3D numerical and experimental study on paraffin wax melting in thermal storage for the nozzle-and-shell, tube-and-shell, and reducer-and-shell models

Paraffin melting experienced in the nozzle-and-shell, tube-and-shell, and reducer-and-shell models in thermal storage with 3D numerical and experimental approach has been studied. The numerical study aims to evaluate the melting process and discover temperature distribution, liquid-solid interface, liquid fraction, and the average surface Nusselt number, while the aim of this experimental study is to determine the distribution of melting temperature. The comparison of temperature distribution between the numerical approach and experimental one indicates a good agreement. The comparison result between the three models shows that the melting process of the nozzle-and-shell model is the best, followed by tube-and-shell and reducer-and-shell models, successively. To finish the melting process, the time required is 6130 s for the nozzle-and-shell model, while tube-and-shell model requires 8210 s and reducer-and-shell model requires 12280 s.