Review and comparison of magnet designs for magnetic refrigeration

TL;DR

This paper reviews and compares various permanent magnet designs for magnetic refrigeration, analyzing their efficiency based on magnetic flux, volume, and material use to identify the most effective configurations.

Contribution

It provides a detailed efficiency analysis of existing magnet designs and offers recommendations for optimal magnet design in magnetic refrigeration systems.

Findings

Identified the most efficient magnet design based on the figure of merit $\\Lambda_{cool}$.

Compared multiple magnet configurations to evaluate their magnetic flux density and material usage.

Proposed guidelines for designing improved magnets for magnetic refrigeration applications.

Abstract

One of the key issues in magnetic refrigeration is generating the magnetic field that the magnetocaloric material must be subjected to. The magnet constitutes a major part of the expense of a complete magnetic refrigeration system and a large effort should therefore be invested in improving the magnet design. A detailed analysis of the efficiency of different published permanent magnet designs used in magnetic refrigeration applications is presented in this paper. Each design is analyzed based on the generated magnetic flux density, the volume of the region where this flux is generated and the amount of magnet material used. This is done by characterizing each design by a figure of merit magnet design efficiency parameter, $\Lambda_\mathrm{cool}$. The designs are then compared and the best design found. Finally recommendations for designing the ideal magnet design are presented based on the analysis of the reviewed designs.