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now o days golobal warming is one major enviornmental problem facing by the mankind. smr is an alternative technology that can give cooling effect without using the cfc's
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SOLAR MAGNETIC
REFRIGERATION
M.JYOTHI KUMAR CH. PRASHANTH MECHANICAL ENGINEERING
KAMALA INSTITUTE OF TECHNOLOGY & SCIENCE
SINGAPURAM, KARIMNAGAR
CONTENTS
INTRODUCTION
DRAW BACKS PRESENT REFRIGERATION
SYSTEM
INTRODUCING SMR
ENERGY CONVERSTIONS
MECHANISM OF ENERGY CONVERSTION
MERITS &DEMERITS
CONCLUSION
INTRODUCTION
•Refrigeration is the process of
removing heat from an enclosed
space, or from a substance.
•Primary purpose of refrigeration is
lowering the temperature of
enclosed space and then maintaining
that lower temperature
DRAW BACKS
REFRIGERENT:
DUE TO THE EMPLOYMENT OF
REFRIGERENTS DEPLETION OF OZONE
LAYER IS TAKING PLACE WHICH RESULTS
IN THE GLOBAL WARMING
INTRODUCING SMRSMR(SOLAR MAGNETIC REFRIGERATION)
which is the combination of two projects
1. SOLAR ELECTRICITY (Converting sun’s
light energy in to electrical energy)
2. MAGNETIC REFRIGERATION(Magnetic
refrigeration is a cooling technology based on the
magneto caloric effect)
Solar cycle
PRINCIPLE OF MR
Magneto calorific effect is a magneto-
thermodynamic phenomenon in which
reversible change in temperature of a
material is caused due to a changing
magnetic field
If a temperature of magnet is increased from lower to
higher range at certain temperature magnet looses the
magnetic field.
Currie temperature Depends on individual property of
each material
As Energy input to the magnet is increased the
orientation of the magnetic dipoles in a magnet starts
loosing orientation and vice versa. At Currie temperature
as magnet looses energy to the media it regains the
property.
Currie effect
STEPS IN MR CYCLE
Adiabatic magnetization
Isomagnetic enthalpy transfer
Adiabatic demagnetization
Isomagnetic entropic transfer
• The increasing external magnetic field
(+H) causes the magnetic dipoles of
the atoms to align
• The net result is that the item heats
up (T + ΔT)
Adiabatic magnetization:
• This added heat can then be removed
by a fluid like water
• The magnetic field is held constant to
prevent the dipoles from reabsorbing
the heat
Isomagnetic enthalpic transfer
• The substance is returned to another
adiabatic (insulated) condition so the total
entropy remains constant
• thermal energy causes the domains to
overcome the field, and thus the sample
cools
Adiabatic Demagnetization
The magnetic field is held
constant to
prevent the material from heating
back up
The material is placed in thermal
contact with the environment
being refrigerated
Isomagnetic entropic transfer
Operation:
cooling
DEMAGNETIZATION
PARAMAGNETICMATERIAL
MAGNETIZATION
Comparison between Magnetic Refrigeration and Vapor Compression Refrigeration
Magnetic household refrigeration appliances
Magnetic cooling and air conditioning in buildings and houses
Central cooling system
Refrigeration in medicine
Cooling in food industry and storage
Cooling in transportation
Cooling of electronic equipment
applications
MR do not use hazardous or environmentally damaging chemicals
Purchase cost may be high, but running costs are 20% less than the conventional chillers
Ozone depleting refrigerants are avoided in this system, hence it more eco-friendly
Operation is quite as this system does not have compressor
High efficiencyExtremely low temperatures are possible(< 1k)
Advantages of Magnetic Refrigeration
High initial cost
Problems of thermal and magnetic
hysteresis
Technical difficulties in construction
Limitations:
Conclusion:
Magnetic refrigeration is a
technology that has proven to be
environmentally safe. Computer models
have shown 25% efficiency improvement
over vapor compression systems.
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