Experimental and numerical investigations on tilt filling design of metal foam in a heat storage tank

The use of metal foam as a filler in heat storage tanks proves advantageous in compensating for the low thermal conductivity of phase change materials. However, the filling of metal foam can impede natural convection within the tank. Partially filled metal foam enables both strong natural convection in the upper pure phase change material region and enhanced thermal conductivity of the metal foam. This paper proposes inclining the upper surface of the metal foam to further strengthen natural convection in the upper region. Following experimental verification, a series of heat storage tanks with different metal foam inclination forms for latent heat storage were numerically simulated and compared. The results indicate that complete melting time was shortest for the case 5 (ab-type model with a = 0, b = 91.8), at 5320s, which represents an 18.8% reduction compared to benchmark case 9. Furthermore, comparison of the cases with inclined upper surfaces indicated that the clockwise inclination pattern resulted in greater time savings than the counterclockwise pattern. The results of this study offer valuable insights for the design of partially filled heat storage tanks.