Achieving kilowatt-scale elastocaloric cooling by a multi-cell architecture.

Abstract

Elastocaloric cooling using shape memory alloys (SMAs) has attracted considerable interest as an environmentally friendly, energy-efficient alternative to conventional vapour-compression refrigeration1,2. However, the limited cooling power of existing devices (≤300 W) hampers the commercialization of this technology3,4. Here we constructed a kilowatt-scale elastocaloric cooling device using compressive tubular NiTi in an 'SMAs in series-fluid in parallel' architecture, referred to as the multi-cell architecture. A large specific cooling power of 12.3 W g-1 was achieved by the large surface-area-to-volume ratio of thin-walled tubular NiTi at high-frequency operation (3.5 Hz), complemented by graphene nanofluid as an efficient heat transfer agent. Furthermore, the multi-cell architecture ensures a sufficient elastocaloric mass for tight assembly while maintaining a low system fluid pressure. Our device achieves a cooling power of 1,284 W on the fluid side at zero temperature lift during the initial 500,000 cycles, demonstrating the potential of this green cooling technology for a decarbonized future5,6.