Research Progresses of Thermal Switch Device and Its Applications in Prototype Devices of Electrocaloric Refrigeration

The electrocaloric effect is a novel solid-state refrigeration technology that is considered an option to replace traditional vapor compression refrigeration owing to its advantages, such as low cost, high coefficient of performance (COP), and miniaturization. Currently, the main limitation that hinders the application of electrocaloric refrigeration devices is the insufficient temperature change in materials exhibiting the single-chip electrocaloric effect. In device design, the use of a regenerative or series structure can increase the system temperature span to the level of engineering applications. This study introduces the concept, performance indicators, and current research achievements of thermal switch devices in a series of electrocaloric refrigeration devices. Using the principle of the electrocaloric effect, the adaptability of different types of thermal switches in electrocaloric refrigeration devices was analyzed, and the research results of regenerative and a series of electrocaloric refrigeration prototype devices were presented. Simulations and analyses of the impact of thermal switching devices on the performance of refrigeration devices were conducted using a series of electrocaloric refrigerators. We believe that the series structure is theoretically suitable for electrocaloric refrigeration devices. The use of the fast response speed and high thermal resistance of thermal switch devices driven by an electric field to drive the fluid medium can assist a series of electrocaloric refrigeration devices to address the current technological limitation and thus unleash the technical potential of electrocaloric refrigeration technology in various refrigeration systems.