Methods for operating an oscillating combustor with pulsed charger

Patent metadata

Field	Value
Publication number	US-9377189-B2
Application number	US-201414187077-A
Country	US
Kind code	B2
Filing date	Feb 21, 2014
Priority date	Feb 21, 2013
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

An oscillating combustor can support a time-sequenced combustion reaction having rich and lean phases by applying a variable voltage charge to a fuel stream or flame that flows adjacent to a conductive or semiconductive flame holder held in electrical continuity with an activation voltage.

First claim

What is claimed is:

1. A method for supporting an oscillating combustion reaction, comprising:
outputting a fuel jet having a continuous rate and an expanding area;
supporting a combustion reaction with the fuel jet;
providing a first flame holder disposed distally along the fuel jet, the first flame holder including a refractory flame holder disposed adjacent to the fuel jet;
providing a second flame holder disposed proximally along the fuel jet, the second flame holder including a conductive metal flame holder disposed adjacent to the fuel jet;
maintaining electrical continuity between the second flame holder and an activation voltage; and
modulating a charge applied to the fuel jet or the combustion reaction;
wherein modulating a charge applied to the fuel jet or the combustion reaction includes periodically applying the charge to the fuel jet or the combustion reaction to cause the combustion reaction to be held by the second flame holder and periodically discontinuing the charge to the fuel jet or the combustion reaction to cause the combustion reaction to be held by the first flame holder.

2. The method for supporting an oscillating combustion reaction of claim 1 , wherein outputting a fuel jet includes outputting the fuel jet through a gas that includes a reagent capable of reacting with fuel of the fuel jet.

3. The method for supporting an oscillating combustion reaction of claim 1 , wherein outputting a fuel jet includes outputting the fuel jet through air or flue gas and causes the fuel jet to entrain the air or the flue gas to progressively dilute the fuel jet.

4. The method for supporting an oscillating combustion reaction of claim 1 , wherein providing a first flame holder disposed distally along the fuel jet includes disposing the first flame holder to be impinged upon by the fuel jet.

5. The method for supporting an oscillating combustion reaction of claim 1 , wherein providing a first flame holder disposed distally along the fuel jet includes disposing the first flame holder at a distance along the fuel jet selected to correspond to a lean fuel-to-oxidizer mixture.

6. The method for supporting an oscillating combustion reaction of claim 1 , wherein providing a second flame holder disposed proximally along the fuel jet includes disposing the second flame holder peripheral to the fuel jet.

7. The method for supporting an oscillating combustion reaction of claim 1 , wherein providing a second flame holder disposed proximally along the fuel jet includes disposing the second flame holder at a distance along the fuel jet selected to correspond to a rich fuel-to-oxidizer mixture.

8. The method for supporting an oscillating combustion reaction of claim 1 , wherein maintaining electrical continuity between the second flame holder and an activation voltage includes holding the second flame holder substantially at voltage ground.

9. The method for supporting an oscillating combustion reaction of claim 1 , wherein maintaining electrical continuity between the second flame holder and an activation voltage includes holding the second flame holder at a voltage opposite in polarity to a polarity of the charge modulated onto the fuel jet or the combustion reaction.

10. The method for supporting an oscillating combustion reaction of claim 1 , wherein modulating a charge applied to the fuel jet or the combustion reaction includes modulating the charge at a frequency of 0.5 to 15 Hertz.

11. The method for supporting an oscillating combustion reaction of claim 1 , wherein modulating a charge applied to the fuel jet or the combustion reaction includes modulating the charge between a first polarity and ground.

12. The method for supporting an oscillating combustion reaction of claim 11 , wherein modulating the charge between a first polarity and ground causes the combustion reaction to jump from the second flame holder up to the first flame holder.

13. The method for supporting an oscillating combustion reaction of claim 11 , wherein modulating the charge between a first polarity and ground causes the combustion reaction to jump from the first flame holder down to the second flame holder.

14. The method for supporting an oscillating combustion reaction of claim 1 , wherein periodically applying the charge to the fuel jet or the combustion reaction to cause the combustion reaction to be held by the second flame holder causes the combustion reaction to periodically occur at a rich fuel-to-oxidizer mixture.

15. The method for supporting an oscillating combustion reaction of claim 14 , wherein causing the combustion reaction to periodically occur at a rich fuel-to-oxidizer mixture includes causing the combustion reaction to periodically occur at an oxidizer-to-fuel ratio of 0.5 to 0.7 times a stoichiometric oxidizer-to-fuel ratio.

16. The method for supporting an oscillating combustion reaction of claim 14 , wherein causing the combustion reaction to periodically occur at a rich fuel-to-oxidizer mixture includes causing the combustion reaction to periodically occur at a reduced temperature compared to another combustion reaction at a stoichiometric fuel-to-oxidizer ratio.

17. The method for supporting an oscillating combustion reaction of claim 1 , wherein periodically discontinuing the charge to the fuel jet or the combustion reaction to cause the combustion reaction to be held by the first flame holder causes the combustion reaction to periodically occur at a lean fuel-to-oxidizer mixture.

18. The method for supporting an oscillating combustion reaction of claim 17 , wherein causing the combustion reaction to periodically occur at a lean fuel-to-oxidizer mixture includes causing the combustion reaction to periodically occur at an oxidizer-to-fuel ratio of 1.3 to 1.5 times a stoichiometric oxidizer-to-fuel ratio.

19. The method for supporting an oscillating combustion reaction of claim 17 , wherein causing the combustion reaction to periodically occur at a lean fuel-to-oxidizer mixture includes causing the combustion reaction to periodically occur at a reduced temperature compared to another combustion reaction at a stoichiometric fuel-to-oxidizer ratio.

Assignees

• Clearsign Comb Corp

Inventors

• Ruiz Roberto
• Colannino Joseph
• Krichtafovitch Igor A
• Wiklof Christopher A

Classifications

• F23C5/00

  Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus (F23C1/00, F23C15/00 take precedence) · CPC title

• F23N5/20

  with a time program acting through electrical means, e.g. using time-delay relays · CPC title

• F23C15/00 Primary

  Apparatus in which combustion takes place in pulses influenced by acoustic resonance in a gas mass {(for generating combustion products of high pressure or high velocity F23R7/00; starting devices F23D11/42)} · CPC title

• F23C99/001 Primary

  Applying electric means or magnetism to combustion (for combustion engines F02B51/04, F02M27/04) · CPC title

• F23C99/00

  Subject-matter not provided for in other groups of this subclass · CPC title