Thermoelectric energy conversion
AssigneeDr. Harold Aspden
InventorsJohn S. Strachan, Harold Aspden
Life of this patent
Estimating the term…
Abstract
A thermopile 30 comprises a stacked assembly of bimetallic layers in which there is full conductor interface contact over the distance separating hot and cold surfaces 31, 32. The assembly may include dielectric layers forming a capacitor stack. A.C. current through the stack is matched in strength to the Seebeck-generated thermoelectric current circulating in each bimetallic layer. The resulting current snakes through the stack to cause Peltier cooling at one heat surface and heating at the other. A.C. operation at a kilocycle frequency enhances the energy conversion efficiency as does heat flow parallel with the junction interface.
Claims12
A thermoelectric energy conversion apparatus comprising a thermopile formed by a laminar assembly of two conductor substances A and B located between external thermal surfaces across which heat is transferred when the surfaces have different temperatures, there being thermocouple junctions formed between the substances A and B, providing, from A to B an A-B junction interface and from B to A a B-A junction interface, and a current flow path connected to electrical circuit means including an electrical control unit linked to an external power system, characterized in that said electrical control unit comprises:
- (a) means for admitting a regulated current to flow through said junctions which is predominantly unidirectional at each junction,
- (b) means for interrupting the current flow cyclically at a steady frequency,
- (c) means for measuring the electrical power throughput, and
- (d) current regulating means for adjusting the peak strength of current flowing between the external power system and the laminar assembly forming the thermocouple junctions, the current regulating means operating to adjust progressively the peak current strength to search for and sustain flow at a threshold peak current level at which the maximum electrical power throughput occurs when the apparatus operates in Seebeck mode.
A thermoelectric energy conversion apparatus comprising a thermopile formed by a laminar assembly of two conductor substances A and B located between external heat sink surfaces across which heat is transferred when the surfaces have different temperatures, there being pairs of thermocouple junctions formed between the substances A and B, activated by thermoelectric action powered by the temperature difference to cause current flow from A to B at an A-B junction interface and current flow from B to A at a B-A junction interface, and a supplementary current flow path connected to electrical circuit means including an electrical control unit linked to an external power system, the apparatus being characterized in that, in combination,
- (a) the A-B and B-A junctions of each thermocouple pair are both formed by surfaces of contact between the same pair of laminar conductor elements of substances A and B, and
- (b) said electrical control unit comprises means for admitting a regulated current to flow along that supplementary current path and through said laminar assembly in a direction transverse to the laminar surfaces of the conductor elements and means for modulating the current cyclically at a frequency in excess of one kilohertz, which current augments and offsets the thermoelectric current at the respective A-B and B-A junctions to cause the weaker junction current to be minimal and the stronger junction current to be predominantly unidirectional but subject to cyclic interruption at the modulating frequency.
A thermoelectric energy conversion apparatus comprising a thermopile formed by a laminar assembly of pairs of conductor elements of substances A and B and dielectric elements of an insulating substance separating each pair of conductor elements located between external heat sink surfaces across which heat is transferred when the surfaces have different temperatures, each such conductor pair thereby comprising a closed conductor circuit activated by thermoelectric action powered by the temperature difference to cause current flow from A to B at an A-B junction interface and current flow from B to A at a B-A junction interface, and a supplementary current flow path connected to electrical circuit means including an electrical control unit linked to an external power system, the apparatus being characterized in that it constitutes a capacitor and said electrical control unit comprises oscillator means for admitting a regulated capacitor current to flow along that supplementary current path and through said laminar assembly in a direction transverse to the laminar surfaces of the conductor elements, which current augments and offsets the thermoelectric current selectively at the respective A-B and B-A junctions to cause the weaker junction current to be minimal and the stronger junction current to be predominantly unidirectional but subject to cyclic interruption at the oscillation frequency.
Dependencies are inferred from the claim text.