21-01-2012, 05:04 PM
MAGNETIC REFRIGERATION
[attachment=16436]
Introduction to Refrigeration
Refrigeration is the process of removing heat from an enclosed space or from a substance and moving it to a place where it is unobjectionable
The primary purpose of refrigeration is lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.
Principle of Magnetic Refrigeration
-Magneto calorific effect is the basic principle on which the
cooling(Magnetic refrigeration) is achieved.
- The Magneto caloric effect (MCE, from magnet and calorie) is a
magneto-thermodynamic phenomenon in which a reversible
change in temperature of a suitable material is caused by exposing
the material to a changing magnetic field
-This is also known as adiabatic demagnetization by low
temperature physicists, due to the application of the process
specifically to affect a temperature drop.
Adiabatic Magnetization
-The substance is placed in an insulated
environment and magnetic field is applied.
- The increasing external magnetic field (+H)
-causes the magnetic dipoles of the atoms to
align.
-As a result material’s magnetic entropy and heat
capacity decreases.
- The net result is that the item heats up
(T + ΔTad).
[attachment=16436]
Introduction to Refrigeration
Refrigeration is the process of removing heat from an enclosed space or from a substance and moving it to a place where it is unobjectionable
The primary purpose of refrigeration is lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.
Principle of Magnetic Refrigeration
-Magneto calorific effect is the basic principle on which the
cooling(Magnetic refrigeration) is achieved.
- The Magneto caloric effect (MCE, from magnet and calorie) is a
magneto-thermodynamic phenomenon in which a reversible
change in temperature of a suitable material is caused by exposing
the material to a changing magnetic field
-This is also known as adiabatic demagnetization by low
temperature physicists, due to the application of the process
specifically to affect a temperature drop.
Adiabatic Magnetization
-The substance is placed in an insulated
environment and magnetic field is applied.
- The increasing external magnetic field (+H)
-causes the magnetic dipoles of the atoms to
align.
-As a result material’s magnetic entropy and heat
capacity decreases.
- The net result is that the item heats up
(T + ΔTad).