A review of elastocaloric cooling: Materials, cycles and system integrations

Abstract

Elastocaloric cooling is a new alternative solid-state cooling technology undergoing early stage research and development. This study presents a comprehensive review of key issues related to achieving a successful elastocaloric cooling system. Fundamentals in elastocaloric materials are reviewed. The basic and advanced thermodynamic cycles are presented based on analogy from other solid-state cooling technologies. System integration issues are discussed to characterize the next generation elastocaloric cooling prototype. Knowledge acquired from the elastocaloric heat engines is provided as the basis for the design of cooling system configuration. Commercially available drivers enabling proper compression and tension are also presented. A few performance assessment indices are proposed and discussed as guidelines for design and evaluation of future elastocaloric cooling system. A brief summary of the up-to-date elastocaloric cooling prototypes is presented as well.

Elastocaloric Cooling on the Miniature Scale: A Review on Materials and Device Engineering

“…Similar trends have been found for elastocaloric systems based on heat transfer between the SMA element and a flowing heat transfer fluid. Increasing the surface‐to‐volume ratio of the elastocaloric material is very important for decreasing the heat transfer times, along with increasing cooling power and COP …”

“…presented and improved a cooling demonstrator based on active regeneration . In the meantime, several reviews of the different elastocaloric cooling devices and materials are available . Comparing the performance data obtained for completely different technologies is hardly possible, as there is no standardized way to determine performance metrics of elastocaloric cooling devices.…”

Effects of Strain Rate and Measuring Temperature on the Elastocaloric Cooling in a Columnar-Grained Cu71Al17.5Mn11.5 Shape Memory Alloy

“…Some related research indicated that a high ∆T value of more than 10 K has been directly measured in Ti-Ni- [7,8], Ni-Fe- [9] and Cu-based SMAs [10], which has laid a good material foundation for the development and application of elastocaloric refrigeration technology. At present, an increasing number of promising elastocaloric refrigeration devices are being developed [11]. In addition to evaluating the RC, the responding speed of SMAs is also a significant factor that influences the system cooling efficiency of the solid refrigeration system.…”

Giant elastocaloric effect covering wide temperature range in columnar-grained Cu71.5Al17.5Mn11 shape memory alloy

“…Thanks to the uniform microstructure, the whole sample would share a compatible deformation during loading; thus, a uniform phase transformation can be induced upon stress, 16 which is vital to the improvement of the coefficient of performance of the elastocaloric refrigeration system. 28 Besides, the columnar-grained Cu-Al-Mn alloy has been reported to show reversible martensitic transformation in loading-unloading tensions upon 1000 cycles, exhibiting a higher cyclic stability than the ordinary polycrystalline counterparts. 17 However, compared to the Ni-Ti-Cu film with high cyclic stability, 11 the functional fatigue of the columnar-grained Cu-Al-Mn alloy leaves much to be desired, motivating us to improve its fatigue property in the following research.…”