1. BY : RAMAKANTH P JOSHI 1JS06ME034

2. Magnetocaloric effect Principle Prototype : Ames lab & astronaut corp America Advantages of magnetic refrigeration Technology comparison Future scope

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

4.  Expansion and compression of gas <30%Fridge, Bicycle pump  Evaporation of liquids very robustplants, animals, weather  Peltier effects not very efficientRadiators  Magnetic refrigeration ~60%Proof of principle apparatus ( Cooling with the help of external magnetic field)

5. Introduction  PRINCIPLE : Magnetocaloric effect due to variable field  Currie temperature (768°C for Fe)

6. 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

7. THERMO DYNAMIC CYCLE Steps of thermodynamic cycle  Adiabatic magnetization  Isomagnetic enthalpic transfer  Adiabatic demagnetization  Isomagnetic entropic transfer

13. (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

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

17. COMPARISON Analogy between magnetic refrigeration and vapor cycle refrigeration

18. COMPRESSIONMAGNETIC Environmental impact Liquid based (CFC) Environmentally safe Cooling efficiency <40%≥60% durability~20 years~50 years

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

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

21. 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

22. CONCLUSION  MCE : dH implies dS  Magnetic refrigeration can be cycled  Magnetic refrigeration demonstrated to be 1.most efficient 2.very compact 3.eco friendly 4.Trouble free  Prominent MCE materials for room temperature : Rare earth metals.

23. BIBLIOGRAPHY BASIC AND APPLIED THERMODYNAMICS by Dr. P K Nag 2/e TMH publication www.wikipedia.com www.freepatentsonline.com www.globlespec.com Research paper: magnetic refrigeration by JEFF JOHNSON