Tuesday, April 23, 2024

New discovery unlocks thermal energy storage optimization

Phase change materials store thermal energy in the form of latent heat and are often integrated with high thermal conductivity metals to make composites that have both high power density and large energy storage capacity.

A team of researchers from Texas A&M University has established foundational design principles for composite phase change materials to store thermal energy rapidly. This breakthrough is expected to dramatically simplify the design process, allowing a near-optimal composite phase change material to be simply calculated without exhaustive computational fluid dynamic calculations or extensive iterative design.

Previously, several studies have investigated the performance of thermal energy storage systems. However, none have yet revealed insights into improving rate performance, optimization, and prediction of performance until now.

The new research has addressed a fundamental question of how to design a composite phase change material that balances both energy density (how much energy can be stored) and power density (how quickly energy can be stored) without adding excess mass or volume.

Funded by the Office of Naval Research, this research provides a theoretical framework to design and optimize cylindrical composites with three figures of merit – minimization of temperature rise, maximization of the effective volumetric heat capacity, and maximization of the effective heat capacity based on mass.

The figures of merit developed in this research can assess the performance of most composite phase change material systems and help design future cylindrical composites while accounting for the thermal loads specific to the thermal storage application.

In addition, the team experimentally demonstrated that treating the system as an effective composite allowed them to quickly simplify the calculations and predict near-optimal structures.

Journal reference:

  1. Achutha Tamraparni, Alison Hoe, Michael Deckard, Chen Zhang, Nathan Malone, Alaa Elwany, Patrick J. Shamberger, Jonathan R. Felts. Design and optimization of composite phase change material for cylindrical thermal energy storage. International Journal of Heat and Mass Transfer, 2023; DOI: 10.1016/j.ijheatmasstransfer.2023.123995