Improvement of the precision of coherent anti-Stokes rotational Raman scattering for oxygen and oxygen containing gas mixtures

氧气和含氧气体混合物相干反斯托克斯旋转拉曼散射精度的提高

• 批准号: 426659749
• 负责人: Professor Dr.-Ing. Thomas Seeger
• 金额: --
• 依托单位: Lehrstuhl für Technische Thermodynamik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426659749?language=en
• 关键词: Improvement; precision; coherent; anti; Stokes

Combustion based on pure oxygen instead of air as an oxidizer is getting more and more important for industrial processes, since this is a possibility to reduce the release of large quantities of climate changing CO2 into the atmosphere. In addition the lack of N2 results in a significant reduction of the NOx emissions. A further optimization of such processes requires a detailed knowledge and understanding of the oxy-fuel combustion process. Therefore experimental data with high temporal and spatial resolution are required. Non-invasive laser based measurement techniques like e.g. CARS are very well qualified for such measurement problems. Beside vibrational CARS nowadays rotational CARS is getting more and more into focus, since it can directly be used for a multi species detection. Nevertheless for a data evaluation a precise modeling of the rotational CARS spectra is necessary. Here is still a strong need for unknown S-branch Raman linewidths. These data are available for pure N2 but not for O2 and combustion relevant gas mixtures.The main objective of this project is to close this gap. By using the time delayed picoseconds rotational CARS technique it is possible to measure the decay rate of the Raman coherence for pure O2 and gas mixtures with O2. These decay rates can be used to calculate the corresponding S-branch Raman linewidths. These data will then help to improve the precision of the rotational CARS Technique for processes involving O2. In addition these correct linewidth information can be used to fit the empirical parameters within the CARS collision models.

基于纯氧而不是空气作为氧化剂的燃烧对于工业过程变得越来越重要，因为这可以减少大量改变气候的二氧化碳排放到大气中。此外，缺少氮气还可以显着减少氮氧化物的排放。此类过程的进一步优化需要对氧燃料燃烧过程有详细的了解和理解。因此需要具有高时间和空间分辨率的实验数据。基于非侵入式激光的测量技术，例如CARS 非常适合此类测量问题。除了振动 CARS 之外，如今旋转 CARS 也越来越受到人们的关注，因为它可以直接用于多物种检测。然而，对于数据评估，旋转 CARS 光谱的精确建模是必要的。这里仍然强烈需要未知的 S 分支拉曼线宽。这些数据适用于纯 N2，但不适用于 O2 和燃烧相关气体混合物。该项目的主要目标是缩小这一差距。通过使用时间延迟皮秒旋转 CARS 技术，可以测量纯 O2 和含 O2 的气体混合物的拉曼相干性衰减率。这些衰减率可用于计算相应的 S 分支拉曼线宽。这些数据将有助于提高涉及 O2 的旋转 CARS 技术的精度。此外，这些正确的线宽信息可用于拟合 CARS 碰撞模型中的经验参数。