Enhancing LHTES efficiency using asymmetric hexagon anisotropic metal foam layer: A comparative study on orientation and scale

The latent heat thermal energy storage devices can store a notable amount of energy in a fairly compact space with minimal environmental impact. However, the heat transfer rate in these systems is limited by inherited low thermal conductivity of most organic materials such as paraffins. This research focuses on addressing the impact of using an engineered anisotropic metal foam layer on heat transfer improvement of latent heat thermal energy storage (LHTES) units. The comprehensive two heat equation models, together with a finite element method, were employed to simulate the energy storage in LHTES unit. The study demonstrates that increasing the size of the Anisotropic Metal Foam Layer (AMFL) significantly enhances the melting of paraffin. The orientation of the AMFL also plays a crucial role, with the larger side positioned near the hot wall contributing more effectively to PCM melting. This optimal arrangement led to a reduction in melting duration by up to 5.28%. AMFL reduced the melting time by 8.2% in case d2 compared to a case with uniform metal foam.