Supercritical fluid thermophysical properties

Franck, E.U. "Thermophysical Properties of Supercritical Fluids with Special Consideration of Aqueous Systems", Fluid Phase Equilib. 1983, 10(2-3), 211-22. 

Due to their peculiar solvent properties, supercritical fluids offer a range of unusual chemical possibilities such as in environmentally benign separation and destruction of hazardous waste, as well as for new materials synthesisd" These intriguing reaction media make it possible to sensitively control reaction rate and selectivity with changes in temperature and pressure. The thermophysical properties of water as well as more than 70 other fluid systems have been formulated and/or compiled by lAPWS and NIST. ... 

Carles P. A brief review of the thermophysical properties of superaitical fluids. J Supercrit Huids 2010 53 2-11. 

Mann, D., Pioro, I., 2015. Study on specitics of thermophysical properties of supercritical fluids in power engineering apphcations. In Proceedings of the 23rd International Conference on Nuclear Engineering (ICONE-23), May 17—21, Chiba, Japan, Paper 1730, 11 Pages. 

Appendix A3 Thermophysical properties of fluids at subcritical and critical/ supercritical conditions ... 

Therefore, the most widely used supercritical fluids as of today and possibly in the future are water, carbon dioxide, helium, and refrigerants. Often, refrigerants, similar to carbon dioxide, are considered as modeling fluids instead of water due to significantly lower critical pressures and temperatures (for example, R-134a Per = 4.0593 MPa Per = 101.06°C), which decreases the complexity and costs of thermal hydraulic experiments. Based on the above mentioned, knowledge of thermophysical properties specifics at critical and supercritical pressures is very important for safe and efficient use of fluids in power and other industries. 

It should be noted that thermophysical properties of 121 pure fluids, including water, carbon dioxide, helium, refrigerants, etc. 5 pseudo-pure fluids (such as air) and mixtures with up to 20 components at different pressures and temperatures, including critical and supercritical regions, can be calculated using the NIST REFPROP software (2010), Version 9.1. 

Supercritical fluids are used intensively in various industries. Therefore, understanding specifics of thermophysical properties and their behavior at critical and supercritical pressures is an important task. Supercritical fluids are considered as single-phase substances in spite of significant variations of all thermophysical properties within critical or pseudocritical regions. Some of these variations in thermophysical properties are similar to those at subcritical pressures during crossing of the saturation line. 

Pioro, I., 2014. Application of supercritical pressures in power engineering specifics of thermophysical properties and forced-convective heat transfer. In Anikeev, V., Fan, M. (Eds.), Supercritical Fluid Technology for Energy and Environmental Applications. Elsevier, pp. 201-233. 

Thermophysical properties of gases, liquids, and fluids at supercritical pressures used in publications of Dr. I. Pioro were calculated according to the National Institute of Standards and Technology software (2010) (http //www.nist.gov/srd/nist23.cfm). 

Technical Appendices, which provides readers with additional information and data on current nuclear power reactors and NPPs thermophysical properties of reactor coolants, thermophysical properties of fluids at suhcritical and critical/supercritical pressures, heat transfer and pressure drop in forced convection to fluids at supercritical pressures, world experience in nuclear steam reheat, etc. 

As mentioned above, numerical computations were carried out [5, 6] based on a k-e model by Jones-Launder. This model has a more general description for turbulence than the mixing length models. Effects of buoyancy force and fluid expansion on the heat transfer to normal fluids are successfully analyzed by the k-e model. Thermophysical properties are treated as variables in the governing equations and evaluated from a steam table library. Thus, extremely nonlinear thermophysical properties of supercritical water are evaluated directly and correctly. This approach is applicable to a wide range of flow conditions of supercritical water. Many cases of different inlet temperatures can be calculated and the relation between the heat transfer coefficient and the bulk enthalpy can be obtained in a wide range. 

Therefore, for the higher-pressure case we may adopt a numerical analysis, based on iterative integration around the loop of the momentum equation (since mass is also conserved) for varying loop power inputs, using the thermophysical properties of the supercritical fluid as a function of actual thermodynamic state. Thus the general flow variation with major loop parameters (elevations, losses etc.) follows Equation (4) but with a non-linear expansion coefficient. 

Features of Supercritical Fluids and Related Catalytic Reactions 471 Table 13.1 Characteristic magnitudes of thermophysical properties. 

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