Particle Handling in Particle-Based Pumped Thermal Energy Storage

Journal Article · Mon May 19 04:00:00 EDT 2025 · Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy

DOI:https://doi.org/10.1115/1.4068502· OSTI ID:2573906

Jeong, Shin Young ^[1]; Hirschey, Jason ^[1]; Shah, Munjal Purnkant ^[1]; Gifford, Jeffrey ^[1]; Martinek, Janna ^[1]; Ma, Zhiwen ^[1]

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1. National Renewable Energy Lab., Golden, CO (United States)

A particle-based pumped thermal electricity storage system stores high-temperature heat (~1000 degrees C) in low-cost silica sand and generates power through an efficient power cycle. Central to this system is a counterflow direct-contact gas/particle fluidized-bed heat exchanger, which can significantly improve the heat exchange process due to the large heat transfer surface area of particles. To showcase a lab-scale 10- to 20-kWe heat exchange process with particles heating up to 300 degrees C, a comprehensive hydrodynamic analysis of the fluidization condition inside the heat exchanger was conducted. The heat exchanger was designed to target for heat exchange process of 10-20 kW and accommodate an air mass flow rate of 0.3-0.7 kg/s. The fluidization condition was set to maintain stable bubbling fluidization, thereby maximizing the particle-to-air heat transfer. An air distributor was designed to equally distribute air over the bed, which can avoid defluidized zones in the heat exchanger. Additionally, particle handling systems including L-valves, screw conveyors, and pneumatic conveyors were developed for the prototype heat exchanger, efficiently conveying high-temperature particles at 0.2-0.5 kg/s. This work lays the foundation for scaling up the system and integrating it into larger energy storage applications, demonstrating its potential for efficient, high-temperature thermal energy storage and power generation.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 2573906
• Report Number(s): NREL/JA-5700-90974
• Journal Information: Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy, Journal Name: Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy Journal Issue: 5 Vol. 1
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
fluidized bed
heat exchanger
particle
particle transport
thermal energy storage