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Introduction What is THERMOACOUSTICS? Sound Waves and Pressure Main Components How it works? What is a Stack? Thermo acoustic Refrigerator Cycle Merits of the technology Demerits

Applications Conclusions References

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Environmental considerations and

legislations that limits/ prohibitsuse of HFCs .

green house gases generation by currently usedrefrigerants resulting in:

ozone depletion global warming

Alternative methods of refrigeration

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Combination of thermodynamics andacoustics to move heat using sound.

fluids temperature rises when compressed

and falls when expanded

heat flows from hot to cold body.

sound to generate waves of pressure thatalternately compress and relax the gasparticles within the tube.

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sound waves propagate through the air viamolecular collisions

cause a disturbance in the air in a closedtube, gets reflected and which in turn createsconstructive and destructive interference

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constructive interference makes themolecules compress, and the destructive

interference makes the molecules expand.

optimal resonant frequency in found to getthe maximum heat transfer rate, using

Where,

f frequency, v velocity of the wave,L length of the tube.

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Houses the Loudspeaker

Houses the gas ( Helium)

The hot and cold heat exchangers

Houses the Stack

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!

Uses inert gas, commonly Helium forrefrigeration

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Closely spaced surfaces aligned parallel to theresonator tube.

provide a medium for heat transfer.

Honeycombed plastic spacers used which

absorb heat locally.

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=

=

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Environmentally friendly workingmedium (air, noble gas)

Only moving part is diaphragm ofthe loudspeaker, so very reliable

and a long life span

The use of air or noble gas as workingmedium offers a large window of

applications because there are no phase

transitions.

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.

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Ice cream storage containers

200 L at 18 degrees Fahrenheit

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Studies show that for relatively small heat loads,TARS compares well with VCRS, thus ideal forcooling of electronic equipments.

TARS run by a thermo acoustic engine may be

prove useful especially in areas where electricity isnot available.

Despite its demerits, TARS will continue to be anarea of interest due to:

no need of lubrication and sliding seals,simplicity,

use of environmentally harmless working fluids

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Jonathanet al., 2006, Thermo acoustic Refrigeration, GSETResearch Journal .

R. Starr et al., 1996, The Reality of a Small Household

Thermo acoustic Refrigerator, International refrigeration and

Air Conditioning Conference.Paper 344.

Standing Waves. Rod Nave, Georgia State University.

Available: http://hyperphysics.phyastr

www.howstuffworks.com

www.stormingmedia.us

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http://hyperphysics.phyastr/http://www.howstuffworks.com/http://www.stormingmedia.us/http://www.stormingmedia.us/http://www.howstuffworks.com/http://hyperphysics.phyastr/

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