thermoacoustic cooling
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Transcript of thermoacoustic cooling
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THERMOACOUSTICREFRIGERATION
Presented by:Prashant LalwaniB.Tech(mech)632
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OUTLINE
INTRODUCTION
DEFINITION
DESIGN DESCRIPTION
APPLICATIONS
CONCLUSION
REFERENCES
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INTRODUCTION
Thermoacoustic refrigerator is a mechanical devicewhich converts mechanical work to temperaturedifference that can be used in cooling.
This is done through acoustic waves.
Thermoacoustics is based on the principle that
sound waves are pressure waves. These sound waves
propagate through the air via molecular collisions.
The molecular collisions cause a disturbance in the
air, which in turn creates constructive and destructiveinterference. The constructive interference makes the
molecules compress, and the destructive interference
makes the molecules expand. This principle is the
basis behind the thermoacoustic refrigerator.
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DEFINITION
Thermoacoustic refrigerator :It is adevice which converts acoustic power torefrigeration.
Linear motor : It is a device thatproduces linear oscillatory motion in a gasor acoustic power.
Thermoacoustic engine : It is a device
that produces linear oscillatory motion oracoustic power utilizing heat.
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DESIGN DESCRIPTION
Thermoacoustic Refrigerator :
Unpressurized System
Air as Gas Medium
Loudspeaker as Acoustic Driver
Variable design (stacks)
Advantages of Thermoacoustic
Refrigeration : No Environmentally-Harmful Refrigerants
Mechanically Simple
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Main Prototype Components :
Speaker
Gas
Tube Stack
Heat Exchangers
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STACK:The most important piece of a thermoacousticdevice is the stack. The stack consists of a large number
of closely spaced surfaces that are aligned parallel to theto the resonator tube. The purpose of the stack is toprovide a medium for heat transfer as the sound waveoscillates through the resonator tube.
RESONATING TUBE:The standing sound wave isproduced in a resonating tube.
HEAT EXCHANGER: Both ends of the stack isconnected to heat exchangers, thus coupling the stackto a heat source or heat sink, the transfer of heat wouldbe more efficient.
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Speaker Tube
Stack Heat Exchangers
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APPLICATIONS:
Cooling or heating
Upgrading industrial waste heat
Cheap energy source
BENEFITS: No moving parts
Environmentally friendly
Use of simple materials
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CONCLUSION:
Thermoacoustic refrigerators use sound waves togenerate cooling. Furthermore, they use inert gases thatare friendly to the environment. Their unique workingmechanism and promising future have attracted manyresearchers.
the effectiveness of thermoacoustic refrigeration forelectronic devices, low cost, high efficiency coolingdevices have broad applications in commercial industriesand households.
Thermoacoustic refrigerators use acoustic waves to
transfer heat. Although their benefits compared withtheir vapour-compression counterparts areenvironmental friendliness, robustness and simplicity,they are currently still less efficient than traditionalvapour-compression refrigerators.