Effects of hydrogen addition on soot formation in flames: experimental investigation by laser imaging

大量科学研究表明，碳氢化合物不完全燃烧时产生的烟尘颗粒对公众健康构成严重威胁。了解碳烟的形成机理有助于减少碳烟的排放及其对人类健康和环境的不利影响。减少碳烟的策略取决于对碳烟形成机制的了解，这可能有助于碳烟分布测量的能力，包括可靠地测量碳烟参数，如颗粒尺寸、数密度和碳烟体积分数。氢气对碳烟形成的影响是该项目关注的焦点。文献表明，在烟尘火焰中引入氢可以增强或抑制烟尘颗粒及其前体的形成，具体取决于操作条件。掺氢火焰是通过在火焰中替换/添加一定量的氢燃料，在保持一定的参数不变的情况下获得的。在过去的20年里，激光诱导白炽灯(LII)已被大量研究证明是一种有用的诊断工具，可用于在层流和湍流火焰、气缸内燃烧和发动机废气表征等广泛应用中对碳烟体积分数进行空间和时间分辨测量。这项技术将用于本项目的目的。总的来说，本项目的目的是了解碳烟的形成机理，并确定通过在燃料/空气混合物中添加氢气来减少碳烟排放的策略。

Numerous scientific studies have indicated that soot particles, commonly produced during the incomplete combustion of hydrocarbons, pose a serious public health risk. Understanding the formation mechanism of soot is helpful for reducing the emission of soot and its adverse effects on human health and the environment. Strategies for reduction of soot depend on the understanding of soot formation mechanisms, which may be aided by the capabilities of soot distributions measurements, including reliable measurement of soot parameters such as particle size, number density, and soot volume fraction. The effect of hydrogen on soot formation is a focus of attention for this project. Literature has shown that the introduction of hydrogen into sooting flames enhances or inhibits the formation of soot particles and their precursors depending on the operating conditions. Hydrogen-doped flames are obtained by replacing/adding a certain amount of Hydrogen fuel in the flame, by keeping certain parameters constant. Over the past 20 years, laser-induced incandescence (LII) has proven in numerous studies to be a useful diagnostic tool for spatially and temporally resolved measurement of soot volume fraction in a wide range of applications, such as laminar and turbulent flames, in-cylinder combustion, and engine exhaust gas characterisation. This technique will be used for the purpose of this project.Overall, the aim of this project is to understand the formation mechanism of soot and determining strategies towards soot emission reduction by adding Hydrogen in fuel/air mixtures.