For thermodynamic performance to be optimized particular attention must be paid to the fluid’s thermal pressure coefficients and thermodynamic properties. A new analytical expression based on the statistical mechanics is derived for R11, R13, R14, R22, R23, R32, R41, and R113 refrigerants, using the intermolecular forces theory. In this paper, temperature dependency of the parameters of R11, R13, R14, R22, R23, R32, R41, and R113 refrigerants to calculate thermal pressure coefficients in the form of first order has been developed to second and third orders and their temperature derivatives of new parameters are used to calculate thermal pressure coefficients. These problems have led us to try to establish a function for the accurate calculation of the thermal pressure coefficients of R11, R13, R14, R22, R23, R32, R41, and R113 refrigerants based on statistical-mechanics theory for different refrigerants. 1. Introduction Popular interest in the use of refrigerant blends started in the late 1950s. The emphasis was placed on energy savings through the reduction of irreversibility in the heat exchanger and on capacity variation during operation through the control of the fluid composition. Worldwide legislation has been enacted through the United Nations environmental program to reduce stratospheric ozone depletion. The Montreal Protocol was approved in 1987 to control production of the suspected ozone-depleting substances, among them chlorofluorocarbons and hydrochlorofluorocarbons, commonly used as refrigerants in the industry. For example, chlorofluorocarbons-(CFCs-) 11, 12 and 113 have been successfully used to determine groundwater recharge ages in the industry. Relatively good agreement exists between individual CFC ages and ages derived from other tracers [1–6]. The precise meaning of the internal pressure is contained in a generalized manner in the following well-known thermodynamic equations. United forces of external and internal pressure equalize the thermal pressure which tries to expand the matter. If the thermal pressure of a refrigerant is available, then the thermodynamics properties of refrigerant can be calculated easily. Liquids and dense fluids are usually considered to be complicated on a molecular scale, and a satisfactory theory of liquids only began to emerge in the 1960. However, they show a number of experimental regularities, some of which have been known by theoretical basis [7–10]. The first is the internal pressure regularity, in which is linear with respect to for each isotherm, where is the molar density, is the internal
References
[1]
J. D. Happell, R. M. Price, Z. Top, and P. K. Swart, “Evidence for the removal of CFC-11, CFC-12, and CFC-113 at the groundwater-surface water interface in the Everglades,” Journal of Hydrology, vol. 279, no. 1–4, pp. 94–105, 2003.
[2]
R. Span and W. Wagner, “Equations of state for technical applications. III. Results for polar fluids,” International Journal of Thermophysics, vol. 24, no. 1, pp. 111–162, 2003.
[3]
K. A. Gillis, “Thermodynamic properties of seven gaseous halogenated hydrocarbons from acoustic measurements: CHClFCF3, CHF2CF3, CF3CH3, CHF2CH3, CF3CHFCHF2, CF3CH2CF3, and CHF2CF2CH2F,” International Journal of Thermophysics, vol. 18, no. 1, pp. 73–135, 1997.
[4]
E. W. Lemmon and R. T. Jacobsen, “An international standard formulation for the thermodynamic properties of 1,1,1-trifluoroethane (HFC-143a) for temperatures from 161 to 450 K and pressures to 50 MPa,” Journal of Physical and Chemical Reference Data, vol. 29, p. 521, 2000.
[5]
M. J. Assael, J. Millat, V. Vesovic, and W. A. Wakeham, “The Thermal conductivity of methane and tetrafluoromethane in the limit of zero density,” Journal of Physical and Chemical Reference Data, vol. 19, p. 1137, 1990.
[6]
J. W. Magee, S. L. Outcalt, and J. F. Ely, “Molar heat capacity Cv, vapor pressure, and (p, ρ, T) measurements from 92 to 350 K at pressures to 35 MPa and a new equation of state for chlorotrifluoromethane (R13),” International Journal of Thermophysics, vol. 21, no. 5, pp. 1097–1121, 2000.
[7]
R. Dohrn and J. M. Prausnitz, “A simple perturbation term for the Carnahan-Starling equation of state,” Fluid Phase Equilibria, vol. 61, no. 1-2, pp. 53–69, 1990.
[8]
L. Boltzmann, Lectures on Gas Theory, University of California Press, Berkeley, Calif, USA, 1964.
[9]
V. Moeini, “New regularity for internal pressure of dense fluids,” Journal of Physical Chemistry B, vol. 110, no. 7, pp. 3271–3275, 2006.
[10]
V. Moeini and M. Deilam, “Determination of molecular diameter by PVT,” ISRN Physical Chemistry, vol. 2012, Article ID 521827, 5 pages, 2012.
[11]
R. B. Stewart and T. Jacobsen, “Thermodynamic properties of argon from the triple point to 1200 K with pressures to 1000 MPa,” Journal of Physical and Chemical Reference Data, vol. 18, p. 639, 1989.
[12]
R. D. Goodwin, “Carbon monoxide thermophysical properties from 68 to 1000 K at pressures to 100 MPa,” Journal of Physical and Chemical Reference Data, vol. 14, p. 849, 1985.
[13]
R. Span and W. Wagner, “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, vol. 25, p. 1509, 1996.
[14]
R. T. Jacobsen, R. B. Stewart, and M. Jahangiri, “Thermodynamic properties of nitrogen from the freezing line to 2000？K at pressures to 1000？MPa,” Journal of Physical and Chemical Reference Data, vol. 15, no. 2, pp. 735–909, 1986.
[15]
B. A. Younglove and J. F. Ely, “Thermophysical properties of fluids. II. methane, ethane, propane, isobutane, and normal butane,” Journal of Physical and Chemical Reference Data, vol. 16, p. 577, 1987.
[16]
R. D. Goodwin, “Benzene thermophysical properties from 279 to 900 K at pressures to 1000 Bar,” Journal of Physical and Chemical Reference Data, vol. 17, p. 1541, 1988.
[17]
R. D. Goodwin, “Toluene thermophysical properties from 178 to 800 K at pressures to 1000 Bar,” Journal of Physical and Chemical Reference Data, vol. 18, p. 1565, 1989.
[18]
V. Moeini, F. Ashrafi, M. Karri, and H. Rahimi, “Calculation of thermal pressure coefficient of dense fluids using the linear isotherm regularity,” Journal of Physics Condensed Matter, vol. 20, no. 7, Article ID 075102, 2008.
[19]
V. Moeini, “Internal pressures of lithium and cesium fluids at different temperatures,” Journal of Chemical and Engineering Data, vol. 55, no. 3, pp. 1093–1099, 2010.
[20]
V. Moeini, “Calculation of thermal pressure coefficient of lithium fluid by pVT data,” ISRN Physical Chemistry, vol. 2012, Article ID 724230, 11 pages, 2012.
[21]
T. M. Reed and K. E. Gubbins, Applied Statistical Mechanics, McGraw-Hill, 1973.
[22]
W. D. Weatherford, R. K. Johnston Jr., and M. L. Valtierra, “Kinematic Viscosity of Liquid Rubidium from 67° to 688°C,” Journal of Chemical and Engineering Data, vol. 9, pp. 520–524, 1964.
[23]
F. Roehlich, F. Tepper, and R. L. Rankin, “Surface tension of four alkali metals to 1000°C,” Journal of Chemical and Engineering Data, vol. 13, no. 4, pp. 518–521, 1968.
[24]
K. Mutsuda, K. Tamura, and M. Inui, “Instability of the electron gas in an expanding metal,” Physical Review Letters, vol. 98, Article ID 096401, 2007.
[25]
K. Matsuda, S. Naruse, K. Hayashi, K. Tamura, M. Inui, and Y. Kajihara, “Structural study of expanded fluid cesium,” Journal of Physics: Conference Series, vol. 98, no. 1, Article ID 012003, 2008.
[26]
K. Tamura, K. Matsuda, and M. Inui, “Structural and electronic properties of expanding fluid metals,” Journal of Physics: Condensed Matter, vol. 20, Article ID 114102, 2008.
[27]
V. Moeini, “Internal pressures of sodium, potassium, and rubidium fluids at different temperatures,” Journal of Chemical & Engineering Data, vol. 55, no. 12, pp. 5673–5680, 2010.
[28]
G. Parsafar and E. A. Mason, “Linear isotherms for dense fluids: a new regularity,” Journal of Physical Chemistry, vol. 97, no. 35, pp. 9048–9053, 1993.
[29]
G. Parsafar, V. Moeini, and G. Najafi, “Pressure dependency of liquid vapor pressure: gibbs prediction improvement,” Iranian Journal of Chemistry & Chemical Engineering, vol. 20, pp. 37–43, 2001.
[30]
http://webbook.nist.gov/chemistry/.
[31]
J. O. Hirschfelder, C. F. Curtiss, and R. B. Bird, Molecular Theory of Gases and Liquids, John Wiley & Sons, New York, NY, USA, 2nd edition, 1964.
[32]
Y. Ghayeb, B. Najafi, V. Moeini, and G. Parsafar, “Calculation of the viscosity of supercritical fluids based on the modified Enskog theory,” High Temperatures-High Pressures, vol. 35-36, no. 2, pp. 217–226, 2003.
