Effect of partial cooling-heating configurations on the enhanced latent thermal energy storage performance

A low rate of ice melting can be addressed by adding nanoscale particles of high thermal conductivity; however, other simple and effective techniques are also possible for further enhancement of the thermal characteristics and melting process of ice as well as other phase storage materials for thermal energy storage. In the present numerical study, two techniques combining partial heating and inversion of the active cavity walls in addition to adding hybrid nanoparticles (Cu and Al2O3) are investigated for the sake of enhancing the phase change in the cavity. Modeling is based on Lattice-Boltzmann techniques; numerical predictions are successfully compared with experimental and theoretical published data. The thermal behavior of the enhanced phase change material is analyzed for various Rayleigh and Fourier numbers and nanoparticle concentrations. The isotherms, streamlines, interface position, liquid fraction evolution, and full melting duration are analyzed. The outcomes show that for each concentration investigated, there is a different best configuration for reducing the ice melting time. 76% reduction in the melting time was achieved with a nanoparticle concentration of 6% (hybrid copper and alumina) and proper simultaneous heating and cooling configuration. These findings can guide designing efficient ice-based systems.