超高压共轨柴油机油气室匹配仿真研究

介绍了超高压共轨系统工作原理,基于Fire软件分别建立了进气道和燃烧室的仿真模型,并在利用试验验证了模型准确性的基础上,通过模型分析了油、气、室参数间的匹配关系对超高压共轨柴油机性能的影响,为进一步改善柴油机的性能和实现油、气、室参数间的优化匹配提供了理论依据。结果表明:在超高压喷射条件下,同一喷孔直径匹配的涡流比越大(1.21~3.62范围内),越有利于改善柴油机性能,并且喷孔直径越大,改善的效果越明显,当3.62涡流比匹配0.30mm喷孔直径时,可获得最高的平均有效压力,并且此时具有最好的排放效果;同一喷孔直径匹配的燃烧室口径比越小,越有利于改善柴油机性能,并且喷孔直径越小,改善的效果越明显,当0.75燃烧室口径比匹配0.23mm喷孔直径时,可获得最佳的动力性和排放性。

Simulation of Air,Fuel and Chamber Matching for Ultra High Pressure Common Rail Diesel Engine

The working principle of ultra high pressure common rail system was introduced ,the intake port and combustion chamber simulation models were built respectively with Fire software ,and the effects of matching relationship between air , fuel and combustion chamber parameters on engine performance were then analyzed .It provided the theoretical evidence for fur-ther improving engine performance and optimizing the parameter matching .The results show that the larger swirl ratio within the range of 1 .21 to 3 .62 at the same nozzle diameter is more beneficial to improve engine performance and the effects of larger nozzle diameter are more effective under ultra high pressure injection conditions .When the swirl ratio is 3 .62 and the nozzle di-ameter is 0 .30 mm ,the highest brake mean effective pressure and the optimal emission effect can be achieved .The smaller combustion chamber aperture ratio at the same nozzle diameter is more helpful to improve engine performance and the smaller nozzle diameter will strengthen the effects .When the combustion chamber aperture ratio is 0 .75 and the nozzle diameter is 0 .23 mm ,the best dynamic and emission performance can be acquired .