Numerical investigation of the effect of the number of fins on the phase-change material melting inside a shell-and-tube cylindrical thermal energy storage

Abstract

A numerical analysis of the fin count that affects phase change material (PCM) melting within a cylindrical shell-and-tube thermal energy storage (TES) is provided. Using the ANSYS/FLUENT 16 tool, the enthalpy-porosity combination was quantitatively evaluated. PCMs made of paraffin wax were used in this experiment (RT42). The results of this investigation show that fins significantly affect melting, which reduces the time required to finish the operation. Since melting relies on natural convection, which has a sluggish rate of heat transfer, the process takes longer when there are no fins. The melting process takes 900 min to finish. The melting fraction grew monotonically with the number of fins, and the curve had an initial sharp trend followed by a gradual one. When more PCMs transitioned from a solid state to a liquid state over time, the pace at which they melted decreased, and the thermal resistance between the solid-liquid interface and the heat transfer surface increased. With the same heat storage effect, the maximum time difference was 236 min, and the biggest time difference was caused by the number of fins at 81.4 %. The total melting time was greatly affected by the number of fins in the design.

Keywords

• Melting process
• Phase-changing materials
• Fins
• Heat transfer
• District heat
• Thermal energy storage (TES)