A comparison between different materials with mechanocaloric effect

Caloric refrigeration can be a viable alternative to the traditional vapour compression technology since a caloric solid refrigerant has zero vapour pressure and therefore is ecological with no direct Ozone Depletion Potential and zero direct Global Warming Potential. Caloric refrigeration embraces four main cooling techniques, each one based on a different caloric effect. This paper is focused upon materials that display mechanocaloric properties, with a transition induced through the application of variable pressure (barocaloric cooling) or uniaxial stress (elastocaloric cooling). Materials that display solid-state caloric effects driven by applied pressure/stress could lead to more accessible and economic technological solutions. By means of a two-dimensional mathematical model an energy analysis is performed with the most performing elastocaloric and barocaloric materials to explore the potential of mechanocaloric cooling. Temperature span, cooling power and coefficient of performance have bene evaluated. Results demonstrate best mechanocaloric materials, like Cu68.13Zn15.74Al16.14 and (NH4)2MoO2F4, provide energy performances better than those of traditional vapour compression plants.