Thermo-electric auxiliary power unit

• US 20090139207A1
• Filed: 11/30/2007
• Published: 06/04/2009
• Est. Priority Date: 11/30/2007
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Reiners, Eric A., Taher, Mahmoud A., Johnson, Kris W.
• Application Number:
  US11/987,548
• Publication Number:
  US 20090139207A1
• Time in Patent Office: Days
• US Class Current: 60/274
• CPC Class Codes: F01N 2590/08 for heavy duty applications, e.g. trucks, buses, tractors, locomotives
• CPC Class Codes: F01N 3/025 using fuel burner or by adding fuel to exhaust
• CPC Class Codes: F01N 3/2882 Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices combined with absorbents or adsorbents only F01N3/0814; combined with particulate filters F01N3/035
• CPC Class Codes: F01N 3/2889 with heat exchangers in a single housing
• CPC Class Codes: F01N 5/025 the device being thermoelectric generators
• CPC Class Codes: H10N 10/13 characterised by the heat-exchanging means at the junction
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An auxiliary power unit disclosed. The auxiliary power unit includes an exhaust passage configured to direct a flow of exhaust from a primary mover, a catalyst substrate disposed within the exhaust passage, and a heater configured to heat the catalyst substrate. The auxiliary power unit also includes a cooling jacket associated with the exhaust passage. The auxiliary power unit further includes a thermo-electric device disposed between the cooling jacket and the exhaust passage. The thermo-electric device is configured to generate electrical power from a temperature gradient created by the heater and the cooling jacket when the primary mover is non-operational.

Claims

1. An auxiliary power unit, comprising:

an exhaust passage configured to direct a flow of exhaust from a primary mover;

a catalyst substrate disposed within the exhaust passage;

a heater configured to heat the catalyst substrate;

a cooling jacket associated with the exhaust passage; and

a thermo-electric device disposed between the cooling jacket and the exhaust passage, the thermo-electric device being configured to generate electrical power from a temperature gradient created by the heater and the cooling jacket when the primary mover is non-operational.

2. The auxiliary power unit of claim 1, further including an electric-powered fuel pumping arrangement configured to pressurize fuel directed to the heater.

3. The auxiliary power unit of claim 2, wherein the heater is configured to direct pressurized fuel into the exhaust passage and ignite the pressurized fuel to heat the catalyst substrate.

4. The auxiliary power unit of claim 1, wherein the thermoelectric device is configured to generate electrical power from the temperature gradient created by the heater and the cooling jacket when the primary mover is operational.

5. The auxiliary power unit of claim 4, wherein the heater is turned off when the electrical power is generated during operation of a primary mover.

6. The auxiliary power unit of claim 1, further including an electric pump configured to pressurize coolant directed to the cooling jacket.

7. The auxiliary power unit of claim 1, wherein the heater is configured to regenerate the catalyst substrate.

8. The auxiliary power unit of claim 1, wherein the thermo-electric device includes a thermoelectric material having zero-dimensional quantum dots.

9. The auxiliary power unit of claim 1, wherein the thermoelectric device includes a thermoelectric material having one-dimensional nano wires.

10. The auxiliary power unit of claim 1, wherein the thermo-electric device includes a thermo-electric material having one of two-dimensional quantum wells and superlattice structures.

11. The auxiliary power unit of claim 1, wherein the thermo-electric device includes a thermo-electric material having a figure of merit ZT between about 1 and about 10.

12. The auxiliary power unit of claim 1, wherein the thermo-electric device includes a P element and an N element made of differing thermo-electric materials.

13. The auxiliary power unit of claim 1, wherein the thermo-electric device includes bulk thermo-electric materials.

14. A method of generating auxiliary power, comprising:

generating heat to warm an exhaust treatment device;

directing the heat toward a thermoelectric material when a primary mover is non-operational;

cooling the thermo-electric material to produce a temperature gradient across the thermo-electric material; and

generating electrical power from the temperature gradient.

15. The method of claim 14, wherein the exhaust treatment device is not regenerated when electrical power is generated from the temperature gradient.

16. The method of claim 14, further including processing and storing the electrical power.

17. The method of claim 14, further including generating electrical power from the temperature gradient when the primary mover is operational.

18. The method of claim 14, further including generating electrical power from the temperature gradient when regenerating the exhaust treatment device.

19. A machine, comprising:

an engine configured to produce a power output directed toward moving the machine;

an exhaust passage configured to direct a flow of exhaust;

a catalyst substrate disposed within the exhaust passage;

an electrically-powered fuel pumping arrangement configured to pressurize fuel;

a heater configured to receive pressurized fuel from the fuel pumping arrangement and ignite the fuel to heat the catalyst substrate;

an electrically-powered cooling system configured to pressurize and direct coolant to transfer heat from the engine;

an auxiliary power unit configured to convert thermal energy to electrical energy and being operable when the engine is non-operational, the auxiliary power unit including;

a cooling jacket associated with the exhaust passage; and

a thermo-electric device disposed between the cooling jacket and the exhaust passage, the thermoelectric device being configured to generate electrical power from a temperature gradient created by the heater and the cooling jacket when the primary mover is non-operational.

20. The machine of claim 19, wherein the thermoelectric device includes high efficient materials having at least one of a zero-dimensional quantum dots thermo-electric material, a one-dimensional nano wires thermo-electric material, a two-dimensional quantum well thermo-electric material, and a superlattice structured thermo-electric material.