Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Performance of magnetic refrigerators operating with different magnetic profiles
Submission Author:
Fábio Pinto Fortkamp , SC
Co-Authors:
Fábio Pinto Fortkamp, Gusttav Bauermann Lang, Jaime Lozano, Jader Riso Barbosa Jr.
Presenter: Fábio Pinto Fortkamp
doi://10.26678/ABCM.COBEM2017.COB17-1067
Abstract
Magnetic refrigeration is a technology based on the concept of the active magnetic regenerator (AMR), which is a solid porous matrix of magnetocaloric material that undergoes temperature variations according to changes in the magnetization synchronized with oscillatory fluid flows. The magnetic field can be applied to the AMR in different profiles (waveforms). In this work, the performance of a magnetic refrigerator is evaluated in terms of two of the most common magnetic profiles: an instantaneous profile and a rectified cosine profile. The results show that the performance of an AMR operating with the instantaneous profile is consistently better than an AMR using the cosine profile with the same average high magnetic field and same minimum value, and that this improvement is higher for larger utilizations (ratio of solid to fluid thermal capacities). For an AMR frequency of 1 Hz and an utilization of 1.0, the cooling capacity of an AMR device operating with the instantaneous profile was 196.3 % higher than the equivalent rectified cosine profile. The instantaneous profile was then analyzed in more detail, and it was concluded that using high values of magnetic field allows for smaller regenerators and lower mass flow rates to keep a desired level of cooling power.
Keywords
magnetic refrigeration, active magnetic regenerator, Numerical Modeling, magnetocaloric effect
