乙醇/柴油混合燃料燃烧过程数值模拟

Numerical Simulation on High Pressure Common Rail Diesel Engine Uses Diesel-ethanol Mixed Fuel

利用CFD分析软件AVL FIRE对高压共轨柴油机燃用柴油乙醇混合燃料的燃烧过程进行模拟,通过建立三维仿真模型研究发动机燃用不同掺比燃料的燃烧特性,并对模型的准确性进行了验证。计算了乙醇掺比对发动机燃烧过程中缸内压力、累积放热量及放热率等的影响;模拟出了不同配比混合燃料下高压共轨柴油机的各方面的性能。模拟结果得出:在中高负荷下,乙醇的低十六烷值、高汽化潜热值和含氧对发动机燃烧过程中的缸内压力和放热率的影响较大,发动机燃用E10具有最佳的动力性和经济性。

Using CFD simulation tool FIRE to simulate the combustion process that a high pressure common rail diesel engine use diesel-ethanol mixed fuel , and a 3 D simulation model was established and validated .using the established model to study the combustion characteristic of the mixed fuel ,calculating the influence of the mixing ratio of ethanol on the mean pressure in the cylinder ,accumulated heat release and rate of heat release and so on;various performances that the diesel engine uses mixed fuel were calculated .The result shows that ：in high load condition , the low cetane number , high latent heat of vaporization and the proportion of oxygen of the ethanol have great effect on the mean pressure in the cylinder and the heat release rate ,the diesel engine has the best dynamic and economic performance with E 10 mixed fu-el .