R152a !short name (same as file name) 75-37-6 !CAS number 1,1-difluoroethane HFC-152a !synonym1 R-152a !synonym2 66.051 !molecular weight [g/mol] 154.56 !triple pt temperature [K] 249.127 !normal boiling pt [K] 386.411 !critical temperature [K] 4516.75 !critical pressure [kPa] 5.571450 !critical density [mol/L] 0.27521 !acentric factor 2.262 !dipole moment [Debye]; Meyer & Morrison, J Phys Chem (1991) IIR !default reference state 6.001 !version number ! compiled by M. McLinden and S.A. Klein ! NIST Thermophysics Division, Boulder, Colorado ! 11-01-95 MM, original version ! 01-24-96 SAK, add transport models ! 03-13-96 MM, modify transport data to fit new program structure ! 03-15-96 MM, ditto + correct term in conductivity correlation ! 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 ! 01-21-97 MM, recast viscosity model in terms of new VS1 (composite model) ! 01-31-97 MM, change pointer for ECS reference viscosity from VS3 to VS1 ! 02-07-97 MM, recast thermal cond model of Perkins into new TC1 form ! 02-20-97 MM, add default reference state ! 02-26-97 MM, put t.c. critical enhancement into TK1 form ! 02-26-97 MM, add version number and pointer to visc critical enhancement (both future use) ! 03-06-97 MM, modify ECS-transport to new format ! 03-20-97 MM, use Krauss correlation for thermal conductivity (at least temp) ! N.B. critical enhancement not yet implemented ! 03-25-97 MM, set Psi,Chi coeff in ECS-transport to 1,0 pending refit of data ! go back to Perkins t.c. correlation ! 05-14-97 MM, change power of T in collision integral to integer ! 08-21-97 MM, purge exponentials from values read by GUI (e.g. model limits) ! 09-23-97 MM, add critical enhancement for Krauss t.c. corr and use it ! 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 #EOS !equation of state specification BWR MBWR equation of state; Outcalt & McLinden (1995). ?LITERATURE REFERENCE \ ?S.L. Outcalt and M.O. McLinden. A modified Benedict-Webb-Rubin equation of ? state for the thermodynamic properties of R152a (1,1-difluoroethane). ? accepted for publication in J. Phys. Chem. Ref. Data vol. 25 (1996). \ ?\ ?ABSTRACT \ ?A modified Benedict-Webb-Rubin (MBWR) equation of state has been developed for ? R152a (1,1-difluoroethane). The correlation is based on a selection of ? available experimental thermodynamic property data. Single-phase ? pressure-?volume-temperature (PVT), heat capacity, and sound speed data, as well ? as second virial coefficient, vapor pressure, and saturated liquid and saturated ? vapor density data, were used with multi-property linear least-squares fitting ? to determine the 32 adjustable coefficients of the MBWR equation. Ancillary ? equations representing the vapor pressure, saturated liquid and saturated ? vapor densities, and the ideal gas heat capacity were determined. ? Coefficients for the equation of state and the ancillary equations are given. ? Experimental data used in this work covered temperatures from 162 K to 453 K ? and pressures to 35 MPa. The MBWR equation established in this work may be ? used to predict thermodynamic properties of R152a from the triple-point ? temperature of 154.56 K to 500 K and for pressures up to 60 MPa except in the ? immediate vicinity of the critical point.\ ?\ !end of info section 154.56 !lower temperature limit [K] 500.0 !upper temperature limit [K] 60000.0 !upper pressure limit [kPa] 18.07 !maximum density [mol/L] CPP !pointer to Cp0 model 66.051d0 !molecular weight [g/mol] 154.56d0 !triple point temperature [K] 0.0641d0 !pressure at triple point [kPa] 18.061d0 !density at triple point [mol/L] 249.127d0 !normal boiling point temp [K] 0.27521d0 !acentric factor 386.411d0 4516.75d0 5.57145d0 !Tc [K], pc [kPa], rhoc [mol/L] 386.411d0 5.57145d0 !reducing parameters [K, mol/L] 5.57145d0 !gamma 0.08314471d0 !gas constant [L-bar/mol-K] 32 1 !Nterm, Ncoeff per term -0.101623317192d-01 0.215677129618d+01 -0.648581254334d+02 0.122535596303d+05 -0.206805988259d+07 -0.379836507323d-03 -0.441333232984d+00 0.158248874708d+03 0.564062216256d+06 -0.124115350431d-03 0.494972178825d+00 -0.208058039834d+03 -0.131403187106d-01 0.212083848812d+00 -0.151263785082d+03 0.311108025395d-01 -0.115280979645d-02 0.437040025765d+00 -0.965596535032d-02 -0.242705525346d+06 -0.518042519989d+08 -0.119070545681d+05 0.459333195257d+09 -0.719317286511d+02 -0.840102861460d+04 -0.102910957390d+01 -0.325913880841d+05 -0.412362182230d-02 0.175102808144d+01 -0.198636624640d-04 -0.421363036104d-02 -0.198696760653d+01 #AUX !auxiliary model specification CPP polynomial fit for ideal gas heat capacity; Outcalt & McLinden (1996). ?LITERATURE REFERENCE \ ?S.L. Outcalt and M.O. McLinden. A modified Benedict-Webb-Rubin equation of ? state for the thermodynamic properties of R152a (1,1-difluoroethane). ? accepted for publication in J. Phys. Chem. Ref. Data vol. 25 (1996). \ ?\ !end of info section 150.0 !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 27.89465d0 0.00 !c(i), power of T 9.134686d-2 1.00 2.079961d-4 2.00 -2.317613d-7 3.00 @TRN !transport model specification ECS Extended Corresponding States model for transport props (R134a ref. fluid). ?LITERATURE REFERENCES \ ?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). \ ? !end of info section 240.0 !lower temperature limit [K] 430.0 !upper temperature limit [K] 60000.0 !upper pressure limit [kPa] 15.90 !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) 0.46115 !Lennard-Jones coefficient sigma [nm] 354.84 !L-J coefficient epsilon/kB [K] 1 0 0 !number of terms in f_int term in Eucken correlation, spare1, spare 2 1.3200d-3 0.0 0.0 0.0 !coeff, power of T, spare 1, spare 2 0 0 0 !number of terms in psi (visc shape factor): poly,spare1,spare2 0 0 0 !number of terms in chi (t.c. shape factor): poly,spare1,spare2 #ETA !viscosity model specification VS1 pure fluid viscosity model of Kraus et al. (1996). ?LITERATURE REFERENCE \ ?Krauss, R., Weiss, V.C., Edison, T.A., Sengers, J.V. and Stephan, K. (1996). ? Transport properties of 1,1-Difluoroethane (R152a). Int. J. Thermophysics ? 17: 731-757.\ ?\ !end of info section 240.0 !lower temperature limit [K] 440.0 !upper temperature limit [K] 20000.0 !upper pressure limit [kPa] 15.90 !maximum density [mol/L] 1 !number of terms associated with dilute-gas function CI1 !pointer to reduced effective collision cross-section model 0.46115 !Lennard-Jones coefficient sigma [nm] 354.84 !Lennard-Jones coefficient epsilon/kB [K] 1.0d0 1.0d0 !reducing parameters for T, eta 0.2169614d0 0.5d0 !Chapman-Enskog term 0 !number of terms for initial density dependence 0 5 1 2 0 0 !# resid terms: close-packed density; simple poly; numerator of rational poly; demoninator of rat. poly; numer of exponential; demon exponential 1.0d0 5.571537d0 51.12d0 !reducing parameters for T, rho (= 368 kg/m^3, note: Krauss uses MW = 66.05), eta (= the pseudo-critical viscosity) -0.139987d+0 0.00 0.00 0.00 0 !E5*E6; powers of tau, del, del0; power of del in exponential [0 indicated no exponential term present] -0.737927d-1 0.00 1.00 0.00 0 !E1 0.517924d+0 0.00 2.00 0.00 0 !E2 -0.308875d+0 0.00 3.00 0.00 0 !E3 0.108049d+0 0.00 4.00 0.00 0 !E4 -0.408387d+0 0.00 0.00 0.00 0 !E5 -2.917330d+0 0.00 0.00 0.00 0 !-E6 term in denominator 1.000000d+0 0.00 1.00 0.00 0 !rho/rhoc term in denominator NUL !pointer to critical enhancement auxiliary function (none used) #AUX !collision integral model specification CI1 collision integral model (empirical form in terms of log(T*)) ?LITERATURE REFERENCE \ ?Krauss, R., Weiss, V.C., Edison, T.A., Sengers, J.V. and Stephan, K. (1996). ? Transport properties of 1,1-Difluoroethane (R152a). Int. J. Thermophysics ? 17: 731-757.\ ?\ !end of info section 240.0 !lower temperature limit [K] 440.0 !upper temperature limit [K] 0.00 !(dummy) upper pressure limit 0.00 !(dummy) maximum density 5 !number of terms 0.4425728d+0 0 !coeff, power of Tstar -0.5138403d+0 1 0.1547566d+0 2 -0.2821844d-1 3 0.1578286d-2 4 #TCX !thermal conductivity model specification TC1 pure fluid thermal conductivity model of Kraus et al. ?LITERATURE REFERENCE \ ?Krauss, R., Weiss, V.C., Edison, T.A., Sengers, J.V. and Stephan, K. (1996). ? Transport properties of 1,1-Difluoroethane (R152a). Int. J. Thermophysics ? 17: 731-757.\ ? !end of info section 160.0 !lower temperature limit [K] !Krauss claims only 240 K, but seems to extrapolate fine 440.0 !upper temperature limit [K] 20000.0 !upper pressure limit [kPa] 17.91 !maximum density [mol/L] 2 0 !# terms for dilute gas function: numerator, denominator 1.0d0 1.0d-3 !reducing parameters for T, tcx [Krauss corr in mW/m.K] -1.49420d+01 0.00d0 !coeff, power in T 9.73283d-02 1.00d0 4 0 !# terms for background gas function: numerator, denominator 1.0d0 5.571450d0 1.115d-03 !reducing par for T, rho (rho_c), tcx 9.18090d+00 0.00d0 1.00d0 0.00d0 !coeff, powers of t, rho, spare for future use 1.18577d+01 0.00d0 2.00d0 0.00d0 -5.44730d+00 0.00d0 3.00d0 0.00d0 1.71379d+00 0.00d0 4.00d0 0.00d0 TK3 !pointer to critical enhancement auxiliary function #AUX !thermal conductivity critical ehancement model TK3 simplified thermal conductivity critical enhancement of Olchowy & Sengers ?LITERATURE REFERENCE\ ?Olchowy, G.A. and Sengers, J.V. (1989). A simplified representation for ? the thermal conductivity of fluids in the critical region. ? Int. J. Thermophysics 10: 417-426.\ ?\ ?as applied to R134a by:\ ?Krauss, R., Weiss, V.C., Edison, T.A., Sengers, J.V. and Stephan, K. (1996). ? Transport properties of 1,1-Difluoroethane (R152a). Int. J. Thermophysics ? 17: 731-757.\ ?\ !end of info section 160.0 !lower temperature limit [K] 440.0 !upper temperature limit [K] 20000.0 !upper pressure limit [kPa] 17.91 !maximum density [mol/L] 9 0 0 0 !# terms: critical-terms, spare, spare, spare 1.0d0 1.0d0 1.0d0 !reducing par for T, rho, tcx 0.630d+00 !gnu (universal exponent) 1.239d+00 !gamma (universal exponent) 1.03d+00 !R0 (universal amplitude) 0.063d+00 !z (universal exponent--not used for t.c., only viscosity) 1.075d+00 !c (constant in viscosity eqn = 1/[2 - (alpha + gamma)/(2*nu)], but often set to 1) 1.894d-10 !xi0 (amplitude) [m] 0.0487d+00 !gam0 (amplitude) [-] 4.37d-10 !qd_inverse (modified effective cutoff parameter) [m] 579.617d+00 !tref (reference temperature) [= 1.5 * 386.411 K] #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 154.56 !lower temperature limit [K] (Okada lists 273 K, should extrapolate) 386.411 !upper temperature limit [K] 0.00 !(dummy) upper pressure limit 0.00 !(dummy) maximum density 1 !number of terms 386.41d0 !critical temperature used by Okada & Higashi (dummy) 0.05906d0 1.221d0 !sigma0 and n @END c 1 2 3 4 5 6 7 8 c2345678901234567890123456789012345678901234567890123456789012345678901234567890