CO_2和H_2对HCCI二甲醚发动机燃烧影响的数值模拟

Numerical Study on the Effects of CO_2 and H_2 on Combustion in a Dimethyl Ether HCCI Engine

模拟了燃用DME的HCC I发动机的燃烧过程,研究了进气添加剂CO2和H2对其着火时刻和指示功的影响。结果表明:CO2能延迟着火时刻,降低缸内压力和温度,从而扩大HCC I燃烧运行范围;H2也可推迟着火,并能有效提高发动机的指示功。为了既控制着火始点,又提高发动机指示功,提出进气中同时添加适量CO2和H2,并就此进行了计算。

With a single-zone model and chemical kinetics mechanism, the homogeneous charge compression ignition （HCCI） combustion process in a diesel engine fueled with dimethyl ether （DME） is simulated. The effect of CO2 and H2 as intake air additives on ignition time and indicated work is studied. The results show that CO2 delays ignition and decreases in-cylinder pressure and temperature, which widens the operating range of HCCI engine. H2 also delays ignition, and increases indicated work effectively as well. Finally, the proper proportions of CO2 and H2 added simultaneously into intake air for both controlling ignition time and raising indicated work are given with calculation.