Email this article 
Post a Comment 
Modernization of the design of a measuring cell for determining the thermal diffusivity of salt melts using the laser flash method
- Authors: Chernyshev S.1, Khrustov A.V.1, Rudenko A.V.1, Vlasov M.I.1
-
Affiliations:
- Institute of High-Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences
- Issue: No 1 (2025)
- Pages: 73-84
- Section: Articles
- URL: https://bakhtiniada.ru/0235-0106/article/view/278782
- DOI: https://doi.org/10.31857/S0235010625010077
- ID: 278782
Cite item
Open Access
Access granted
Abstract
In this work, a well-known cell for measuring the diffusivity of fluoride salt melts by the laser flash method has been modernized. Alkali metal halide melts, such as the eutectic mixture FLiNaK (46.5 mol% LiF – 11.5 mol% NaF – 42 mol% KF), are considered promising materials for use in nuclear power engineering, particularly in molten salt reactors (MSRs), where they act as coolants and actinide fission media. This makes the study of their thermophysical properties extremely important for the design of reactor cores and heat transfer systems. However, as data from the literature show, measurements of the thermal diffusivity of FLiNaK melts are accompanied by significant discrepancies associated with the influence of unaccounted for heat transfer factors and errors in experimental techniques. The laser flash method is one of the preferred methods for studying the thermal diffusivity of salt melts at high temperatures due to its ability to account for convective and radiative heat transfer. However, this method using a known cell leads to overestimated values of thermal diffusivity due to dissipated heat flow. In order to modernize this cell, a numerical model was built in COMSOL Multiphysics, which allowed us to study the influence of materials (Ni, BN, Au) and cell geometry on the heat transfer processes. Data analysis allowed to obtain an optimized cell design that minimized the fraction of heat flow lost, reduced the time to reach the temperature peak, eliminated the need for calibration measurements and extended the temperature range of measurements. Experimental validation of the improved cell was carried out using Netzsch LFA 467 HT HyperFlash equipment. The data obtained confirmed the possibility of more accurate measurement of FLiNaK diffusivity in the temperature range of 550-800°C. Particularly, using of the modernized measuring cell improves the reproducibility of the results and reduces the data scatter, reducing measurement error from 33,8 to 2,6%. These widens the prospects for further studies of high temperature melts, contributing to the development of new generation MSR technologies.
Full Text
About the authors
Savelii Chernyshev
Institute of High-Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences
Author for correspondence.
Email: chernishov@ihte.ru
Russian Federation, Ekaterinburg
A. V. Khrustov
Institute of High-Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences
Email: chernishov@ihte.ru
Russian Federation, Ekaterinburg
A. V. Rudenko
Institute of High-Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences
Email: chernishov@ihte.ru
Russian Federation, Ekaterinburg
M. I. Vlasov
Institute of High-Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences
Email: chernishov@ihte.ru
Ekaterinburg
References
- Ignatiev V.V. Molten Salt Reactors // Reference Module in Earth Systems and Environmental Sciences. 2020. P. 2–16.
- Dr. Charles, W. Forsberg. Molten Salt Reactors (MSRs) // The Americas Nuclear Energy Symposium (ANES 2002), American Nuclear Society. 2002. P. 16–18.
- Mignacca B., Locatelli G. Economics and finance of Molten Salt Reactors // Progress in Nuclear Energy. 2020. № 129.
- J. Serp. The molten salt reactor (MSR) in generation IV: overview and perspectives // Progress in Nuclear Energy. 2014. № 77. P. 308–319.
- Holcomb D.E., Cetiner S.M. An overview of liquid-fluoride-salt heat transport systems // U.S. Department of energy. 2010. P. 156.
- Ambrosek J., Anderson M., Sridharan K., Current status of knowledge of the fluoride salt (FLiNaK) heat transfer // Nucl. Technol. 2009. 165. № 2. P. 166–173.
- Khokhlov V., Ignatiev V., Afonichkin V. Evaluating physical properties of molten salt reactor fuoride mixtures // Journal of Fluorine Chemistry. 2009. № 130. P. 30–37.
- McMurray J.W., et al. Roadmap For Thermal Property Measurements of Molten Salt Reactor systems // Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). 2021. № 1865. P. 4–22.
- Williams D.F., Toth L.M., Clarno K.T. Assessment of Candidate Molten Salt Coolants For the Advanced High-Temperature Reactor (AHTR) // Oak Ridge National Laboratory. 2006. № 12.
- Magnusson J.M., Memmott M., Munro T. Review of thermophysical property methods applied to fueled and un-fueled molten salts // Annals of Nuclear Energy. 2020. № 146.
- Chliatzou C.D., Assael M.J., Antoniadis K.D., Huber M.L., Wakeham W.A. Reference Correlations for the Thermal Conductivity of 13 Inorganic Molten Salts. // Journal of Physical and Chemical Reference Data. 2018. 47. № 3.
- Santini R., Tadrist L., Pantaloni J., Cerisier P. Measurement of thermal conductivity of molten salts in the range 100–500 C, Int. J. // Heat Mass Transfer. 1984. 27. № 4. P. 623–626.
- Cooke J.W. Development of the variable-gap technique for measuring the thermal conductivity of fluoride salt mixtures // U.S. Atomic energy commission. 1973. № W-7405-eng 26.
- Ryan C. Gallagher, Anthony Birri, Nick Russell, N. Dianne B. Ezell. Design and performance of a variable gap system for thermal conductivity measurements of high temperature, corrosive, and reactive fluids // International Journal of Heat and Mass Transfer. 2022. № 192.
- Smirnov M.V., Khokhlov V.A., Filatov E.S. Thermal conductivity of molten alkali halides and their mixtures // Electrochimica Acta. 1987. 32. P. 1019–1026.
- Khokhlov V., Korzun I., Dokutovich V., Filatov E. Heat capacity and thermal conductivity of molten ternary lithium, sodium, potassium, and zirconium fluorides mixtures. // Journal of Nuclear Materials. 2011. 1–3. № 410. P. 32–38.
- Rudenko A., Redkin A., Il’ina E., Pershina S., Mushnikov P., Zaikov Y., Kumkov S., Liu Y., Shi W. Thermal Conductivity of FLiNaK in a Molten State. // Materials. 2022. 15. № 5603. P. 2–14.
- Cheng J.-H., Zhang P., An X.-H., Wang K., Zuo Y., Yan H.-W., Li, Z. A Device for Measuring the Density and Liquidus Temperature of Molten Fluorides for Heat Transfer and Storage // Chinese Physics Letters. 2013. 30. № 12. P. 126–501.
- An X.-H., Cheng J.-H., Yin H.-Q., Xie L.-D., Zhang P. Thermal conductivity of high temperature fluoride molten salt determined by laser flash technique. // International Journal of Heat and Mass Transfer. 2015. № 90. P. 872–877.
- Coulson J.M., Richardson J.F. Chemical Engineering // Pergamon Press. 1990. 1.
- Bejan A. Heat Transfer, Wiley // Evolution, Design and Performance. 1993. P. 611.
- Kato Y., Furukawa K., Araki N., Kobayasi K. Thermal diffusivity measurement of molten salts by use of a simple ceramic cell. // In Proceedings of the 8th European Thermophysical Properties Conference. 1982. 15.
- Robertson S., Wiser R., Yang W., Kang D., Choi S., Baglietto E., Short, M. The curious temperature dependence of fluoride molten salt thermal conductivity. // J. Appl. Phys. 2022. № 131.
- Ryan C. Gallagher, Anthony Birri, Nick G. Russell, Anh-Thu Phan, Aïmen E. Gheribi. Investigation of the thermal conductivity of molten LiF-NaF-KF with experiments, theory, and equilibrium molecular dynamics // Journal of Molecular Liquids. 2022. № 361.
- A. Cape, G.W. Lehman. Temperature and finite pulse-time effects in the flash method for measuring thermal diffusivity // J. Appl. Phys. 1963. 34 (7). 1909–1914.
- L. Dusza. Combined solution of the simultaneous heat loss and finite pulse corrections with the laser flash method // High Temp.-High Press. 1995–1996. 27/28. 467–473.
Supplementary files
