Abstract Ammonia is considered as a carbon-free alternative fuel and hydrogen carrier to realize green and renewable energy conversion, but the oxidation mechanism of NH3 still needs to be improved and validated by more experimental data. In this study, the laminar burning velocity (LBV) was measured in a constant volume vessel at various equivalence ratios, initial temperatures, and oxygen fractions up to undiluted condition. Thirteen latest NH3 kinetics mechanisms were collected and compared with each other and the experiments. Results showed that large discrepancies of predictions presented between different mechanisms. The maximum LBV of undiluted NH3/O2 mixtures could reach 125.05 cm/s. The maximum predicted LBV of NH3/O2 is nearly two times higher than the minimum one for NH3/O2 mixtures. The reduced Okafor (2019) and Zhang (2017) mechanism gave the best agreement with experiments for lean and rich mixtures, respectively. Sensitivity analysis of rate constant, species thermal, and transport parameters were adopted to identify the critical reactions and species in the premixed flame. It was found that because of the coupled nature of the properties mentioned above in the premixed flame, the species involved in the essential reactions also exhibit substantial thermal and transport sensitivities.

中文翻译：

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常温和高温下氧氨层流燃烧速度的测量

摘要 氨被认为是实现绿色和可再生能源转换的无碳替代燃料和氢载体，但NH3的氧化机理仍有待于更多实验数据的改进和验证。在这项研究中，层流燃烧速度 (LBV) 在恒定体积容器中以各种当量比、初始温度和氧气含量测量，直至未稀释条件。收集了 13 种最新的 NH3 动力学机制，并相互比较和进行了实验。结果表明，不同机制之间存在较大的预测差异。未稀释的 NH3/O2 混合物的最大 LBV 可达到 125.05 cm/s。NH3/O2 的最大预测 LBV 几乎是 NH3/O2 混合物的最小预测值的两倍。还原的 Okafor (2019) 和 Zhang (2017) 机制分别与稀混合物和浓混合物的实验最吻合。采用速率常数、物种热和传输参数的灵敏度分析来识别预混火焰中的关键反应和物种。发现由于在预混火焰中上述性质的耦合性质，参与基本反应的物质也表现出显着的热和传输敏感性。