某型相继增压柴油机缸内燃烧数值模拟研究

Numerical Study For Combustion Process of an STC Diesel Engine

利用FIRE软件建立了某型相继增压柴油机燃烧及排放仿真计算模型,研究了不同负荷对燃烧排放的影响以及相继增压切换点的燃烧与排放性能,分析了缸内压力、温度等参数随曲轴转角的变化以及SOOT、NO等的分布情况。结果表明:随着负荷的增加,燃烧滞燃期缩短,缸内温度、压力、放热率、SOOT以及NO排放均增加;相继增压柴油机在1TC工况时,混合气更加均匀,燃烧更加完全,因此做功能力高于2TC,燃烧温度和放热率均低于2TC,NO及SOOT排放性能均优于2TC工况。

In this paper, a combustion and emission simulation model for sequential turbo charging （STC） diesel engine was established by FIRE software. Combustion emissions of diesel under different load and the combustion and emissions performance of switching point were studied, then the diesel engine cylinder pressure, temperature changing with the crank and the distribution of SOOT and NO were analyzed. The result show that as the load increased, the combustion ignition delay was decreased and cylinder temperature, pressure, heat release rate, SOOT and NO emissions are increased; the mixture formation was more homogeneous and combustion was more complete in 1TC, so the 1TC condition is powerful than the 2TC conditions. 1TC conditions of temperature and heat release rate is less than 2TC conditions. The NO and SOOT emissions performance of the 1TC condition are better than the 2TC conditions.