利用OH自由基发射光谱测量氧炔焰燃烧温度

Temperature determination of an oxyacetylene flame based on the OH radical emission spectrum

利用OH自由基A-X电子带系的发射光谱来测量氧炔焰的燃烧温度。以双原子自由基能级结构和分子光谱理论为基础,通过确定OH自由基不同振转能级的布居数及Einstein跃迁几率等参数,得到了任意转动温度、振动温度和展宽条件下的谱线强度分布。进行发射光谱实验,测量了氧炔焰中不同火焰高度的OH自由基的发射光谱。通过理论光谱和实验数据的对比分析发现,不同振动带系的谱支强度分别表征了粒子的转动温度和振动温度,并由此最终确定了氧炔焰不同火焰高度的燃烧温度分别为3 125K和3 380K。

The combustion temperature of an oxyacetylene flame was determined by measuring the optical emission spectrum of the OH radicals using molecular spectra theory and a spectral temperature determination method. Key parameters for the radiative transitional intensity were evaluated theoretically, including the radical population and the Einstein coefficient for the different vibrational and rotational energy levels. The rotational and vibrational temperatures independently affect the simulated spectrum and its assignment. Distinct measurements of the oxyacetylene flame temperature were obtained by measuring at different distances from the nozzle. The intensities of the theoretical and experimental spectral lines are compared to obtain the rotational and vibrational temperatures with rotational temperatures of 3 125 K to 3 380 K.