Modification of scaled equation of state to determine the pressure in the CO2 critical region

Authors

DOI:

https://doi.org/10.15587/2706-5448.2022.261858

Keywords:

carbon dioxide, critical point, scale equation of state, real gas equation of state, cubic equation of state, phase transition, fluctuation phenomena, thermodynamic parameters, Redlich-Kwong-Aungier model

Abstract

The object of the research is carbon dioxide and its pressure distribution depending on the range of temperature and density in the region of the critical point. One of the most problematic areas of methods for finding thermodynamic parameters of a real gas is insufficient accuracy in calculations in the places of occurrence and rapid development of fluctuation phenomena, which are inherent in phase transitions of the first and second terms. For a more detailed and accurate description of the nature of the thermodynamic parameters in the region of the critical point, scaling and crossover equations of state were developed. Such equations, due to the presence of regular and scaling parts, allow describing the thermodynamic parameters of a real gas not only directly near the critical point, but also at some distance from it, maintaining a small error relative to experimental data. The article proposes an equation of state, which contains a scaling part described according to the rules of statistical physics, and a regular part in the form of a classical cubic equation of state. The equation is used to calculate the pressure of carbon dioxide in the region around the critical point from 300 K to 305 K. The article proposes a correlation equation for the scaling correction of the regular part (Redlich-Kwong-Aungier model) of the crossover equation of state, which is related to the scaling part the equation of state is a crossover function. The obtained results for the pressure in the critical region showed good agreement with the baseline data. The error relative to the experimental data is halved compared to the original model of the Redlich-Kwong-Aungier equation. The obtained results ensure the applicability of the proposed method in the temperature range from 300 K to 305 K. Due to the simplicity of the form of the regular equation of state and the small number of empirical coefficients for the large-scale equation of state, the obtained method can be used for practical problems of computational hydrodynamics without spending a lot of computing time.

Author Biography

Hanna Vorobiova, National Aerospace University «Kharkiv Aviation Institute»

Postgraduate Student

Department of Aircraft Engine Design

References

  1. Schofield, P. (1969). Parametric representation of the equation of state near a critical point. Physical Review Letters, 22 (12), 606–608. doi: http://doi.org/10.1103/physrevlett.22.606
  2. Chapela, G. A., Rowlinson, J. S. (1974). Accurate representation of thermodynamic properties near the critical point. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 70, 584–593. doi: http://doi.org/10.1039/f19747000584
  3. Hasan, O., Sandler, S. I. (1998). Modeling vapor-liquid equilibria: cubic equations of state and their mixing rules. Cambridge University Press, 19–25.
  4. Lee, S., Joonhyeon, J., Wonsoo, K., Tong-Seek, C. (2008). A new model approach for the near-critical point region: 1. Construction of the generalized van der Waals equation of state. The Journal of Physical Chemistry B, 112 (49), 15725–15741. doi: http://doi.org/10.1021/jp8002855
  5. Span, R., Wolfgang, W. (1996). A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100 K at pressures up to 800 MPa. Journal of physical and chemical reference data, 25 (6), 1509–1596. doi: http://doi.org/10.1063/1.555991
  6. Bezverkhy, P. P., Martynets, V. G., Matizen, E. V. (2009). Equation of state for He4, including a regular and a scalar part. Low Temperature Physics, 35 (10), 471–747. doi: http://doi.org/10.1063/1.3253391
  7. Bezverkhii, P. P., Martynets, V. G., Matizen, E. V. (2007). A scaling equation of state near the critical point and the stability boundary of a liquid. Journal of Engineering Thermophysics, 16 (3), 164–168. doi: http://doi.org/10.1134/s1810232807030083
  8. Vinhal, A. P. C. M., Yan, W., Kontogeorgis, G. M. (2019). Modeling the critical and phase equilibrium properties of pure fluids and mixtures with the crossover cubic-plus-association equation of state. Journal of Chemical & Engineering Data, 65 (3), 1095–1107. doi: http://doi.org/10.1021/acs.jced.9b00492
  9. Kolawole, A., Hutton-Prager, B. (2020). Modeling the solubility of Alkyl Ketene Dimer in supercritical carbon dioxide: Peng-Robinson, group contribution methods, and effect of critical density on solubility predictions. Fluid Phase Equilibria, 507, 112415. doi: http://doi.org/10.1016/j.fluid.2019.112415
  10. Aungier, R. H. (1995). A fast, accurate real gas equation of state for fluid dynamic analysis applications. Journal of Fluids Engineering, 117 (2), 277–281. doi: http://doi.org/10.1115/1.2817141
  11. Vorobieva, H. (2021). Modification of the Redlich-Kwong-Aungier Equation of State to Determine the Degree of Dryness in the CO2 Two-phase Region. Journal of Mechanical Engineering, 24 (4), 17–27. doi: http://doi.org/10.15407/pmach2021.04.017
  12. Span, R., Wolfgang, W. (1996). A new equation of state for carbon dioxide covering the fluid region from the triple point temperature to 1100 K at pressures up to 800 MPa. Journal of physical and chemical reference data, 25 (6), 1509–1596. doi: http://doi.org/10.1063/1.555991
  13. Anisimov, M. A., Rabinovich, V. A., Sychev, V. V. (1990). Termodinamika kriticheskogo sostoianiia individualnykh veshchestv. Mosсow: Energoatomizdat, 192.
  14. Patashinskii, A. Z., Pokrovskii, V. L. (1982). Fluktuatcionnaia teoriia fazovykh perekhodov. Mosсow: Nauka, 381.

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Published

2022-06-30

How to Cite

Vorobiova, H. (2022). Modification of scaled equation of state to determine the pressure in the CO2 critical region. Technology Audit and Production Reserves, 3(1(65), 12–19. https://doi.org/10.15587/2706-5448.2022.261858

Issue

Vol. 3 No. 1(65) (2022): Industrial and technology systems

Section

Materials Science: Reports on Research Projects

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Copyright (c) 2022 Hanna Vorobiova

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