TAR

THERMOACOUSTIC REFRIGERATION

BY

BHAVYA RANI U

PRESENTATION TOPIC

BACKGROUND INFORMATION

THERMOACOUSTIC CYCLE

FUNDAMENTALS OF THERMOACOUSTIC THEORY

DESGN

APPLICATION

CONCLUSION

UNPRESSURIED SYSTEM

AIR AS GAS MEDIUM

LOUDSPEAKER AS ACOUUSTIC DRIVER

VARIABLE DESIGN[STACK]

THERMOACOUSTIC REFRIGERATION IS UTILIZATION OF ACOUSTIC POWER TO GENERATE TEMPERATURE DIFFRENCE

Convention refrigerator

• Compressor

• refrigerants

Thermo acoustic refrigerator

• Loudspeaker

• Inert gases

Difference between convention refrigeration and thermo acoustic refrigeration

THERMOACOUSTIC’S BENEFIT

ENVIRONMENTAL REGULATION

• NO CFC EMISSION

DESIGN

• SIMPLE AND ROBUST DESIGN

PRODUCTION

• COST EFFICIENT MANUFACTURING

Motivation

• Pros– Uses sound for refrigeration –no harmful

chemicals (CFC’s, HFC’s, HCFC’s)

– Few moving parts—more reliable

– Not harmful to the environment

• Cons– Most efficient is approaching 40% of Carnot limit

– 20-30% overall efficiency

MAIN PROTOTYPE COMPONENTS

• POWER CAPACITY

• FREQUENCY RESPONSE

CONSIDERATION

• 10 INCH

• OPERATING AT LOW FREQUENCY

• 400W MAX POWER

CHOICE

CONSIDERATION

• PHYSICAL PROPERTIES

• SEALING

• COST

CHOISE

• AIR

• ATMOSPHERIC PRESSURE

CONSIDERATIONS•LENGTH•DIAMETER•SOUND REFLECTION•LOW ACOUSTIC LOSSES•SOUND TRANSMISSION

CHOICE•1.5” PVC TUBE

•FLAT END

CONSIDERATIONS

GAP SIZEMATERIAL PROPERTIESMATERIAL THICKNESSLOCATIONLENGTHDOES NOT IMPEDE WAVE

CHOICE

PAPER ALUMINUM SCREEN

STACK

ConsiderationsMaterialType

ChoiceAluminumWater Circulated

HEAT EXCHANGERS

DESIGN OPTIMIZATION FLOW CHART

TARGET PARAMETER

RESONATOR LENGTH

OPERATING CONDITION

FABRICATION CONVERGE

OPTIMISATION

FREQUENCYAVERAGE PRESSURE

TYPE OF GAS STACK

MATERIALSTACK

LOCATION

WAVE LENGTH

DYNAMIC PRESURRE

THERMAL CONDUCTIVIT

Y

SPECIFIC HEAT

CAPACITY

STACK SPACING

STACK GEOMETRY

RESONATOR GEOMETRY

POWER/BOUNDRY LAY ER TRADE

OFF

HEAT ADDITION

TEMPARATURE

HEAT REJECTION

TEMPERATURE

COOLING TEMPERATURE

COOLING POWER

MAXIMISE ENGINE

EFFICIENCY

MAXIMISE REFRIGERATOR

COP

MAXIMISE OVERALL COP

MINIMISE SIZE

MAXIMISE POWER

ASSUMPTIONS• WAVE PROPOGATION IS AXIAL AND PLAIN• WAVE MOTION PROCESS ARE ISENTROPIC • THE WORKING FLUID’S OF VISCOUS FORCE ARE NEGLIGIBLE• THE RESONATOR AND COMPONENTS ARE ACOUSTICALLY RIGID• THE MEAN TEMPERATURE IS MUCH LARGER THAN DEVOLPED TEMPERATURE GRADIENT •THE ACOUSTIC WAVE LENGTH IS MUCH LARGER THAN THE STACK LENGH

MOVING COIL LOUDSPEAKER• INSIDE 2 MAGNETS WITH METAL COIL BETWEEN THEM, CURRENT IS INDUCED CAUSING

COIL TO MOVE• CREATES SOUND WAVES UP TO 200 DB!

RESONATOR— WHERE GAS COOLING AND COMPRESSION TAKE PLACE•USES INERT GAS, COMMONLY HELIUM

STACK• SERIES OF SMALL PARALLEL CHANNELS THROUGH WHICH PRESSURE AND VELOCITY OF WAVES CHANGE• IN BETWEEN THE HEAT EXCHANGERS

HEAT EXCHANGERS• HOT HEAT EXCHANGER TO REMOVE EXCESS HEAT• COLD HEAT EXCHANGER FOR REFRIGERATION

HOW IT WORKS

EFFICIENCY

APPLICATION

NASA

• PRESERVE BLOOD AND URINE SAMPLES

• STAR USED

FOR SPACE SHUTTLE MISSION

US NAVY

• WANTS ACOUSTIC REFRIGERATORS FOR SUBMARINES NO HARMFUL FLUIDS

• REFRIGERANT LEAKS ON SUBS ARE A DEADLY PROBLEM

• COOL RADAR ELECTRONICS ONBOARD WARSHIP

POTENTIAL

• SATELLITE SENSOR

• SUPERFAST COMPUTER

• BEN &JERRYS ICE CREAM STORAGE CONTAINERS

A/C and Refrigeration Technologies Compared

Technology

Under DevelopmentCurrent Technology

Recently Introduced

Technology

Recently Introduced

Technology

Relative Performance

MeasuresThermoacoustics Vapor Compression Hydrocarbons Carbon Dioxide

Ozone Depletion Potential None CFCs, HCFCs None None

Greenhouse Effects None Very High Low Low

Energy Efficiency - power

gridHigh Moderate Moderate High Moderate

Energy Efficiency - solar

power100% Not Practical Not Practical Not Practical

Operating Mode Proportional On/Off On/Off On/Off

Initial Equipment Costs Low High High Very High

Maintenance Costs None Moderate Moderate Moderately High

Operating Life Cycle Very Long Moderate Moderate Moderate

MARKET REPORTAS PER TEKIN OZCAY IN CANADA

THE STUDY IS MAINLY BASED ON THE SECONDARY RESEARCH THAT IS CONDUCTED ON WIDE VARIETY OF RELEVANT MATERIALS

MARKET SIZE: 830,000 REFRIGERATORS ANNUALLY SOLD IN CANADA

SALES OF MAJOR HOUSEHOLD APPLIANCES: $ 1.4 BILLION

COMPETITION: ELECTROLUX (FRIGIDAIRE)

GENERAL ELECTRIC

KENMORE

MAYTAG

WHIRLPOOL

PLUS 30 OTHERS

CONCLUSION

• A THERMO ACOUSTIC ENGINE STUDIES IN THE COMBINED THERMO ACOUSTIC ENGINE REFRIGERATOR SYSTEMS AREA ARE ONLY A HANDFUL

• THIS WORK IS ONLY ONE IN OPEN LITERATURE TO USE STANDING WAVE THERMO ACOUSTIC REFRIGERATOR SYSTEMS TO COOL HIGH TEMPERATURES

• ANALYSIS OF TAR CAN BE OBTAINED BY SOFTWARE DELTA WHICH IS

USED TO INVESTIGATE PARAMETERS LIKE PRESSURE ,TYPE OF GAS FREQUENCY

REFERENCES

• A THERMOACOUSTIC ENGINE REFRIGERATORSYSTEM FOR SPACE EXPLORATION MISSION BY SUDEEP SASTRY

• THERMOACOUSTIC REFRIGERATION BY STEVEN L GARRET AND THOMAS J HOFLER

• EVALUATION OF THERMO ACOUSTIC CYCLES FOR COOLING APPLICATIONS BY INSU PAEK*, JAMES E. BRAUN, AND LUC MONGEAU RAY W. HERRICK LABORATORIES, SCHOOL OF MECHANICAL ENGINEERING, PURDUE UNIVERSITY WEST LAFAYETTE, INDIANA, USA

• MARKET FEASIBILITY STURY OF THERMOACOUSTIC REFRIGERATION BY TEKIN OZCAY

• DESIGN OF THERMOACOUSTIC REFRIGERATOR BY ANDERS MURILLO MILLIKEN TAYLER