Optimization of Magnetic Refrigerators by Tuning the Heat Transfer Medium and Operating Conditions

TL;DR

This paper presents an experimental approach to optimize the operating conditions of a magnetic refrigerator, demonstrating a 24% increase in performance by tuning parameters like frequency and flow rate.

Contribution

It introduces a methodology for optimizing single-stage AMR operation conditions to maximize temperature span and efficiency near room temperature.

Findings

Optimal operating frequency identified

Flow rate and displaced volume ratio optimized

Refrigeration performance increased by 24%

Abstract

A new experimental test bed has been designed, built, and tested to evaluate the effect of the systems parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as the refrigerant, silicon oil as the heat transfer medium, and a magnetic field of 1.3 T was cycled. This study focuses on the methodology of single stage AMR operation conditions to get a higher temperature span near room temperature. Herein, the main objective is not to report the absolute maximum attainable temperature span seen in an AMR system, but rather to find the systems optimal operating conditions to reach that maximum span. The results of this research show that there is a optimal operating frequency, heat transfer fluid flow rate, flow duration, and displaced volume ratio in an AMR system. By optimizing these parameters the refrigeration performance increased by 24%. It is expected that such optimization will permit the design of a more efficient magnetic refrigeration system.