suraj corrected

Upload: suraj-antony

Post on 05-Apr-2018

241 views

Category:

Documents


0 download

TRANSCRIPT

  • 7/31/2019 Suraj Corrected

    1/22

    1

  • 7/31/2019 Suraj Corrected

    2/22

  • 7/31/2019 Suraj Corrected

    3/22

    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

    3

  • 7/31/2019 Suraj Corrected

    4/22

    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

    4

  • 7/31/2019 Suraj Corrected

    5/22

    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.

    5

  • 7/31/2019 Suraj Corrected

    6/22

    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

    6

  • 7/31/2019 Suraj Corrected

    7/22

    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.

    7

  • 7/31/2019 Suraj Corrected

    8/22

    Houses the Loudspeaker

    Houses the gas ( Helium)

    The hot and cold heat exchangers

    Houses the Stack

    8

  • 7/31/2019 Suraj Corrected

    9/229

  • 7/31/2019 Suraj Corrected

    10/22

    !

    Uses inert gas, commonly Helium forrefrigeration

    10

  • 7/31/2019 Suraj Corrected

    11/22

  • 7/31/2019 Suraj Corrected

    12/22

    Closely spaced surfaces aligned parallel to theresonator tube.

    provide a medium for heat transfer.

    Honeycombed plastic spacers used which

    absorb heat locally.

    12

  • 7/31/2019 Suraj Corrected

    13/22

  • 7/31/2019 Suraj Corrected

    14/22

    14

  • 7/31/2019 Suraj Corrected

    15/22

    =

    =

    15

  • 7/31/2019 Suraj Corrected

    16/22

    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.

    16

  • 7/31/2019 Suraj Corrected

    17/22

    .

    17

  • 7/31/2019 Suraj Corrected

    18/22

    Ice cream storage containers

    200 L at 18 degrees Fahrenheit

    18

  • 7/31/2019 Suraj Corrected

    19/22

    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

    19

  • 7/31/2019 Suraj Corrected

    20/22

    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

    20

    http://hyperphysics.phyastr/http://www.howstuffworks.com/http://www.stormingmedia.us/http://www.stormingmedia.us/http://www.howstuffworks.com/http://hyperphysics.phyastr/
  • 7/31/2019 Suraj Corrected

    21/22

    21

  • 7/31/2019 Suraj Corrected

    22/22

    22