SIMULATION OF MAGNETIC REFRIGERATION SYSTEMS WITH THERMAL DIODES AND AXIAL CONDUCTIVE HEAT TRANSFER

摘要

In conventional magnetic refrigeration cycles with heat transfer fluid, the achievable cycle frequency, andrntherefore, specific cooling capacity is limited. Furthermore, ineffective use of magnet in low frequencyrndevices makes them expensive. In this work, as an alternative technique, utilizing conductive heat transferrncontrolled by two different types of thermal diodes, gas-liquid and contact-break diodes, is investigated. Forrnthat purpose two software models are made to simulate the performance of a magnetic refrigerator with eachrnof the diodes. The results of simulations are presented and comparison is made between these results andrnthe results of older studies which used ideal properties. According to the results, due to the limited thermalrnconductivity of the magnetocaloric materials, the increase in the capacity becomes small with too highrnfrequencies. Among the thermal diodes and materials studied, the liquid metal Galinstan as the conductingrnfluid in an active diode gave the best results.