Abstract: The linear range extender is a new type of vehicle power with free dynamic characteristics. In order to accurately reveal its special combustion and emission characteristics, a simulation method featuring coupled iteration of dynamics and thermodynamics was proposed, and a multi-dimensional combustion reaction and pollutant generation model considering dynamic coupling behavior and thermoelectric interaction was constructed. Compared with the conventional range extender, the influence of the unique motion characteristics of the linear range extender on its combustion and emission performance was studied. The results show that the linear range extender has slower effective compression and faster expansion, resulting in lagging behind the conventional range extender all in the process of fuel injection, atomization and air mixing, which makes the maximum combustion pressure and temperature not only smaller and but also the duration shorter. Therefore, the further combustion reactivity of CO is weakened, resulting in more CO pollutants remaining after combustion ends. However, the low combustion temperature also inhibits the generation of NO and Soot, bringing cleaner combustion products, and due to the overall oxygen-rich state in the cylinder, the HC emission of the linear range extender is also slightly less.

Key words: vehicle engineering; linear range extender; dynamic coupling; combustion; emission; comparison

摘要： 直线增程器是一种具有自由动力学特点的新型车载动力，为准确揭示其特殊的燃烧与排放特征，提出了动力学与热力学耦合迭代的仿真方法，构建了考虑动力学耦合行为、热电相互作用的多维燃烧反应与污染物生成模型，并对比常规增程器，研究了直线增程器独特运动特征对其燃烧排放性能的影响效应。结果发现：直线增程器具有更慢的有效压缩和更快的膨胀，导致燃料的喷入、雾化、与空气混合等过程均滞后于常规增程器，使得最高燃烧压力和温度不仅更小且持续期也更短，这削弱了CO的进一步燃烧反应活性，导致燃烧结束后存在更多CO污染物，但低的燃烧温度也抑制了NO和Soot的生成数量，带来了更清洁的燃烧产物，且由于缸内整体处于富氧状态，直线增程器的HC排放也略少。

关键词: 车辆工程；直线增程器；动力学耦合；燃烧；排放；对比