煤油自点火特性的实验研究

在加热激波管中利用反射激波点火,采用壁端压力和CH*发射光作为点火指示信号,测量了气相煤油/空气混合物的点火延时,点火温度为1100-1500K,压力为2.0×105和4.0×105Pa,化学计量比(Φ)为0.2、1.0和2.0.分析了点火温度、压力和化学计量比对点火延时的影响.结果显示,化学计量比为1.0和2.0时活化能几乎是相同的,但与化学计量比为0.2时的活化能差异很大,拟合得到了不同化学计量比条件下点火延时随温度变化的关系式.点火延时与已有的动力学机理进行对比,实验结果与Honnet等人的动力学机理吻合得很好.对不同化学计量比条件下的反应进行了敏感度分析,结果表明在化学计量比为0.2时,对点火延时敏感的关键反应与化学计量比为1.0时的有很大差异.

Experimental Study of Autoignition Characteristics of Kerosene

The ignition delay times of gas-phase kerosene/air mixtures were measured behind reflected shock waves,using side-wall pressure and CH * emission measurements in a heated shock tube.The experiments were performed over the temperature range of 1100-1500 K,at pressures of 2.0×10 5 and 4.0× 10 5 Pa,and for equivalence ratios(Φ)of 0.2,1.0,and 2.0.The effects of temperature,pressure,and equivalence ratio on the ignition delay time were investigated.The global activation energy for kerosene/air varies significantly when the equivalence ratio changes from 0.2 to 1.0,whereas the global activation energy at an equivalence ratio of 1.0 is almost the same as that at 2.0.Three correlations for the ignition delay time under three different equivalence ratios were deduced.The current data were compared with available kinetic mechanisms,and were found to be in good agreement with the predictions of Honnet et al. Chemical mechanism sensitivity analyses for different equivalence ratios were performed;the results showed that the ignition sensitivity at an equivalence ratio of 0.2 is quite different from those at 1.0 and 2.0.