Highly Efficient Drive System for Elastocaloric Heat Pumps and Cooling Systems

The need for alternative cooling technologies aside from compressor based cooling is growing since more and more refrigerants get regulated. One promising technology is cooling with the elastocaloric effect by using a phase change of elastocaloric materials that induces a temperature change within the material. The crucial point in the commercialization of this technology is the efficiency of the elastocaloric system including elastocaloric material and the drivetrain. Literature often gives values for the efficiency without including the actuator that drives the system although this is necessary to determine the overall total efficiency. In this study, we introduce a highly efficient drive system based on energy recuperation and deduce the efficiency of this concept. The actuator drive consists of an oscillating armature and is driven by reluctance forces. For the characterization of the system, the elastocaloric material is exchanged with preloaded springs. This gives rise to the possibility of measuring the efficiency of the actuator system itself without considering the elastocaloric material. The efficiency of the drive system is determined to be η A = 95.7 % .