物理化学学报 >> 2014, Vol. 30 >> Issue (8): 1426-1431.doi: 10.3866/PKU.WHXB201405231

热力学,动力学和结构化学 上一篇    下一篇

跨接VTSRK方程计算烃类的pVT性质

申爱景, 段远源, 杨震   

  1. 清华大学热科学与动力工程教育部重点实验室, 二氧化碳资源化利用与减排技术北京市重点实验室, 北京 100084
  • 收稿日期:2014-03-24 修回日期:2014-05-22 发布日期:2014-07-18
  • 通讯作者: 段远源 E-mail:yyduan@mail.tsinghua.edu.cn
  • 基金资助:

    国家自然科学基金(51236004)资助项目

pVT Properties of Alkanes Using Crossover VTSRK Equation of State

SHEN Ai-Jing, DUAN Yuan-Yuan, YANG Zhen   

  1. Beijing Key Laboratory for CO2 Utilization and Reduction Technology, Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, P. R. China
  • Received:2014-03-24 Revised:2014-05-22 Published:2014-07-18
  • Contact: DUAN Yuan-Yuan E-mail:yyduan@mail.tsinghua.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51236004).

摘要:

烃类pVT性质的精细表征对能源动力、化工等领域应用有重要价值,临界区热力性质描述是难点之一.本文建立了烷烃(C1-C20)的跨接比容平移Soave-Redlich-Kwong(SRK)(跨接VTSRK)状态方程,在SRK状态方程的基础上引入了比容平移和跨接方法,以改善饱和液相密度和近临界区域热力学性质的计算精度,方程参数被表达为物质临界参数和偏心因子的函数. 比较结果表明,跨接方程对烷烃(C1-C20)饱和蒸气压、饱和气相密度、饱和液相密度的计算平均偏差分别为1.01%、1.83%和0.93%,显著优于原方程,单相区和近临界区的pVT性质计算精度也比原状态方程有较大改善. 进一步将方程推广到环烷烃(环丙烷、环戊烷和环己烷)和苯、甲苯的计算,也获得了较好效果,验证了方程的预测能力.

关键词: 烃类, pVT性质, 临界区, 跨接, 比容平移, SRK状态方程

Abstract:

Accurate predictions of the pVT properties of alkanes are very important since they are associated with many fundamental aspects in energy, power engineering, and chemical engineering fields. Predicting the properties of alkanes in the critical region, however, remains challenging. In this work, a crossover volume translation Soave-Redlich-Kwong (SRK) equation of state (EoS) was developed for C1 to C20 alkanes, in which volume translation and crossover methods were combined to improve the description of saturated liquid densities and thermodynamic properties in the critical region. The parameters of the crossover equation are set as constants or expressed as functions of critical parameters and the acentric factor. Comparisons showed that the average deviations of the crossover volume translation SRK equation results for C1 to C20 alkanes were 1.01% for vapor pressure, 1.83% for saturated vapor density, and 0.93% for saturated liquid density, and these deviations are much lower than those obtained with the SRK equation of state. In addition, prediction results for properties in the single phase region and the critical region from the crossover equation were in better agreement with experimental data than those from the SRK equation. The crossover volume translation SRK equation was also extended to the pVT properties of cycloalkanes (cyclopropane, cyclopentane, and cyclohexane), benzene and toluene. The prediction results were also satisfactory, demonstrating the superior predictive ability of the crossover equation of state.

Key words: Alkane, pVT property, Critical region, Crossover, Volume translation, SRK equation of state

MSC2000: 

  • O642