The curious temperature dependence of fluoride molten salt thermal conductivity
Name
5.0088059.pdf
Description
Published version
Size
3.92 MB
Format
Adobe PDF
Checksum (MD5)
c49725a9a3930f3da0d636ff415b0e6d
Author(s)
Robertson, Sean G
Wiser, Ralph
Yang, Wonseok
Kang, Dokyu
Choi, Sungyeol
Baglietto, Emilio
Short, Michael P
Date Issued
June 14, 2022
Journal
Journal of Applied Physics
Publisher
AIP Publishing
Citation
Robertson, Sean G, Wiser, Ralph, Yang, Wonseok, Kang, Dokyu, Choi, Sungyeol et al. 2022. "The curious temperature dependence of fluoride molten salt thermal conductivity." Journal of Applied Physics, 131 (22).
Version
Final published version
Abstract
To optimize the efficiency and safety of molten salt-based energy applications, accurate molten salt thermophysical property data are required. For molten fluorides, existing thermal conductivity results have large uncertainties and contradict the current theory by eliciting a positive temperature coefficient. Transient grating spectroscopy (TGS), a technique previously deemed reliable by the theoretical community, has been used to measure the thermal conductivity of fluorides (FLiNaK) for the first time. Results show a fairly flat but slightly increasing thermal conductivity as a function of temperature. The technique has been shown to not suffer from contributions from convection and radiation, an explanation used to discount the results of alternative experimental techniques. In addition to thermal conductivity, sound speed data as a function of temperature have also been obtained for the first time in FLiNaK. The use of accurate sound speed data in theoretical models of thermal conductivity provides better but not complete agreement with the results from TGS. The continued existence of a positive temperature coefficient highlights the need for new mechanistic proposals for why TGS, or current theoretical models, are unable to capture the correct temperature dependence for fluoride molten salt thermal conductivity.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1063/5.0088059
