Thermoelectric device for use with Stirling engine

1. A Stirling engine exhaust gas manifold comprising:

a first thermoelectric device positioned so that a hot side of the first thermoelectric device contacts exhaust gas conveyed in the exhaust gas manifold and a cold side of the first thermoelectric device contacts air outside the exhaust gas manifold;

a second thermoelectric device positioned so that a hot side of the second thermoelectric device contacts exhaust gas conveyed in the exhaust gas manifold, wherein the second thermoelectric device is so positioned to be operating under a disparate temperature range from the first thermoelectric device, and a cold side of the first thermoelectric device contacts air outside the exhaust gas manifold;

a first voltage regulator electrically coupled to the first thermoelectric device and a second voltage regulator electrically coupled to the second thermoelectric device, each of the first and second voltage regulators comprising a solid state switch and an inductor electrically coupled to the solid state switch, wherein each solid state switch regulates a voltage received from the coupled thermoelectric device to provide a single common voltage, and wherein each inductor provides energy to the solid state switch coupled thereto in response to changes in current of a regulated single common voltage.

2. The exhaust gas manifold according to claim 1 , wherein the first thermoelectric device comprises a bismuth telluride semiconductor comprising a series of n-type layers doped with selenium and p-type layers doped with antimony.

3. The exhaust gas manifold according to claim 2 , wherein the second thermoelectric device comprises a bismuth telluride semiconductor comprising a series of n-type layers doped with selenium and p-type layers doped with antimony.

4. The exhaust gas manifold according to claim 3 , wherein the first thermoelectric device comprises a series of n-type layers and p-type layers in accordance with the temperature range to be experienced by the first thermoelectric device and the second thermoelectric device comprises a bismuth telluride semiconductor comprises a series of n-type layers and p-type layers in accordance with the temperature range to be experienced by the first thermoelectric device.

5. The exhaust gas manifold according to claim 1 , wherein the first voltage regulator regulates the first voltage to mitigate the effect of at least one of position of the first thermoelectric device in relation to the position of the second thermoelectric device, a composition of the first thermoelectric device in relation to a composition of the second thermoelectric device, or fluctuation in exhaust gas temperature.

6. The exhaust gas manifold according to claim 1 , further comprising a second voltage regulator associated with the second thermoelectric device.

7. The exhaust gas manifold according to claim 6 , wherein the second voltage regulator regulates a second voltage received from the second thermoelectric device in accordance with a single output voltage common to the first thermoelectric device and a second thermoelectric device positioned on the manifold.

8. The exhaust gas manifold according to claim 7 , wherein regulation of the second voltage is performed to mitigate any effects resulting from fluctuation in exhaust gas temperature.

9. The exhaust gas manifold according to claim 1 , further comprising an insulating layer covering the exhaust gas manifold such that the cold side of the first thermoelectric device is exposed to the air outside the exhaust gas manifold.

10. The exhaust gas manifold according to claim 9 , wherein the insulating layer comprises at least one of fiber glass or ceramic.

11. A Stirling engine comprising:

a first thermoelectric device coupled to an exhaust gas manifold, the first thermoelectric device positioned so that a hot side of the first thermoelectric device contacts exhaust gas conveyed in the exhaust gas manifold and a cold side of the first thermoelectric device contacts air outside the exhaust gas manifold;

a first voltage switching regulator associated with the first thermoelectric device, further comprising

a first solid state switch in series with the voltage to be regulated; and

a first inductor electrically coupled to the solid state switch for receiving current therefrom;

a second thermoelectric device coupled to the exhaust gas manifold, the second thermoelectric device positioned so that a hot side of the second thermoelectric device contacts exhaust gas conveyed in the exhaust gas manifold and a cold side of the second thermoelectric device contacts air outside the exhaust gas manifold; wherein the second thermoelectric device is positioned relative to the first thermoelectric device in accordance with the relative compositions of the first thermoelectric device and the second thermoelectric device;

a second voltage switching regulator associated with the second thermoelectric device, further comprising:

a second solid state switch in series with the voltage to be regulated; and

a second inductor electrically coupled to the second solid state switch for receiving current therefrom;

an insulating layer covering the exhaust gas manifold such that the cold side of the first thermoelectric device and the cold side of the second thermoelectric device are exposed to the air outside the exhaust gas manifold; and

wherein the first inductor and the second inductor provide voltage to the first voltage switching regulator and the second voltage switching regulator, respectively, in response to changes in current thereby providing a regulated common voltage.

12. The Stirling engine according to claim 11 , wherein the insulating layer comprises at least one of fiber glass or ceramic.

13. The Stirling engine according to claim 11 , wherein voltage regulation of the first thermoelectric device and voltage regulation of the second thermoelectric device is performed such that voltage output of the first thermoelectric device and voltage output of the second thermoelectric device are in accordance with a common voltage output.

14. The Stirling engine according to claim 11 , wherein the first thermoelectric device comprises a bismuth telluride semiconductor comprising a series of n-type layers doped with selenium and p-type layers doped with antimony and the second thermoelectric device comprises a bismuth telluride semiconductor comprising a series of n-type layers doped with selenium and p-type layers doped with antimony.

15. The Stirling engine according to claim 14 , wherein the respective series of n-type and p-type layers, and degree of selenium doping in the n-type layer and antimony doping in p-type layer, in the first thermoelectric device and second thermoelectric device is a function of an operating temperature range to be experienced by the first thermoelectric device and the operating temperature range to be experienced second thermoelectric device.

16. A method of improving efficiency of a Stirling engine, comprising:

positioning a first thermoelectric device on an exhaust gas manifold, the first thermoelectric device positioned so that a hot side of the first thermoelectric device contacts exhaust gas and a cold side of the first thermoelectric device contacts air outside the exhaust gas manifold;

positioning a second thermoelectric device on the exhaust gas manifold, the second thermoelectric device positioned so that a hot side of the second thermoelectric device contacts exhaust gas and a cold side of the second thermoelectric device contacts air outside the exhaust gas manifold, positioning of the second thermoelectric device is based upon the compositions of the first thermoelectric device and the second thermoelectric device;

covering the exhaust gas manifold with an insulating layer such that the exterior surface of the exhaust gas manifold is covered with the insulating layer while leaving the cold side of the first thermoelectric device and the cold side of the second thermoelectric device exposed to the air outside the exhaust gas manifold;

regulating, with a first solid state switch and a first inductor, the voltage output of the first thermoelectric device;

regulating, with a second solid state switch and a second inductor, the voltage output of the second thermoelectric device such that the voltage output of the first thermoelectric device and the voltage output of the second thermoelectric device are in accordance with a common output voltage defined for any thermoelectric device generating voltage from the exhaust gas; and

receiving into the inductor associated with at least one of the first solid state switch or the second solid state switch, energy in the form of an electric current associated with the first voltage or the second voltage, wherein the energy received is available for subsequent processing by at least one of the first solid state switch or the second solid state switch when at least one of the voltage output of the first device or the voltage output of the second device is below the common output voltage.

17. The method according to claim 16 , wherein the first thermoelectric device comprises a bismuth telluride semiconductor comprising a series of n-type layers doped with selenium and p-type layers doped with antimony and the second thermoelectric device comprises a bismuth telluride semiconductor comprising a series of n-type layers doped with selenium and p-type layers doped with antimony, the respective series of n-type and p-type layers, and degree of selenium doping in the n-type layer and antimony doping in p-type layer, in the first thermoelectric device and second thermoelectric device is a function of an operating temperature range to be experienced by the first thermoelectric device and the operating temperature range to be experienced second thermoelectric device.

18. The method of claim 16 , wherein the compositions of the first thermoelectric device and the second thermoelectric device are substantially equal, positioning the second thermoelectric device on the exhaust gas manifold at a position having a substantially equal temperature to a temperature of the exhaust gas manifold at the position of the first thermoelectric device.

19. The method of claim 16 , wherein the compositions of the first thermoelectric device and the second thermoelectric device are dissimilar, positioning the second thermoelectric device on the exhaust gas manifold at a position having a temperature different to the temperature of the exhaust gas manifold at the position of the first thermoelectric device.