基于PC-SAFT的CO_(2)混合工质相平衡计算  

Vapor-liquid Equilibrium Calculation of CO_(2)-based Mixture Based on PC-SAFT Equation of State

作　　者：王竞宇 田华[1] 石凌峰 王轩[1] 舒歌群[1,2] 孙瑞 WANG Jingyu;TIAN Hua;SHI Lingfeng;WANG Xuan;SHU Gequn;SUN Rui(State Key Laboratory of internal combustion engine,Tianjin University,Beijing 300354,China;Department of Thermal Science and Energy Engineering,University of Science and Technology of China,Beijing 230026,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300350 [2]中国科学技术大学热科学和能源工程系,安徽合肥230026

出　　处：《工程热物理学报》2024年第3期683-688,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.52022066)。

摘　　要：统计缔合流体理论(PC-SAFT)能够应用于CO_(2)动力循环中CO_(2)混合工质物性的预测。PC-SAFT状态方程在计算CO_(2)混合工质气液相平衡时,其收敛性较差。本文介绍一种利用基于基团贡献法的蒸气压估算方法为PC-SAFT状态方程提供初值,从基团角度来预测CO_(2)混合工质气液平衡的方法。该方法在很多情况下的准确度高于Refprop 9.0计算结果,尤其在较高的CO_(2)比例下。对于温度滑移较大的CO_(2)混合工质计算中,该方法不会计算出Refprop 9.0中不平滑的尖点,避免了在一些情况下出现反常的计算结果,是一种稳定可靠的计算方法。Perturbed Chain-Statistical Associating Fluid Theory(PC-SAFT)equation of state(EoS)can be applied to predict the physical properties of CO_(2)-based mixtures in the CO_(2) power cycle.The convergence of PC-SAFT EoS is poor when calculating vapor-liquid equilibrium(VLE)of CO_(2)-based mixtures.In this paper,the vapor pressure estimation method based on group con-tribution is used to provide the initial value for the PC-SAFT EoS and complete the calculation of the VLE of CO_(2)-based mixtures from the perspective of groups.The accuracy of this method is higher than that of REFPROP 9.0 in many cases,especially in the case of a high CO_(2) ratio.For the calculation of CO_(2)-based mixtures with large temperature slips,this method will not calculate the uneven cusps in REFPROP 9.0.It avoids abnormal calculation results in some cases and is a stable and reliable calculation method.

关 键 词：PC-SAFT 气液相平衡 CO_(2)混合物 CO_(2)动力循环 

分 类 号：TK123[动力工程及工程热物理—工程热物理]