经过低温等离子体后柴油机颗粒物氧化反应机理函数的确定

Oxidation Mechanism Function of Diesel Particulate Matter with Non-Thermal Plasma

以热重试验结果为基础,研究了被捕集到低温等离子体发生装置极板上的柴油机颗粒物的氧化反应机理函数。采用Malek法,将试验结果与常用的固体反应机理函数获得的曲线、经验公式(empirical formula,EF)拟合的曲线进行对比。研究结果表明:常用的固体机理函数获得的标准曲线、反应速率曲线与试验结果一致性较差;加热速率分别为5、10、20K/min时,通过EF经验公式拟合得到的反应速率曲线与试验得到的反应速率曲线基本重合,且相关系数分别为0.968 1、0.992 4、0.990 4。以加热速率为10K/min得到的幂指数确定的颗粒物氧化反应机理函数为f(α)=α-0.29(1-α)1.54[1-ln(1-α)]3.93。三种不同的加热速率条件下,由该机理函数获得的标准曲线与试验曲线变化趋势十分相似,可以较为准确地反映柴油机颗粒物的氧化反映机理。在不同加热速率条件下得到的指前因子lnA与活化能E保持了很好的线性关系,满足公式lnA=0.136E-7.015,相关系数为0.994。

diesel particulate matter captured on a non-thermal plasma reactor electrode plate was studied. The analysis method of Malek was used and experimental curves were compared with the standard ones obtained with the commonly used functions of solid reaction mechanism and the empirical formula （EF） function. Results show that there are huge differences between the experimental curves and the standard ones. The fitted reaction rate curves derived with the EF function agree to the experimental ones at the heating rates of 5 K/min, 10 K/min and 20 K/min with the correlations of 0. 968 1, 0. 992 4 and 0. 990 4 respectively. An oxidation mechanism function f（α）=α-0.29（1-α）1.54[1-ln（1-α）]3.93 w a s obtained w i t h the heating rate of 10 K / min . The standard curves derived from this oxidation mechanism function /（a） at three heating rates are very close to the experimental ones, indicating that this oxidation mechanism function can represent the diesel particulate matter oxidation mechanism. Linearity keeps between the pre-exponential factor InA and the activation energy E, which satisfies the function l n A = 0. 136E-7. 015 with the correlation of 0. 994.