thermoacoustic cooling

7/28/2019 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.

thermoacoustic cooling

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