Elastocaloric Cooling Device: Materials and Modeling

In the last decade we have witnessed the development of alternative solid-state cooling technologies based on so-called ferroic (caloric) effects. A large effort nowadays is devoted to investigating solid-state refrigeration using the magnetocaloric effect (change of temperature upon application of a magnetic field). However, the possibility of inducing a thermodynamic transition by means of mechanical stress, i.e. the elastocaloric effect in superelastic materials, opens up new routes for solid-state refrigeration. 

In this work, we show the superelastic behavior and related elastocaloric effect of commercial Ni-Ti wires, obtained experimentally as well as through phenomenological modeling (based on the experimentally obtained results). Furthermore, different design solutions of potential elastocaloric cooling devices are presented and discussed. The most promising solution is further investigated through numerical modeling using a detailed system model in order to estimate its cooling power and efficiency (COP) at different operating conditions. In the end, we propose guidelines about the required material properties for an efficient elastocaloric cooling device.