STUDY OF THE HEAT-TRANSFER BEHAVIOR OF A LATENT-HEAT THERMAL-ENERGY STORAGE UNIT WITH A FINNED TUBE

A theoretical model for predicting the transient behavior of a shell-and-tube storage unit with the PCM on the shell side and the HTF circulating inside the tubes is presented. The tubes are bare or finned. The multidimensional phase change problem is tackled with an enthalpy based method coupled to the convective heat transfer from the HTF. The numerical model is validated with experimental data. A series of numerical experiments are then undertaken to assess the effects of (1) the shell radius, (2) the mass flow rate and inlet temperature of the HTF and (3) the presence of fins attached to the inner tubes on the thermal behavior of the thermal unit. Results show that the annular fins are most effective for moderate mass flow rates and small inlet temperatures.