Thermal performance of cold thermal energy storage system with fin and fin–foam structures

The heat transfer performance of most cold thermal energy storage (CTES) devices is limited by the low thermal conductivity of phase change materials (PCMs) and the increase in the thickness of PCMs. A comparative work was performed to explore the heat transfer performance of CTES systems with a fin structure (Fin-CTES) and a fin–foam structure (Fin–foam-CTES). The heat transfer performance, temperature distribution, and thermal effectiveness of Fin-CTES and Fin–foam-CTES at different inlet temperatures and volume flow rates of heat transfer fluid were investigated and compared. Results demonstrated that the overall heat transfer performance of Fin–foam-CTES is better than that of Fin-CTES. However, compared with the PCM in Fin-CTES, that in Fin–foam-CTES has a greater degree of supercooling, reaching 4.35 °C at the maximum. In the discharging (melting) process, Fin-CTES and Fin–foam-CTES have almost similar heat transfer effectiveness, in which the maximum difference is only 0.0107. That is, the enhanced heat transfer effect of the natural convection of the liquid PCM and the metal foam is basically the same during the discharging process.