Publish Date: 13.10.2022

Category: News from the University

A PERMANENT-DYNAMIC ELASTOCALORIC REGENERATOR WITH RECORD-BREAKING COOLING AND HEATING PERFORMANCE

As part of the ERC project SUPERCOOL (Superelastic Porous Structures for Efficient Elastocaloric Cooling), researchers from the University of Ljubljana’s Faculty of Mechanical Engineering demonstrated the development and operation of a new concept for a compression-loaded elastocaloric regenerator for use in cooling devices and heat pumps of the future. The elastocaloric regenerator developed as part of this project is the first in the world to achieve permanent-dynamic performance, along with record-breaking cooling and heating characteristics that exceed the specific properties of all caloric cooling devices to date.

Cooling, air conditioning and heating are essential for modern society. While global demand for cooling and efficient heating has grown exponentially over the last decade, our standard vapour-compression cooling and heat extraction technology is old, relatively inefficient and still makes use of environmentally harmful coolants. Vapour-compression cooling technology is therefore one of the main contributors to the greenhouse effect. Ironically, the more we cool ourselves, the greater our cooling needs will be. But the worst is yet to come. For example, the electricity used to power air-conditioning in the US already exceeds the total electricity consumption for the whole of Africa. It is estimated that by mid-century, the number of air conditioners worldwide will grow from the current 1.6 billion to 5.6 billion. At such a rate of increase in cooling demand, energy use for cooling will overtake total energy use for heating in 2060, and by the end of the century will exceed it by more than 60%. Alternative technologies that have shown great potential in recent years include elastocaloric cooling and heating, which is based on harnessing the elastocaloric effect during cyclic loading of shape-memory materials. Such materials are completely harmless to the environment, and elastocaloric technology can potentially outperform vapour-compression technology. One of the main limitations of this technology, which hinders its commercial application, is the limited durability of shape memory-materials under cyclic loading.

The research results, published on 20 September 2022 in the prestigious journal Joule (IF=46,048), demonstrate the feasibility of developing permanent-dynamic elastocaloric devices with exceptional cooling and heating characteristics, thus opening the door to the further development of efficient and environment-friendly elastocaloric cooling devices and heat pumps.

As the project leader, Asst. Prof. Jaka Tušek, explained: “In addition to elastocaloric cooling technology, the findings of the SUPERCOOL project will also influence many other fields, such as medicine, construction and mechanical engineering, where shape-memory materials are already widely used, but their potential and limitations are not yet well understood.”

The project is the second out of six European Research Council (ERC) Starting Grant projects currently under way in Slovenia. This is also the first such grant for early-career researchers under the Horizon 2020 programme, with EUR 1.4 million over five years (2019–2023).

The paper is freely available at the following links:

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