醚类燃料低温氧化过氧化物的中红外激光吸收光谱研究

Formation and bond cleavage of peroxide intermediates are key steps to the chain-branching reactions in combustion, which are pivotal to the development of combustion kinetic models.Detection and accurate measurement of peroxide intermediates generated by multiple O2 addition steps in the low temperature oxidation of ether flues are critical to understand the intrinsic reaction mechanism and non-regular exhaust of these fuels. This project proposes to apply a new type of external cavity quantum cascade laser that covers 7 to 8 microns to measure the unique fingerprint absorption peaks arising from COO and HOO bonds of peroxide intermediates generated by dimethyl ether and diethyl ether during the low temperature oxidation reactions in flow reactors and jet stirred reactors, by using highly sensitive astigmatic multipass cell rapid scan method, Farady rotation and mid infrared cavity ring down spectroscopy.By assignment of the complex absorption peaks of the combustion intermediates, we will apply high resolution infrared spectroscopy as a new combustion diagnostic tool to capture these transient species.This project will allow us to determine concentration profiles of a number of peroxides under various combustion conditions, including temperature, ratio, and residence time, elucidate formation and bond cleavage mechanism of peroxides molecules, improve the kinetic models of low temperature oxidation and provide fundamental research fundation for the usage of next generation clean fules.

醚类燃料的低温氧化会生成各种过氧化物,发现并精确测量这些过氧化物对研究醚类燃料的低温氧化机理和排放物产生有重要作用。本项目拟选用外腔式中红外量子级联激光器结合高灵敏的多程池、法拉第旋转和光腔衰荡光谱方法,针对过氧化物在7-8微米波段的特征吸收峰,原位测量二甲醚和乙醚在流动反应器和射流搅拌反应器中低温氧化产生的过氧化物中间体。从指认复杂红外光谱的特征吸收峰入手,将高分辨率红外光谱方法应用到燃烧诊断研究,解决过氧化物中间体的定量检测问题,揭示过氧化物随反应器温度、当量比和滞留时间变化的规律。发展二甲醚和乙醚的低温氧化反应动力学模型,阐明过氧化物的产生和分解路径,探索非规排放物产生机理,为醚类燃料的实际应用提供研究基础。

本项目选用中红外量子级联激光器结合高灵敏的光谱测量方法，针对过氧化物在7-8微米波段的特征吸收峰，原位测量二甲醚和乙醚在流动反应器和射流搅拌反应器中低温氧化产生的过氧化物中间体。从指认复杂红外光谱的特征吸收峰入手，将高分辨率红外光谱方法应用到燃烧诊断研究，解决过氧化物中间体的定量检测问题。发展了一种有效的中红外量子级联激光火焰测温方法，具有无背景、高灵敏的优点，适合针对动态火焰进行高频测温，成功的应用于高碳烟火焰、球形发展火焰和不稳定的旋流火焰测温，极大地促进了针对层流火焰结构、火焰发展、和旋流火焰热声不稳定性的研究，在国家急需的燃烧室燃烧测量诊断中具有极大的应用潜力。