代理汽油在均质压燃内燃机中燃烧特性的模拟研究

在均质压燃（HCCI）内燃机中,燃烧主要由化学动力学控制。研究燃料的化学动力学反应机理对了解和控制HCCI具有重要意义。本文利用CHEMKIN多区模型,研究了由正庚烷、异辛烷和甲苯混合而成的代理汽油的燃烧特性。计算结果显示,多区模型弥补了单区模型中出现的温度压强陡升缺点,能更好地反映缸内真实燃烧过程。多区温度分布区间越广,则燃烧提前,燃烧持续期长。各区NOx排放和温度分布趋势类似。HC和CO排放主要集中在燃烧不完全的第1区。

Numerical Simulation on the Combustion Characteristic of Gasoline Surrogate in Homogeneous Charge Compression Ignition Engine

In Homogeneous Charge Compression Ignition（HCCI） engine,combustion is controlled by chemical kinetics.Studies on chemical mechanism of the fuel are of great importance to understand and control HCCI engine.By CHEMKIN multi-zone model,the combustion characteristic of gasoline surrogate constituted by n-heptane,iso-octane and toluene are discussed.Unlike the single zone model,the results from our multi-zone model do not show a steep increase and abrupt turning pressure and temperature.A wider temperature distribution among zones leads to an advance of combustion and longer duration.Distribution of NOx among zones is similar with temperature distribution.HC and CO emissions are concentrated in zone one where the combustion is incomplete.