On the cooling potential of elastocaloric devices for building ventilation

Ulpiani, Giulia; Saliari, M.; Bruederlin, Florian; Kohl, Manfred; Ranzi, Gianluca

doi:10.1016/j.solener.2021.10.025

Cited by 11 publications

(2 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The evolution of adiabatic temperature changes of the NiTi wires with the training cycle is shown in Supplementary Note S 5 . Similarly, the NiTi dog-bone specimen was trained 61 – 63 for 200 tensile cycles with a strain range of 7% at a strain rate of 7 × 10 −4 s −1 .…”

Section: Methodsmentioning

confidence: 99%

Continuous and efficient elastocaloric air cooling by coil-bending

Li,

Hua,

Sun

2023

Nat Commun

View full text Add to dashboard Cite

Elastocaloric cooling has emerged as an eco-friendly technology capable of eliminating greenhouse-gas refrigerants. However, its development is limited by the large driving force and low efficiency in uniaxial loading modes. Here, we present a low-force and energy-efficient elastocaloric air cooling approach based on coil-bending of NiTi ribbons/wires. Our air cooler achieves continuous cold outlet air with a temperature drop of 10.6 K and a specific cooling power of 2.5 W g−1 at a low specific driving force of 26 N g−1. Notably, the cooler shows a system coefficient of performance of 3.7 (ratio of cooling power to rotational mechanical power). These values are realized by the large specific heat transfer area (12.6 cm2 g−1) and the constant cold zone of NiTi wires. Our coil-bending system exhibits a competitive performance among caloric air coolers.

show abstract

Section: Methodsmentioning

confidence: 99%

Continuous and efficient elastocaloric air cooling by coil-bending

Li,

Hua,

Sun

2023

Nat Commun

View full text Add to dashboard Cite

show abstract

“…[51][52][53][54][55][56][57][58][59][60][61][62][63][64] For an actual cooler or heat pump, it always operates at a finite temperature lift between the hot side (heat sink) with a temperature of T h and the cold side (heat source) with a temperature of Tc. [65][66][67][68][69][70][71][72][73][74][75][76][77] Comprehensive characterizations of the superelastic and elastocaloric effects of NiTi and NiTi-based SMAs in the desired temperature range are vital to the development of this cutting-edge technology for green heating and air-conditioning.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the temperature-dependent superelastic and elastocaloric effects of a NiTi tube under compression at 293–330 K

Cheng,

Yan,

et al. 2024

AIP Advances

View full text Add to dashboard Cite

Comprehensive characterizations of the superelastic and elastocaloric effects of NiTi and NiTi-based shape memory alloys (SMA) in the operation temperature region are highly desirable for using them in elastocaloric coolers with a large temperature lift. In this article, we report the superelastic and elastocaloric effects of a commercially available superelastic polycrystalline NiTi SMA tube with an outer diameter of 5 mm and a wall thickness of 1 mm between 293 and 330 K. The NiTi tube sample was subjected to a training of 250 cycles to stabilize its superelastic and elastocaloric effects. We observed that temperature dependencies existed for both superelastic and elastocaloric effects of the NiTi tube, and stress–strain curves differed much between isothermal and adiabatic loading conditions. The largest temperature rise and temperature drop measured at 293 K under an applied strain of 3.66% and a strain rate of 0.1 s−1 during loading and unloading were 21 and 11 K, respectively. The loading conditions (loading function and holding time) also impacted the superelastic effect of the NiTi tube. We identified two major reasons for the irreversibility of the adiabatic temperature change: the hysteresis heat dissipation and the temporary residual strain after unloading, and they affected the cooling performance of the elastocaloric cooler in different ways. We investigated the dependencies of the superelastic and elastocaloric effects on the maximum applied strain and the temperature distribution on the NiTi tube during loading and unloading. The results are beneficial to the modeling of elastocaloric coolers with large temperature lifts.

show abstract