氮气的高温热力学性质研究

Study on the thermodynamic properties of nitrogen at high temperature

摘要:

考虑氮分子振动与转动的相互作用和振动的非谐性, 采用振动转子和非谐振子模型近似, 结合氮分子精确的光谱常数, 建立了准确的配分函数表达式及相关的热力学函数式. 在100~6000 K范围内, 首次系统研究了氮分子的平动、振动和转动分别对摩尔内能、相对摩尔焓、等压摩尔热容、标准摩尔熵及标准摩尔吉布斯自由能的贡献. 结果与实验和理论符合很好, 表明在100~6000 K范围内计算的氮气的各热力学参数是准确可信的, 同时也提供了一种准确计算热力学参数的方法.

Abstract:

Considering the interaction between the nitrogen molecular vibration and rotation as well as the anharmonicity of vibration, together with the precise spectral constants of nitrogen molecules, which allows us to establish the exact partition function and the thermodynamic functions of nitrogen molecules by using the vibration rotor and the non-harmonic oscillator approximation. In the range of 100 to 6000 K, the author made a groundbreaking effort to systematically probe into the contribution of the translation, vibration and rotation of nitrogen molecules to the molar internal energy, relative molar enthalpy, isobaric molar heat capacity, standard molar entropy and standard molar Gibbs free energy. The calculated results agree well with the experiment and theory. It indicates that the calculated thermodynamic parameters of the nitrogen are accurate and credible in the range of 100~6000 K, and also provides a method for calculating the thermodynamic parameters accurately.