Multiphysics multiscale modeling of molten salt coolants and applications.
Mauricio Tano-Retamale, LPSC, Grenoble
Contact : Cyrille Bonamy
Abstract :
The present seminar will deal with the multiphysics and multiscale aspects of when modeling molten salt coolants. These coolants has been addressed due to a large and rising interest in using them for modern energy applications, such as thermal energy storage units, solar concentration facilities, and for nuclear power production, between others. These sort of coolants are interesting since they allow us to increase the operating temperatures of energy storage and conversion systems, without significant upsurges in their pressure or in the thermal degradation processes of the coolant. This, in turn, allows us to increase the energy conversion efficiency, while potentially reducing the mechanic constraints on materials. During this seminar, I will present the research work on molten salts that we have performed during my Ph.D. thesis at LPSC-Grenoble during the years 2015-2018.
In the first part of the seminar, a general idea of the models needed for molten salt coolants of coolants will be presented. Then, the turbulence modeling and the phases change process will be addressed in further detail. In the first place, the development of turbulence in molten salts will be examined. In this section, a set of RANS non-linear eddy viscosity turbulent models will be examined. This sort of models provides a good compromise between precision and computational cost, making them very useful for industrial design tasks. Furthermore, the GEATFOAM will be presented. This is a tool developed on the OpenFOAM® platform that allows us to automatically generate adapted non-linear eddy-viscosity turbulent models for a-priori specified flow conditions. In the next section, the multiscale aspects of the phase change process (solidification/melting) in molten salts will be examined. An adapted multiscale-coupled model, which is able to capture the influence of the different scales during the phase change process will be presented. The details of the numerical implementation of this model in OpenFOAM® will also be provided. In addition, the experiments that allows testing the models developed will also be presented for both sections.
In summary, the main objective of this seminar is to present the scientific progress that have been done in modeling molten salt coolants, as well as the open research questions that have to be answered to envision further improvements in the molten salt coolant technology.