Transcript
THERMOELECTRIC POWER
GENERATION
BY:
P.KIRANMAYI
DEPARTMENT OF EEE
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CONTENTS
Introduction
Why Thermoelectricity ???
Principle
Working and Construction
Material of choice for TEG
Simulations
Advantages and Disadvantages
Applications
Conclusion
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INTRODUCTION:
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THERMOELECTRIC POWER GENERATION
USING WASTE - HEAT ENERGY AS AN
ALTERNATIVE GREEN TECHNOLOGY
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Why thermoelectricity ???
Increasing energy demand!!!
Increasing pollution!!!
Increasing IC heat!!!
Green energy production by
thermoelectricity.
Automobile waste heat thermoelectric
power generation.
On chip thermoelectric cooling.
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Why thermoelectricity ???
IEA,
WEO,
2008
Nasty Problems
Green energy
Production by
thermoelectricity
Automobile waste
heat thermoelectric
power generation
Choudhary et. al,
Nature nano. (2009)
On chip
thermoelectric
cooling (BiTe )
Green Solutions from thermoelectricity !!!
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PRINCIPLE
SEEBECK EFFECT, PELTIER EFFECT.
WORKING MECHANISM OF
A THERMOCOUPLE.
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SEEBECK EFFECT
S= dV / dT;
S is the Seebeck Coefficient with units of Volts per Kelvin
S is positive when the direction of electric current is same as the direction of thermal current
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PELTIER EFFECT:
П <0 ; Negative Peltier coefficient
High energy electrons move from right to left.
Thermal current and electric current flow in opposite directions.
(electronic)
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PELTIER COOLING
П >0 ; Positive Peltier coefficient
High energy holes move from left to right.
Thermal current and electric current flow in same direction.
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3/17/2014
WORKING
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Fig: schematic diagram of TEG.
Thermoelectric Materials
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( )e g
TZT
- Seebeck Coefficient
- Electrical Resistivity
- Thermal Conductivity
e – Electronic
g – Lattice
Figure of Merit:
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Material of choice for
thermoelectricityTE Parameters
Materials
Metals
Insulators
Semiconductors
Semiconductors most suitable TE material.
Allow separate control of G (electrons) and κ (phonons).
Electrical
Conductivity
(G)
Seebeck
Coefficient
(S)
Thermal
Conductivity
(κ)
High~102 W/m-K
High
Moderate10-3S/m
High~120 μV/K
Very High~107 S/m
Low ~ 10μV/K
Low~10-2-10-4 W/m-K
Low~10 W/m-K
Extremely
low (~10-10S/m)
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SIMULATIONS
A TEG MODULE MODEL WITH INITIALLY 8
TEG MODULES WAS RUN
THEORETICAL POWER OBTAINED –
56.347W
POWER OBTAINED IN SIMULATION –
51.42W
TO INCREASE OUTPUT NUMBER OF TE
MODULES INCREASED TO 18
NEW OUTPUT – 122.67W 13
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ADVANTAGES AND
DISADVANTAGESADVANTAGES:
Environmentally friendly
Recycles wasted heat energy
Scalability, meaning that the device can be applied to any size
heat source from a water heater to a manufacturers equipment
Reliable source of energy
Lowers production cost
DISADVANTAGES:
TE material is expensive
Structural failure of TE element at high temperatures
Electrical resistivity increases 14
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APPLICATIONS
Water Cooler
Cooled
Car Seat
Electronic Cooling
Laser Cooling
TE
Si bench
1 kW Generator for Diesel Truck
Demonstrated capability to produce
1 kW of
electric power from Diesel engine
exhaust.
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CONCLUSION
THUS, BY USING TEG, THE WASTE HEAT CAN BE
USED TO GENERATE ELECTRICITY.
SIMULATIONS AND EXPERIMENTS HAS BEEN
CONDUCTED AND MORE EFFICIENT SYSTEMS CAN BE
DEVELOPED IN FUTURE WITH NANOCRYSTALLINE
APPROACH.
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REFERENCES:
1. Thermo-electrics: Basic principles and New Materials Development by Nolas, Sharp and Goldsmid
2. Thermoelectric Refrigeration by Goldsmid
3. Thermodynamics by Callen. Sections 17-1 to 17-5
4. Abram Joffe, “The Revival of Thermoelectricity,” Scientific American, vol. 199, pp. 31-37, November 1958.
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