超临界流体热力学函数的理论计算

Ｄｕａｎ等（１９９２。１９９６）基于分子间相互作用势能模型，建立了一个适合于超临界流体的状态方程，此方程能反演出世界上几十个实验室测定的成千上万个纯组分及混合物的ＰＶＴ（压力、体积、温度）数据（温压范围：Ｐ〈２ＧＰａ，Ｔｃ〈Ｔ〈２０００Ｋ）。最近的研究发现，此方程能准确预测Ｈ２Ｏ、ＣＯ２、ＣＨ４、Ｎ２及它们的混合物在Ｔ＝１．３Ｔｃ，Ｐ＝０到Ｔ＝２０００Ｋ，Ｐ＝１０ＧＰａ这一温压范围内的压力、体积、

Theoretical Calculation of Thermodynamic Functions of Supercritical Fluids

Based on the intermolecular potentials, Duan et al. (1992,1996) developed an equation of state (EOS) for supercritical fluids. This equation reproduces thousands of PVT data points for both pure systems and mixtures below 2. 0 GPa (20 kbar) from the supercritical temperature to about 2000 K. Furthermore, this EOS can predict all available experimental data (PVT properties, fugacity, enthalpy, and supercritical phase seperation) with accuracy close to experiments from 1. 3 times of the critical temperature and zero pressure up to about 2000 K and 10 GPa (100 kbar) for the fluids H2O, CO2, CH4 and N2 and their mixtures.