Natural rubber based elastocaloric solid-state refrigeration device: design and performances of a single stage system

The elastocaloric effect denotes the ability of a material to release or absorb heat when the material is stretched and released respectively. This effect may be used to design an alternative cooling device. This work focuses on the development of a cooling device using natural rubber (NR) as the elastocaloric material. It consists of a solid-solid heat exchange between a cyclically stretched elastocaloric material and two exchangers, respectively put in contact with the elastocaloric material when it is stretched or released. An experimental device was designed and tested in order to assess the temperature span and cooling power (PC) achievable by NR based single stage device. The effect of the thickness of the NR is also discussed. It is shown that it was possible to transfer nearly 60% of the heat absorption potential of the NR from the cold heat exchanger. From the measurements, the highest PC was found to be 390 mW (430 W kg-1) for a 600 mu m thick sample, and 305 mW (540 W kg-1) for a 400 mu m thick sample. The temperature span was found to be similar for both materials, ranging 1.5 degrees C-1.9 degrees C.