Compressor diffuser non-return valve and method for starting gas turbine engines
AssigneeA/S Kongsberg Vapenfabrikk
InventorPer Klaebo
Life of this patent
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Abstract
Gas turbine engine starting method and apparatus includes the engine turbine and rotary compressor components coupled for dependent rotation; a compressor plate diffuser with an integral, floating plate one-way valve; a housing receiving diffused compressed air for channeling to the combustor; and a source of pressurized air connected for admission to the housing during startup at a point upstream of combustor and downstream of one-way valve for initiating rotation of the turbine and coupled compressor.
Claims16
Apparatus for starting a gas turbine engine of the type having a rotary compressor for compressing air, a combustor for combusting the compressed air with fuel to produce combustion gases under pressure, and a turbine for expanding the combustion gases to produce mechanical work, the turbine and the compressor being coupled for dependent rotation, the apparatus comprising:
- (a) diffuser means operatively connected to the rotary compressor to receive and convert the high velocity air to low velocity, higher pressure air;
- (b) means operatively connected to said diffuser means for receiving and collecting the low velocity, higher pressure compressed air and channeling said higher pressure air to said combustor, said collecting means including a housing, a high pressure gas flow path being defined through said diffuser means and said housing, and to the combustor;
- (c) means for supplying pressurized gas to said housing at a point upstream of the combustor and downstream of said diffuser means in said flow path during engine startup;
- and
- (d) valve means integral with said diffuser means for preventing reverse flow of said pressurized gas through the compressor, the pressurized gas flowing through the combustor and being expanded in the turbine to cause rotation of the turbine and the compressor and to establish a flow of pressurized air to the combustor,
- wherein said diffuser means includes a plate-type radial diffuser and said housing means receives higher pressure air from said plate diffuser, and wherein said valve means is associated with said plate diffuser, and wherein said plate diffuser includes
- (i) a nozzle portion having an inner edge defining an axially directed plate diffuser inlet, and a radially directed flared outer edge,
- (ii) a planar member oriented perpendicular to said plate diffuser inlet axis and spaced from said nozzle,
- (iii) a plate member positioned between said nozzle and said planar member, the radially outer portion of said plate member together with the spaced adjacent outer nozzle edge forming a radially directed plate diffuser exit when said plate member abuts said planar member, and
- (iv) plate securing means for providing unrestricted axial movement of said plate member between an unsealing position against said planar member and a sealing position against said nozzle, the introduction of said pressurized gas during startup causing a net pressure force on said plate to move said plate member to said sealing position, and the impact force of high velocity air from the compressor during subsequent normal operation causing movement of said plate member to said unsealing position.
Method for starting a gas turbine engine having a rotary compressor and diffuser for providing high pressure air, a combustor for combusting fuel with the compressed air to produce combustion gases, and a turbine for expanding the combustion gases to produce mechanical work, the turbine and the compressor being mechanically coupled for dependent rotation, the method comprising
- (a) introducing pressurized gas into the compressed air flow path between the diffuser and the combustor;
- (b) preventing back flow of pressurized gas through the diffuser and compressor using one way valve means associated with the diffuser;
- (c) expanding the pressurized gas through the turbine to cause rotation of the turbine and the compressor;
- and
- (d) returning the one way valve to normal open position under the influence of the flow of compressed air from the rotating compressor,
- wherein the diffuser includes a plate type diffuser stage and the valve means includes an axially floating plate member mounted in the plate diffuser, and wherein said preventing step includes the step of translating said plate member into a sealing position under the force of the pressurized gas.
Apparatus for starting a gas turbine engine of the type having a rotary compressor for compressing air, a combustor for combusting the compressed air with fuel to produce combustion gases under pressure, and a turbine for expanding the combustion gases to produce mechanical work, the turbine and the compressor being coupled for dependent rotation, the apparatus comprising
- (a) diffuser means operatively connected to the rotary compressor to receive and convert the high velocity air to low velocity, higher pressure air;
- (b) means operatively connected to said diffuser means for receiving and collecting the low velocity, higher pressure compressed air and channeling said higher pressure air to said combustor, said collecting means including a housing, a high pressure gas flow path being defined through said diffuser means and said housing, and to the combustor;
- (c) means for supplying pressurized gas to said housing at a point upstream of the combustor and downstream of said diffuser means in said flow path during engine startup;
- and
- (d) valve means integral with said diffuser means for preventing reverse flow of said pressurized gas through the compressor, the pressurized gas flowing through the combustor and being expanded in the turbine to cause rotation of the turbine and the compressor and to establish a flow of pressurized air to the combustor,
- wherein said diffuser means includes a plate-type radial diffuser and said housing means receives higher pressure air from said plate diffuser, and wherein said valve means is associated with said plate diffuser, and
- wherein said plate diffuser includes
- (i) a nozzle portion having an inner edge defining an axially directed plate diffuser inlet, and a radially directed flared outer edge,
- (ii) a planar member oriented perpendicular to said plate diffuser inlet axis and spaced from said nozzle,
- (iii) a plate member positioned between said nozzle and said planar member, the radially outer portion of said plate member together with the spaced adjacent outer nozzle edge forming a radially directed plate diffuser exit when said plate member abuts said planar member,
- (iv) plate securing means for providing unrestricted axial movement of said plate member between an unsealing position against said planar member and a sealing position against said nozzle, the introduction of said pressurized gas during startup causing a net pressure force on said plate to move said plate member to said sealing position, and the impact force of high velocity air from the compressor during subsequent normal operation causing movement of said plate member to said unsealing position;
- and
- (e) means for decreasing the total force applied to said plate member by said pressurized gas, said force decreasing means including
- (i) said plate member having a planar area significantly less than the area circumscribed by said nozzle outer edge, and
- (ii) a recess formed in said planar member for receiving said plate member when said plate member is in the unsealing position.
Dependencies are inferred from the claim text.