【作者】 张秋芳；

【导师】 段远源；

【作者基本信息】 清华大学 ， 动力工程及工程热物理， 2005， 硕士

【摘要】 制冷、空调、热泵行业广泛使用的氯氟烃类物质(CFCs)和含氢氯氟烃类物质(HCFCs)对大气臭氧层有破坏作用并且产生温室效应,因此对这两类工质替代物的热物性研究成为最近十多年来国内外研究的热点,同时将饱和碳氢化合物(HCs)作为制冷工质混合物组元之一也是一个新的研究趋势。气液相平衡性质是纯制冷工质和混合制冷工质最基本最重要的热力学性质之一,气液相平衡性质的研究对于制冷空调设备的设计优化及制冷工质的其它热物性研究都是非常重要的。本文首先选用PR、SRK和CSD三类经验方程对含卤代烃二元混合物进行气液相平衡研究,优化得到了多种二元混合物关于这三类状态方程的二元交互作用系数;与实验数据比较表明该优化值能够高精度地再现气液相平衡实验数据。对于混合工质而言,选择合适的混合规则并寻找一个通用的适合于所有卤代烃混和工质的交互作用系数关联式是十分重要的。本文在第一部分工作的基础上,探讨了含卤代烃二元混合物的交互作用系数的规律,得到了一个同时考虑偏心因子和偶极矩的二元交互作用系数关联式,该关联式能较高精度地再现气液相平衡实验数据。本文关联式与文献关联式比较表明,本文关联式的计算精度较高,适用的混合物范围也更广。在分子水平上研究物质性质不仅在理论上具有重要意义,在实际工程应用中也有很强的指导意义。本文从统计力学出发,探讨了分子间各种作用力对状态方程的贡献,将微扰软链理论应用于乙烷族卤代烃物质,通过饱和蒸气压实验数据和饱和液相密度实验数据优化得到了多种乙烷族卤代烃的纯物质的方程参数;并且发现这些物质的方程参数与分子结构间存在一定的规律性。更多还原

【Abstract】 As CFCs and HCFCs refrigerants deplete the ozone layer and cause theglobal warming, which are widely used in refrigeration, air-conditioning andheat pump industrial fields, the research on the thermophysical properties ofCFCs and HCFCs alternatives becomes a hot issue. Meanwhile, there has beenincreasing interest in using saturated hydrocarbon as one of the component ofthe refrigerant mixtures.The vapor-liquid equilibria (VLE) property is one of the most importantthermodynamic properties for pure and blended refrigerants, and it isnecessary for optimization design of refrigeration or air-conditioningequipments.For PR, SRK and CSD equations of state (EOS), the VLE experimentaldata have been correlated and the interaction parameters of many binaryrefrigerant mixtures have been obtained. The calculated results using theequations of state with the optimized kij shows very good agreements with theexperimental data.Based on the accentricity and reduced dipole moment, a new correlationfor the binary interaction parameters kij has been proposed. The correlationrepresents the properties of VLE very well by comparing with theexperimental data and the other correlations before.An EOS based on Perturbed-Soft-Chain Theory has been used tocalculate the thermophysical properties of halogenated ethanes. The equationcontains three parameters and the parameters of 12 kinds of halogenatedethanes have been fitted to experimental data for saturated vapor pressure andsaturated liquid density. Comparison of the EOS predictions with NISTREPROP 7.1 shows that this EOS can accurately represent the pvT data in thesingle-and two-phase regions. The parameters also follow a pattern that isrelated to the molecular structure.更多还原