Thermo-electric auxiliary power unit

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.

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.