末端气体自燃前燃料的氧化放热化学动力学模拟

Chemical Kinetic Modeling of Heat Release due to Fuel Oxidation Preceding Autoignition of End Gas

低温化学反应能够产生大量的活性基 ,并有显著的热量释放 ,足以使末端气体温度提高到自燃的程度。作者基于低温化学反应机理 ,建立了一个简易化学动力学模型 ,当给定混合气的量和初始计算温度时 ,该模型能预测出混合气氧化反应的温度、累积放热量以及产物浓度随曲轴转角的变化曲线。用此模型预测了 PRF75燃料在倒拖发动机上压缩自燃前的氧化放热过程 ,结果表明 。

Low temperature reaction can produce a large number of free radicals and a considerable heat release which may raise the temperature of end gas to the point of ignition.In this paper,a reduced chemical kinetic model based on low temperature chemistry has been developed.When the quantity of the initial fuel air mixture and initial temperature are given,the temperature,heat release and species concentrations as a function of crank angle can be predicted by using this model.In the present work it has been used to predict the heat release due to preflame reaction for a blend of primary reference fuels with octane rating of 75 in a motored research engine.The results of prediction agree fairly well with the experimental results.