摘要
为研究掺氢对天然气充量均质压燃(homogeneous charge compression ignition,HCCI)发动机的燃烧及排放特性的影响,基于化学反应动力学软件包CHEMKIN中的零维模型模拟天然气HCCI发动机在掺氢比为0%~40%时的燃烧过程及排放,并对其进行数值分析。结果表明:掺入氢气后缸内温度和放热率先略下降后上升而缸内压力变化不明显,着火时刻随掺氢比增加不断提前,CO和CO_(2)的生成浓度降低而NO的生成浓度上升。掺入氢气为体系提供大量H,使链分支和链传递反应加快,HO_(2)和OH生成速度加快,造成着火时刻提前。NO的总生成速率随掺氢比增加而加快。
In order to investigate the effects of hydrogen enrichment on the combustion and emission formation processes of natural gas homogeneous charge compression ignition(HCCI)engines,based on the chemical kinetics software of CHEMKIN,a single-zone model was used to calculate the in-cylinder processes of natural gas HCCI engine fueled with different hydrogen fractions(from 0%to 40%in volumetric fraction).The numerical results show that the trend of change in the in-cylinder temperature and heat release rate after adding hydrogen shows a slight decrease at first and then an increase.However,the effect of adding hydrogen on the in-cylinder pressure is not obvious.And the increase in the ratio of hydrogen incorporation leads to an earlier ignition time.As the hydrogen doping ratio increases,the mole fractions of CO and CO_(2) decrease while the mole fraction of NO shows an opposite trend.A large amount of H is supplied to the system after adding hydrogen,which accelerates the chain branching and chain transfer reactions.And the generation rates of HO_(2) and OH are accelerated,resulting in an earlier ignition time.The total formation rate of NO increases with the increase of hydrogen doping ratio.
作者
李延吉
许多
宋瑞雯
李明泽
LI Yanji;XU Duo;SONG Ruiwen;LI Mingze(Clean Energy Key Laboratory of Liaoning,Shenyang Aerospace University,Shenyang 110136,China)
出处
《内燃机工程》
CAS
CSCD
北大核心
2022年第6期27-36,共10页
Chinese Internal Combustion Engine Engineering
基金
辽宁省自然科学基金项目(20180550324)
辽宁省教育厅项目(L201707)。
关键词
掺氢天然气
内燃机
充量均质压燃
化学反应动力学
hydrogen enriched natural gas
internal combustion engine
homogeneous charge compression ignition(HCCI)
chemical reaction kinetics
