Elastocaloric Devices for Next-Generation Refrigeration and Heat Pumps

Webinar 8

SPEAKER I

Jaka Tušek (University of Ljubljana, Slovenia)

Elastocaloric cooling and heating: From the elastocaloric effect towards fatigue-resistant devices

 

Abstract: Elastocaloric cooling/heating is emerging as a promising alternative to nowadays widely used, but environmentally harmful vapor compression technology. It is based on the elastocaloric effect that occurs in superelastic shape memory materials, such as Ni-Ti based alloys.

In the first part of the talk, I will present the basics of the elastocaloric effect and different concepts of the elastocaloric devices developed to date. In the second part of the talk, I will focus on the development of fatigue-resistant elastocaloric regenerative device based on Ni-Ti tube loaded in compression and a loading mechanism that allows for work recovery. In the final part of the talk, I will discuss future improvements, such as more efficient elastocaloric materials and better regenerator structures, required for further bosting the efficiency of elastocaloric devices.

 

Related publications:

  • J. Tušek, K. Engelbrecht, D. Eriksen, S. Dall’Olio, J. Tušek, N. Pryds, A regenerative elastocaloric heat pump, Nature Energy 1 (2016) 16134
  • Ž. Ahčin, S. Dall’Olio, A. Žerovnik, U. Žvar Baškovič, L. Porenta, P. Kabirifar, J. Cerar, S. Zupan, M. Brojan, J. Klemenc, J. Tušek, High-performance cooling and heat pumping based on fatigue-resistant elastocaloric effect in compression, Joule 6 (2022) 2338-2357

 

SPEAKER II

Julie Slaughter (Ames National Laboratory, U.S. Department of Energy)

Compact, Low-Force Elastocaloric Devices and Their Applications

 

Abstract: Advanced laboratory-scale devices using commercially-available nickel-titanium alloys (Nitinol) as refrigerants show great promise to meet the performance, efficiency, and scalability needed for applications such as refrigeration, air conditioning, and heat pumping. Because it is based on a solid-state phase transformation it does not rely on harmful refrigerants, high pressure fluid lines, and noisy compressors used in today’s technology.

While there are many materials that exhibit the elastocaloric effect, I will focus on the properties of superelastic nickel-titanium alloys (Nitinol) and how it can be used in active elastocaloric regenerators. Next, I will discuss a low-force active regenerator based on a composite structure tailored for air conditioning. My discussion will center around recent results and how this concept can be scaled to a larger device, including work recovery. I will also discuss a second elastocaloric device concept that is based on bending Nitinol wires or strips. This device is aimed at personal cooling and can be scaled up for full-sized air conditioning. Finally, I will discuss future applications and the materials and devices needed to support this emerging technology.

This work was supported by the U.S. Department of Energy (DOE) and the U.S. Department of Defense. The research was performed at Ames National Laboratory, which is operated for the U.S. DOE by Iowa State University under contract # DE-AC02-07CH11358.

 

Related publications:

  • Czernuszewicz, A., Griffith, L., Slaughter, J., & Pecharsky, V. (2020). Low-force compressive and tensile actuation for elastocaloric heat pumps. Applied Materials Today, 19, 100557. https://doi.org/10.1016/j.apmt.2020.100557
  • Slaughter, J., Czernuszewicz, A., Griffith, L., & Pecharsky, V. (2020). Compact and efficient elastocaloric heat pumps — Is there a path forward? Journal of Applied Physics, 127(19), 194501. https://doi.org/10.1063/5.0003275