TOPIC-THERMOELECTRIC GENERATORS AND DEVELOPMENTS

NAME-SANDEEP KUMARROLL NO.-152nd SEM

WHAT IS THERMOELECTRIC GENERATOR?

A Thermoelectric generator (TEG) is a solid state device.

TEG converts heat directly into electrical energy.

Electricity produce because of temperature difference in conductor

Thermoelectric generators function like heat engines , but are less bulky and have no moving parts and are completely silent.

WHY WE NEED THERMOELECTRIC GENERATORS ? 2/3rd parts of ENERGY produce in power station is lost as the

heat. Heat energy produces by burning of fuels are used to spin turbine

which produce Mechanical energy and further this mechanical energy used to rotate generator to produce electricity

In thermoelectric generator waste heat is directly converted to electrical energy.

SOME THERMOELECTRIC GENERATORS ARE :-

HOMEMADE THERMOELECTRIC GENERATORS

RADIOISOTOPE THERMOELECTRIC GENERATOR

ELECTRONIC ASPECTS A thermoelectric generator is made of many pairs of p-type and n-type

elements

Holes are charge carriers in p-type which have positive seebeck coefficient while in n-type electrons are charge carriers which have negative seebeck coefficient.

Voltage potential develop across the p-n junction is proportional to the differences in the Seebeck coefficient in each element and the temperature of the junction.

Electrons as the charge carriers in n-type and Holes as the charge carriers in p-type are move from high heated area of the conductor to low heated area of the conductor

Because of the movements of charge carriers current will produce inside the conductor

MECHANICAL ASPECTS

Heat source (fuel) P and N type

semiconductor stack (TE module)

Heat sink (cold side) Electrical load

(output voltage)

The figure shows the construction of thermoelectric power generator.

There is a burner in which the propane fuel is used as heating source in one side.

The exhaust is used to transmit a burnt fuel. On the other side, a cold junction is kept. The thermoelectric module (TE) (consist of number of p-type and N-

type semiconductor pellets connected in series or parallel depending on the served load)) is kept in between the hot and cold junction.

The electrical out (load) is taken from the TE module.

MATHEMATICAL ASPECTSFIGURE OF MERIT The performance of thermoelectric devices depends on the figure of merit (ZT)

of the material , which is given by

Where α- Seebeck coefficient, ρ - the electrical resistivity, λ - the thermal conductivity, and T – the temperature

HOW TO CONVERT HEAT PRODUCED BY C.P.U OF COMPUTER INTO ELECTRICITY ?

Benefits of TEGs no moving elements environmental safety no working fluids and gases low-noise operation reduced size and weight high reliability — KRYOTHERM guarantees lifetimes of more than 200

000 hours for our TECs smooth and fine adjustment of cooling capacity and temperature resistance to mechanical loads operation in any spatial position easy switching from cooling to heating mode.

REFERENCE Tianqi Yang, Jinsheng Xiao, Wenyu Zhao, Qingjie Zhang,”Structural Optimization of Two-stage

Thermoelectric Generator for Wide Temperature Range Application”,2011 IEEE. ] Xiaodong Zhang, C.C. Chan, and Wenlong Li,” An Automotive Thermoelectric Energy System with

Parallel Configuration for Engine Waste Heat Recovery”, IEEE trasactions on industrial electronics 2010.

] L.M. Goncalves and J.G. Rocha,” Application of Microsystems Technology in the Fabrication of Thermoelectric Micro-Converters”, Solid State Circuits Technologies, Book edited by: Jacobus W. Swart.

Joao Paulo Carmo,Luis Miguel Goncalves and Jose Higino Correia, “Thermoelectric microconverter for energy harvesting systems”, IEEE transactions on industrial electronics, VOL. 57, NO. 3, march 2010

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