Combustion chamber

• US 6,106,278 A
• Filed: 05/15/1998
• Issued: 08/22/2000
• Est. Priority Date: 05/17/1997
• Status: Expired due to Term

• Current Assignee: Ansaldo Energia Switzerland AG (Ansaldo Energia SPA)
• Original Assignee: ABB Research Ltd. (ABB Limited)
• Inventors: Andersson, Leif, Lloyd, Jonathan, Jansohn, Peter
• Primary Examiner(s): Price, Carl D
• Application Number:
  US09/079,396
• Time in Patent Office: 830 Days
• Field of Search: 431/11, 431/8, 431/350, 431/351, 431/352, 431/353, 431/243, 431/158, 431/12, 60/751, 60/755, 60/756, 60/752, 60/758, 60/759, 60/760, 60/746, 60/747, 60/736
• US Class Current: 431/243
• CPC Class Codes: F23C 7/06 for heating the incoming air arrangements of regenerators and recuperators F23L15/00
• CPC Class Codes: F23D 14/62 Mixing devices; Mixing tubes
• CPC Class Codes: F23D 2206/10 Turbines

Abstract

The object of the invention is to provide a novel combustion chamber which has an improved air supply and also ensures an optimum incident flow to the burners when the mass flows of cooling and combustion air are different. According to the invention, this is achieved in that the at least one cooling duct (10) is extended right into the plenum (13) and is formed inside the plenum (13) as a diffuser (14) having an orifice (12) leading into the plenum (13). The at least one opening (15, 15'"'"') in the burner dome (4) is arranged in the region of the diffuser (14) or directly downstream of its orifice (12). A bypass duct (16, 16'"'"') having an orifice (17, 17'"'"') leading into the plenum (13) follows downstream of each opening (15, 15'"'"'). The orifice (17, 17'"'"') of each bypass duct (16, 16'"'"') is oriented at least approximately in parallel with the orifice (12) of the diffuser (14) and is also designed so as to be offset step-like to the outside. Each bypass duct (16, 16'"'"') is provided with a pressure-regulating device (18, 18'"'"').

Claims

1. A combustion chamber having a plenum which is defined to an outside by a burner dome, the plenum intended for receiving at least one main air flow having a first air flow direction, having at least one burner arranged in the plenum, a combustion space formed downstream of the plenum in the first air flow direction, at least one cooling air duct leading into the plenum and encasing the combustion chamber, and having at least one opening formed in the burner dome and intended for a secondary air flow, the secondary air flow having a second air flow direction, wherein

(a) the at least one cooling air duct is extended right into the plenum and is formed inside the plenum as a diffuser, the at least one cooling air duct having an orifice leading into the plenum,

(b) the at least one orifice opening in the burner dome is arranged in the region of the diffuser,

(c) a bypass duct having an orifice leading into the plenum is arranged downstream of each opening in the first air flow direction,

(d) the orifice of each bypass duct is oriented at least approximately in parallel with the orifice of the diffuser and is also designed so as to be offset step-like to the outside,

(c) each bypass duct is provided with a pressure-regulating device.

2. The combustion chamber as claimed in claim 1, wherein at least one further opening is formed in the burner dome downstream of each opening in the second air flow direction, each further opening has a bypass duct arranged downstream in the second air flow direction and having an orifice leading into the plenum, each bypass duct has a pressure-regulating device, and the orifices of the bypass ducts are offset step-like and are arranged at least approximately parallel to one another.

3. The combustion chamber as claimed in claim 1, wherein the pressure-regulating devices are designed as honeycombs.

4. The combustion chamber as claimed in claim 3, wherein the honeycombs are arranged on the air inlet side in the bypass ducts.

5. The combustion chamber of claim 3, wherein at least one of the honeycombs is designed in such a way that it can be closed.

6. The combustion chamber of claim 5, wherein at least the honeycomb arranged furthest downstream in the second air flow direction is provided with a holder for a honeycomb cover.

7. The combustion chamber as claimed in claim 1, wherein each pressure-regulating device consists of a barrier plate, which closes the opening and has at least one impact hole passing through the barrier plate, and of an impingement surface arranged in the interior of the bypass duct.

8. The combustion chamber as claimed in claim 7, wherein at least one of the impact holes of each pressure-regulating device is designed in such a way that the impact holes may be closed.

9. The combustion chamber as claimed in claim 8, wherein the impact holes of each barrier plate which is arranged furthest downstream in the second air flow direction is provided with a holder for a hole cover and a hole cover.

10. The combustion chamber as claimed in claim 1, wherein at least two openings are in each case formed in the burner dome and are distributed uniformly in a plane lying at least approximately transversely to the main air flow.

11. The combustion chamber of claim 1, wherein the at least one orifice opening in the burner dome is arranged directly downstream of its orifice in the first air flow direction.