Gas turbine with Coulombic thermal protection

Patent metadata

Field	Value
Publication number	US-9284886-B2
Application number	US-201213712652-A
Country	US
Kind code	B2
Filing date	Dec 12, 2012
Priority date	Dec 30, 2011
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A gas turbine is configured to operate with a high temperature combustion gas stream. The gas turbine may include a combustor that provides a combustion gas stream including charged particles and at least one turbine stage including at least one high temperature surface that may be driven with a voltage selected to repel the charged particles. The at least one high temperature surface may output a film-cooling layer including cool air, the film-cooling layer being stabilized by Coulombic forces between the voltage and the charged particles.

First claim

What is claimed is:

1. A gas turbine, comprising:
a combustor configured to output a combustion gas stream;
a turbine including at least one turbine stage configured to receive the combustion gas stream;
one or more high temperature surfaces in the combustor, the turbine, or the combustor and the turbine;
a voltage source operatively coupled to at least one of the high temperature surfaces, and configured to at least intermittently apply a voltage having a polarity to the high temperature surface; and
one or more sources of charged particles, configured to add charged particles to the combustion gas stream before the combustion gas stream reaches the high temperature surface, the charged particles having a first sign;
wherein the first sign has the same polarity as the polarity of the voltage to which at least one of the high temperature surfaces is driven.

2. The gas turbine of claim 1 , wherein the at least one turbine stage includes turbine blades held or driven to the voltage having the same polarity as the charged particles in the combustion gas stream.

3. The gas turbine of claim 1 , wherein the high temperature surface includes one or more of a turbine blade, a turbine inlet guide vane, a turbine stator, a turbine shaft, or a combustor wall.

4. The gas turbine of claim 1 , wherein the combustor is configured to output the combustion gas stream including the charged particles having the first sign.

5. The gas turbine of claim 4 , wherein the one or more sources of charged particles further includes at least one selected from the group consisting of
one or more fuel injectors configured to be at least periodically driven to a voltage having a polarity the same as the polarity of the charged particles and
one or more electrodes proximate the one or more fuel injectors and configured to be at least periodically driven to a voltage having a polarity the same as the polarity of the charged particles;
wherein the one or more fuel injectors or one or more electrodes are configured to at least periodically attract and remove from the combustion gas stream charged particles having a second sign opposite to the first sign.

6. The gas turbine of claim 1 , wherein the at least one high temperature surface further comprises:
at least one air channel inside the high temperature surface configured to distribute cool air; and
a plurality of holes or slots at or near a leading edge of the high temperature surface configured to supply the cool air to a surface of the high temperature surface;
wherein the cool air forms a film-cooling layer between the surface of the high temperature surface and the combustion gas stream.

7. The gas turbine of claim 6 , wherein the film-cooling layer is stabilized by Coulombic repulsion of the charged particles by the voltage to which the high temperature surface is held or driven.

8. The gas turbine of claim 6 , wherein the voltage and a concentration of the charged particles are selected to maintain a Richardson number sufficient to stabilize the film-cooling layer.

9. The gas turbine of claim 8 , wherein the Richardson number is defined as:
Ri =( gh )/ u 2 ,
where:
g is an acceleration of the combustion gas stream away from the high temperature surface due to Coulombic interaction between the charged particles and the voltage to which the high temperature surface is held or driven,
h is a representative distance from the surface of the high temperature surface, and
u is a representative velocity of the combustion gas stream relative to a film-cooling layer velocity.

10. The gas turbine of claim 6 , wherein the combustion gas stream is held away from the high temperature surface by Coulombic repulsion of the charged particles and a momentum cascade from the charged particles to non-charged particles.

11. The gas turbine of claim 1 , wherein the one or more sources of charged particles includes an electrode for generating the charged particles, and further comprising:
at least one voltage source configured to drive the electrode and the high temperature surfaces.

12. The gas turbine of claim 11 , wherein the voltage source is configured to drive the electrode and the high temperature surfaces to constant voltages.

13. The gas turbine of claim 11 , wherein the voltage source is configured to drive the electrode and the high temperature surfaces to modulated voltages.

14. The gas turbine of claim 13 , wherein the voltage source is configured to drive the high temperature surfaces with a phase delay from the electrode to allow for time for the charged particles to stream from the electrode to the high temperature surfaces.

15. The gas turbine of claim 11 , wherein the at least one electrode includes at least a portion of a fuel injector.

16. The gas turbine of claim 1 , further comprising;
at least one shaft operatively coupled to the turbine; and
an electric power generator operatively coupled to the at least one shaft.

17. The gas turbine of claim 1 , further comprising:
at least one shaft operatively coupled to the turbine; and
a ducted fan or propeller operatively coupled to the at least one shaft.

18. An aircraft including the gas turbine of claim 1 .

19. An electric power generator including the gas turbine of claim 1 .

20. A method for operating a gas turbine, comprising:
outputting a combustion gas stream from a combustor to a turbine, the combustion gas stream including charged particles having a first charge;
applying to at least one high temperature surface of the combustor or the turbine a first voltage selected to repel the charged particles having the first charge; and
operating one or more sources of charged particles to add the charged particles to the combustion gas stream.

21. The method for operating a gas turbine of claim 20 , wherein outputting a combustion gas stream including charged particles having the first charge further comprises:
operating the combustor and the one or more sources of charged particles to produce the combustion gas stream including the charged particles.

22. The method for operating a gas turbine of claim 21 , wherein operating the combustor to produce the combustion gas stream including the charged particles further comprises:
at least periodically driving one or more fuel injectors or one or more electrodes proximate the one or more fuel injectors to a voltage having a polarity the same as the polarity of the charged particles to at least periodically attract and remove from the combustion gas stream charged particles having a second charge opposite to the first charge.

23. The method for operating a gas turbine of claim 20 , wherein outputting a combustion gas stream including charged particles having the first charge further comprises:
operating one or more sources of charged particles in the combustor to add the charged particles to the combustion gas stream.

24. The method for operating a gas turbine of claim 23 , further comprising:
holding the combustion gas stream away from the at least one high temperature surface by Coulombic repulsion of the charged particles and a momentum cascade from the charged particles to non-charged particles.

25. The method for operating a gas turbine of claim 20 , further comprising:
providing cool air through a plurality of holes or slots at or near a leading edge of the at least one high temperature surface to form a film-cooling layer between surfaces of the at

Assignees

• Clearsign Comb Corp

Inventors

• Breidenthal Robert E

Classifications

• F02C7/18 Primary

  the medium being gaseous, e.g. air {(F02C7/125 takes precedence)} · CPC title

• F02C7/00

  Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants (controlling F02C9/00) · CPC title

• Y02T50/676

  Cross-Sectional Technologies · mapped topic

• F05D2260/202

  by film cooling · CPC title

• F02M27/04

  by electric means, {ionisation, polarisation} or magnetism · CPC title