Lean-rich axial stage combustion in a can-annular gas turbine engine
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
F02G-003/00
F23R-003/34
F23R-003/28
출원번호
US-0739316
(2013-01-11)
등록번호
US-9366443
(2016-06-14)
발명자
/ 주소
Laster, Walter R.
Szedlacsek, Peter
출원인 / 주소
SIEMENS ENERGY, INC.
인용정보
피인용 횟수 :
0인용 특허 :
7
초록▼
An apparatus and method for lean/rich combustion in a gas turbine engine (10), which includes a combustor (12), a transition (14) and a combustor extender (16) that is positioned between the combustor (12) and the transition (14) to connect the combustor (12) to the transition (14). Openings (18) ar
An apparatus and method for lean/rich combustion in a gas turbine engine (10), which includes a combustor (12), a transition (14) and a combustor extender (16) that is positioned between the combustor (12) and the transition (14) to connect the combustor (12) to the transition (14). Openings (18) are formed along an outer surface (20) of the combustor extender (16). The gas turbine (10) also includes a fuel manifold (28) to extend along the outer surface (20) of the combustor extender (16), with fuel nozzles (30) to align with the respective openings (18). A method (200) for axial stage combustion in the gas turbine engine (10) is also presented.
대표청구항▼
1. A method for axial stage combustion in a gas turbine engine comprising: mixing air and fuel to form a lean air-fuel mixture of air and fuel in a first stage of combustion of a can-annular combustor of the gas turbine engine, wherein the lean air-fuel mixture of air and fuel has an equivalence rat
1. A method for axial stage combustion in a gas turbine engine comprising: mixing air and fuel to form a lean air-fuel mixture of air and fuel in a first stage of combustion of a can-annular combustor of the gas turbine engine, wherein the lean air-fuel mixture of air and fuel has an equivalence ratio of less than one;igniting the lean air-fuel mixture at the first stage of combustion to create hot combustion gas having a first temperature and free radicals;disposing an air-fuel mixing arrangement in a second stage of combustion of the can-annular combustor, the second stage of combustion located downstream from the first stage of combustion, the air-fuel mixing arrangement coupled to receive fuel delivered in the second stage of combustion by a plurality of fuel nozzles and further coupled to receive a flow of air in the second stage of combustion;mixing air and fuel received by the air-fuel mixing arrangement to form a rich air-fuel mixture of air and fuel in the second stage of combustion, wherein the rich air-fuel mixture of air and fuel has an equivalence ratio of greater than one;wherein the mixing of air and fuel received by the air-fuel mixing arrangement comprises adjustably varying a volumetric flow rate of fuel delivered in the second stage of combustion by the fuel nozzles by way of respective valves in each fuel nozzle to adjustably vary the equivalence ratio of the rich air-fuel mixture,injecting the rich air-fuel mixture into the second stage of combustion; andigniting the rich air-fuel mixture in the hot combustion gas at the second stage of combustion, such that the first temperature and the free radicals of the hot combustion gas promote combustion of the rich air-fuel mixture within a predetermined hydrocarbon emissions limit, and the first temperature of the hot combustion gas increases to a second temperature. 2. The method of claim 1, wherein the rich air-fuel mixture has an equivalence ratio between 3 and 10. 3. The method of claim 2, wherein the rich air-fuel mixture has an equivalence ratio between 3 and 5. 4. The method of claim 1, wherein the equivalence ratio of the rich air-fuel mixture is reduced as it diffuses into the hot combustion gas so that when the rich air-fuel mixture is diffused into the hot combustion gas, the second temperature is less than an emission threshold temperature. 5. The method of claim 1, wherein a split of a total amount of air between the lean air-fuel mixture and the rich air-fuel mixture is between 0.5% and 3.5% in the rich air-fuel mixture; and wherein a split of a total amount of fuel between the lean air-fuel mixture and the rich air-fuel mixture is between 5% and 20% in the rich air-fuel mixture. 6. The method of claim 5, wherein the split of the total amount of air is between 0.5 and 2% in the rich air-fuel mixture and wherein the split of the total amount of fuel is between 5 and 15% in the rich air-fuel mixture. 7. A method for axial stage combustion in a gas turbine engine comprising: mixing a lean air-fuel mixture in a first stage of combustion of a can-annular combustor of the gas turbine engine, wherein the lean air-fuel mixture has an equivalence ratio of less than one;igniting the lean air-fuel mixture at the first stage of combustion to create hot combustion gas having a first temperature and free radicals;mixing a rich air-fuel mixture with an equivalence ratio of greater than one;injecting the rich air-fuel mixture into the hot combustion gas at a second stage of combustion of the can-annular combustor downstream from the first stage; andigniting the rich air-fuel mixture in the hot combustion gas at the second stage of combustion, such that the first temperature and the free radicals of the hot combustion gas promote combustion of the rich air-fuel mixture within a predetermined hydrocarbon emissions limit, and the first temperature of the hot combustion gas increases to a second temperature, wherein the first temperature is in a range of 1300-1500 degrees C. and wherein the second temperature is in a range of 1500-1700 degrees C. 8. The method of claim 1, wherein the igniting of the lean air-fuel mixture generates a first degree of an emission in the hot combustion gas, wherein the igniting of the rich air-fuel mixture increases the first degree of the emission to a second degree of the emission, and wherein the second degree of the emission is within a predetermined emission limit. 9. The method of claim 8, wherein the emission comprises NOx. 10. A gas turbine engine comprising: a can-annular combustor comprising a first stage of combustion, wherein air and fuel are mixed to form a lean air-fuel mixture of air and fuel, wherein the lean air-fuel mixture has an equivalence ratio of less than one wherein ignition of the lean air-fuel mixture forms hot combustion gas having a first temperature and free radicals;a transition in fluid communication between the combustor and a turbine;a combustor extender in fluid communication between the combustor and the transition;a plurality of wall openings formed through the combustor extender;a fuel manifold extending along an outer surface of the combustor extender, said fuel manifold comprising a plurality of fuel nozzles aligned to deliver fuel through the respective plurality of wall openings; andan air-fuel mixing arrangement disposed in a second stage of combustion the air-fuel mixing arrangement coupled to receive fuel delivered by the plurality of fuel nozzles and further coupled to receive a flow of air to form a rich air-fuel mixture of air and fuel with an equivalence ratio of greater than one,wherein the second stage of combustion is disposed downstream from the first stage of combustion, wherein the air-fuel mixing arrangement supplies the rich air-fuel mixture, wherein the rich air-fuel mixture is ignited in the hot combustion gas, such that the first temperature and the free radicals of the hot combustion gas promote combustion of the rich air-fuel mixture within a predetermined hydrocarbon emissions limit, and the first temperature of the hot combustion gas increases to a second temperature,wherein the air-fuel mixing arrangement comprises:a mixer positioned between the fuel manifold and the outer surface of the combustor extender at each of the plurality of openings, said mixer including a first opening aligned with the respective fuel nozzle to receive fuel from the respective fuel nozzle and a second opening to receive the air flow; anda scoop positioned at each of the plurality of openings said scoop configured to receive the fuel and the air flow from the mixer, said scoop is further configured to direct the rich air-fuel mixture of the fuel and the air flow into the respective opening,wherein each fuel nozzle of the fuel manifold includes a valve to adjustably vary a volumetric flow rate of fuel directed into the first opening and to adjustably vary an equivalence ratio of the air-fuel mixture directed into the respective opening. 11. A gas turbine engine comprising: a can-annular combustor comprising a first stage of combustion, wherein air and fuel are mixed to form a lean air-fuel mixture of air and fuel, wherein the lean air-fuel mixture has an equivalence ratio of less than one, wherein ignition of the lean air-fuel mixture forms hot combustion gas having a first temperature and free radicals;a transition in fluid communication between the combustor and a turbine;a combustor extender in fluid communication between the combustor and the transition;a plurality of wall openings formed through the combustor extender;a fuel manifold extending along an outer surface of the combustor extender, said fuel manifold comprising a plurality of fuel nozzles aligned to deliver further fuel through the respective plurality of wall openings; andan air-fuel mixing arrangement disposed in a second stage of combustion, the air-fuel mixing arrangement coupled to receive the further fuel delivered by the plurality of fuel nozzles and further coupled to receive a flow of air to form in the second stage of combustion a rich air-fuel mixture of air and fuel with an equivalence ratio of greater than one,wherein the second stage of combustion is disposed downstream from the first stage of combustion wherein the air-fuel mixing arrangement supplies the rich air-fuel mixture wherein the rich air-fuel mixture is ignited in the hot combustion gas, such that the first temperature and the free radicals of the hot combustion gas promote combustion of the rich air-fuel mixture within a predetermined hydrocarbon emissions limit, and the first temperature of the hot combustion gas increases to a second temperature,wherein the first temperature is in a range of 1300-1500 degrees C. and wherein the second temperature is in a range of 1500-1700 degrees C. 12. The gas turbine engine of claim 11, wherein the air-fuel mixing arrangement comprises: a mixer positioned between the fuel manifold and the outer surface of the combustor extender at each of the plurality of openings, said mixer including a first opening aligned with the respective fuel nozzle to receive fuel from the respective fuel nozzle and a second opening to receive the air flow; anda scoop positioned at each of the plurality of openings, said scoop configured to receive the fuel and the air flow from the mixer, said scoop is further configured to direct the rich air-fuel mixture of the fuel and the air flow into the respective opening. 13. The gas turbine engine of claim 12, wherein the second opening of the mixer is an annular opening to receive the air flow and wherein the first opening is formed in a central cross sectional region of the mixer. 14. The gas turbine engine of claim 12, wherein the scoop takes a conical shape that is angled inward toward an interior of the combustor extender. 15. The gas turbine engine of claim 11, wherein the plurality of openings are formed along an outer circumference of the outer surface of the combustor extender and wherein the fuel manifold is configured to extend along the outer circumference of the outer surface of the combustor extender. 16. The gas turbine engine of claim 11, further comprising: a sleeve around an outer surface of the combustor, said sleeve including a supply line to direct fuel to the fuel manifold;a controller to supply fuel through the supply line to the fuel manifold, based on a load of the gas turbine engine exceeding a threshold load. 17. The gas turbine engine of claim 11, wherein the plurality of openings formed through the combustor extender are oval shaped. 18. A method for axial stage combustion in a gas turbine engine comprising: mixing air and fuel to form a lean air-fuel mixture of air and fuel in a first stage of combustion;igniting the lean air-fuel mixture at the first stage of combustion of the gas turbine engine to create hot combustion gas having a temperature below a predetermined NOx production threshold limit;mixing further air and fuel to form a rich air-fuel mixture of air and fuel with an equivalence ratio of air and fuel greater than or equal to three;injecting the rich air-fuel mixture into the hot combustion gas at a second stage of combustion downstream from the first stage; andutilizing heat of the hot combustion gas and free radicals therein to ignite the rich air-fuel mixture such that the rich air-fuel mixture of air and fuel is combusted within a predetermined hydrocarbon emissions limit and the temperature of the hot combustion gas is increased by a threshold amount to a temperature still below the NOx production threshold limit, wherein the temperature of the hot combustion gas is increased from within a range of 1300-1500 degrees C to within a range of 1500-1700 degrees C. 19. A method for axial stage combustion in a gas turbine engine comprising: igniting a lean air-fuel mixture at a first stage of combustion of the gas turbine engine to create hot combustion gas having a temperature below a predetermined NOx production threshold limit;mixing a rich air-fuel mixture with an equivalence ratio greater than or equal to three;injecting the rich air-fuel mixture into the hot combustion gas at a second stage of combustion downstream from the first stage; andutilizing heat of the hot combustion gas and free radicals therein to ignite the rich air-fuel mixture such that the rich air-fuel mixture is combusted within a predetermined hydrocarbon emissions limit and the temperature of the hot combustion gas is increased by a threshold amount to a temperature still below the NOx production threshold limit, wherein the temperature of the hot combustion gas is increased from within a range of 1300-1500 degrees C. to within a range of 1500-1700 degrees C.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (7)
Buchheim Rolf (Brunswick DEX), Combustion chamber for gas turbines.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.