ianhbell
commented
3 years ago I believe the implemented models are not the same. The webbook uses a rather old version of REFPROP behind the scenes
Metadata from the webbook
Equation of state and auxiliary model Leachman, J.W.; Jacobsen, R.T.; Lemmon, E.W., Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen, to be published in J. Phys. Chem. Ref. Data, 2008. [all data]
Auxiliary model and surface tension McCarty, R.D.; Hord, J.; Roder, H.M., Selected Properties of Hydrogen (Engineering Design Data), NBS Monograph 168, National Bureau of Standards, Boulder, CO, 1981, 0. [all data]
Thermal conductivity and dielectric constant Kunz, O.; Klimeck, R.; Wagner, W.; Jaeschke, M., The GERG-2004 Wide-Range Reference Equation of State for Natural Gases and Other Mixtures, to be published as a GERG Technical Monograph, Fortschr.-Ber. VDI, VDI-Verlag, Düsseldorf, 2006. [all data]
Additional Information Equation of state The uncertainty in density is 0.1% at temperatures from the triple point to 250 K and at pressures up to 40 MPa, except in the critical region, where an uncertainty of 0.2% in pressure is generally attained. In the region between 250 and 450 K and at pressures from 0.1 to 300 MPa, the uncertainty in density is 0.04%. At temperatures between 450 and 1000 K, the uncertainty in density increases to 1%. At pressures between 300 and 2000 MPa, the uncertainty in density is 8%. Speed of sound data are represented within 0.5% below 100 MPa. The estimated uncertainty for heat capacities is 1.0%. The estimated uncertainties of vapor pressures and saturated liquid densities calculated using the Maxwell criterion are 0.2% for each property.
Thermal conductivity The uncertainty in thermal conductivity below 100 K is estimated to be 3% below 150 atm and up to 10% below 700 atm. For temperatures around 100 K at low densities, the uncertainty is about 1%. Above 100 K, the uncertainty is estimated to be on the order of 10%.
Viscosity The uncertainty in viscosity ranges from 4% to 15%.
And from REFPROP 10:
Assael, M.J., Assael, J.-A.M., Huber, M.L., Perkins, R.A., and Takata, Y., "Correlation of the Thermal Conductivity of Normal and Parahydrogen from the Triple Point to 1000 K and up to 100 MPa," J. Phys. Chem. Ref. Data, 40(3), 033101, 2011.
The estimated uncertainty is less than 4% from 100 K to 1000 K at pressures to 100 MPa. For temperatures from the triple point to 100 K, at pressures to 12 MPa, we estimate the uncertainty to be 7%, except near the critical point. The model behaves in a physically reasonable manner for extrapolations to pressures above 12 MPa at temperatures below 100 K, but will be subject to larger uncertainties.
arnaudcharolais
Description
Looking at the thermal conductivity of hydrogen in Refprop 9.1 and the NIST Webbook website, I find it varies by up to 12%. I didn’t find any other issue resolving the problem, but it may be related to issue #376.
Steps to Reproduce
Expected behavior: Get the same results
Actual behavior: Differences between the two methods appear, increasing with the temperature
Versions
REFPROP Version: 9.1 Operating System and Version: Windows 10 Access Method: Python CoolProp wrapper
Additional Information