Design of a Flat Channel Experiment to Study Molten Salt Thermal Radiation Heat Transfer

摘要

Molten salts are currently being considered in various innovative nuclear reactor designs due to their unique properties. Some of these advanced reactor designs use molten salts as both a fuel carrier and coolant. In other designs, they are instead considered only as primary and/or intermediate circuits coolant. Thanks to the experimental data gathered from the Molten-salt Reactor Experiment (MSRE) at ORNL and the advances made on numerical multi-physics tools, high detailed models can now be developed to support the design and safety studies of these innovative reactors. Nevertheless, the modeling of some molten salts phenomena requires further improvements. To mention a few of them: phase change, radiative heat transfer, corrosion of reactor materials, fission products retention and thermodynamic properties. Accordingly, one of the objectives of the H2020 European project SAMOSAFER is to develop more accurate heat transfer models needed for safety studies of Molten Salt Reactors (MSRs) and their comparison against experimental data. In particular, radiative heat transfer in the molten salt used in the fuel and primary circuits is one of the aspects currently being studied in SAMOSAFER. While under most conditions, radiative heat transfer is not expected to be the main heat transfer mechanism, its effects cannot be neglected at the high temperatures found during some accidental conditions or in geometries where the fluid can be considered as optically thin (e.g. in the heat exchanger). The studies of radiative heat transfer are being carried-out in the SWATH [1] (Salt at WA11: Thermal ExcHanges) facility at the CNRS Grenoble. This facility uses a discontinuous working principle to stablish a stable flow by regulating pressure difference between two tanks as shown in Fig. 1.