柴油机燃用生物柴油的碳烟排放模拟

开展柴油机燃用生物柴油时碳烟生成量的研究，基于广安碳烟模型提出一种计算生物柴油的碳烟排放公式。以实测示功图作为输入数据，结合喷雾与空气卷吸子模型、油滴蒸发燃烧子模型、传热子模型以及广安博之碳烟子模型，建立柴油机燃用生物柴油时碳烟排放准维预测模型，计算柴油机燃用生物柴油时碳烟生成量。结果表明，十三工况的计算值与试验实测碳烟排放量吻合，该模型适用于工程上含氧燃料的碳烟排放模拟。与柴油相比，由于柴油机燃用生物柴油时着火时刻提前，较早地达到碳烟生成的触发温度，燃烧开始阶段生成碳烟增加；但是由于生物柴油属于含氧燃料，其峰值和最终排出量都比柴油低大约50％。

Simulation of Soot Emission From Diesel Engine Fueled With Biodiesel

The study on the soot emission characteristics of DI diesel engine operating on diesel/biodiesel was conducted, and a predictive formula based on hiroyasu soot submodel for soot emission of the biodiesel was proposed. Based on the measured indicator diagram, a quasi-dimensional particulate emission model for the engine fueled with biodiesel was established by combining a fuel spray impinging and air entrainment submodel, droplet’s evaporation and combustion submodel, the heat transfer submodel and hiroyasu soot submodel, and the in-cylinder soot mass was calculated. The results indicate that the theoretical results alculated agree well with experimental results converted from the experiment results, and that the model is suitable for soot emission prediction of diesel engine fueled with oxygenated fuels. The ignition start of biodiesel engine is early to reach the trigger temperature of soot formation, so soot emission increases in the initial stage of combustion. Since the oxygen concentration at combustion area is high due to the oxygenated property of biodiesel, the peak and final emission value of soot is reduced by more than 50% compared with that of 0# diesel.