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~ ~ Intro to Thermoelectrics ~ ~
Hot
Cold
+
+-
Thermoelectric Effects
S=Voltage response per T [V/K]
n
Hot
Cold
VOC
+p
Seebeck Coeff, S
TSSV npOC
Thermocouple
Thermoelectric Effects
I
n
Hot
Cold
Load
+I I
I
p
Power Generation
S=Voltage response per T [V/K]
n
Hot
Cold
VOC
+p
Seebeck Coeff, S
TSSV npOC
Thermocouple
Thermoelectric Effects
I
n
Hot
Cold
Load
+I I
I
p
Power Generation
S=Voltage response per T [V/K]
n
Hot
Cold
VOC
+p
Seebeck Coeff, S
TSSV npOC
Thermocouple
I
n
Hot
Cold
Power
Supply
+I I
I
p
IQ np
Refrigeration
ST Peltier Coeff, = Heat removed per charge [J/C]
/T = S =Entropy per charge [J/K per C]
Characteristics of TED Performance
k
TSZT
2
Seebeck Coeff.(~heat carried per charge)
electrical conductivity
thermal conductivity(heat leakage)
Figure of Merit
0
0.1
0.2
0.3
0.4
0.5
0 1 2 3 4 5
Eff
icie
ncy
Efficiency as Heat Engine
Th=600 C,
Tc=20C
ZT
Eff
icie
ncy
Hot
Cold
Load
+
Energy Flows in the US
EIA / LLNL
Units of ExaJoules / yr: 1 EJ = 1018 J.
Fossils:
Global
Warming
Total: 3.2 x 1012 W
54 kg of CO2
per person-day
1.0 GJ per person-day
Imports: Security5.4 L of oil per person-day
38%
effic.
Thermoelectric ApplicationsPower GenerationTemperature Control
Space Probe: long life
PCR
Optoelectronics (Melcor)
Fairbanks (DEER2006)
Energy Scavenging...?
"Climate Controlled Seat" (Amerigon / BSST)
Two BMW images from Jeff Snyder's website.
Energy Flows in a Car
Energy Flows in a Car
Urban cycle 30 mph avg, 22 mpg. Fueleconomy.gov; F. Stabler, GM. DOE Thermoelectrics Workshop 2004.
Radiator
Com
bu
stio
n
TH
450 - 650 C
40%
30%
25%
5%
12.5 kW
Engine
=30%
Gasoline
50 kW
Driveline Losses
Propulsion &Accessories
15 kW
2.5 kW12.5 kW
22 mpg
Exhaust Gas
20 kW
Energy Flows in a Car
Exhaust Gas
Radiator
Driveline Losses
Engine
=30%
Com
bu
stio
nGasoline
50 kW
20 kW
15 kW
2.5 kW
30%
25%
5%37.9 kW
11.4 kW
1.9 kW
3.0 kW
9.5 kW
40%
TE Waste Heat Scavenging
=20%
12.2 kW
Propulsion &Accessories
12.5 kW
22 mpg
29 mpgTH
450 - 650 C
Recommended