NUMERICAL INVESTIGATION OF A HIGH-TEMPERATURE ENERGY STORAGE
Nitrate solar salt had been analyzed as a storage medium for the applications of the hightemperature solar energy storage system. The numerical investigation of the storage system would save time, cost, and effort. In this study, a simulation study using ANSYS CFX software was utilised. This study was validated against an experimental setup, which was designed for heat transfer study of storage material. An Ansys-CFX code that is built and developed to simulate the phase change material (PCM) inside the storage system, was presented. The developed model was validated against experimental data using the same dimensions of the storage system and the same storage material (Case 1 was PCM (only nitrate solar salt; KNO3: NaNO3 by 40:60 molar ratio) and case 2 was nano-PCM (0.5 wt.% Fe2O3+ nitrate solar salt)). This validation ensured the feasibility of using CFD as a design tool. According to Ziskind (2021), the enthalpy porosity techniques can be defined as apparent analogy between the liquid state of PCM inside the mushy zone and the following fluid flow into a porous medium. This techniques had been implemented in the CFX code to show the charging process of the phase change material. It was shown that the natural convection effect was presented in the liquid phase during the charging process. In addition, nano-PCM shows an improvement of charging process by 17.021%. According to the transient temperature measurements, it was found that there was a good match between the experimental data and the data from the CFX code with error less than 5%.
Keywords: CFX Code, Simulation Study, Improved Heat Transfer, Charging Processes, HighTemperature Solar Energy Storage Sy