THERMOELECTRIC GENERATOR

AIMTo design a project that can be used to utilize the waste heat energy of car engines into electricity for multipurpose use in Automobiles. This system should be economical, easy to implement and does not produce any burden on car efficiency or engine efficiency.

Figure 1: Conceptual design of thermoelectric generator producing electricity from waste heat in the engine exhaust. Copyright BMW.

INTRODUCTION

An Thermoelectric generator (TEG) is a device that converts waste heat in an internal combustion engine (IC) into electricity using the Seebeck Effect. A typical TEG consists of three main elements: A hot-side heat exchanger, a cold-side heat exchanger, thermoelectric materials. ATEGs can convert waste heat from an engine's coolant or exhaust into electricity. By reclaiming this otherwise lost energy, ATEGs decrease fuel consumed by the electric generator load on the engine.

PRINCIPLE OF OPERATION

TEGs, thermoelectric materials are packed between the hot-side and the cold-side heat exchangers. The thermoelectric materials are made up of p-type and n-type semiconductors, while the heat exchangers are metal plates with high thermal conductivity.

PROJECT DESCRIPTION

Aim of our project is to design a thermo electric generator that could generate electricity from the waste heat of car engine on one side of peltier plates and heat sinking on other side at atmospheric temperature. The complete Thermo Electric Generator would be based on Seebeck Effect that is reverse of peltier effect. The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice-versa. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely, when a voltage is applied to it, it creates a temperature difference.

PELTIER ELEMENT

Figure 1: Peltier Element (to be used in Thermo Electric Generator Design)

PERFORMANCE OF

PELTIER ELEMENTSThermoelectric junctions are generally only around 5–10%

as efficient as the ideal refrigerator (Carnot cycle), compared with 40–60% achieved by conventional compression cycle systems (reverse Rankine systems using compression/ expansion). Due to the relatively low efficiency, thermo electric cooling is generally only used in environments where the solid state nature (no moving parts, maintenance-free, compact size) outweighs pure efficiency.

Figure 2: Peltier element schematic. Thermoelectric legs are thermally in parallel and electrically in series

INNER VIEW OF PELTIER PLATE

OPERATING TIPS

Max. Operating Temperature: 80 degree CelsiusDo not exceed Imax or Vmax when operating module.Protection options (seeling)Life expectancy: 200,000 hoursFailure rate based on long time testings: 0.2%

WORKING OF TEG

GRAPH: DELTATEMPERATURE v/s POWER

ADVANTAGES OVER EXISTING TECHNOLOGY

No moving parts. Therefore they require little or no maintenance.

Enables reduced, low-noise operation of cooling fans.Suitable for manufacture in very small sizes. Therefore ideal

for microelectronics.Lightweight.Long life. Exceeds 200,000 hrs MTBF (Mean Time Between

Failures).Controllable (by voltage / current).Small size.Fast, dynamic response.Enhanced ratio between heat sink and target element.

APPLICATIONS

AUTOMOTIVE THERMO ELECTRIC GENERATOR- An attempt to harvest the waste heat energy produced by the car engine.

Thus,electricity produced can be used in the car to- - glow car indicators - run music system - charge batteriesCANDLE OPERATED TABLE LAMPELECTRICITY FROM TEA CUPELECTRICITY FROM LAPTOP CHARGERDESIGN OF HIGHLY EFFICIENT THERMO ELECTRIC GENERATOR GLACIERSSOLAR CELLS- Solar cells use only the high frequency part of the radiation, while the low

frequency heat energy is wasted. Several patents about the use of thermoelectric devices in tandem with solar cells have been filed. The idea is to increase the efficiency of the combined solar/thermoelectric system to convert the solar radiation into useful electricity.

THANKS…