掺氢天然气HCCI发动机燃烧特性数值模拟研究  

Numerical Simulation of Combustion Characteristics for a HCCI Engine Fueled with Natural Gas and Hydrogen

作　　者：李岳林[1] 沈嘉诚 LI Yuelin;SHEN Jiacheng(Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学,长沙410114

出　　处：《汽车工程学报》2019年第3期182-192,共11页Chinese Journal of Automotive Engineering

基　　金：国家自然科学基金(51176014);湖南省自然科学基金(2016JJ2003)

摘　　要：为了研究不同运转参数对掺氢天然气均质压燃(HCCI)发动机的燃烧特性影响,基于Chemkin模拟软件,结合GRI-Mech3.0化学反应动力学机理,建立了HCCI发动机的数值模型。数值模拟了掺氢天然气HCCI发动机在掺氢体积比为5%时不同运转参数下的燃烧特性,主要包括对发动机燃烧过程中缸内压力、温度、燃烧放热率和NO_x排放的影响。结果表明,在掺氢天然气HCCI发动机燃烧过程中,转速变化对缸内温度、压力和燃烧放热率的影响不大,但NO_x排放随转速增大而减小;缸内温度、压力、燃烧放热率及NO_x排放随过量空气系数增大而降低;缸内压力、燃烧放热率及NO_x排放随进气压力增大而提高,进气压力对缸内温度影响较小;缸内温度、压力、燃烧放热率及NO_x排放随进气温度增大而提高。为实际改善掺氢天然气HCCI发动机的燃烧动力性、经济性和减少排放提供了理论依据。In order to study the influence of different operating parameters on combustion characteristics of the HCCI engine fueled with natural gas and hydrogen. Based on the Chemkin simulation software,combined with the GRI-Mech3.0 chemical reaction kinetics mechanism,a numerical model of the HCCI engine was established. The combustion characteristics of engine fueled with 5% hydrogen(volume percentage) were numerically simulated with different operating parameters. The main research includes the influence of different operating parameters on the pressure,temperature,the combustion heat release rate and NOx emission in the engine combustion process. The results show that the temperature,pressure and the combustion heat release rate change little for different speeds. However,the amount of NOx emission decreases with the increase of the rotational speed. The temperature,pressure,the combustion heat release rate and the formation of NOx in the cylinder decrease with the increase of the excess air ratio and increase with the increase of the inlet temperature. The pressure in the cylinder,the combustion heat release rate and the formation of NOx increase with the increase of the inlet pressure and the temperature of the engine cylinder,however,change with relatively small amounts. The paper provides a theoretical basis for improving the combustion power,economy and emission reduction of the HCCI engine fueled with natural gas and hydrogen.

关 键 词：掺氢天然气 均质压燃 燃烧特性 发动机 数值模拟 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]