Summary:
Researchers in UCLA’s Department of Mechanical and Aerospace Engineering have developed an innovative thermal storage system that dynamically adapts to thermal fluctuations of phase change materials, significantly enhancing heat transfer efficiency.
Background:
Phase change materials (PCMs) are used to store and release thermal energy during phase transitions from solid to liquid and back again. PCMs are essential for a wide range of applications, including thermal management systems for consumer electronics, solar energy, lighting, and heat and cooling systems in vehicles, aircraft, spacecraft, and buildings. Conventional PCMs may suffer from slow heat absorption and release, which can lead to overheating of the heat source, and most expand significantly during heating. To overcome that problem, modern PCM heat sinks incorporate a void space, or a small volume of air, within the envelope volume. This requires that envelope walls be thick enough to withstand the pressures that are developed. Therefore, there is a clear need for a thermal storage device that can overcome these challenges and provide reliable, efficient heat transfer.
Innovation:
Professor Pirouz Kavehpour and his research team have created an innovative thermal storage system that does not require a void space and thereby accommodates a much thinner shell wall than those in conventional PCM heat sinks. The device maintains a uniform temperature within the PCM and offers a tenfold improvement in response time by dynamic adjusting to optimize heat transfer. By increasing the heat transfer surface area between the structure and PCM, energy density of the system is enhanced by nearly 50%. This proposed solution has a wide array of industrial cooling applications, including in avionics, consumer electronics, and high power lighting settings.
Potential Applications:
● Solar thermal energy storage systems
● Battery and electric vehicle thermal management
● Integrated heating and cooling systems for buildings
● Consumer electronics
● Lighting systems
● Aircraft and spacecraft cooling systems
Advantages:
● Lightweight, rapid-response system
● Dynamic adjustments to PCM expansion
● Enhanced energy density
● Increased heat transfer efficiency
● Optimized storage capacity
State of Development:
The proposed storage device has been replicated and tested against current models that combine PCM with fins. The results demonstrate the FAST-Storage device offers the highest storage capacity, lowest weight, fastest response time, and no void formations.
Related Papers:
1. High-density, high-temperature thermal energy storage and retrieval, Richard E Wirz, Antoine Philippe Pierre Stopin, A Tse Louis, Adrienne G Lavine, H. Pirouz Kavehpour, Reza Baghaei Lakeh, Benjamin I Furst, Gabriela Bran,Miguel A Garcia-Garibay
2. US Patent US20150060008A1, 2015 Low-cost hybrid energy storage system, Pirouz Kavehpour et al.,
3. US Patent US20180238196A1, 2018 Storage-combined cold, heat and power, Sammy Houssainy, Mohammad Janbozorgi, Walid Ismail, Pirouz Kavehpour
4. US Patent US20190301749A1, 2019 Effect of natural convection on thermal energy storage in supercritical fluids, RB Lakeh, et al.
5. Energy Sustainability, 55515 (V001T05A001), 2013 Wang, Q., Jackson, J.A., Ge, Q., Hopkins, J.B., Spadaccini, C.M., Fang, N.X., 2016,
6. “Lightweight Mechanical Metamaterials with Tunable Negative Thermal Expansion,” Physical Review Letters, 117(17): 175901 (6 pages) (featured as the first highlighted article in the issue by the editor's suggestion on the journal's website).Kuppens, P.R., Bessa, M.A., Herder, J.L., Hopkins, J.B., 2021
7. “Compliant Mechanisms that Use Static Balancing to Achieve Dramatically Different States of Stiffness,” Journal of Mechanisms and Robotics, 13(2):021010 Hopkins, J.B., Song, Y., Lee, H., Fang, N.X., Spadaccini, C.M., 2016
8. “Polytope Sector-based Synthesis and Analysis of Microstructural Architectures with Tunable Thermal Conductivity and Expansion,” Journal of Mechanical Design, 138(5): 051401 Hopkins, J.B., Lange, K.J., Spadaccini, C.M.
9. “Synthesizing the Compliant Microstructure of Thermally Actuated Materials Using Freedom, Actuation, and Constraint Topologies,” Proc. of the ASME 2012 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE, Chicago, IL, August 2012.Kochmann, D.M., Hopkins, J.B., Valdevit, L., 2019
10. “Multiscale Modeling and Optimization of the Mechanics of Hierarchical Metamaterials,” MRS Bulletin, 44(10): pp. 773-781Poon, R., Hopkins, J.B., 2019
11. “Phase-changing Metamaterial Capable of Variable Stiffness and Shape Morphing,” Advanced Engineering Materials, 21(12): 1900802 (5 pages) (selected by the editor to be featured in Advanced Science News)
Reference:
UCLA Case No. 2022-240