柴油替代燃料典型芳香烃组分低温氧化反应动力学研究

Low temperature oxidation reaction kinetics of fuel is important to solve problems relevant to ignition process in engines and also play an important role in the development of advanced engines. Aromatics with mid-to-long alkyl-chain length are important components in transportation diesel fuel and they are also considered as ideal representatives of aromatic component in diesel surrogate fuels. In this proposal, the low temperature flow reactor and jet stirred reactor oxidation of mid-to-long alkyl-chain length aromatics will be investigated in a jet stirred reactor and a flow reactor using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry as diagnostic method. Key low temperature oxidation intermediates such as phenylalkyl peroxides, phenylalkyl hydroperoxides are expected to be detected and identified to provide evidence for confirming low temperature oxidation pathways. Quantum chemistry calculation methods will be sued to obtain thermodynamic properties of species in the kinetic model, as well as low temperature reaction potential energy surfaces. Rate coefficients of key reactions will also be calculated by using kinetic theory. Base on the experimental and theoretical results, kinetic models of alkylbenzenes will be construct, and then the measured concentration profiles will be used to validate and optimize kinetic models to obtain accurate kinetic models of alkylbenzens with mid-to-long alkyl chain length, which can be used to develop combustion kinetic model of diesel surrogate fuel.

低温氧化反应动力学对于解决发动机着火相关技术难题和发展先进发动机技术具有重要意义，中长支链烷基苯是柴油中的重要芳香烃组份，同时也被用作柴油替代燃料中理想的芳香烃组分代表，对柴油替代燃料模型的构建具有重要作用。本项目拟使用高灵敏度和高分辨率的同步辐射真空紫外光电离质谱结合射流搅拌反应器与流动反应器，研究四种长支链烷基苯在不同工况条件下的低温氧化。实验将对长支链烷基苯低温氧化中关键的过氧化物、过氧自由基、氢过氧化物和其它低温氧化中间产物进行探测与鉴定，为低温氧化反应路径以及低温氧化模型的发展提供实验依据。同时，将使用理论计算方法对低温氧化中关键物种热力学数据、低温氧化反应路径以及关键反应速率常数进行计算，在此基础上构建中长支链烷基苯燃料的低温燃烧模型，结合本项目实验结果对模型进行全面的验证，获得兼具精确性和适用性的低温氧化详细模型，使模型能够适用于柴油替代燃料燃烧反应动力学模型发展之中。

针对前人在长支链烷基苯低温氧化反应动力学研究方面的局限性，本项目使用高灵敏度和高分辨率的同步辐射真空紫外光电离质谱结合射流搅拌反应器与流动反应器，研究了长支链烷基苯在不同工况条件下的低温氧化。项目首先对烷基苯低温氧化关键中间产物苯氧基与环戊二烯基的实验与模型研究，得到了这两类关键中间产物准确详细的子机理。然后分别对长支链烷基苯二甲苯、正丙基苯、正丁基苯以及更大质量烷基苯的低温氧化进行了实验研究，对关键的过氧化物、过氧自由基、氢过氧化物和其它低温氧化中间产物进行探测与鉴定，为中长支链烷基苯的低温氧化反应路径以及低温氧化模型的发展提供实验依据。最后，项目使用理论计算方法对低温氧化中关键物种热力学数据、低温氧化反应路径以及关键反应速率常数进行了计算，在此基础上构建了中长支链烷基苯燃料的低温燃烧模型，结合本项目实验结果对模型进行全面的验证，获得了兼具精确性和适用性的低温氧化详细模型。