SEMINAR ON MAGNETIC REFRIGRATION Attractive ALTERNATIVE COOLING TECHNOLOGY

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SEMINAR ONMAGNETIC REFRIGRATIONAttractive
ALTERNATIVE COOLING TECHNOLOGY

• BY
• RAMAKANTH P JOSHI
• 1JS06ME034

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outline
Magnetocaloric effect Principle Prototype
Ames lab astronaut corp America Advantages of
magnetic refrigeration Technology
comparison Future scope
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magnets

• Ferromagnetic materials alloy of Al, Ni,Fe,Co
• Paramagnetic materials Cr,Mn, Pt, Pd, K, Cu.
• Diamagnetic materials Zn, Bismuth, antimony.

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WAYS TO COOL

• Expansion and compression of gas lt30 Fridge,
  Bicycle pump
• Evaporation of liquids very robust plants,
  animals, weather
• Peltier effects not very efficient Radiators
• Magnetic refrigeration 60 Proof of
  principle apparatus
• ( Cooling with the help of external magnetic
  field)

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Introduction

• PRINCIPLE Magnetocaloric effect due to variable
  field

• Currie temperature
• (768C for Fe)

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Demonstration of MCE
In a small physics experiment the magneto
calorific effect in a gadolinium sample is
demonstrated. Magnetization heats the sample up
and demagnetization cools it down
B
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Thermo dynamic cycle

• Steps of thermodynamic cycle
• Adiabatic magnetization
• Isomagnetic enthalpic transfer
• Adiabatic demagnetization
• Isomagnetic entropic transfer

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Graphical representation
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regenerators
(a) Tubes Cu or Ag (b) Perforated plates
stainless steel (c) Wire screens - Cu (d)
Particle beds ceramic or metal sphere
AIM To achieve good thermal conductivity
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Desired Properties of working materials

• Large magneto calorific effect
• Significant MCE at reasonable fields
• Curie temperature
• Environment friendly materials
• Affordable, abundant and easily synthesizable
  materials

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Working Materials
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comparison
Analogy between magnetic refrigeration and vapor
cycle refrigeration
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Technology comparison
COMPRESSION MAGNETIC
Environmental impact Liquid based (CFC) Environmentally safe
Cooling efficiency lt40 60
durability 20 years 50 years
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Advantages of magnetic refrigeration

• Green technology
• Noise-less technology
• Very high thermodynamic efficiency
• Low energy consumption
• Simple design and building
• Long life
• Low pressure

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Ideal applications

1. House hold refrigerators appliances
2. Central cooling systems
3. Room air conditioners
4. Supermarket refrigeration ( display cabinets)

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Future scope

• Less mass of magnet by 3-d field concentration
• Higher volume fractions of porous structures
• Higher frequencies of rotation
• Application of hybrid materials

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CONCLUSION

• MCE dH implies dS
• Magnetic refrigeration can be cycled
• Magnetic refrigeration demonstrated to be
• most efficient
• very compact
• eco friendly
• Trouble free
• Prominent MCE materials for room temperature
  Rare earth metals.

Use of Magnetic refrigerator reduces wastage of
energy
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BIBLIOGRAPHY
BASIC AND APPLIED THERMODYNAMICS by Dr. P K Nag
2/e TMH publication   www.wikipedia.com   www.free
patentsonline.com   www.globlespec.com   Research
paper magnetic refrigeration by JEFF JOHNSON    
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THANK YOU