Boosting thermal energy storage: Study identifies optimal 3D skeleton for faster melting phase change materials
image: (a) Three-dimensional physical model; (b) two-dimensional physical model; (c) localized enlargement of mushy zone
Credit: Pengzhen Zhu, Baoming Chen, Liyan Sui, Hongchen Li, Kun Li & Yu Jian.
As the global energy crisis intensifies, the demand for efficient thermal energy storage technology has never been higher. A research team from the School of Thermal Engineering at Shandong Jianzhu University has made a significant breakthrough in enhancing the performance of phase change materials (PCMs) by identifying the most efficient triply periodic minimal surface (TPMS) skeletal structures for heat transfer.
Phase change energy storage technology, which stores and releases energy during the transition between solid and liquid states, offers high energy density and stable temperatures. However, its widespread application has been hindered by the low thermal conductivity of common PCMs. To overcome this, researchers have explored embedding high-conductivity metal skeletons into the materials.
In a study published in the journal ENGINEERING Energy (formerly Frontiers in Energy), the research team utilized the 3D lattice Boltzmann method (LBM) to simulate and compare four types of TPMS skeletons: Gyroid, Diamond, Primitive, and I-graph and wrapped package-graph (I-WP).
The Gyroid Advantage
The comparative analysis revealed that the geometry of the skeleton plays a crucial role in the melting process. The PCM embedded with the Gyroid skeleton exhibited the fastest heat transfer, achieving a complete melting time 24.1% shorter than that of the I-WP skeleton. This efficiency is attributed to the Gyroid structure's unique twisted and complex pore structure, which provides a larger heat exchange area at the same porosity level compared to traditional cylindrical or rectangular fins.
Key Findings on Melting Dynamics
The researchers further investigated the influence of various dimensionless parameters on the Gyroid-based composite PCM:
- Rayleigh Number (Ra): Increasing the $Ra$ number from $10^4$ to $10^6$ significantly enhanced natural convection, reducing the complete melting time by 60.44%.
- Prandtl Number (Pr): A higher $Pr$ number was found to accelerate the migration of the "mushy zone"—the region where solid and liquid phases coexist—leading to faster overall melting.
- Local Thermal Non-Equilibrium (LTNE): The study highlighted the importance of the LTNE effect, showing that temperature differences between the skeleton and the PCM are significant and complex, peaking near the heating surface.
Future Implications
“TPMS structures are designed with high flexibility and parameter controllability, making them ideal for high-end thermal management applications,” said Professor Baoming Chen, the corresponding author of the study. “Compared to conventional metal foams, these skeletons can be easily customized and produced via 3D printing technology.”
This research provides critical theoretical support for the development of high-efficiency energy storage systems, with potential applications ranging from the thermal management of electronic devices and batteries to large-scale renewable energy storage.
JOURNAL: ENGINEERING Energy (formerly Frontiers in Energy)
DOI: 10.1007/s11708-024-0967-z
Article Link: https://link.springer.com/article/10.1007/s11708-024-0967-z
Cite this article:
Zhu P, Chen B, Sui L, et al. Three-dimensional numerical simulation of melting characteristics of phase change materials embedded with various TPMS skeletons. Front. Energy, 2025, 19(2): 157-174. https://doi.org/10.1007/s11708-024-0967-z