SEMINAR ONSEMINAR ON

MAGNETIC REFRIGERATIONMAGNETIC REFRIGERATION

PRESENTED BYPRESENTED BY

GANESH PRALHAD BHARAMBEGANESH PRALHAD BHARAMBE

UNDER THE ABLE GUIDANCE OFUNDER THE ABLE GUIDANCE OF

PROF. A. M. PATIL.PROF. A. M. PATIL.

DEPARTMENT OF MECHANICAL ENGINEERING,DEPARTMENT OF MECHANICAL ENGINEERING,

PADMABHUSHAN VASANTRAODADA PATIL INSTITUTE OF PADMABHUSHAN VASANTRAODADA PATIL INSTITUTE OF TECHNOLOGY,TECHNOLOGY,

BUDHAGAON, DIST. SANGLI. MAHARASHTRA. BUDHAGAON, DIST. SANGLI. MAHARASHTRA.

ACKNOWLEDGEMENTACKNOWLEDGEMENT

THE AUTHOR OF THIS SEMINAR IS THE AUTHOR OF THIS SEMINAR IS THANKFUL TO PROF. A.M. PATIL AND THANKFUL TO PROF. A.M. PATIL AND PROF. DANGE FROM MECHANICAL PROF. DANGE FROM MECHANICAL DEPARTMENT FOR GIVING VALUABLE DEPARTMENT FOR GIVING VALUABLE GUIDANCE FOR PREPARING THIS GUIDANCE FOR PREPARING THIS SEMINAR. THEIR INSPIRATIONS HAVE SEMINAR. THEIR INSPIRATIONS HAVE SUCCEEDED IN GIVING A FULL FORM SUCCEEDED IN GIVING A FULL FORM AND SHAPE OF THIS SUBJECT IN DEPTH.AND SHAPE OF THIS SUBJECT IN DEPTH.

GP BHARAMBE GP BHARAMBE

CONTENTSCONTENTS

>>Basic principles of magnetic refrigerationBasic principles of magnetic refrigeration

>Thermodynamic cycle>Thermodynamic cycle

>>Materials : Working materials, DevelopmentMaterials : Working materials, Development in materials and Nano composits in materials and Nano composits

which can play important role in which can play important role in upgradin the efficiency of materials upgradin the efficiency of materials

>Commercial aspects>Commercial aspects

>Historical background >Historical background

MAGETIC REFRIGERATIONMAGETIC REFRIGERATION

AIMS OF SEMINAR : AIMS OF SEMINAR :

To understand the principle and mechanism for generatingTo understand the principle and mechanism for generating

cooling effect using the magnet.cooling effect using the magnet.

Materials and process Materials and process

Commercial aspects .Commercial aspects .

Nano technology Nano technology

HistoryHistory

Practical cases of equipment building Practical cases of equipment building

Introduction : PrincipleIntroduction : Principle

Mageto calorific effect is the basic principle on which the cooling Mageto calorific effect is the basic principle on which the cooling is achieved.is achieved.

All magnets bears a property called Currie effect i.e. If a All magnets bears a property called Currie effect i.e. If a temperature of magnet is increased from lower to higher range at temperature of magnet is increased from lower to higher range at certain temperature magnet looses the magnetic field. certain temperature magnet looses the magnetic field.

Currie temperature. Depends on individual property of each Currie temperature. Depends on individual property of each material.material.

As Energy input to the magnet is increased the orientation of the As Energy input to the magnet is increased the orientation of the magetic dipoles in a maget starts loosing orientation. And vice a magetic dipoles in a maget starts loosing orientation. And vice a versa at currie temperature as maget looses energy to the media it versa at currie temperature as maget looses energy to the media it regains the property. regains the property.

Thermo dynamic cycleThermo dynamic cycle

DETAILS OF THE THERMODYNAMIC CYCLE DETAILS OF THE THERMODYNAMIC CYCLE

PROCESS IS SIMILAR TO GAS COMPRESSION AND PROCESS IS SIMILAR TO GAS COMPRESSION AND EXPANSION CYCLE AS USED IN REGULAR EXPANSION CYCLE AS USED IN REGULAR REFRIGERATION CYCLE. REFRIGERATION CYCLE.

Steps of thermodynamic cycle - Steps of thermodynamic cycle -

Adiabatic magnetization Adiabatic magnetization

Isomagnetic enthalpic transfer Isomagnetic enthalpic transfer

Adiabatic demagnetization Adiabatic demagnetization

Isomagnetic entropic transferIsomagnetic entropic transfer

Adiabatic magnetization Adiabatic magnetization

Procedure to be followed :Procedure to be followed :

> Substance placed in insulated environment. > Substance placed in insulated environment.

> Magnetic field +H increased. > Magnetic field +H increased.

> Magnetic dipoles of atoms to align, thereby> Magnetic dipoles of atoms to align, thereby material decreases.material decreases.

> Total Entropy of the item is not reduced, and > Total Entropy of the item is not reduced, and item heats upitem heats up

Isomagnetic enthalpic transferIsomagnetic enthalpic transfer

> Added heat removed by fluid, gas – gaseous or > Added heat removed by fluid, gas – gaseous or

liquid helium liquid helium

> Magnetic field held constant to prevent the dipoles > Magnetic field held constant to prevent the dipoles

from reabsorbing the heat. from reabsorbing the heat.

> After a sufficient cooling magnetocaloric material > After a sufficient cooling magnetocaloric material

and coolant are seperated and coolant are seperated

Adiabatic DemagnetizationAdiabatic Demagnetization

>Substance returned to another adiabatic >Substance returned to another adiabatic ( insulated ) condition( insulated ) condition

>Entropy remains constant>Entropy remains constant

>Magnetic field is decreased, >Magnetic field is decreased,

>Thermal energy causes the magnetic moments to >Thermal energy causes the magnetic moments to overcome the field and sample cools ( adiabatic overcome the field and sample cools ( adiabatic temperature change )temperature change )

>Energy transfers from thermal entropy to >Energy transfers from thermal entropy to magnetic entropy ( disorder of the magnetic dipoles magnetic entropy ( disorder of the magnetic dipoles ))

Isomagnetic entropic transferIsomagnetic entropic transfer

> Material is placed in thermal contact with the > Material is placed in thermal contact with the environment being refrigerated.environment being refrigerated.

> Magnetic field held constant to prevent from > Magnetic field held constant to prevent from heating back up heating back up

> Because the working material is cooler than the > Because the working material is cooler than the refrigerated environment, heat energy migrates refrigerated environment, heat energy migrates into the working material ( +Q )into the working material ( +Q )

**********Once the refrigerent and refrigerated Once the refrigerent and refrigerated environment are in thermal equillibrium, the cycle environment are in thermal equillibrium, the cycle begins a new begins a new

Advantages of Magnetic RefrigerationAdvantages of Magnetic Refrigeration

> Purchase cost may be high, but running costs > Purchase cost may be high, but running costs are 20% less than the conventional chillersare 20% less than the conventional chillers

> Thus life cycle cost is much less.> Thus life cycle cost is much less.

> Ozone depleting refrigerants are avoided in this > Ozone depleting refrigerants are avoided in this system, hence it more eco-friendly.system, hence it more eco-friendly.

> Energy saving would lessen the strain on our > Energy saving would lessen the strain on our household applianceshousehold appliances

> Energy conservation and reducing the energy > Energy conservation and reducing the energy costs are added advantages.costs are added advantages.

Working MaterialsWorking Materials

> Magneto caloric effect is an intrinsic porperty of > Magneto caloric effect is an intrinsic porperty of magnetic solid. magnetic solid.

> Ease of application and removal of magnetic > Ease of application and removal of magnetic effect is most desired propery of material. It is effect is most desired propery of material. It is individual characteristics and strongly depends individual characteristics and strongly depends on : on :

Curie temperature, Curie temperature, Degree of freedom for magnetic dipoles during Degree of freedom for magnetic dipoles during

ordering and randomization of particals.ordering and randomization of particals.

> ferrimagnets, antiferromagnets and spin glass > ferrimagnets, antiferromagnets and spin glass sytems are not suitable for this applicationsytems are not suitable for this application

Alloys of gadolinium producing 3 to 4 K per tesla Alloys of gadolinium producing 3 to 4 K per tesla of change in magnetic field are used for magnetic of change in magnetic field are used for magnetic refrigeration or power generation purposes.refrigeration or power generation purposes.

xxxxx AsandMnfePHSiFeLa 11 ,13)(

Development in Working MaterialsDevelopment in Working Materials

> > Recent research on materials exhibit a giant entropy Recent research on materials exhibit a giant entropy change showed. Alloys of gadolinium are promising change showed. Alloys of gadolinium are promising materials as below as compared to existing stocks.materials as below as compared to existing stocks.

GdGd55(Si(Six x GeGe1 – x 1 – x ))4, 4, La(FexSi1 – x)13Hx La(FexSi1 – x)13Hx

> These are some of the most promising substitute for > These are some of the most promising substitute for Gadolinium.Gadolinium.

Such materials are called as magnetocaloric effect Such materials are called as magnetocaloric effect materials materials

Development in Working MaterialsDevelopment in Working Materials Magnetic refrigeration works in the vicinity of a material’s Curie Magnetic refrigeration works in the vicinity of a material’s Curie

temperaturetemperature

The range of operation is = +/- 20 The range of operation is = +/- 20

In 1950’s MRC operated near by 1 to 30 K, in 1976 this range had In 1950’s MRC operated near by 1 to 30 K, in 1976 this range had expanded to 80 C around the Curie temperature.expanded to 80 C around the Curie temperature.

1997 lead this activity to built commecial and industrial use.1997 lead this activity to built commecial and industrial use.

Using the Ericcson’s cycle system refrigerator was built and used for Using the Ericcson’s cycle system refrigerator was built and used for 1500 hrs continuously.1500 hrs continuously.

Gd alloys, most notably Gd alloy, most notably Gd5(Si2Ge2), due Gd alloys, most notably Gd alloy, most notably Gd5(Si2Ge2), due to simultaneous magnetic and crystallographic first order transition, to simultaneous magnetic and crystallographic first order transition, the adiabatic temperature rise was 30% higher than that of Just Gd the adiabatic temperature rise was 30% higher than that of Just Gd and 200 – 600 % than previous refrigerent materials. and 200 – 600 % than previous refrigerent materials.

Development in Working MaterialsDevelopment in Working Materials Material Dy0.5Er0.5)Al2 has paramagnetic to ferromagnetic Material Dy0.5Er0.5)Al2 has paramagnetic to ferromagnetic

transition at 40 k where the large peak occur. transition at 40 k where the large peak occur.

Similar is Gd5(Si0.33Ge3.67) shows enormous peakSimilar is Gd5(Si0.33Ge3.67) shows enormous peak

It is possible to predict weight to mass ratio of components which It is possible to predict weight to mass ratio of components which produce maximum constant magnetic entropy. This technique produce maximum constant magnetic entropy. This technique allows one to find a suitable material composition which has a allows one to find a suitable material composition which has a constant slope on MCE vs temperature plot. It should have good constant slope on MCE vs temperature plot. It should have good magnetocaloric effect and could withstand the process of cooling. magnetocaloric effect and could withstand the process of cooling.

Gadolinium silicon germanium ternary system ( Gd-Si-Ge ), with Gadolinium silicon germanium ternary system ( Gd-Si-Ge ), with stoichiometry of Gd5(SixGe1-x)4stoichiometry of Gd5(SixGe1-x)4

Transition temperatures of the alloys formed by Gd, Tb, Dy, Ho, Er, Transition temperatures of the alloys formed by Gd, Tb, Dy, Ho, Er, Tm and Lu shows transitions with transitions above 180 k. Tm and Lu shows transitions with transitions above 180 k.

Development in Working MaterialsDevelopment in Working Materials

10 Amorphous materials shows high 10 Amorphous materials shows high resistivity and improved corrosion resistivity and improved corrosion resistance which aids the process of resistance which aids the process of magnetic refrigeration.magnetic refrigeration.

Amorphous alloys may be able to fill up Amorphous alloys may be able to fill up the gaps between 100 to 200 kthe gaps between 100 to 200 k

Gd0.54Er0.46)NiAl has 11 top effects, is Gd0.54Er0.46)NiAl has 11 top effects, is currently being implemented in currently being implemented in Erriccson cycle refrigerators. Erriccson cycle refrigerators.