NPL electrocaloric project could change the refrigeration industry
December 17, 2013 - Scientists at the U.K.’s National Physical Laboratory (NPL) and Imperial College are working to make the current method of refrigeration and air-conditioning a thing of the past via the electrocaloric effect.
By Anthony Capkun
The electrocaloric effect is a phenomenon in which a material changes temperature under an applied electric field. Current domestic refrigeration relies on a continuous cycle of compression and expansion of chemicals (vapour compression). Freon gas, for example, can be cooled and condensed into a liquid. This liquid then absorbs heat from the refrigeration area, causing it to re-evaporate, where it begins the cycle again.
These chemicals have a fairly low efficiency, says NPL, requiring high energy input to create adequate cooling. They also require bulky apparatus, making them unsuitable for smaller applications, such as cooling electronics.
Thermoelectric and magnetic cooling technologies have been put forward as environmentally friendly alternatives to vapour compression, but they struggle to compete due to intrinsically low energy efficiency (maximum 10%), says NPL, and the need for large and expensive magnets to generate the fields needed to run magnetic coolers.
“An electrocaloric cooler, however, could potentially deliver higher efficiency than vapour compression, as the creation of an electric field requires less energy than the compression process to create the same level of cooling,” argues Maciej Rokosz, Ph.D. student at NPL and Imperial. “It could also offer reduced size and weight, making it viable for applications like cooling electronics.”
Tatiana Correia, a scientist at NPL who is leading the project, adds “Our experience in this area makes us confident that, over the next three years, we can develop the first electrocaloric refrigerator ever to operate close to room temperature”.
“However we are still very keen to hear from industry, who can work with us to look at the different applications this could be applied to,” concluded Correia.