Perpustakaan Digital ITB

FLiNaK is one of the molten fluoride salts used in Molten Salt Reactor (MSR) applications. The purity of FLiNaK molten salt is a crucial requirement in nuclear energy systems for MSR. Therefore, the purification of FLiNaK is necessary to meet the required standards for MSR applications by H2/HF gas injection. The distribution of H2 and HF gases within the molten salt during the purification process is interesting to be investigated. However, there is currently no literature that observes the distribution of H2 and HF gases within the molten salt during the purification process. One suitable method for determining gas distribution within the molten salt is Computational Fluid Dynamics (CFD). Therefore, in this study, CFD simulations were performed to examine the effect of the inlet location on the volume fraction of HF and H2 gases within the molten salt during the purification process. The simulation process involved constructing a 3D geometry of the system using Inventor Professional software and imported into ANSYS Fluent under the "Geometry" section. Then, meshing is performed to divide the system into smaller partitions. Subsequently, a simulation setup is performed to select suitable models to simulate the molten salt purification process. The multiphase model used in this study is the Volume of Fluid (VoF) model with explicit formulation. The simulation then continued by inputting the physical and thermodynamic properties of FLiNaK salt, hydrogen gas, and HF gas, defining boundary conditions, and performing initialization and calculation processes. The simulation results were analyzed using graphs and tables to assess the effect of vessel geometry on the distribution of HF and H2 gas. Three simulations were conducted: Simulation 1 with the inlet at the top of the vessel, Simulation 2 with the inlet submerged within the FLiNaK molten salt, and Simulation 3 with the inlet positioned at the bottom of the vessel. The results showed that the inlet position affects the distribution of H2 and HF gas in molten salt. Simulation 1 and Simulation 2 resulted in highly concentrated H2 and HF gases on the surface of the molten salt. Simulation 3, with the inlet at the bottom, produced a more uniform distribution of HF gas compared to the other simulations. Based on the results, it is recommended to use the vessel design presented in Simulation 3 for molten salt purification utilizing H2/HF gas.