成都,2007 年 8 月
中国内燃机学会燃烧净化节能分会 2007 年学术年会论文集
稀燃天然气掺氢发动机的热效率与排放特性
马凡华,王宇,刘海全,李勇,汪俊君,赵淑莉
(清华大学汽车安全与节能国家重点实验室,北京,100084)
摘要:为了分析在天然气中掺入氢气对发动机经济性和排放性的影响,本文在一台 6 缸天然气发动机开展了不同体积掺氢比
的氢气/天然气混合燃料(HCNG)的稀燃效率与排放特性的实验研究。实验证实掺氢能够明显的拓宽燃料的稀燃极限,提
高稀燃能力,加快燃烧速度。在未进行点火提前角优化时,掺氢不利于发动机的热效率,在同一过量系数下也会使NOx排放
升高,但可以使发动机正常工作在更稀的情况下,从而降低NOx排放。在最佳扭矩点火提前角时,掺氢可以提高发动机的指
示热效率,降低未燃CH4和CO的排放,改善NOx与未燃碳氢(主要为CH4)的trade-off关系。
关键词:天然气掺氢发动机;稀燃;稀燃极限;指示热效率;排放
中图分类号:TK421.2 文献标志码:A
Thermal efficiency and emission characteristics of a lean burn HCNG engine
Ma FanHua, Wang Yu, Liu Haiquan, Li Yong, Wang Junjun,Zhao Shuli
(State key laboratory of Automobile safety and energy, Tsinghua University, Beijing, China,100084 )
Abstract: In order to analyze the effect of hydrogen addition in CNG on engine’s thermal efficiency and emissions, an experimental
research was conducted on a 6-cylinder CNG engine using variable compositions of natural gas/hydrogen mixtures (HCNG). The
results show that hydrogen enhancement in CNG can significantly extend the lean operation limit, improve the lean burn ability and
decrease combustion duration. The experiments conducted at unchanged spark timing shows that hydrogen addition does no good to
thermal efficiency and NOx emission increases with the increase of hydrogen fraction. However, the engine can be operated much
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