Numerical study of a cascade cycle for the reciprocating solid-state magnetic refrigerator

Abstract

In this research, a novel reciprocating solid state magnetic refrigeration (MR) cycle at room temperature is described and numerically simulated. An ingenious double-layer structural design enables the regenerative process to be spontaneously completed between high- and low-temperature magnetocaloric material (MCM) lattices. Layering MCMs with different Curie temperature points are adopted to optimize the cycle, and the temperature span and temperature distribution characteristics are compared between single- and multi-layer regenerators. The effects of crucial variables, including the model’s structural parameter, operating parameter, MCM type and arrangement, are discussed in detail. With an applied magnetic field of 1.0 T, a maximum no-load temperature span of 14.6 K is obtained when using gadolinium as MCM. If the LaFeCoSi alloys are adopted in the multi-layer regenerator, the temperature span increases from 14.6 K to 22.6 K, i.e., an enhancement of 56.9 %. In addition, an improvement in cascade cycle refrigeration performance will occur with increasing lattice number, contact time and operating temperature. The results reveal good potential for bulk applications. Meanwhile, the implementation method and suggested improvements can serve as guidelines for solid state MR design and optimization.