【作者】 胡家文；

【导师】 殷辉安；

【作者基本信息】 成都理工大学 ， 矿物学、岩石学、矿床学， 2002， 博士

【摘要】 为了促进流体状态方程的改进和发展，同时也为了满足人们在地质流体热力学计算方面的多种要求，作者对立方型方程的理论基础进行了较系统的研究，同时发展了一系列能够适用于小分子地质流体的维里方程，并改进了文献中的几种立方型方程。本文的研究内容主要包括： 1 以维里方程为基础，对文献中的一些立方型状态方程分别进行了近似的和严格的推导，对一些半经验立方型方程的参数进行了分析与解释。这些结果为维里型和立方型方程在特定条件下的相互转换提供了理论依据。作者还用同样方法得到了一些新的三次方程，其中有些可能具有较好的应用前景。 2 将第二维里系数的理论值较精确地拟合为几种简单的表达式，并据此导出了立方型状态方程中二次项温度函数的新形式 该式简单、通用，不含偏心因子，具有真正的预测功能和坚实的理论基础，原则上适用于所有Van der Waals型方程。用该式改进的RKS、PR和PT方程在精度与适用范围方面均与原方程十分相近。 3 采用一种特殊的临界参数法导出了第二至第六维里系数在临界温度下的近似表达式。结合前面得到的第二维里系数拟合式，作者提出了几种多参数维里方程，并用其中的五次方程预测了一些强极性流体的汽液平衡，结果显著地优于常见的立方型方程。 4 建立了一些可用于精确计算超临界纯流体PVT关系的新的维里方程，同时改进两种立方型方程。 1)通用四次和五次维里方程： 它们对包括强极性、弱极性、非极性及量子流体在内的小分子地质流体（H₂O-CO₂-CH₄-CO-H₂-O₂-N₂）具有良好的通用性；在临界温度以上到4000～5000K、零压到90～200GPa范围内，计算体积的平均偏差分别为1.0％～3,5％和0.7％～3.0％。用上述两方程对一些二、三元超临界流体混合物pVT性质和汽液平衡的计算偏差小于实验误差，或与之很接近。 2)高次维里方程。对上述地质流体，在临界温度以上到4000～5000K、零压到90～600GPa范围内，计算体积的平均偏差为0.3％～0.8％。 3)改进的Holloway方程和van der Waals方程。其所适用的温压范围比Holloway方程 成都理工大学博士学位论文 更宽，计算体积的平均偏差为 0．9W2．10。5 用上述通用五次维里方程预测了纯流体在低温高压下的逸度系数、剩余恰和剩余嫡。更多还原

【Abstract】 In order to promote the improvement and development of the equations of state for fluids and meet the different requests in thermodynamic calculation of geological fluids, the author made a systematic study on the theoretical bases of some cubic equations, as well as modifying some cubic equations, developing some virial equations for geological fluids composed of small molecules. The research mainly included following content:1 Based on the virial equation, some of the cubic equations of state in the literature were derived appoximately and strictly, respectively, and the parameters in some quasi-empirical cubic equations were also analyzed and interpreted. The results can offer a theoretical basis for the mutual transformation of the virial and cubic equations under some specific conditions. Besides, the author also derived some new cubic equations, and some of them may be well perspective in application.2 The theoretical values of the second virial coefficient are precisely fitted into some simple expressions. According to one of them, a new temperature function for the quadratic terms in cubic equations was derived:The function is simple, general, without acentric factor, truly predictive, theoretically sound, and applicable to all the van der Waals-type equations. The precisions and the applicable ranges of the modified RKS, PR and PT equation are very similar to those of the original equations. A special critical parameter method was used to derive the approximate expression of the second upto sixth virial coefficient at critical temperature. Combined with the formerly fitted expressions of the second virial coefficient, some multi-parameter virial equations are proposed. Among them, a quintic virial equation was chosen to predict the vapor-liquid equilibria of some very polar fluids, and the results are notably better than those of the usual cubic equations. Some virial equations for the precise calculation of the supercritical geological fluids were put forward, and two cubic equations were also improved. 1) general quartic and quintic virial equation:They are general for geological fluids composed of small molecules including very polar, weakly polar, non-polar and quantum fluids (F^O-CC^-CI-LrCO-I-k-Ch-N^). In the range from critical temperature upto 4000~5000K, 0 upto 90~200GPa, the average deviation of the calculated volumes (ADV) was within 1.0%~3.5%, 0.7%~3.0%, respectively. The pVT properties of some binary and ternary mixtures of the supercritical fluids were calculated with the two equations above, and the deviations were less than or very close to the experimental ones.2) High-order virial equation. For the above geological fluids in the range from critical temperature upto 4000-5000K, 0 upto 90~600GPa, the AD F was within 0.3%~0.8%.3) Modified Holloway and van der Waals equation. Its applicable/ and Tranges are wider than Holloway equation. TheADFwas within 0.9%~2.1%.5 The fugacity coefficients, residual enthalpies and residual entropies of the pure fluids at low temperatures and high pressures were predicted with the general quintic virial equation.更多还原