氨/柴油双燃料船用中速发动机燃烧及排放特性OACSTPCD
Combustion and emission characteristics of an ammonia/diesel dual fuel marine medium speed engine
基于一台缸径为400 mm的船用中速柴油机开展计算流体力学(CFD)数值模拟,研究在进气道喷射氨气、缸内直喷柴油的双燃料燃烧模式下发动机的燃烧和排放特性.计算结果表明:随着氨预混合气当量比增加,氨气的燃烧效率提高,但会导致爆压增高;柴油能量比提高,会提高燃烧效率,但过高的柴油能量比会使柴油燃烧不充分,导致CO排放量增加;适当降低发动机压缩比能延长滞燃期,从而提高燃烧效率和指示热效率.当发动机压缩比为13、氨气预混合气当量比为0.55、柴油能量比为10％时,燃烧爆发压力为18.2 MPa,指示热效率达到47.2％,发动机能够获得较为优越的综合性能.
Computational fluid dynamics(CFD)numerical simulations were conducted based on a 400 mm bored marine medium-speed engine,in which ammonia was port injected and ignited by pilot diesel,to investigate the combustion and emission characteristics.The results showed that as the equivalent ratio of premixed ammonia increased,the combustion efficiency of ammonia and the peak firing pressure increased.The increase of diesel energy fraction led to improvement of combustion efficiency.However,extremely high diesel energy fraction resulted in incomplete combustion,which will lead to increased CO emissions.Moreover,a reasonable decrease of compression ratio led to extension of ignition delay,which increased combustion efficiency and indicated thermal efficiency.Finally,when the compression ratio,equivalence ratio of premixed ammonia,and diesel energy fraction are 13,0.55 and 10％,respectively,an excellent overall performances of the ammonia/diesel duel-fuel engine are achieved,yielding an in-cylinder peak firing pressure of 18.2MPa,an indicated thermal efficiency of 47.2％.
冷先银;高晓亮;魏胜利;何志霞
江苏大学能源研究院,江苏镇江 212000江苏大学汽车与交通工程学院,江苏 镇江 212000
能源与动力
船用发动机氨气柴油当量比柴油能量比压缩比
marine engineammoniadieselequivalence ratiodiesel energy fractioncompression ratio
《华中科技大学学报（自然科学版）》 2024 (001)
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国家自然科学基金面上项目(51876083);江苏省重点研发计划资助项目(BE2019009-5).
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