Experimental demonstration of a dispatchable latent heat storage system with aluminum-silicon as a phase change material. (15th November 2018)

• Record Type: Journal Article
• Authors: Rea, Jonathan E.; Oshman, Christopher J.; Singh, Abhishek; Alleman, Jeff; Parilla, Philip A.; Hardin, Corey L.; Olsen, Michele L.; Siegel, Nathan P.; Ginley, David S.; Toberer, Eric S.
• Is Part Of: Applied energy. Volume 230(2018)
• Page Start: 1218
• Page End: 1229
• Publication Date: 2018-11-15
• Subjects: Thermal energy storage -- Phase change material -- Concentrating solar power -- Thermal valve -- Heat pipe -- Thermosyphon; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2018.09.017
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: Design and construction of a dispatchable latent heat thermal storage system. Heat transfer near uniform temperature via heat pipes and aluminum-silicon PCM. On/off heat flow control using a valved thermosyphon. Integration of subsystems with small temperature drops at interfaces. Abstract: In this work, we present the design, construction, and experimental results of a prototype latent heat thermal energy storage system. The prototype consists of a thermal storage tank with 100 kg of the aluminum-silicon eutectic as a phase change material, a valved thermosyphon that controls heat flow from the thermal storage tank to the power block, and thermoelectric generators for conversion of heat to electricity. We tested the prototype over four simulated days, where each day consisted of four phases of operation: charging, discharging, simultaneous charging and discharging, and storage. Our results show three major conclusions. First, the thermal energy storage system was able to receive and distribute heat with small temperature gradients – less than 5 °C throughout the thermal storage tank. Second, the valved thermosyphon was able to effectively control heat transfer, demonstrating an on/off thermal conductance ratio of 430. Third, the interfaces between subsystems had small temperature drops: of the ∼ 560 °C temperature drop from the thermal storage tank to the heat rejection system, ∼ 525 °C occurred across the power block. This work overcomes the challenges of integrating previously-developed subsystems together, providing a proof-of-concept of this system.