High-performance multimode elastocaloric cooling system

Abstract

Developing zero–global warming potential refrigerants has emerged as one area that helps address global climate change concerns. Various high-efficiency caloric cooling techniques meet this goal, but scaling them up to technologically meaningful performance remains challenging. We have developed an elastocaloric cooling system with a maximum cooling power of 260 watts and a maximum temperature span of 22.5 kelvin. These values are among the highest reported for any caloric cooling system. Its key feature is the compression of fatigue-resistant elastocaloric nitinol (NiTi) tubes configured in a versatile multimode heat exchange architecture, which allows the harnessing of both high delivered cooling power and large temperature spans. Our system shows that elastocaloric cooling, which only emerged 8 years ago, is a promising direction for commercializing caloric cooling.

Editor’s summary

Vapor compression cooling often relies on refrigerants that are greenhouse gases or have other issues with flammability and toxicity. Caloric cooling is a different strategy that instead relies on moving solids through a phase transition. Qian et al . developed an elastocaloric cooling device that compresses fatigue-resistant bundles of nickel–titanium tubes to obtain an attractive cooling power and maximum temperature difference. The device is competitive relative to other caloric strategies and may be attractive for eventual commercialization. —Brent Grocholski

Abstract

Compressing metal refrigerants in a versatile heat-exchange design leads to the delivery of technologically relevant cooling performance.