GB1594463A

GB1594463A - Combustion equipment

Info

Publication number: GB1594463A
Application number: GB753077A
Authority: GB
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 1978-02-07
Filing date: 1978-02-07
Publication date: 1981-07-30

Description

(54) IMPROVMENTS IN OR RELATING TO COMBUSTION EQUIPMENT (71) We, ROLLS-ROYCE LIMITED, a British Company of 65 Buckingham Gate London, SW1E 6AT, formerly Rolls-Royce (1971) Ltd., of Norfolk House, St. Janes Square, London SW17 4JR, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to combustion equipment, for example the combustion equipment of gas turbine engines, and is particulariy concerned with the problem of carbon deposition in such combustion equipment.

In some circumstances, carbon is deposited on the combustion chamber head and lumps of carbon eventually become dislodged causing considerable damage to downstream parts of the engine such as the high pressure turbine blades. It is an object d the invention to provide an improved apparatus which will at least partially prevent such carbon deposition.The present invention provides combustion equipment for a gas turbine engine comprising a cornbustion chamber having a dome shaped head diverging immediately downstream of a parallel walled central aperture, a swirl vane assembly, comprising inner and outer concentric cylindrical walls with swirl vanes extending therebetween, secured to and spaced apart from the parallel walled central aperture, a fuel nozzle located in the central aperture and positioned within the inner cylindrical wall of the swirl vane assembly, a flare located in the central aperture immediately downstream of the swirl vane assembly spaced apart from and secured to the wall defining the central aperture and extends into the combustion chamber, a flow passage being formed between the central aperture wall and the flare and the outer cylindrical wall of the swirl vane assembly, an annular air passage being formed between a portion of the head of the combustion chamber and the flare, the swirl vane assembly having a plurality of apertures formed in the outer cylindrical wall to allow air from the compressor of the gas turbine engine to flow through the apertures into the flow passage and the annular air passage and thence over the internal surface of the head portion od the combustion chamber.

The present invention will now be more particularly described with reference to the accompanying drawing which shows a partsection through a combustion chamber head incorporating one form of the present invention.

In the drawing, there is shown the upstream portion of part of the combustion equipment of a gas turbine engine (not shown).

The portion comprises a compressor air inlet duct 10 which receives air from the compressor of the engine, a swirler vane assembly 12 and combustion chamber head 14. The swirler vane assembly 12 surrounds a central aperture 16 in which a fuel nozzle (not shown) can be fitted.

A cylindrical flare 18 is secured immediately downstream of the twirler vane assembly 12 and extends into the combustion chamber defining a passage 22 in conjunction with the inner part of the head 14.

The swirler vane assembly 12 has a ring of apertures 20 through which compressed air from the engine compressor can flow to the passage 22. The configuration of the passage 22 is designed so that both the velocity of the air issuing from the passage 22 matches the velocity of the re-oirculating primary air in the combustion chamber and that the air from the passage flows over the surface of the head 14 to reduce the build-up of carbon on the head.

With the flare configurations shown in the drawing, the accretion of carbon on the head 14 has either been prevented or considerably reduced.

Although the invention is primarily intended for diesel fuelled gas turbine engines, it can also be used advantageously with kerosene fuelled engines.

WHAT WE CLAIM IS: - 1. Combustion equipment for a gas tur

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. (54) IMPROVMENTS IN OR RELATING TO COMBUSTION EQUIPMENT (71) We, ROLLS-ROYCE LIMITED, a British Company of 65 Buckingham Gate London, SW1E 6AT, formerly Rolls-Royce (1971) Ltd., of Norfolk House, St. Janes Square, London SW17 4JR, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to combustion equipment, for example the combustion equipment of gas turbine engines, and is particulariy concerned with the problem of carbon deposition in such combustion equipment. In some circumstances, carbon is deposited on the combustion chamber head and lumps of carbon eventually become dislodged causing considerable damage to downstream parts of the engine such as the high pressure turbine blades. It is an object d the invention to provide an improved apparatus which will at least partially prevent such carbon deposition.The present invention provides combustion equipment for a gas turbine engine comprising a cornbustion chamber having a dome shaped head diverging immediately downstream of a parallel walled central aperture, a swirl vane assembly, comprising inner and outer concentric cylindrical walls with swirl vanes extending therebetween, secured to and spaced apart from the parallel walled central aperture, a fuel nozzle located in the central aperture and positioned within the inner cylindrical wall of the swirl vane assembly, a flare located in the central aperture immediately downstream of the swirl vane assembly spaced apart from and secured to the wall defining the central aperture and extends into the combustion chamber, a flow passage being formed between the central aperture wall and the flare and the outer cylindrical wall of the swirl vane assembly, an annular air passage being formed between a portion of the head of the combustion chamber and the flare, the swirl vane assembly having a plurality of apertures formed in the outer cylindrical wall to allow air from the compressor of the gas turbine engine to flow through the apertures into the flow passage and the annular air passage and thence over the internal surface of the head portion od the combustion chamber. The present invention will now be more particularly described with reference to the accompanying drawing which shows a partsection through a combustion chamber head incorporating one form of the present invention. In the drawing, there is shown the upstream portion of part of the combustion equipment of a gas turbine engine (not shown). The portion comprises a compressor air inlet duct 10 which receives air from the compressor of the engine, a swirler vane assembly 12 and combustion chamber head 14. The swirler vane assembly 12 surrounds a central aperture 16 in which a fuel nozzle (not shown) can be fitted. A cylindrical flare 18 is secured immediately downstream of the twirler vane assembly 12 and extends into the combustion chamber defining a passage 22 in conjunction with the inner part of the head 14. The swirler vane assembly 12 has a ring of apertures 20 through which compressed air from the engine compressor can flow to the passage 22. The configuration of the passage 22 is designed so that both the velocity of the air issuing from the passage 22 matches the velocity of the re-oirculating primary air in the combustion chamber and that the air from the passage flows over the surface of the head 14 to reduce the build-up of carbon on the head. With the flare configurations shown in the drawing, the accretion of carbon on the head 14 has either been prevented or considerably reduced. Although the invention is primarily intended for diesel fuelled gas turbine engines, it can also be used advantageously with kerosene fuelled engines. WHAT WE CLAIM IS: -

1. Combustion equipment for a gas tur i bine engine comprising a combustion chamber having a dome shaped head diverging immedi- ately downstream of a parallel walled central aperture, a swirl vane assembly, comprising inner and outer concentric cylindrical walls with swirl vanes extending therebetween, secured to and spaced apart from the parallel walled central aperture, a fuel nozzle located in the central aperture and positioned within the inner cylindrical wall of the swirl vane assembly, a flare located in the central aper ture immediately downstream of the swirl vane assembly spaced apart from and secured to the wall defining the central aperture and extends into the combustion chamber, a flow passage being formed between the central aperture wall and the flare and the outer cylindrical wall of the swirl vane assembly, an annular air passage being formed between a portion of the head of the combustion cham- ber and the flare, the swirl vane assembly heaving a plurality of apertures formed in the outer cylindrical wall to allow air frcm the compressor of the gas turbine engine to flow through the apertures into the flow passage and the annular air passage and thence over the internal surface of the head portion of the combustion chamber.

2. Combustion equipment constructed and arranged for use and operation substantially as hereinbefore described with reference to and as shown in the accompanying drawing.