SIMPLIFIED REACTION-MECHANISMS FOR THE OXIDATION OF HYDROCARBON FUELS IN FLAMES
SIMPLIFIED REACTION-MECHANISMS FOR THE OXIDATION OF HYDROCARBON FUELS IN FLAMES
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DOI：
10.1080/00102208108946970
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发表时间：
1981-01-01
影响因子：
1.9
通讯作者：
DRYER, FL
中科院分区：
文献类型：
--
作者：
WESTBROOK, CK;DRYER, FL
采用层流火焰数值模型研究了烃类燃料氧化的简化反应机理。研究的机理类型包括一个和两个整体反应步骤以及准整体机理。为了在选定的燃料和空气混合物中提供计算和实验观察到的火焰速度之间的最佳一致性，改变了反应速率参数。确定了不同反应速率参数对层流火焰性能的影响，并给出了确定反应速率参数最佳值的简单方法。研究的燃料包括从甲烷中提取的烷烃、一些甲基取代烷烃、乙炔和有代表性的烯烃、醇和芳烃。结果表明，通常采用的一阶燃料和氧化剂同时依赖全局速率表达式的选择，不能得出火焰速度对当量比或压力的正确依赖，也不能正确预测丰富可燃性极限。然而，对于所有被测试的燃料，速率参数的最佳选择适当地再现了丰富和稀薄的可燃性极限，以及火焰速度对压力和等效比的依赖。两步法和准全局法也能得到火焰温度和燃烧气体成分的信息。然而，所研究的简化机制都不能准确描述火焰本身的化学结构。
Simplified reaction mechanisms for the oxidation of hydrocarbon fuels have been examined using a numerical laminar flame model. The types of mechanisms studied include one and two global reaction steps as well as quasi-global mechanisms. Reaction rate parameters were varied in order to provide the best agreement between computed and experimentally observed flame speeds in selected mixtures of fuel and air. The influences of the various reaction rate parameters on the laminar flame properties have been identified, and a simple procedure to determine the best values for the reaction rate parameters is demonstrated. Fuels studied includen-paraffins from methane ton-decane, some methyl-substitutedn-paraffins, acetylene, and representative olefin, alcohol and aromatic hydrocarbons. Results show that the often-employed choice of simultaneous first order fuel and oxidizer dependence for global rate expressions cannot yield the correct dependence of flame speed on equivalence ratio or pressure and cannot correctly predict the rich flammability limit. However, the best choice of rate parameters suitably reproduces rich and lean flammability limits as well as the dependence of the flame speed on pressure and equivalence ratio for all of the fuels examined. Two-step and quasi-global approaches also yield information on flame temperature and burned gas composition. However, none of the simplified mechanisms studied accurately describes the chemical structure of the flame itself.