Gas turbine combustor and combustion method therefor

Claim 2

A multistage combustion type gas turbine combustor comprising a head combustion chamber means disposed at a head of said combustor for effecting first stage premix combustion of fuel premixed with combustion air, a first stage burner disposed at an upstream side of said head combustion chamber means and including a swirler and a fuel nozzle having a tip disposed upstream of a fuel-air mixture outlet of said swirler for introducing premixed fuel and air into said head combustion chamber means, a rear combustion chamber means connected to a downstream side of said head combustion chamber means for effecting second stage combustion of fuel premixed with combustion air, a second stage burner including a swirler, independent of said first stage burner and disposed downstream of said head combustion chamber means, for introducing the fuel air-mixture into said rear combustion chamber means, and means for regulating a flow rate of combustion air to be premixed with fuel and introduced into at least one of said head combustion chamber means and said rear combustion chamber means so as to form a suitable fuel and air premixture to effect premixed fuel combustion to thereby reduce NO x production, said means for regulating a flow rate of combustion air being disposed upstream of said swirlers thereby regulating a flow rate of combustion air.

Claim 3

A gas turbine combustor as defined in claim 1, wherein a means, independent of said first stage burner, is provided in said head combustion chamber means for producing a pilot combustion flame and stabilizing premix combustion flame generated in said head combustion chamber means.

Claim 4

A gas turbine combustor as defined in claim 1, wherein a plurality of pilot burners are provided in said head combustion chamber means and said rear combustion chamber means.

Claim 5

A gas turbine combustor as defined in claim 2, wherein said head combustion chamber means has a reduced cross-sectional area at a downstream side thereof, and a plurality of first stage burners are provided at said cross-sectional area portion to inject premixed fuel and air into a central portion of said head combustion chamber means.

Claim 6

A gas turbine combustor comprising: a head combustion chamber means disposed at a head of said combustor for effecting first stage combustion, a first stage burner provided on an upstream side of said head combustion chamber means for introducing premixed fuel and air into said head combustion chamber means to effect a first stage premix combustion in said head combustion chamber means, said first stage burner having a swirler and a fuel nozzle including a tip disposed upstream of a fuel and air outlet of said swirler, a pilot burner provided adjacent to said first stage burner for a pilot combustion flame in said head combustion chamber means, a rear combustion chamber means connected to a downstream side of said head combustion chamber means for effecting second stage combustion, a second stage burner independent of said first stage burner and disposed at a downstream side of said head combustion chamber means and on an upstream side of said rear combustion chamber means for introducing premixed fuel and air into said rear combustion chamber means to effect a second stage premix combustion, and an air flow regulating means provided in said combustor to regulate a flow rate of first stage combustion air to be premixed with first stage fuel and a flow rate of second stage combustion air to be premixed with second stage fuel, thereby providing suitable fuel air premixture to effect lean combustion.

Claim 7

A gas turbine combustor comprising: a head combustion chamber means disposed at a head of said combustor for effecting first stage combustion, a first stage burner provided on an upstream side of said head combustion chamber means for introducing premixed fuel and air into said head combustion chamber means to effect a first stage premix combustion in said head combustion chamber means, said first stage burner having a swirler and a fuel nozzle including a tip disposed upstream of a fuel and air outlet of said swirler, a pilot burner provided adjacent to said first stage burner for a pilot combustion flame in said head combustion chamber means, a rear combustion chamber means connected to a downstream side of said head combustion chamber means for effecting second stage combustion, a second stage burner independent of said first stage burner and disposed at a downstream side of said head combustion chamber means and on an upstream side of said rear combustion chamber means for introducing premixed fuel and air into said rear combustion chamber means to effect a second stage premix combustion, and an air flow regulating means provided in said combustor to regulate a flow rate of first stage combustion air to be premixed with first stage fuel and a flow rate of second stage combustion air to be premixed with second stage fuel, thereby providing suitable fuel air premixture to effect lean combustion.

Claim 8

A gas turbine combustor as defined in claim 5, wherein said second stage burner is provided with a plurality of premixed fuel and air outlets arranged circumferentially of said rear combustion chamber means.

Claim 9

A gas turbine combustor as defined in claim 6, wherein said first stage burner is provided with a plurality of annularly arranged premixed fuel and air outlets, and said pilot burner is located at a center of said first stage burner, whereby premix combustion flame produced by said first stage burner is made stable by combustion flame produced by said pilot burner.

Claim 10

A gas turbine combustor comprising: a combustor liner means for defining a cylindrical head combustion chamber means at a head of said combustor and a cylindrical rear combustion chamber means on a downstream side of said head combustion chamber means, said rear combustion chamber means having a larger diameter than said head combustion chamber means; an axially elongated outer casing surrounding said combustor liner means with a space therebetween for defining an air passage; a first stage burner disposed at an upstream side of said head combustion chamber means and having a swirler with annularly arranged outlets for premixed fuel and air and a fuel nozzle having a tip disposed upstream of said outlets for mixing fuel therefrom with air at an upstream side of said outlets to provide the premixed fuel and air; a pilot burner disposed adjacent to said first stage burner for producing a combustion flame; a second stage burner independent of said first stage burner and having a swirler with annularly arranged outlets for premixed fuel and air, said outlets being disposed between an outer surface of a downstream end portion of said head combustion chamber means and an inner surface of an upstream end portion of said rear combustion chamber means; and a combustion air flow regulating means at an upstream side of said swirlers for regulating a flow rate of combustion air to be led to said first stage burner from said space and a flow rate of combustion air to be led to said second stage burner from said space.

Claim 11

A gas turbine combustor comprising: a combustor liner means for defining a cylindrical head combustion chamber means at a head of said combustor and a cylindrical rear combustion chamber means on a downstream side of said head combustion chamber means, said rear combustion chamber means having a larger diameter than said head combustion chamber means; an axially elongated outer casing surrounding said combustor liner means with a space therebetween for defining an air passage; a first stage burner disposed at an upstream side of said head combustion chamber means and having a swirler with annularly arranged outlets for premixed fuel and air and a fuel nozzle having a tip disposed upstream of said outlets for mixing fuel therefrom with air at an upstream side of said outlets to provide the premixed fuel and air; a pilot burner disposed adjacent to said first stage burner for producing a combustion flame; a second stage burner independent of said first stage burner and having a swirler with annularly arranged outlets for premixed fuel and air, said outlets being disposed between an outer surface of a downstream end portion of said head combustion chamber means and an inner surface of an upstream end portion of said rear combustion chamber means; and a combustion air flow regulating means at an upstream side of said swirlers for regulating a flow rate of combustion air to be led to said first stage burner from said space and a flow rate of combustion air to be led to said second stage burner from said space.

Claim 12

A gas turbine combustor as defined in claim 8, wherein said combustion air flow regulating means comprises a guide ring having a plurality of air holes each communicating with said first and second stage burners to introduce combustion air, and a mechanism for axially sliding said guide ring so that opening areas of said air holes opening to each of said first and second stage burners are selectively changeable.

Claim 13

A gas turbine combustor as defined in claim 8, wherein said pilot burner has combustion air supply passages independent of said space defining said air passage.

Claim 14

A combustion method for a gas turbine combustor comprising a head combustion chamber for effecting first stage combustion and a rear combustion chamber for effecting second stage combustion, said method comprising the steps of: premixing first stage fuel with combustion air; swirling and supplying the resultant first stage fuel air premixture into said head combustion chamber; regulating a flow rate of the combustion air to be premixed with the first stage fuel before swirling so that the first stage fuel air premixture will be suitable to effect lean premix combustion; firing and combusting the first stage fuel air premixture in said head combustion chamber when the turbine is in a low load operation; premixing second stage fuel with combustion air; swirling and supplying the resultant second stage fuel-air premixture into the rear combustion chamber in a downstream region of said head combustion chamber when the turbine reaches a high load operation, the second stage fuel air premixture being fired by a premixed first stage fuel combustion flame, and combusted in addition to the premixed first stage fuel combustion; and regulating a flow rate of the combustion air to be premixed with the second stage fuel so as to provide a fuel-air ratio to effect lean premixed combustion.

Claim 15

A combustion method for a gas turbine combustor comprising a head combustion chamber for effecting first stage combustion and a rear combustion chamber for effecting second stage combustion, said method comprising the steps of: premixing first stage fuel with combustion air; swirling and supplying the resultant first stage fuel air premixture into said head combustion chamber; regulating a flow rate of the combustion air to be premixed with the first stage fuel before swirling so that the first stage fuel air premixture will be suitable to effect lean premix combustion; firing and combusting the first stage fuel air premixture in said head combustion chamber when the turbine is in a low load operation; premixing second stage fuel with combustion air; swirling and supplying the resultant second stage fuel-air premixture into the rear combustion chamber in a downstream region of said head combustion chamber when the turbine reaches a high load operation, the second stage fuel air premixture being fired by a premixed first stage fuel combustion flame, and combusted in addition to the premixed first stage fuel combustion; and regulating a flow rate of the combustion air to be premixed with the second stage fuel so as to provide a fuel-air ratio to effect lean premixed combustion.

Claim 16

A combustion method for a gas turbine combustor comprising a head combustion chamber for effecting first stage combustion and a rear combustion chamber for effecting second stage combustion, said method comprising the steps of; supplying fuel and air into said head combustion chamber and mixing said fuel and air in said head combustion chamber; igniting and effecting a diffusion combustion of the fuel and air mixture to thereby form a pilot flame; supplying first stage fuel into a first stage burner provided in said head combustion chamber; supplying combustion air to said first stage nozzle to premix the combustion air with the first stage fuel while regulating a flow rate thereof so as to increase the flow rate with an increasing first stage fuel amount at an initial stage and then to provide a fuel-air premixture to effect lean premix combustion; supplying and swirling the premixed first stage fuel and air into said head combustion chamber; firing the premixed first stage fuel and air by the pilot flame to combust the first stage fuel and air at an initial and a low load operation of the turbine; supplying second stage fuel to a second stage burner provided in said rear combustion chamber; supplying combustion air to said second stage burner to premix the second stage burner combustion air with the second stage fuel while regulating a flow rate thereof so as to increase the second stage burner combustion air with an increasing of second stage fuel and to provide a fuel-air premixture to effect lean premixed combustion; and supplying, independently of the premixed first fuel and air, the premixed second stage fuel and air into said rear combustion chamber, the premixed second stage fuel and air being fired by the first stage premixed fuel combustion flame and combusted therein thereby effecting premixed combustion in addition to the first stage combustion when the turbine is in a high load operation.

Claim 17

A combustion method for a gas turbine combustor comprising a head combustion chamber for effecting first stage combustion and a rear combustion chamber for effecting second stage combustion, said method comprising the steps of; supplying fuel and air into said head combustion chamber and mixing said fuel and air in said head combustion chamber; igniting and effecting a diffusion combustion of the fuel and air mixture to thereby form a pilot flame; supplying first stage fuel into a first stage burner provided in said head combustion chamber; supplying combustion air to said first stage nozzle to premix the combustion air with the first stage fuel while regulating a flow rate thereof so as to increase the flow rate with an increasing first stage fuel amount at an initial stage and then to provide a fuel-air premixture to effect lean premix combustion; supplying and swirling the premixed first stage fuel and air into said head combustion chamber; firing the premixed first stage fuel and air by the pilot flame to combust the first stage fuel and air at an initial and a low load operation of the turbine; supplying second stage fuel to a second stage burner provided in said rear combustion chamber; supplying combustion air to said second stage burner to premix the second stage burner combustion air with the second stage fuel while regulating a flow rate thereof so as to increase the second stage burner combustion air with an increasing of second stage fuel and to provide a fuel-air premixture to effect lean premixed combustion; and supplying, independently of the premixed first fuel and air, the premixed second stage fuel and air into said rear combustion chamber, the premixed second stage fuel and air being fired by the first stage premixed fuel combustion flame and combusted therein thereby effecting premixed combustion in addition to the first stage combustion when the turbine is in a high load operation.

Claim 18

A multistage combustion type gas turbine combustor comprising: a head premix combustion chamber at a head of said combustor for effecting a first stage premix combustion of fuel premixed with combustion air during a load operation; a first premixing means for premixing fuel and air and for injecting the premixed fuel and air into said head combustion chamber to effect a premix combustion, said first premixing means having a swirler through which the premixed fuel and air is injected; a rear premix combustion chamber, connected to a downstream side of said head premix combustion chamber, for effecting second stage premix combustion during middle and high load operation of the turbine; a second premixing means independent of said first premixing means for premixing fuel and air and for injecting the premixed fuel and air into said rear premix combustion chamber to effect premix combustion, said second premixing means being axially separated from said first premixing means; and first flow rate regulator means disposed at an upstream side of said swirler for regulating a flow rate of air directed to said first means so that a mixing ratio of fuel and air premixed by said first premixing means is suitable to achieve a lean premix combustion to thereby reduce NO x emission.

Claim 19

A multistage combustion type gas turbine combustor comprising: a head premix combustion chamber at a head of said combustor for effecting a first stage premix combustion of fuel premixed with combustion air during a load operation; a first premixing means for premixing fuel and air and for injecting the premixed fuel and air into said head combustion chamber to effect a premix combustion, said first premixing means having a swirler through which the premixed fuel and air is injected; a rear premix combustion chamber, connected to a downstream side of said head premix combustion chamber, for effecting second stage premix combustion during middle and high load operation of the turbine; a second premixing means independent of said first premixing means for premixing fuel and air and for injecting the premixed fuel and air into said rear premix combustion chamber to effect premix combustion, said second premixing means being axially separated from said first premixing means; and first flow rate regulator means disposed at an upstream side of said swirler for regulating a flow rate of air directed to said first means so that a mixing ratio of fuel and air premixed by said first premixing means is suitable to achieve a lean premix combustion to thereby reduce NO x emission.

Claim 20

A multistage combustion type gas turbine combustion according to claim 13, wherein said combustor further includes a second flow rate regulator means for regulating a flow rate of air directed to said second premixing means so that a mixing ratio of fuel and air premixed by said second premixing means is suitable to achieve a lean premix combustion to thereby reduce NO x emission, and means for simultaneously operating said first and second regulator means.

Claim 21

A gas turbine combustor according to claim 14, wherein a means are provided at an upstream side of said head combustion chamber for producing pilot diffusion combustion flame to stabilize a premix combustion flame produced in said head combustion chamber so that a lean premix combustion stabilized by the pilot diffusion combustion flame is effected.

Claim 22

A multistage combustion type gas turbine combustor as according to claim 15, wherein said first premixing means comprises an outer annular partition, an inner annular partition coaxially disposed in said outer annular partition with an annular space therebetween, and a plurality of swirler vanes arranged in said annular space to provide a plurality of outlets for premixed fuel and air along an inner circumference of said head premix combustion chamber, whereby premixed fuel and air are whirled and supplied into said head premix combustion chamber to be combusted therein.

Claim 23

A multistage combustion type gas turbine combustor according to claim 16, wherein said means for producing pilot diffusion combustion flame comprises a fuel nozzle, a plurality of swirler vanes mounted around said fuel nozzle, said fuel nozzle and said swirler vanes are disposed in said inner annular partition to fire the premixed fuel and air supplied by said first means into said head premix combustion chamber and stabilize the premix combustion flame.

Claim 24

A multistage combustion type gas turbine combustor, according to claim 13, wherein said head premix combustion chamber includes a first cylindrical liner for defining said head premix combustion chamber, said rear premix combustion chamber including a second cylindrical liner for defining said rear premix combustion chamber, said second cylindrical liner having a larger diameter than a diameter of said first cylindrical liner, and said second means axially slidably disposed in an annular space formed between said first and second cylindrical liners.

Claim 25

A multistage combustion type gas turbine combustor according to claim 18, wherein said second premixing means comprises an outer annular member inserted in and slidable on said second cylindrical liner, an inner annular member disposed in said outer annular member with an annular space therebetween, and a plurality of swirler vanes in said annular space, said first cylindrical liner being slidably inserted in said inner annular member.

Claim 26

A multistage combustion type gas turbine combustor according to claim 13, wherein said first premixing means comprises a plurality of swirler vanes arranged in a annular form to provide a plurality of outlets along an inner circumference of said head premix combustion chamber so that premixed fuel and air is introduced into said head combustion chamber while swirling, and a pilot burner is provided so as to be surrounded by said plurality of outlets, a fuel nozzle and a plurality of swirler vanes mounted on a surrounding said fuel nozzle.

Claim 27

A combustion method for a gas turbine combustor, the method comprising the steps of: providing a head combustion chamber means at a head of said combustor for effecting a first stage premix combustion of fuel premixed with combustion air, providing a first stage burner having a swirler and fuel nozzle, locating a tip of the fuel nozzle upstream of a fuel-air mixture outlet of said swirler, connecting a rear combustion chamber means to a downstream side of said head combustion chamber means for effecting second stage combustion of fuel premixed with combustion air, providing a second stage burner including a swirler, independent of said first stage burner and disposed downstream of said head combustion chamber means, for introducing the fuel air mixture into said rear combustion chamber means, and regulating a flow rate of combustion air to be premixed with fuel and introduced into at least one of said head combustion chamber means and said rear combustion chamber means so as to form a suitable fuel and air premixture to effect premixed fuel combustion to thereby reduce NO x combustion.

Claim 28

A combustion method for a gas turbine combustor, the method comprising the steps of: providing a head combustion chamber means at a head of said combustor for effecting a first stage premix combustion of fuel premixed with combustion air, providing a first stage burner having a swirler and fuel nozzle, locating a tip of the fuel nozzle upstream of a fuel-air mixture outlet of said swirler, connecting a rear combustion chamber means to a downstream side of said head combustion chamber means for effecting second stage combustion of fuel premixed with combustion air, providing a second stage burner including a swirler, independent of said first stage burner and disposed downstream of said head combustion chamber means, for introducing the fuel air mixture into said rear combustion chamber means, and regulating a flow rate of combustion air to be premixed with fuel and introduced into at least one of said head combustion chamber means and said rear combustion chamber means so as to form a suitable fuel and air premixture to effect premixed fuel combustion to thereby reduce NO x combustion.

Claim 29

A combustion method according to claim 21, further comprising the step of: producing a pilot combustion flame and stabilizing a premix combustion flame generated in said head combustion chamber means.

Claim 30

A combustion method for a gas turbine combustor, the method comprising the steps of: providing a head combustion chamber means at a head of said combustor for effecting a first stage combustion providing a first stage burner including a swirler and fuel nozzle, locating a tip of the fuel nozzle upstream of a fuel-air mixture outlet of said swirler, for introducing premixed fuel and air into said head combustion chamber means to effect a first stage premix combustion, producing a pilot combustion flame in said head combustion chamber means by a pilot burner provided adjacent to said first stage burner, connecting a rear combustion chamber means to a downstream side of said head combustion chamber means for effecting second stage combustion, introducing premixed fuel and air into said rear combustion chamber means to effect a second stage premix through a second stage burner, independent of said first stage burner, disposed on an upstream side of said rear combustion chamber means, and regulating an air flow in said combustor to regulate a flow rate of the first stage combustion air to be premixed with the first stage fuel and a flow rate of the second stage combustion air to be premixed with the second stage fuel so as to provide a suitable fuel air premixture to effect lean combustion.

Claim 31

A combustion method for a gas turbine combustor, the method comprising the steps of: providing a head combustion chamber means at a head of said combustor for effecting a first stage combustion providing a first stage burner including a swirler and fuel nozzle, locating a tip of the fuel nozzle upstream of a fuel-air mixture outlet of said swirler, for introducing premixed fuel and air into said head combustion chamber means to effect a first stage premix combustion, producing a pilot combustion flame in said head combustion chamber means by a pilot burner provided adjacent to said first stage burner, connecting a rear combustion chamber means to a downstream side of said head combustion chamber means for effecting second stage combustion, introducing premixed fuel and air into said rear combustion chamber means to effect a second stage premix through a second stage burner, independent of said first stage burner, disposed on an upstream side of said rear combustion chamber means, and regulating an air flow in said combustor to regulate a flow rate of the first stage combustion air to be premixed with the first stage fuel and a flow rate of the second stage combustion air to be premixed with the second stage fuel so as to provide a suitable fuel air premixture to effect lean combustion.