Thermodynamic Properties of R-32, Difluoromethane

Temperature Pressure Density Volume Int. energy Enthalpy Entropy C, CF Sound speed Joule-Thomson Therm, cond. 

Temperature K Pressure MPa Density mol/dm3 Volume dm3/mol Int. energy kj/mol Enthalpy kj/mol Entropy kJ/(mol-K) Cv kJ/(mol-K) C, kJ/(mol-K) Sound speed m/s Joule-Thomson K/MPa Therm, cond. mW/(m K) 

The values in these tables were generated from the NIST REFPROP software (Lemmon, E. W., McLinden, M. O., and Huber, M. L., NIST Standard Reference Database 23 Reference Fluid Thermodynamic and Transport Properties—REFPROP, National Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, Md., 2002, Version 7.1). The primary source for the thermodynamic properties is Tillner-Roth, R., and Yokozeki, A., 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, /. Phys. Chem. Ref. Data 26(6) 1273-1328,1997. Validated equations for the viscosity are not currently available for this fluid. The source for thermal conductivity is unpublished however, the fit uses the functional form found in Marsh, K., Perkins, R., and Ramires, M. L. V., Measurement and Correlation of the Thermal Conductivity of Propane from 86 to 600 K at Pressures to 70 MPa, /. Chem. Eng. Data 47(4) 932-940, 2002. 

For the equation of state, typical uncertainties are 0.05% for density, 0.02% for the vapor pressure, and 0.5% to 1% for the heat capacity and speed of sound in the liquid phase. In the vapor phase, the uncertainty in the speed of sound is 0.02%. For thermal conductivity, the estimated uncertainty of the correlation is 5%, except for the dilute gas and points approaching critical where the uncertainty rises to 10%. 

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