Abstract
Refrigerant R134a (1,1.1,2-tetrafuoroethane) is a leading substitute for refrigerant R12. As such, there has been worldwide activity to develop accurate wide-range equations of state for this fluid. In this study. we have developed a new selection algorithm for determining high-accuracy equations of state in the Helmholtz representation. This method combines least-squares regression analysis with simulated annealing optimization. Simulated annealing, unlike stepwise regression, allows for the controlled acceptance of random increases in the objective function. Thus, this procedure produces a computationally efficient selection algorithm which is not susceptible to the function-space local-minima problems present in a purely stepwise regression approach. Two equations are presented in this work and compared against experimental data and other high-accuracy equations of state for R134a. One equation was produced strictly by using stepwise a regression algorithm, while the other was produced using the simulated-annealing selection algorithm. In both cases the temperature dependence of the equations was restricted to have no terms whose exponents were greater than live.
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References
Montreal Protocol on Substances that Deplete the Ozone Layer: Final Act. UNEP (1987).
M. L. Huber and J. F. ElyInt. J. Refrig. 18:1 (1994).
W. Wagner, A Ncw Correlation Method for Thermodynamic Data Applied to the Vapour-Pressure Curve of Argon. Nitrogen and Water.Fortschr.-Ber. VDI-Z, Reihe 3. Nr. 39 (1977).
K. M. de Reuck and B. Armstrong,Cryogenics 19:505 (1979).
S. G. Penoncello. R. T. Jacobsen. R. C. Williams. and E. W. Lemmon, IEA-Annex 18: Equation of State Comparisons for HFC-134a and HCFC-123 (1993).
R. Tillner-Roth and H. D. Baehr.J. Phys. Chem. Ref. Data (in press).
A. R. H. Goodwin and M. R. Moldover,J. Chem. Phys. 93:2741 (1990).
H. J. R. Guedes and J. A. Zollweg,Int. J. Refrig. 15:351 (1992).
S. Nakagawa. H. Sato. and K. Watanabe,27th N'atl. Heat Transfer Symp., Japan (1990), p.421.
A. Saitolt, S. Nakagawa, H. Sato, and K. Watanabe,J. Chem. Eng. Data 35:107 (1990).
R. Tillner-Roth and H. D. Baehr,J. Chem. Thermodyn. 24:413 (1992).
L. A. Weber,Int. J. Theemophys. 10:617 (1989).
J. W. Magee,Int. J. Refrig. 15:372 (1992).
M. O. McLinden, J. S. Gallagher, L. A. Weber, G. Morrison, D. Ward, A. R. H. Goodwin, M. R. Moldover, J. W. Schmidt, H. B. Chae, T. J. Bruno, J. F. Ely, and M. L. Huber,ASHRAE Trans. 95:263 (1989).
R. Schmidt and W. Wagner,Fluid Phase Equil. 19:175 (1985).
M. L. Huber and J. F. Ely,Int. J. Refrig. 15:393 (1992).
R. T. Jacobsen and R. B. Stewart,J. Phys. Chem. Ref. Data 2:757 (1973).
M. L. Huber and M. O. McLinden.Proc. Int. Conf., Purdue University (1992), pp. 453–462.
S. Kirkpatrick, C. D. Gelatt, and M. P. Vecchi,Science 220:671 (1983).
V. Cerny,J. Opt. Theory Appl. 45:41 (1985).
N. Metropolis, A. W. Rosenbluth, M. N. Rosenbluth, and A. H. Teller,J. Chem. Phys. 21:1087 (1953).
G. Morrison and D. K. Ward,Fluid Phase Equil. 62:65 (1991).
R. Tillner-Roth and H. D. Baehr,J. Chem. Thermodyn. 25:377 (1993).
H. Hou, B. H. Gammon, K. N. Marsh, and J. C. Holste,Int. J. Refrig. 15:365 (1990).
J. Klomfar, J. Hruby, and O. Sifner,Int. J. Thermophys. 14:727 (1993).
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Shubert, K.B., Ely, J.F. Application of a new selection algorithm to the development of a wide-range equation of state for refrigerant R134a. Int J Thermophys 16, 101–110 (1995). https://doi.org/10.1007/BF01438961
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DOI: https://doi.org/10.1007/BF01438961