碳烟产生于碳氢燃料高温热解或不完全燃烧。碳烟一方面会对环境和人体造成危害，另一方面可以作为炭黑材料被广泛应用，为了更好地控制其排放和生成，需要深入探究和认识碳烟的生成特性和机理。 为了减少实际复杂流动环境的干扰，获取准确而详细的碳烟特性，本研究采用两套实验室反应装置，包括前人搭建的层流预混火焰和新搭建的流动管反应器，并使用小孔稀释取样方法对碳烟颗粒定量取样，同时结合多种测量手段获取碳烟生成总量、粒径分布、颗粒形态以及生成延迟时间等信息。选取C2碳烟燃料（乙炔，乙烷和乙烯）为对象，研究在热解及宽当量比氧化过程中碳烟生成特性，并探究燃料结构、温度、当量比及反应气氛的影响，同时结合数值模拟手段对结果进行分析。 首先，本文探究了C2碳氢燃料层流预混火焰中的详细碳烟生成特性，发现在火焰温度和碳氧比一定情况下，碳烟生成量呈现乙烷>乙烯>乙炔的趋势，乙炔火焰的碳烟成核最弱，且粒径演变很慢，颗粒形态最简单；模拟结果表明，三种火焰的PAHs生成路径类似，由于燃料结构中碳氢比差异而导致乙烷火焰当量比最高从而碳烟生成量最多。其次，本研究将圆管小孔稀释采样技术应用于流动管出口，定量地获取了乙烯热解中碳烟粒径分布，发现其存在双峰分布的演变特性，且受燃料浓度和温度强烈影响，同时标定了流动管中碳烟生成延迟时间，发现其遵循阿累尼乌斯规律。然后，在流动管实验台基础上，进一步探究了低温和高当量比条件下碳烟的生成特性，一方面获取了在预混火焰中由于火焰不稳定而无法准确测量的碳烟信息，另一方面也加深了对极端条件下碳烟机理的认识。在较高温度下，碳烟生成量随当量比单调增加，而较低温度下存在随当量比增加先上升后下降的规律；少量O2会促进PAHs生成从而促进成核，大量O2存在则会抑制碳烟生成。最后，本研究系统地探究了CO2添加对碳烟生成的影响，CO2浓度提升会先促进后抑制乙烯热解中碳烟生成，原因是CO2会与碳氢组分反应产生羟基，少量羟基会促进C3成核路径，从而加速碳烟成核和长大过程，而大量羟基则产生强烈氧化效应。 本工作通过实验测量和模拟分析的方法探究了C2碳氢燃料的生成特性，并系统地研究了燃料结构、温度、当量比和反应气氛的影响，加深了对碳烟生成机理的认识，并为发展和优化碳烟模型提供可靠数据。

Soot is a byproduct produced from the pyrolysis or incomplete combustion of hydrocarbon fuels. On one hand, it is harmful to the environment and the human body; on the other hand, it is a widely-used functional material named as carbon black. It is therefore very important to control its emission and production. In order to reduce the interference of the complex environment in the practical industrial production, a laminar premixed stagnation flame configuration and a laminar flow tube reactor combined with small orifice samling method were used in this study. A variety of measurement methods were applied to obtain accurate and detailed sooting characteristics including total soot yield, particle size distribution, particle morphology, and soot induction delay time. This study is aimed at investigating the soot particle formation characteristics in fuel-rich combustion and pyrolysis of C2 hydrocarbons and exploring the effects of the fuel structure, temperature, equivalent ratio, and reaction atmosphere. Numerical simulation was also conducted to analyze the experimental results. Firstly, the detailed soot characteristics were explored in the laminar premixed flames of C2 hydrocarbon fuels. The results show that under a certain flame temperature and C/O ratio, the soot yield presented a trend of ethane> ethylene> acetylene. In the acetylene flame, the starting point of soot formation is the latest, the evolution of PSDs is the slowest, and the structure of the aggregates is the simplest. The reaction pathway analysis reveals that the paths to produce benzene are similar in all three flames. The soot yield is the largest in the ethane flame since the equivalence ratio is highest due to the lowest C/H ratio in the fuel molecule. Secondly, the orifice dilution sampling technique was applied at the outlet of the flow reactor to quantitatively obtain the particle size distribution of soot particles during fuel pyrolysis. It was found that there was a bimodal distribution during the soot formation process and the particle size distribution as well as the soot yield are strongly affected by the fuel concentration and temperature. The soot induction delay time in the flow tube was determined and was found to follow the Arrhenius law. Thirdly, the effects of low temperature and high equivalent ratio on the formation of soot particles were further explored. It was found that at higher temperatures, the soot yield monotonically increased with the equivalence ratio, while at lower temperatures soot formation increased first then decreased as equivalence ratio rised. A small amount of oxygen would promote the formation of PAHs and thus nucleation, while a large amount of oxygen would inhibit soot formation. Finally, the effect of CO2 addition on soot formation was explored. An increase of CO2 concentration will first promote and then inhibit soot yield during ethylene pyrolysis. The specific reason is that CO2 can generate hydroxyl radicals, and a small amount of hydroxyl radicals intensifies PAHs formation through C3 reaction pathways, which accelerates soot nucleation and growth process, while a large number of hydroxyl radicals would have a strong oxidation effect. In this thesis, the soot formation characteristics of C2 hydrocarbons were studied through experimental measurements and modeling. The effects of fuel structure, temperature, equivalent ratio and reaction atmosphere on soot formation were explored, which deepened the understanding of the soot formation mechanism and provided reliable data for soot model development.