Processing & Properties of Floor and Wall Tiles.pptx
Unit 2_Thermoelectric effect.pptx
1. Unit-2 Direct Energy Conversion Principles and Types
Thermo Electric Generators
• Seeback effect
• Peltier effect
• Thomson effect
• Thermoelectric convertors
• Brief description of the construction of thermoelectric generator
2. Introduction
• The pioneer in thermoelectrics was a German scientist Thomas Johann Seebeck
(1770-1831)
• Thermoelectricity refers to a class of phenomena in which a temperature difference
creates an electric potential or an electric potential creates a temperature
difference.
• Thermoelectric power generator is a device that converts the heat energy into
electrical energy based on the principles of Seebeck effect
• Later, In 1834, French scientist, Peltier and in 1851, Thomson (later Lord Kelvin)
described the thermal effects on conductors
3. Thermo electric Generator
• The pioneer in thermoelectrics was a German scientist Thomas Johann Seebeck
(1770-1831)
• Thermoelectricity refers to a class of phenomena in which a temperature difference
creates an electric potential or an electric potential creates a temperature
difference.
• Thermoelectric power generator is a device that converts the heat energy into
electrical energy based on the principles of Seebeck effect
• Later, In 1834, French scientist, Peltier and in 1851, Thomson (later Lord Kelvin)
described the thermal effects on conductors
19. Peltier Effect
• When an electric current flows across an isothermal junction of two
dissimilar materials, there is evolution or absorption of heat at the
junction
• Its a reversible effect
• If heat is evolved when the current flows in on direction, the same amount of
heat is absorbed at the junction if the current is also reversed
20. Peltier Effect
• α1-2 : Peltier coefficient
• Defined as: Heat evolved or absorbed at the junction per unit curret flow,
per unit time
21. Thomson Effect
• When an electric current flows through a material having a temperature gradient,
there is evolution or absorption of heat
• Its a reversible process
• Reversing the direction of current flow reverses the direction of heat transfer without change
is magnitude
22. Thomson Effect
• When an electric current flows through a material having a temperature gradient,
there is evolution or absorption of heat
• Its a reversible process
• Reversing the direction of current flow reverses the direction of heat transfer without change
is magnitude
23. Thomson Effect
• σ : Thomson coefficient
• Defined as: Heat evolved or absorbed at the junction per unit time time
per unit current and per unit temperature gradient
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