R32 !short name (same as file name) 75-10-5 !CAS number difluoromethane HFC-32 !synonym1 R-32 !synonym2 52.024 !molecular weight [g/mol] 136.34 !triple pt temperature [K] 221.499 !normal boiling pt [K] 351.255 !critical temperature [K] 5782. !critical pressure [kPa] 8.1500846 !critical density [mol/L] 0.27680 !acentric factor 1.978 !dipole moment [Debye]; Meyer & Morrison JCED 36:409 (1991) IIR !default reference state 6.001 !version number ! compiled by M. McLinden, NIST Thermophysics Division, Boulder, Colorado ! 11-01-95 MM, original version ! 03-17-96 MM, add transport correlations compiled by S.A. Klein ! 03-18-96 MM, add dipole moment ! 06-17-96 MM, add ECS-thermal conductivity coefficients fitted by S.A. Klein ! 08-19-96 MM, add surface tension fit ! 01-31-97 MM, change pointer for ECS reference viscosity from VS3 to VS1 ! 02-20-97 MM, add default reference state ! 02-26-97 MM, add version number (future use) ! 03-11-97 MM, modify ECS-transport to new format ! 03-25-97 MM, set Psi,Chi coeff in ECS-transport to 1,0 pending refit of data ! 05-15-97 EWL, add parameters for ECS viscosity correlation ! 05-23-97 EWL, change default EOS to that of Tillner-Roth ! 08-21-97 MM, purge exponentials from values read by GUI (e.g. model limits) ! 10-24-97 MM, read in f_int term in Eucken correlation in ECS method for t.c. ! change reference fluid EOS for ECS-transport from BWR to FEQ ! 11-13-97 MM, enter thermal conductivity shape factor fitted to data #EOS !equation of state specification FEQ fundamental (Helmholtz) equation of state; Tillner-Roth & Yokozeki (1997). ?LITERATURE REFERENCE \ ?R. Tillner-Roth and A. Yokozeki. An international standard equation of state ? for difluoromethane (R-32) for temperatures from the triple point at 136.34 K ? to 435 K and pressures up to 70 MPa. ? Submitted to J. Phys. Chem. Ref. Data, (1997).\ ?\ !end of info section 136.340 !lower temperature limit [K] 435.000 !upper temperature limit [K] 70000.0 !upper pressure limit [kPa] 27.4734 !maximum density [mol/L] CPP !pointer to Cp0 model 52.024 !molecular weight [g/mol] 136.34 !triple point temperature [K] 0.480d-1 !pressure at triple point [kPa] 27.4734 !density at triple point [mol/L] 221.499 !normal boiling point temperature [K] 0.27680 !acentric factor 351.255 5782.0 8.1500846 !Tc [K], pc [kPa], rhoc [mol/L] 351.255 8.1500846 !reducing parameters [K, mol/L] 8.314471 !gas constant [J/mol-K] 19 4 0 0 0 0 !# terms, # coeff/term for: "normal" terms, critical, spare 0.1046634d+1 0.250 1.00 0 !a(i),t(i),d(i),l(i) -0.5451165d+0 1.000 2.00 0 -0.2448595d-2 -0.250 5.00 0 -0.4877002d-1 -1.000 1.00 0 0.3520158d-1 2.000 1.00 0 0.1622750d-2 2.000 3.00 0 0.2377225d-4 0.750 8.00 0 0.2914900d-1 0.250 4.00 0 0.3386203d-2 18.000 4.00 4 -0.4202444d-2 26.000 4.00 3 0.4782025d-3 -1.000 8.00 1 -0.5504323d-2 25.000 3.00 4 -0.2418396d-1 1.750 5.00 1 0.4209034d+0 4.000 1.00 2 -0.4616537d+0 5.000 1.00 2 -0.1200513d+1 1.000 3.00 1 -0.2591550d+1 1.500 1.00 1 -0.1400145d+1 1.000 2.00 1 0.8263017d+0 0.500 3.00 1 #AUX !auxiliary model specification CPP ideal gas heat capacity; Tillner-Roth & Yokozeki (1997). ?LITERATURE REFERENCE \ ?R. Tillner-Roth and A. Yokozeki. An international standard equation of state ? for difluoromethane (R-32) for temperatures from the triple point at 136.34 K ? to 435 K and pressures up to 70 MPa. ? Submitted to J. Phys. Chem. Ref. Data, (1997).\ ?\ !end of info section 136.34 !lower temperature limit [K] 435.00 !upper temperature limit [K] 0.0000 !upper pressure limit [kPa] 0.0000 !maximum density [mol/L] 1.0000000 8.3144710 !reducing parameters for T, Cp0 1 4 !Nterms: polynonial, exponential 0.4004486d+1 0.00d0 0.1160761d+1 798.00d0 0.2645151d+1 4185.00d0 0.5794987d+1 1806.00d0 0.1129475d+1 11510.00d0 @EOS !equation of state specification BWR MBWR equation of state; Outcalt & McLinden (1995). ?LITERATURE REFERENCE \ ?S.L. Outcalt and M.O. McLinden. Equations of state for the thermodynamic ? properties of R32 (difluoromethane) and R125 (pentafluoroethane). ? Int. J. Thermophysics 16, 79-89 (1995). \ ?\ ?ABSTRACT \ ?Thermodynamic properties of difluoromethane (R32) and pentafluoroethane (R125) ? are expressed in terms of 32-term modified Benedict-Webb-Rubin (MBWR) ? equations of state. For each refrigerant, coefficients are reported for the ? MBWR equation and for ancillary equations used to fit the ideal-gas heat ? capacity and the coexisting densities and pressure along the saturation ? boundary. The MBWR coeffients were determined with a multiproperty fit that ? used the following types of experimental data: PVT; isochoric, isobaric, and ? saturated-liquid heat capacities; second virial coefficients; and properties ? at coexistence. The respective equations of state accurately represent ? experimental data from 160 to 393 K and pressures to 35 MPa for R32 and from ? 174 to 448 K and pressures to 68 MPa for R125 with the exception of the ? critical regions. Both equations give reasonable results upon extrapolation ? to 500 K and 60 MPa. Comparisons between predicted and experimental values ? are presented.\ ?\ !end of info section 136.34 !lower temperature limit [K] 500.0 !upper temperature limit [K] 60000.0 !upper pressure limit [kPa] 27.48 !maximum density [mol/L] CP1 !pointer to Cp0 model 52.024d0 !molecular weight [g/mol] 136.34d0 !triple point temperature [K] 0.0477d0 !pressure at triple point [kPa] 27.47d0 !density at triple point [mol/L] 221.494d0 !normal boiling point temp [K] 0.27680d0 !acentric factor 351.35d0 5795.d0 8.2078d0 !Tc [K], pc [kPa], rhoc [mol/L] 351.35d0 8.2078d0 !reducing parameters [K, mol/L] 8.2078d0 !gamma 0.08314471d0 !gas constant [L-bar/mol-K] 32 1 !Nterm, Ncoeff per term -0.131275405202d-03 0.899927934911d+00 -0.281400805178d+02 0.436091182784d+04 -0.837235280004d+06 -0.782176408963d-06 -0.111226606825d+01 0.539331431878d+03 0.288600276863d+06 -0.352264609289d-04 0.189661830119d+00 -0.686549003993d+02 -0.349007064245d-02 -0.749983559476d-01 -0.321524283063d+02 0.913057921906d-02 -0.171082181849d-03 0.503986984347d-01 -0.830354867752d-03 -0.245522676708d+06 -0.107859056038d+08 -0.429514279646d+04 0.808724729567d+08 -0.125945229993d+02 -0.105735009761d+04 -0.904064745354d-01 -0.183578733048d+04 -0.169690612464d-03 0.639250820631d-01 -0.204925767440d-06 -0.165629700870d-03 -0.932607493424d-02 #AUX !auxiliary model specification CP1 polynomial fit for ideal gas heat capacity; Outcalt & McLinden (1995). ?LITERATURE REFERENCE \ ?S.L. Outcalt and M.O. McLinden. Equations of state for the thermodynamic ? properties of R32 (difluoromethane) and R125 (pentafluoroethane). ? Int. J. Thermophysics 16, 79-89 (1995). \ ?\ !end of info section 120.0 !lower temperature limit [K] 500.0 !upper temperature limit [K] 0.00 !upper pressure limit [kPa] 0.00 !maximum density [mol/L] 1.000 1.000 !reducing parameters for T, Cp0 4 0 !Nterms: polynonial, exponential 36.79959d0 0.00 !c(i), power of T -0.06304821d0 1.00 3.757936d-4 2.00 -3.219812d-7 3.00 #TRN !transport model specification ECS Extended Corresponding States model for transport props (R134a reference). ?LITERATURE REFERENCES FOR THE ECS MODEL \ ?Klein, S.A., McLinden, M.O. and Laesecke, A. (1997). An improved extended ? corresponding states method for estimation of viscosity of pure refrigerants ? and mixtures. Int. J. Refrigeration 20: 208-217. \ ?\ ?Huber, M.L., Friend, D.G. and Ely, J.F. Prediction of the thermal ? conductivity of refrigerants and refrigerant mixtures. ? Fluid Phase Equilibria 80: 249-261 (1992). \ ?\ ?DATA SOURCES FOR THERMAL CONDUCTIVITY\ ?The ECS parameters for thermal conductivity were based on the data of:\ ?\ ?Grebenkov, A.J., Kotelevsky, Y.G., Saplitza, V.V., Beljaeva, O.V., ? Zajatz, T.A. and Timofeev, B.D. (1994). Experimental study of thermal ? conductivity of some ozone safe refrigerants and speed of sound in ? their liquid phase. CFCs: The Day After, Joint Meeting of IIR ? Commissions B1, B2, E1, and E2, Padova, Italy, September 21-23, ? IIR, 419-429.\ ?\ ?Perkins, R.A., Laesecke, A., Howley, J.B., Huber, M.L. and ? Nieto de Castro, C.A. (1998). Experimental thermal conductivity and ? thermal diffusivity values for R32, R125, and R134a. National ? Institute of Standards and Technology, NISTIR (in preparation).\ ?\ ?average absolute deviations of the fit from the experimental data were:\ ? Grebenkov: 9.62%; Perkins: 3.17%; overall: 3.45%\ ?\ ?DATA SOURCES FOR VISCOSITY\ ?The ECS parameters for viscosity were based on the data of:\ ?Assael, M.J., Dymond, J.H. and Polimatidou, S.K. (1994). Measurements of the ? viscosity of R134a and R32 in the temperature range 270 - 340 K at pressures ? up to 20 MPa. Int. J. Thermophysics 15: 591-601.\ ?\ ?Bivens, D.B., Yokozeki, A., Geller, V.Z. and Paulaitis, M.E. (1993). ? Transport properties and heat transfer of alternatives for R502 and R22. ? ASHRAE/NIST Refrigerants Conference, August 19-20, Gaithersburg, MD, 73-84.\ ?\ ?Takahashi, M., Shibasaki-Kitakawa, N., Yokoyama, C. and Takahashi, S. ? (1995). Gas viscosity of difluoromethane from 298.15 K to 423.15 K and up ? to 10 MPa. J. Chem. Eng. Data 40: 900-902.\ ?\ ?average absolute deviations of the fit from the experimental data were:\ ? Assael: 0.40%; Bivens: 4.06%; Takahashi: 1.29%; overall: 2.23%\ ?\ ?Lennard-Jones parameters are based on the low-density viscosity data of ? Takahashi. ? !end of info section 136.34 !lower temperature limit [K] 500.0 !upper temperature limit [K] 60000.0 !upper pressure limit [kPa] 27.48 !maximum density [mol/L] FEQ R134a.fld VS1 !model for reference fluid viscosity TC1 !model for reference fluid thermal conductivity 1 !Lennard-Jones flag (0 or 1) (0 => use estimates) 0.4098 !Lennard-Jones coefficient Sigma [nm] 289.65 !L-J coefficient epsilon/kB [K] 2 0 0 !number of terms in f_int term in Eucken correlation, spare1, spare 2 8.1980d-4 0.0 0.0 0.0 !coeff, power of T, spare 1, spare 2 2.2352d-7 1.0 0.0 0.0 2 0 0 !number of terms in psi (visc shape factor): poly,spare1,spare2 0.8647570 0.0 0.0 0.0 !coeff, power of Tr, power of Dr, spare 0.0226451 0.0 1.0 0.0 2 0 0 !number of terms in chi (t.c. shape factor): poly1,poly2,spare 1.2325d+0 0.0 0.0 0.0 !coeff, power of Tr, power of Dr, spare -8.8394d-2 0.0 1.0 0.0 #STN !surface tension specification ST1 surface tension model ?LITERATURE REFERENCE \ ?Okada, M. and Higashi, Y. (1995). Experimental surface tensions for ? HFC-32, HCFC-124, HFC-125, HCFC-141b, HCFC-142b, and HFC-152a. ? Int. J. Thermophysics 16(3): 791-800.\ ?\ !end info 136.34 !lower temperature limit [K] (Okada lists 273 K, should extrapolate) 351.35 !upper temperature limit [K] 0.00 !(dummy) upper pressure limit 0.00 !(dummy) maximum density 1 !number of terms 351.26d0 !critical temperature used by Okada & Higashi (dummy) 0.07216d0 1.252d0 !sigma0 and n @END c 1 2 3 4 5 6 7 8 c2345678901234567890123456789012345678901234567890123456789012345678901234567890