Transcript Slide 1

Bill Brey
M.S. Graduate Student
Mechanical Engineering
Office: 1337 ERB
Email: [email protected]
Hometown: Grayslake, IL
Thesis: Development of a Numerical Model to Simulate Magnetic Hysteresis in an
Active Magnetic Refrigerator
Motivation For Research
• The giant magnetocaloric effect (GMCE) is a recent discovery
that occurs in first order magnetic transition (FOMT) materials
• These materials experience a significant adiabatic temperature
rise when subjected to a magnetic field
• These materials also experience significant hysteresis, which
limits their efficiency if used in a practical AMR device.
• The underlying question is whether the benefit of a greater
temperature change in GMCE materials outweighs the losses
due to hysteresis when compared to using non-hysteretic
magnetocaloric materials as refrigerants.
Project Goals
• Develop and implement a
model of hysteresis into the
existing 1D AMR numerical
model created at the SEL
• Validate the model using
experimental hysteresis data
for different materials
• Compare performance of
hysteretic FOMT materials to
that of non-hysteretic
magnetocaloric materials.
Active Magnetic Regenerative Refrigeration Cycle
Preliminary Results
8
279
7
6
277
With Hysteresis
5
276
No Hysteresis
COP
Temperature [K]
278
4
275
3
274
2
273
0
1
2
4
6
8
10
12
Time [s]
• Single shot cyclic
magnetization/demagnetization
model
• Gradual temperature rise of
hysteretic material when
exposed to sinusoidal applied
magnetic field
0
0
2000
4000
6000
8000
10000
Entropy Generation Rate [W/kg-K]
• Entropy Generation term is
added to the energy balance
equation
• The COP of the 1D AMR
model decreases rapidly as the
entropy rate is increased