The critical pressure ratio (η_c) is an essential parameter for computing the vapor-liquid two-phase critical pressure and mass flow rate of multicomponent hydrocarbon mixtures flowing through valves and leakage orifices. The Homogeneous Non-Equilibrium Diener-Schmidt (HNE-DS) model widely used to calculate η_c assumes that the fluid's volume linearly changes with the pressure (using the Clausius-Clapeyron equation), which is not suitable for multicomponent gas mixtures. In this paper, a new Homogeneous Non-Equilibrium (new-HNE) model is proposed to calculate η_c of gas mixtures. Firstly, a new critical flow compressibility factor (ω_c) is developed from its thermodynamic definition and the Peng-Robinson equation of state (EOS), overcoming the inherent limitations of the Clausius-Clapeyron equation. Then, η_c is correlated to the newly derived ω_c by fitting experimental data at various pressures and gas mass fractions of both single-component and multicomponent gas mixtures, yielding the new HNE-DS model. Results show that, for the water-steam and air-water two-phase flow, the average relative deviations (ARD) between the calculated critical pressure ratios and experimental values are equal to 2.8% and 4.93%, respectively, which represents a significant improvement in comparison with the original HNE-DS model. Moreover, this new model is extended to the applications of Liquefied natural gas (LNG)/liquefied petroleum gas (LPG) fluids, and will further contribute to the calculation of the leakage mass flow rate of fluid flowing through the orifices/valves.

临界压力比（η _Ç）是用于计算汽-液两相的临界压力和质量流量流过阀门和孔口泄漏的多组分烃类混合物的速率的重要参数。齐非平衡迪纳-施密特（HNE-DS）模型广泛用于计算η _ç假定流体的体积线性的压力（使用克劳修斯-克拉贝龙方程），这是不适合的多组分气体混合物的变化。在本文中，一个新的均相非平衡（新-HNE）模型，提出了计算η _ç气体混合物。首先，新的临界流量压缩因子（ω _Ç）是根据其热力学定义和Peng-Robinson状态方程（EOS）开发的，克服了Clausius-Clapeyron方程的固有局限性。然后，η _Ç关联于新导出的ω _Ç通过拟合单组分气体混合物和多组分气体混合物在各种压力和气体质量分数下的实验数据，得出了新的HNE-DS模型。结果表明，对于水蒸汽和空气-水两相流，计算的临界压力比与实验值之间的平均相对偏差（ARD）分别等于2.8％和4.93％，这表明有明显的改进。与原始的HNE-DS模型相比。此外，该新模型扩展到液化天然气（LNG）/液化石油气（LPG）流体的应用，并将进一步有助于计算流经孔/阀的流体的泄漏质量流量。