What the Thermophysical Property Community Should Know About Temperature Scales

Harvey, Allan H.

doi:10.1007/s10765-021-02915-9

Cited by 7 publications

(9 citation statements)

References 48 publications

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“…While it is by no means guaranteed, in this case, the threephase solution is in very good agreement with experimental data from the literature, because the thermodynamic model represents the experimental data well. The isotherm temperature was selected, because it matches a temperature measured by Llave et al 31 (after conversion to the ITS-90 temperature scale 32 ) and is below the critical temperature for both fluids.…”

Section: Algorithmmentioning

confidence: 99%

Algorithm to Identify Vapor–Liquid–Liquid Equilibria of Binary Mixtures from Vapor–Liquid Equilibria

Bell

Deiters

Jäger

2022

Ind. Eng. Chem. Res.

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In this work, we demonstrate that tracing the vapor−liquid equilibria for binary mixtures also includes all the information needed to obtain the three-phase line if one is present. This simple observation serves as a launching point for calculation of the liquid−liquid equilibrium and threephase equilibria, even when one component is supercritical. We close with the demonstration of the automatic construction of an isothermal pressure− composition figure, a capability enabled by solving for the three-phase state. The scripts in the Supporting Information demonstrate in detail how the method is applied.

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Section: Algorithmmentioning

confidence: 99%

Algorithm to Identify Vapor–Liquid–Liquid Equilibria of Binary Mixtures from Vapor–Liquid Equilibria

Bell

Deiters

Jäger

2022

Ind. Eng. Chem. Res.

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“…However, several years ago it was recognized that there was still significant room for improvement in the equation of state. In particular, insufficient attention had been paid to the nuances of cryogenic temperature scales; some conversions to the International Temperature Scale of 1990 (ITS-90) [3,4] were not performed correctly and the equation of state did not satisfy the relationship between temperature and vapor pressure that forms part of the definition of ITS-90. In addition, some cryogenic density data that were taken with a dielectric method had not been corrected for improved knowledge of the dielectric polarizability of helium [5] that should supersede the 1950s values used in the original experimental papers.…”

Section: Background Of This Reportmentioning

confidence: 99%

“…Helium exists as two stable isotopes: 3 He, which contains one neutron, and 4 He with two neutrons. The low-temperature behavior of 3 He differs greatly from that of 4 He because 3 He obeys Fermi-Dirac quantum statistics as opposed to the Bose-Einstein statistics of 4 He.…”

Section: Introductionmentioning

confidence: 99%

An equation of state for the thermodynamic properties of helium

Harvey

2023

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This report documents the equation of state for fluid helium implemented in Version 10 of NIST's REFPROP Standard Reference Database. The equation of state is expressed as the molar Helmholtz energy as a function of temperature and density, and is valid for the normal fluid (helium I) up to 1500 K and 2000 MPa. Limited comparisons with experimental data and with virial coefficients calculated by ab initio methods are provided.

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“…At outer limit levels of the thermosphere, however, the rarity of the atmosphere makes measurement of an experimental T(z) by conventional means more difficult. It is necessary to bring the air into thermal equilibrium with the surface of a thermometer that is calibrated to a specific scale [23]. This process takes time.…”

Section: Thermosphere Measurementsmentioning

confidence: 99%

“…Given the definition of a T-scale [23], and the principles of thermal (T) and mechanical (p) equilibrium:…”

Section: Conflicts Of Interestmentioning

confidence: 99%

Disquisitions Relating to Principles of Thermodynamic Equilibrium in Climate Modelling

Woodcock

2022

Entropy

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We revisit the fundamental principles of thermodynamic equilibrium in relation to heat transfer processes within the Earth’s atmosphere. A knowledge of equilibrium states at ambient temperatures (T) and pressures (p) and deviations for these p-T states due to various transport ‘forces’ and flux events give rise to gradients (dT/dz) and (dp/dz) of height z throughout the atmosphere. Fluctuations about these troposphere averages determine weather and climates. Concentric and time-span average values <T> (z, Δt)) and its gradients known as the lapse rate = d < T(z) >/dz have hitherto been assumed in climate models to be determined by a closed, reversible, and adiabatic expansion process against the constant gravitational force of acceleration (g). Thermodynamics tells us nothing about the process mechanisms, but adiabatic-expansion hypothesis is deemed in climate computer models to be convection rather than conduction or radiation. This prevailing climate modelling hypothesis violates the 2nd law of thermodynamics. This idealized hypothetical process cannot be the causal explanation of the experimentally observed mean lapse rate (approx.−6.5 K/km) in the troposphere. Rather, the troposphere lapse rate is primarily determined by the radiation heat-transfer processes between black-body or IR emissivity and IR and sunlight absorption. When the effect of transducer gases (H2O and CO2) is added to the Earth’s emission radiation balance in a 1D-2level primitive model, a linear lapse rate is obtained. This rigorous result for a perturbing cooling effect of transducer (‘greenhouse’) gases on an otherwise sunlight-transducer gas-free troposphere has profound implications. One corollary is the conclusion that increasing the concentration of an existing weak transducer, i.e., CO2, could only have a net cooling effect, if any, on the concentric average <T> (z = 0) at sea level and lower troposphere (z < 1 km). A more plausible explanation of global warming is the enthalpy emission ’footprint’ of all fuels, including nuclear.

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What the Thermophysical Property Community Should Know About Temperature Scales

Cited by 7 publications

References 48 publications

Algorithm to Identify Vapor–Liquid–Liquid Equilibria of Binary Mixtures from Vapor–Liquid Equilibria

Algorithm to Identify Vapor–Liquid–Liquid Equilibria of Binary Mixtures from Vapor–Liquid Equilibria

An equation of state for the thermodynamic properties of helium

Disquisitions Relating to Principles of Thermodynamic Equilibrium in Climate Modelling

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