Invited Speaker

Dr. Claudia Masselli

Dr. Claudia Masselli

University of Naples Federico II, Italy
Speech Title: The State of the Art, the Breakthrough of the Elastocaloric Cooling and the Development of SUSSTAIN-EL, the First Italian Elastocaloric Device

Abstract: Nowadays about 20% of the worldwide energy consumption is attributable to refrigeration that is almost entirely based on vapor compression refrigeration. Such data derives in a driving force towards the research and development of new cooling techniques that could become an alternative to the vapor compression, meeting the requirements of environmental and energy sustainability. In the general framework of the various emerging proposals, in the scientific literature noteworthy is the class of solid-state cooling techniques based on the caloric effect. Caloric effect is a physical phenomenon manifesting in an increase or a decrease of the temperature of a caloric material due to the adiabatic variation of the intensity of an external field and that is applied. The nature of the applied field (magnetic, electric, mechanical) particularizes it in magneto-, electro-, mechano- (elasto- or baro-) caloric effect. The main advantages shown by caloric refrigeration refer to improvements in terms of energy efficiency and reduction of the environmental impact. This is due both to the solid-state nature of the materials employed as refrigerants (therefore characterized by no global warming potential and zero ozone depletion potential) and to the intrinsically reversible nature of the processes associated with the fields. The choice of the caloric material to be used as refrigerant is a key point for the development of efficient refrigeration systems as it must respond to some specific requirements connected to: the toxicity, the ease of synthesis, the manifestation of a large caloric effect in the range of temperature required for the application, to the mechanical resistance and to the high workability, low costs and ease of availability at international level. In the field of caloric cooling scientific community has devoted the attention specifically toward magnetocaloric and elastocaloric refrigeration. Elastocaloric refrigeration is based on the latent heat associated with the transformation process of the martensitic phase, found in Shape Memory Alloys (SMA) when they are subjected to uniaxial stress cycles of loading and unloading. SMAs are characterized by the mechanical property of being able to return to the initial form once the uniaxial stress has been removed. By exploiting this effect in a reverse regenerative thermodynamic cycle called "Active elastocaloric regenerative refrigeration cycle (AeR)", a satisfactory cooling effect is achievable. The prototypes of elastocaloric cooler developed so far in the world are less than ten units and they are still in a “pre-competitive development activity-phase”, not close to the industrialization and commercialization, yet. Italy has not presented its first prototype of elastocaloric cooler to the scientific community, yet.
The aim of this prensentation is to focus on the main breaktrough of the caloric and more specifically elastocaloric cooling technology in order to provide a general framework of the state of the art. Moreover, the design processes and the steps of development of the first Italian elastocaloric device: SSUSTAIN-EL will be introduced.