THERMOELECTRIC

POWER GENERATOR

CONTENTS

INTRODUCTION

TEG

PRINCIPLE

CONSTRUCTION

WORKING

THEORETICAL PERFORMANCE AND

EFFICIENCY

SIMULATIONS

EXPERIMENT

ADVANTAGES & DISADVANTAGES

FURTHER DEVELOPMENTS

CONCLUSION

INTRODUCTION

ENERGY

THERMOELECTRICITY AND TEG

WASTE HEAT HARVESTING

HISTORY

TEG

COMBINATION OF UNITS OF TE MODULES

THERMAL TO ELECTRICAL

BASIC PRINCIPLE

PRINCIPLE

SEEBECK EFFECT, PELTIER EFFECT AND

THOMSON EFFECT.

WORKING MECHANISM OF A

THERMOCOUPLE.

CONSTRUCTION

TEG SCHEMATICQ

L

HEAT L ELECTRIC

CONDUCTION ,AIR CONTACT

RESISTANCE

P LOAD RESISTOR

HEAT SOURCE

P N

HEAT SINK

HEAT SOURCE - FROM WHICH HEAT IS DRAWN

HEAT SINK - COLD RESERVOIR TO WHICH

HEAT IS DISSIPATED

PAIR OF THEMOCOUPLES - BASED ON TE

ELEMENTS

LOAD RESISTANCE - RL

HEAT FROM EXTERNAL SOURCE – Q

OUTPUT POWER - P

TEG MODULE

PP N N NP

EXHAUST PIPE

1 PAIR

RL

Ta

Q

P

Rhs+Rg

Rc+RCu

Rs+Rp+R

s

RCu+Rc

Rg

Tc

Th

ONE TEG MODULE – MANY PAIRS OF

THERMOCOUPLES BASED ON BISMUTH

TELLURIDE

HEAT SOURCE

HEAT SINK WITH FINS

EQUIVALENT RESISTOR NETWORK

WORKING

HEAT EXCHANGER – HOT SIDE

HEAT SINK WITH FINS – COLD SIDE

DIFFERENCE IN TEMPERATURE ACROSS

THERMOCOUPLES

POTENTIAL DIFFERENCE ACROSS

THERMOCOUPLE

CURRENT FLOW THROUGH THERMOCOUPLE

AND LOAD RESISTOR

POWER IS DEVELOPED

THEORETICAL

PERFORMANCE AND

EFFICIENCY

P = I2RL = (αn-αp)2 (Th-Tc)2 RL / (R+RL)2

η = P/Q = I2RL/ [(αn-αp)ITh-⅟2 I2RL + K(Th-Tc)]

∆T=[(RN+2RS)//(RP+2RS)(TEX-TAMB)]/

[2(RC+RCu+RG)+(RN+2RS)//(RP+2RS)+RHS]

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 – 122.67 ( 22 FINS )

0 20 40 60 80 100 110

60

50

40

30

20

10

0

PO

WE

R (

W)

TEMPERATURE DIFFERENCE (K)

POWER Vs ∆T GRAPH

TH.CASE (300K)

TH. CASE (420K)

M. RESULT (NO PR.)

M. RESULT (PR.)

10 20 30

120

110

100

90

80

70

60

50

40

T. P

OW

ER

(W

)

EXTERNAL FLOW VELOCITY (m/s)

5 FINS

10 FINS

22 FINS

T. POWER Vs EXT. FLOW VELOCITY

EXPERIMENT

ON EXHAUST PIPE OF TOYOTA STARLET

COMMERCIAL BISMUTH TELLUTIDE

MODULE WITH 31 THERMOCOUPLES

ALL BONDED AT 4MPa

LOAD RESISTOR 0.45Ω

CONDUCTED BY PROVIDING BOTH

SIMULATED AND REAL ROAD CONDITIONS

RESULTS ALMOST SIMILAR FOR BOTH

ADVANTAGES AND

DISADVANTAGES

ADVANTAGES

DECREASE PETROLEUM CONSUMPTION

RECYCLE WASTE ENERGY INTO USEFUL

POWER

REDUCES POWER LOSS

IMPROVE EFFICIENCY OF AUTOMOBILES

DISADVANTAGES

TE MATERIAL IS EXPENSIVE

STRUCTURAL FAILURE OF TE ELEMENT AT

HIGH TEMPERATURES

ELECTRICAL RESISTIVITY INCREASES

FIGURE OF MERIT ‘Z’ REDUCES

FURTHER DEVELOPMENT

NANOCRYSTALLINE APPROACH IMPROVES

‘Z’

HIGH PERFORMANCE AND LOW COST COULD

BE BROUGHT

CONCLUSION

SIMULATIONS AND EXPERIMENTS HAS BEEN

CONDUCTED AND MORE EFFICIENT SYSTEMS

CAN BE DEVELOPED IN FUTURE WITH

NANOCYSTALLINE APPROACH.