Predicting chemical kinetics with computational chemistry: is QOOH→HOQO important in fuel ignition?
Predicting chemical kinetics with computational chemistry: is QOOH→HOQO important in fuel ignition?
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用计算化学预测化学动力学：QOOH→HOQO 在燃料点火中重要吗？
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
R. Sumathi
中科院分区：
文献类型：
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作者：
W. Green;Catherina D. Wijaya;Paul E. Yelvington;R. Sumathi
综述了预测化学动力学的研究进展，并将其应用于均质充量压燃（HCCI）发动机的模拟和设计。发动机模拟是敏感的氢过氧烷基（QOOH）自由基化学的细节，这只是部分理解，有一个显着的模拟和实验之间的差异，限制了模拟的有用性。一个可能的解释是，QOOH分解的其他渠道没有考虑在现有的燃烧化学模型。速率常数为这些被忽视的渠道之一，分子内自由基攻击的QOOH过氧化物键形成羟基烷氧基（HOQO）自由基，预测使用量子化学（CBS-QB 3），以测试是否或不建议的通道可以解释所观察到的差异，在发动机模拟。虽然这个通道有一个显着的速率，在过氧化物中的其他O原子的竞争攻击，以形成一个环醚+OH计算是一个数量级更快，所以HOQO通道似乎没有足够快的解释差异。对该反应通道的重要性的连续判断将需要使用现代预测化学动力学软件仔细重新考虑所有耦合的化学活化的QOOH反应通道。
An overview of predictive chemical kinetics is presented, with an application to the simulation and design of homogeneous charge compression ignition (HCCI) engines. The engine simulations are sensitive to the details of hydroperoxyalkyl (QOOH) radical chemistry, which are only partially understood, and there is a significant discrepancy between the simulations and experiment that limits the usefulness of the simulations. One possible explanation is that QOOH decomposes by other channels not considered in existing combustion chemistry models. Rate constants for one of these neglected channels, the intramolecular radical attack on the QOOH peroxide linkage to form hydroxyalkoxyl (HOQO) radicals, are predicted using quantum chemistry (CBS-QB3), to test whether or not this proposed channel can explain the observed discrepancies in the engine simulations. Although this channel has a significant rate, the competing attack on the other O atom in the peroxide to form a cyclic ether+OH is computed to be an order of magnitude faster, so the HOQO channel does not appear to be fast enough to explain the discrepancy. Definitive judgement on the importance of this reaction channel will require a careful reconsideration of all the coupled chemically activated QOOH reaction channels using modern predictive chemical kinetics software.