柴油引燃天然气发动机燃烧过程的研究

Investigation on combustion in natural gas engine with diesel pilot

对柴油引燃天然气发动机的着火过程、燃烧过程进行研究,提出了相应的数学模型,并进行了试验验证。着火模型的基本框架仍然采用Shell模型,但考虑到CH4 对柴油着火过程的影响,修正了Shell模型。对CH4 的均质燃烧过程,以简单的一步表观反应动力学概念的阿伦纽斯(Arrhenius)公式为基础,综合湍流脉动对化学动力学的影响,提出了一个新的燃烧模型。模拟计算借助了KIVA-3软件,修正的Shell模型和燃烧模型作为独立子程序与KIVA-3进行了耦合。研究表明。

The ignition and combustion in a homogeneous nature gas-air charge engine with diesel pilot was analyzed. A new model for the autoignition of pilot diesel in the mixture of methane with air was proposed and validated with experiments. The main frame of the new autoignition model is based on the Shell model, which considers the effect of methane on the autoignition of diesel. Integrating the effect of turbulent pulsation into the Arrhenius equation, a new combustion model was developed. All these models were integrated with the KIVA software as freestanding subroutines. The experimental results indicate that the computed and measured cylinder pressures agree well during the entire duration of combustion.