The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use
07 Jun 2002-Journal of Physical and Chemical Reference Data (American Institute of Physics for the National Institute of Standards and Technology)-Vol. 31, Iss: 2, pp 387-535
TL;DR: The International Association for the Properties of Water and Steam (IAPWS) adopted a new formulation called "The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use" as discussed by the authors.
Abstract: In 1995, the International Association for the Properties of Water and Steam (IAPWS) adopted a new formulation called “The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use”, which we abbreviate to IAPWS-95 formulation or IAPWS-95 for short. This IAPWS-95 formulation replaces the previous formulation adopted in 1984. This work provides information on the selected experimental data of the thermodynamic properties of water used to develop the new formulation, but information is also given on newer data. The article presents all details of the IAPWS-95 formulation, which is in the form of a fundamental equation explicit in the Helmholtz free energy. The function for the residual part of the Helmholtz free energy was fitted to selected data for the following properties: (a) thermal properties of the single-phase region (pρT) and of the vapor–liquid phase boundary (pσρ′ρ″T), including the phase-equilibrium condition (Maxwell criterion), and (b) t...
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TL;DR: A potential model intended to be a general purpose model for the condensed phases of water is presented, which gives excellent predictions for the densities at 1 bar with a maximum density at 278 K and an averaged difference with experiment of 7 x 10(-4) g/cm3.
Abstract: A potential model intended to be a general purpose model for the condensed phases of water is presented. TIP4P/2005 is a rigid four site model which consists of three fixed point charges and one Lennard-Jones center. The parametrization has been based on a fit of the temperature of maximum density (indirectly estimated from the melting point of hexagonal ice), the stability of several ice polymorphs and other commonly used target quantities. The calculated properties include a variety of thermodynamic properties of the liquid and solid phases, the phase diagram involving condensed phases, properties at melting and vaporization, dielectric constant, pair distribution function, and self-diffusion coefficient. These properties cover a temperature range from 123to573K and pressures up to 40000bar. The model gives an impressive performance for this variety of properties and thermodynamic conditions. For example, it gives excellent predictions for the densities at 1bar with a maximum density at 278K and an aver...
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TL;DR: Several biomass hydrothermal conversion processes are in development or demonstration as mentioned in this paper, which are generally lower temperature (200-400 °C) reactions which produce liquid products, often called bio-oil or bio-crude.
Abstract: Hydrothermal technologies are broadly defined as chemical and physical transformations in high-temperature (200–600 °C), high-pressure (5–40 MPa) liquid or supercritical water. This thermochemical means of reforming biomass may have energetic advantages, since, when water is heated at high pressures a phase change to steam is avoided which avoids large enthalpic energy penalties. Biological chemicals undergo a range of reactions, including dehydration and decarboxylation reactions, which are influenced by the temperature, pressure, concentration, and presence of homogeneous or heterogeneous catalysts. Several biomass hydrothermal conversion processes are in development or demonstration. Liquefaction processes are generally lower temperature (200–400 °C) reactions which produce liquid products, often called “bio-oil” or “bio-crude”. Gasification processes generally take place at higher temperatures (400–700 °C) and can produce methane or hydrogen gases in high yields.
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IBM1
TL;DR: A re-parameterization of the standard TIP4P water model for use with Ewald techniques is introduced, providing an overall global improvement in water properties relative to several popular nonpolarizable and polarizable water potentials.
Abstract: A re-parameterization of the standard TIP4P water model for use with Ewald techniques is introduced, providing an overall global improvement in water properties relative to several popular nonpolarizable and polarizable water potentials. Using high precision simulations, and careful application of standard analytical corrections, we show that the new TIP4P-Ew potential has a density maximum at approximately 1 degrees C, and reproduces experimental bulk-densities and the enthalpy of vaporization, DeltaH(vap), from -37.5 to 127 degrees C at 1 atm with an absolute average error of less than 1%. Structural properties are in very good agreement with x-ray scattering intensities at temperatures between 0 and 77 degrees C and dynamical properties such as self-diffusion coefficient are in excellent agreement with experiment. The parameterization approach used can be easily generalized to rehabilitate any water force field using available experimental data over a range of thermodynamic points.
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TL;DR: A survey of all the state-of-the-art formulations of thermophysical properties is presented, finding the most-accurate thermodynamic properties are obtained from multiparameter Helmholtz-energy-explicit-type formulations.
Abstract: Over the last few decades, researchers have developed a number of empirical and theoretical models for the correlation and prediction of the thermophysical properties of pure fluids and mixtures treated as pseudo-pure fluids In this paper, a survey of all the state-of-the-art formulations of thermophysical properties is presented The most-accurate thermodynamic properties are obtained from multiparameter Helmholtz-energy-explicit-type formulations For the transport properties, a wider range of methods has been employed, including the extended corresponding states method All of the thermophysical property correlations described here have been implemented into CoolProp, an open-source thermophysical property library This library is written in C++, with wrappers available for the majority of programming languages and platforms of technical interest As of publication, 110 pure and pseudo-pure fluids are included in the library, as well as properties of 40 incompressible fluids and humid air The source code for the CoolProp library is included as an electronic annex
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TL;DR: In this paper, the vapour pressure of ice and supercooled water is reviewed with an emphasis on atmospheric applications, and various parametrizations are given for the vapor pressure, molar heat capacity, and latent heat of both ice and liquid water.
Abstract: The vapour pressures of ice and supercooled water are reviewed with an emphasis on atmospheric applications. Parametrizations are given for the vapour pressure, molar heat capacity, and latent heat of vaporization of both ice and liquid water. For ice, the experimental vapour pressure data are in agreement with a derivation from the Clapeyron equation. Below 200 K cubic ice may affect the vapour pressure of ice both in the atmosphere and in the laboratory. All of the commonly used parametrizations for the vapour pressure of supercooled water are extrapolations that were not originally intended for use below the freezing point. In addition, the World Meteorological Organization definition of the vapour pressure of supercooled water contains an easily overlooked typographical error. Recent data on the molar heat capacity of supercooled water are used to derive its vapour pressure. Nevertheless, the uncertainty is such that measurements of the deliquescence and freezing behaviour of aerosol particles are beginning to be limited by uncertainties in the thermodynamics of supercooled water. Copyright © 2005 Royal Meteorological Society
1,171 citations
References
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TL;DR: A review of measurements of the effect of temperature, pressure, isotopic composition, and dissolved atmospheric gases on the density of liquid water at temperatures to 100°C is given in this article.
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169 citations
"The IAPWS Formulation 1995 for the ..." refers background in this paper
...The value of the specific gas constant R is derived from values of the molar gas constant Rm [3] and the molar mass M [4], which differ slightly from the accepted values of these quantities at the time this release was prepared....
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01 Jan 1995
TL;DR: In this article, a wide range of topics associated with water, steam, and high-temperature aqueous systems are discussed, such as metastable states and nucleation, supercooled, superheated and stretched water, molecular modeling of aqueusystems, frontiers of physical chemistry, high temperature, and chemical processes in steam cycles.
Abstract: Continuing a trend of covering an increasingly wide range of topics associated with water, steam, and high-temperature aqueous systems, the papers in this book cover: metastable states and nucleation, supercooled, superheated and stretched water, molecular modeling of aqueous systems, frontiers of physical chemistry of aqueous solutions, high-temperature aqueous systems including measurement techniques, hydrothermal oxidation, chemical processes in steam cycles, and plant cycle chemistry.
880 pages,
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67 citations
TL;DR: In this paper, an equation for dimensionless isobaric heat capacity for water at zero pressure has been fitted, in the form of a summation of simple harmonic oscillator functions, to the values published by Woolley.
Abstract: An equation, in the form of a summation of simple harmonic oscillator functions, for dimensionless isobaric heat capacity (specific isobaric heat-capacity divided by the specific ideal-gas constant, cP/R) for water at zero pressure has been fitted to the values published by Woolley. The equation has a very good agreement with the values to which it has been fitted. Comparisons are made with other equations. Equations for ideal-gas dimensionless enthalpy and the ideal-gas dimensionless Gibbs function (specific enthalpy and specific Gibbs function divided by the product of specific ideal-gas constant and thermodynamic temperature respectively, h/RT and g/RT), obtained by appropriate manipulation of the equation for cPR, are also given.
29 citations
"The IAPWS Formulation 1995 for the ..." refers methods in this paper
...[6] Cooper, J. R., Representation of the Ideal-Gas Thermodynamic Properties of Water, Int....
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...The ideal-gas part o of the dimensionless Helmholtz free energy is obtained from an equation for the specific isobaric heat capacity in the ideal-gas state developed by Cooper [6] and reads:...
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...The ideal-gas part oφ of the dimensionless Helmholtz free energy is obtained from an equation for the specific isobaric heat capacity in the ideal-gas state developed by Cooper [6] and reads: o8o o o o o 1 2 3 4 ln ln ln 1 e ,ii i n n n n γ τφ δ τ τ − = ⎡ ⎤= + + + + −⎢ ⎥⎣ ⎦∑ (5) where and with ρc = /δ ρ ρ c = / T Tτ c and Tc according to Eqs....
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