Performance enhancement of triplex tube latent heat storage using fins, metal foam and nanoparticles

Abstract

The inherent low thermal conductivity of latent heat storage materials hinders its effective use due to quite long charging/discharging process. Heat transfer enhancement techniques are promising solutions to overcome this major drawback. In this study, the effect of combining heat transfer techniques including fins of different arrangements, fins-nanoparticles, and fins-metal foam is numerically examined and compared for latent thermal energy storage in a triplex tube. Two fin configurations are examined uniform as well as non-uniform. The predictions of the numerical model are validated by comparisons with experimental data available in the literature. The transient liquid fraction, temperature distribution, and interface position are analyzed for the considered cases. Results show that the non-uniform fin arrangement contributes to improving the thermal energy storage. The non-uniform fin distribution expedites the melting rate by 56.45%. Furthermore, it is shown that the combination of fins-metal foam outperforms the fins-nanoparticles configuration. The time needed for full charging and discharging reduces with fin-metal foam by up to 80.12% and 90.04%, respectively, depending on the fin arrangement. The proposed storage model and results are useful for designing efficient thermal energy storage units.