isobutane !short name (same as file name) 75-28-5 !CAS number 2-methylpropane R600a !synonym1 R-600a !synonym2 58.123 !molecular weight [g/mol] 113.55 !triple pt temperature [K] 261.537 !normal boiling pt [K] 407.85 !critical temperature [K] 3640. !critical pressure [kPa] 3.860 !critical density [mol/L] 0.18529 !acentric factor 0.132 !dipole moment [Debye]--DIPPR: from Nelson, NBS, NSRDS 10 (1967) IIR !default reference state 6.001 !version number ! compiled by M. McLinden, NIST Thermophysics Division, Boulder, Colorado ! 02-01-96 MM, original version ! 06-17-96 MM, add thermal conductivity coefficients fitted by S.A. Klein ! 07-08-96 MM, replace temporary Cp0 with function of Younglove & Ely ! 07-19-96 MM, fix bug on L-J flag for ECS-transport coeff ! 10-03-96 MM, add surface tension fit ! 10-18-96 MM, missing constant in dilute-gas viscosity model ! 10-24-96 MM, add thermal conductivity model of Younglove & Ely ! 10-25-96 MM, add collision integral of Younglove & Ely (needed for conductivity) ! missing Fv(1) in viscosity model ! 01-31-97 MM, change pointer for ECS reference viscosity from VS3 to VS1 ! 02-20-97 MM, add default reference state ! 02-21-97 MM, put viscosity model into revised VS2 format ! 02-26-97 MM, add version number and pointer to visc critical enhancement (both 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 ! 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 #EOS !equation of state specification BWR MBWR equation of state; Younglove & Ely (1987). ?LITERATURE REFERENCE \ ?Younglove, B.A. and Ely, J.F. Thermophysical properties of fluids. II. ? Methane, ethane, propane, isobutane and normal butane. ? J. Phys. Chem. Ref. Data 16:577-798 (1987).\ ? \ ?N.B. all temperatures on IPTS-68\ ? !end of info section 113.55 !lower temperature limit [K] 600.0 !upper temperature limit [K] 35000.0 !upper pressure limit [kPa] 12.81 !maximum density [mol/L] (rho on melting line at 35 MPa) CPP !pointer to Cp0 model 58.123d0 !molecular weight [g/mol] 113.55d0 !triple point temperature [K] 1.948d-5 !pressure at triple point [kPa] 12.755d0 !density at triple point [mol/L] 261.537d0 !normal boiling point temp [K] 0.18529d0 !acentric factor 407.85d0 3640.d0 3.860d0 !Tc [K], pc [kPa], rhoc [mol/L] 407.85d0 3.860d0 !reducing parameters [K, mol/L] 3.860d0 !gamma 0.0831434d0 !gas constant [L-bar/mol-K] 32 1 !Nterm, Ncoeff per term 0.1307325972d-01 0.3927802742d+00 -0.3185427394d+02 0.7608825192d+04 -0.1753919859d+07 -0.2090019755d-02 0.8959557971d+01 -0.6816710130d+04 -0.1111271045d+07 0.3248737572d-03 -0.1046526456d+01 0.6536598969d+03 0.3726503734d-01 0.8553649395d+01 0.2109987236d+04 -0.1401267363d+01 0.5213089327d-01 -0.1925026382d+02 0.7640067895d+00 0.3425854273d+07 -0.3373475924d+09 0.1180683444d+06 0.1529683738d+10 0.3323837416d+04 0.6423169487d+05 0.3891706042d+02 -0.1494755736d+07 -0.1720240173d-01 0.2894195375d+03 0.2005086329d-02 -0.4448393005d+00 0.8028488415d+02 #AUX !auxiliary model specification CPP ideal gas heat capacity function of Younglove & Ely ?LITERATURE REFERENCE \ ?Younglove, B.A. and Ely, J.F. ? Thermophysical properties of fluids. II. Methane, ethane, propane, isobutane ? and normal butane. J. Phys. Chem. Ref. Data 16:577-798 (1987).\ ?\ !end of info section 113.55 !lower temperature limit [K] 600.0 !upper temperature limit [K] 0.00 !upper pressure limit [kPa] 0.00 !maximum density [mol/L] 1.000 8.31434 !reducing parameters for T, Cp0 7 1 !Nterms: polynonial, exponential 1.7027919006d+7 -3.00d0 -4.7269724737d+5 -2.00d0 4.7301406581d+3 -1.00d0 -1.7231723278d+1 0.00d0 5.8491344291d-2 1.00d0 8.9440351886d-6 2.00d0 -1.8274599197d-8 3.00d0 -1.9283021962d+1 3000.d0 @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). \ ?\ ?Thermal conductivity and viscosity data used in the development of the ? extended corresponding states correlations were taken from:\ ?Younglove, B.A. and Ely, J.F. ? Thermophysical properties of fluids. II. Methane, ethane, propane, isobutane ? and normal butane. J. Phys. Chem. Ref. Data 16:577-798 (1987).\ ?\ ?the Lennard-Jones parameters are estimated ? !end of info section 113.55 !lower temperature limit [K] 600.0 !upper temperature limit [K] 35000.0 !upper pressure limit [kPa] 12.81 !maximum density [mol/L] (rho on melting line at 35 MPa) 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) 0.509217 !Lennard-Jones coefficient sigma [nm] 418. !Lennard-Jones 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 VS2 pure fluid viscosity model of Younglove & Ely (1987) ?LITERATURE REFERENCE \ ?Younglove, B.A. and Ely, J.F. Thermophysical properties of fluids. II. ? Methane, ethane, propane, isobutane and normal butane. ? J. Phys. Chem. Ref. Data 16:577-798 (1987). \ ?\ ?N.B. all temperatures on IPTS-68\ ? !end of info section 113.55 !lower temperature limit [K] 600.0 !upper temperature limit [K] 35000. !upper pressure limit [kPa] 12.81 !maximum density [mol/L] (rho on melting line at 35 MPa) CI2 !pointer to collision integral model 0.509217 !Lennard-Jones coefficient sigma [nm] 418. !Lennard-Jones coefficient epsilon/kB [K] 2.0352526600d-1 !const in Eq 19 = 5/16*(k*MW/1000/pi/Na)**0.5*1.0d12 1.6878386520d+0 !coeff for initial density dependence of viscosity (eq 21); Fv(1) 0.0 !Fv(2) 1.40 !Fv(3) 407.85 !Fv(4) -0.2055498053d+2 !coefficients for residual viscosity, eqs (22 - 25) 0.1357076181d+4 !Ev(2) 0.1893774336d+2 !Ev(3) -0.1822277344d+5 !Ev(4) -0.4599387773d-2 !Ev(5) 0.6305247065d+2 !Ev(6) 0.1282253921d+5 !Ev(7) NUL !pointer to critical enhancement auxiliary function (none used) #TCX !thermal conductivity model specification TC2 pure fluid thermal conductivity model of Younglove & Ely (1987) ?LITERATURE REFERENCE \ ?Younglove, B.A. and Ely, J.F. Thermophysical properties of fluids. II. ? Methane, ethane, propane, isobutane and normal butane. ? J. Phys. Chem. Ref. Data 16:577-798 (1987). \ ?\ ?N.B. all temperatures on IPTS-68\ ? !end of info section 113.55 !lower temperature limit [K] 600.0 !upper temperature limit [K] 35000. !upper pressure limit [kPa] 12.81 !maximum density [mol/L] (rho on melting line at 35 MPa) CI2 !pointer to collision integral model 0.509217 !Lennard-Jones coefficient sigma [nm] 418. !Lennard-Jones coefficient epsilon/kB [K] 2.0352526600d-01 !const in Eq 19 = 5/16*(k*MW/1000/pi/Na)**0.5*1.0d12 0.1449797353d+01 !dilute gas terms (Eq 27): Gt(1) -0.1685643887d+00 ! Gt(2) 0.4307008989d-02 !residual terms (Eqs 26, 28-30): Et(1) -0.1509010974d+01 0.4693712392d+03 -0.3554280979d-03 0.1841552874d+00 -0.3892338766d+02 -0.9354624917d-01 0.7114330590d+01 ! Et(8) TK2 !pointer to critical enhancement model (follows immediately) 0.0034718d0 !critical enhancement terms (Eqs D1-D4): X1 10.1207d0 0.466392d0 1.00344d0 ! X4 9.10218d-10 !Z 1.38054d-23 !Boltzmann's constant, k 1.6878386520d+0 !coeff for initial density dependence of viscosity (eq 21); Fv(1) 0.0 !Fv(2) 1.40 !Fv(3) 407.85 !Fv(4) -0.2055498053d+2 !coefficients for residual viscosity, eqs (22 - 25) 0.1357076181d+4 !Ev(2) (the viscosity is also used in conductivity correlation) 0.1893774336d+2 !Ev(3) -0.1822277344d+5 !Ev(4) -0.4599387773d-2 !Ev(5) 0.6305247065d+2 !Ev(6) 0.1282253921d+5 !Ev(7) #AUX !viscosity model specification CI2 collision integral model of Younglove & Ely (1987) ?LITERATURE REFERENCE \ ?Younglove, B.A. and Ely, J.F. Thermophysical properties of fluids. II. ? Methane, ethane, propane, isobutane and normal butane. ? J. Phys. Chem. Ref. Data 16:577-798 (1987).\ ?\ ?N.B. all temperatures on IPTS-68\ ? !end of info section 134.86 !lower temperature limit [K] 500.00 !upper temperature limit [K] 0.00 !(dummy) upper pressure limit 0.00 !(dummy) maximum density 9 !number of terms -3.0328138281 !Omega (eq 20): coeffs of {(e/kT)**((4-n)/3)} 16.918880086 !N.B. there is misprint in Younglove & Ely, the exponent -37.189364917 ! is ((4-n)/3) not ((n+2)/3) 41.288861858 -24.61592114 8.948843096 -1.8739245042 0.209661014 !N.B. wrong sign in Younglove & Ely, Table 2 -0.009657044 #STN !surface tension specification ST1 surface tension model ?LITERATURE REFERENCE \ ?Baidakov, V.G. and Sulla, I.I. (1985). Surface tension of propane and isobutane at ? near-critical temperatures. Russian Journal of Physical Chemistry 59: 551-554.\ ?\ !end info 113.55 !lower temperature limit [K] 407.85 !upper temperature limit [K] 0.00 !(dummy) upper pressure limit 0.00 !(dummy) maximum density 2 !number of terms 407.8d0 !critical temperature used by Baidakov & Sulla (dummy) 0.05756d0 1.290d0 !sigma0 and n -0.009554d0 2.290d0 @END c 1 2 3 4 5 6 7 8 c2345678901234567890123456789012345678901234567890123456789012345678901234567890