学学报》2025年第1期70-80,共11页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金项目(52301382);湖北省自然科学基金项目(2022CFB730);企业委托项目(20213h0491).

摘　　要：以船用单缸柴油机为研究对象,采用氨气预混、柴油直喷的燃烧模式,通过试验方式探讨喷油正时对氨/柴油双燃料发动机燃烧与排放特性的影响。结果表明,与纯柴油模式相比,喷入氨气后,发动机缸压峰值P_(max)降低,着火时刻推迟,燃烧持续期增加,最大压力升高率R_(max)减少,CO_(2)和NO_(x)的排放下降,未燃氨和N_(2)O的排放显著增加。在双燃料模式下,随着柴油喷射时刻的提前,缸内燃烧情况改善,P_(max)和R_(max)增大,未燃氨和N_(2)O排放下降,NO_(x)排放上升,碳烟排放先减后增,CO_(2)排放无显著变化;随着负荷的增加,P_(max)和R_(max)增大,但氨气喷射量的增加降低了缸内空气充量,使得着火时刻推迟,燃烧持续期增加,CO_(2)、碳烟和NOx的排放增加,未燃氨和N_(2)O的排放降低。如果优先考虑燃烧平稳性,25%和75%负荷率下的喷油正时最佳值为-5°CA;若以降低温室气体排放为首要目标,25%负荷率下的喷油正时最佳值为-15°CA,75%负荷率下的喷油正时最佳值为-10°CA;若以降低NOx排放为首要目标,25%和75%负荷率下的喷油正时均为-5°CA。With a marine single-cylinder diesel engine as the research object,the effects of injection timing on combustion and emission characteristics of the ammonia/diesel dual-fuel engine were studied by using the combustion mode of ammonia premix and diesel direct injection.The results show that,compared with pure diesel mode,after ammonia injection,the peak cylinder pressure P_(max) of the dual-fuel engine drops,the ignition time is delayed,the combustion duration is extended,maximum pressure rise rate R_(max) decreases,the emissions of CO_(2) and NO_(x) decrease,and the emissions of unburned ammonia and N2O increase significantly.In dual-fuel mode,with the advance of diesel injection time,the in-cylinder combustion situation is improved,P_(max) and R_(max) rise,the emissions of unburned ammonia and N2O decrease,NO_(x) emission increases,the soot emission decrease first and then increase,and CO_(2) emission has no significant change.As the load increases,P_(max) and R_(max) rise,but the increase in ammonia injection reduces the air charge in the cylinder,so the ignition time is delayed and the combustion duration is extended.Meanwhile,the emissions of CO_(2),soot and NO_(x) increase,and the emissions of unburned ammonia and N2O decrease.The optimal injection timing is-5°CA at 25%and 75%load rates when the combustion stability is given priority.If the primary goal is to reduce greenhouse gas emission,the optimal injection timing is-15°CA at 25%load rate and-10°CA at 75%load rate.With NO_(x) emission reduction as the primary objective,the injection timing is-5°CA for both 25%and 75%load rates.

关 键 词：氨/柴油双燃料发动机 喷油正时 放热规律 燃烧特征参数 尾气排放 

分 类 号：U664.121[交通运输工程—船舶及航道工程]