Thermodynamics of elastocasloric cooling and heat pump cycles

Elastocaloric cooling is an emerging solid-state cooling technology and has experienced fast development over the last decade. This study aims to systematically introduce the thermodynamic description of elastocaloric cooling and heat pump cycles by derivation from the classical first law and the second law of thermodynamics. The thermodynamic cycle description is then used to discuss the temperature and path-dependent material COP. The impact of incomplete phase transition is analyzed and compared to previous results in the literature. The importance of work recovery and heat recovery is also revisited. Finally, the relationship between the thermodynamic cycle description and the simulation models is discussed.