Samukov Konstantin, Vega-Maza David, Lemmon Eric W, Diky Vladimir, Lasala Silvia
Université de Lorraine, CNRS, LRGP, 54000 Nancy, France.
Group of Energy, Economy and Systems Dynamics (GEEDS), Bioeconomy Research Institute BioEcoUVa, University of Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain.
Int J Thermophys. 2025;46(7):95. doi: 10.1007/s10765-025-03565-x. Epub 2025 May 10.
A new thermodynamic model is presented, capable of accurately representing the vapour-liquid equilibrium pressures and densities, and liquid phase densities and enthalpies of dissociating dinitrogen tetroxide (NO ⇄ 2NO). The model is based on the Peng-Robinson equation of state coupled with advanced mixing rules. The -required but non-measurable- critical coordinates of the pure components forming the reactive mixtures are optimized, within a variability range defined in a previous study, to fit experimental vapour-liquid equilibrium data. The optimized parameters are then validated by comparing calculated thermodynamic properties with available experimental data in the subcritical region. The negligible impact of the higher temperature reaction 2NO ⇄ 2NO + O, within the vapour-liquid equilibrium region where the optimisation is performed, is also proven. The resulting model is finally compared with the currently most accurate available equation of state, showing comparable results when considered both the scatter in available experimental data and the relative simplicity of the proposed equation of state. In particular, the proposed model demonstrates the satisfactory capability of a cubic equation of state to accurately reproduce both saturation pressures and saturation densities without requiring volume translation.
The online version contains supplementary material available at 10.1007/s10765-025-03565-x.
提出了一种新的热力学模型，该模型能够准确表示解离四氧化二氮（N₂O₄⇄2NO）的气液平衡压力和密度、液相密度以及焓。该模型基于Peng-Robinson状态方程并结合了先进的混合规则。在先前研究定义的可变范围内，对形成反应混合物的纯组分所需但不可测量的临界坐标进行优化，以拟合实验气液平衡数据。然后通过将计算的热力学性质与亚临界区域的现有实验数据进行比较来验证优化后的参数。还证明了在进行优化的气液平衡区域内，高温反应2NO⇄2NO + O₂的影响可忽略不计。最终将所得模型与当前最精确的可用状态方程进行比较，考虑到现有实验数据的离散性和所提出状态方程的相对简单性，结果显示具有可比性。特别是，所提出的模型证明了立方状态方程在不需要体积平移的情况下准确再现饱和压力和饱和密度的令人满意的能力。
在线版本包含可在10.1007/s10765-025-03565-x获取的补充材料。
