0
Research Papers

Modeling of Thermomagnetic Phenomena in Active Magnetocaloric Regenerators

[+] Author and Article Information
Paulo V. Trevizoli

POLO—Research Laboratories for Emerging
Technologies in Cooling and Thermophysics,
Department of Mechanical Engineering,
Federal University of Santa Catarina,
Florianópolis, SC 88040-900, Brazil
e-mail: trevizoli@polo.ufsc.br

Jader R. Barbosa, Jr.

Mem. ASME
POLO—Research Laboratories for Emerging
Technologies in Cooling and Thermophysics,
Department of Mechanical Engineering,
Federal University of Santa Catarina,
Florianópolis, SC 88040-900, Brazil
e-mail: jrb@polo.ufsc.br

Armando Tura

IESVic—Institute for Integrated Energy Systems,
Department of Mechanical Engineering,
University of Victoria,
PO Box 1700 STN CSC,
Victoria, BC V8W 2Y2, Canada
e-mail: atura@uvic.ca

Daniel Arnold

IESVic—Institute for Integrated Energy Systems,
Department of Mechanical Engineering,
University of Victoria,
PO Box 1700 STN CSC,
Victoria, BC V8W 2Y2, Canada
e-mail: dsarnold@uvic.ca

Andrew Rowe

IESVic—Institute for Integrated Energy Systems,
Department of Mechanical Engineering,
University of Victoria,
PO Box 1700 STN CSC,
Victoria, BC V8W 2Y2, Canada
e-mail: arowe@uvic.ca

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received August 23, 2013; final manuscript received January 7, 2014; published online April 11, 2014. Assoc. Editor: S.A. Sherif.

J. Thermal Sci. Eng. Appl 6(3), 031016 (Apr 11, 2014) (10 pages) Paper No: TSEA-13-1145; doi: 10.1115/1.4026814 History: Received August 23, 2013; Revised January 07, 2014

The active magnetic regenerator (AMR) consists of a porous matrix heat exchanger whose solid phase is a magnetocaloric material (solid refrigerant) that undergoes a reversible magnetic entropy change when subjected to a changing magnetic field. The cooling capacity of the cycle is proportional to the mass of solid refrigerant, operating frequency, volumetric displacement of the heat transfer fluid and regenerator effectiveness. AMRs can be modeled via a porous media approach and a model has been developed in this work to simulate the time-dependent fluid flow and heat transfer processes in the regenerator matrix. Gadolinium (Gd) is usually adopted as a reference material for magnetic cooling at near room temperature and its magnetic temperature change and physical properties were accounted for through a combination of experimental data and the Weiss-Debye-Sommerfeld (WDS) theory. In this paper, the interaction of the applied magnetic field waveform with the heat transfer fluid displacement profile and the influence of demagnetizing effects on the AMR performance are investigated numerically. The numerical model is evaluated against experimental data for a regenerator containing spherical Gd particles.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic description of the processes in a thermomagnetic Brayton cycle

Grahic Jump Location
Fig. 2

Entropy-temperature diagram for a magnetocaloric material and the quantification of the magnetocaloric effect

Grahic Jump Location
Fig. 3

Specific heat capacity of gadolinium as a function of temperature for several values of applied magnetic field

Grahic Jump Location
Fig. 4

Experimental apparatus

Grahic Jump Location
Fig. 5

Applied magnetic field waveforms (simulated)

Grahic Jump Location
Fig. 6

No load numerical results for the three waveforms

Grahic Jump Location
Fig. 7

Load numerical results for different waveforms for the hot source at 290 K

Grahic Jump Location
Fig. 8

Load numerical results for different waveforms for the hot source at 295 K

Grahic Jump Location
Fig. 9

numerical results for different waveforms for the hot source at 300 K

Grahic Jump Location
Fig. 10

Numerical dimensionless temperature transient of the solid phase at the hot and cold ends of the regenerator for the different waveforms

Grahic Jump Location
Fig. 11

Numerical instantaneous cooling capacity for the different waveforms

Grahic Jump Location
Fig. 12

Rectified sinusoidal waveform for the applied magnetic field and the effective field in different volumes along the regenerator length

Grahic Jump Location
Fig. 13

Comparison between the experimental data and numerical results for the no load tests

Grahic Jump Location
Fig. 14

Comparison between the experimental and numerical load results for a stroke of 15 mm, frequency of 0.5 Hz and different hot source temperatures

Grahic Jump Location
Fig. 15

Comparison between the experimental and numerical load results for a frequency of 0.75 Hz, hot source temperature of 298 K and different strokes

Grahic Jump Location
Fig. 16

Comparison between the experimental and numerical load results for a hot source temperature of 298 K and a temperature span of 5 K

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In