A coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine

Abstract

The present invention discloses a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, which relates to the technical field of gas turbine combustion chambers and solves the problem that existing coaxial staged burners are difficult to achieve stable combustion using a single liquid or gas fuel under any load working conditions. The coaxial staged burner comprises: a mounting flange, a main fuel sleeve and a swirler; a fuel supply interface is provided on the mounting flange; four-stage fuel sleeves are coaxially nested in the main fuel sleeve; the swirler consists of a central duty class, a first-stage premixing stage, a second-stage premixing stage, a first-stage hub and a second-stage hub; when liquid fuel works alone, the fuel enters the swirl channel through the duty class liquid fuel nozzle and the second-stage blade liquid fuel hole to achieve premixing and evaporation processes; when gas fuel works alone, the fuel enters the swirl channel through the first-stage blade fuel hole and the second-stage blade gas fuel hole to be mixed.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine combustion chambers, and in particular to a coaxial staged burner used in a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine. Background Art

[0002] Dual-fuel gas turbines utilize the same burner, enabling long-term, stable operation using two fuels. Dual-fuel combustion technology can broaden the application scope, fuel efficiency, and economic viability of gas turbine units. Natural gas and other combustible gases are often produced as associated gases during offshore production. While the total amount is relatively small, if not effectively utilized, it can cause environmental pollution and energy waste. Dual-fuel gas turbines are widely used on offshore oil and gas platforms due to their ease of maintenance and high power density.

[0003] Gas turbine pollutant emissions are primarily related to the combustion chemical reactions within the combustion chamber. Major pollutants include nitric oxide, unburned hydrocarbons, nitrogen oxides, and soot. Currently, nitrogen oxide emissions are the most challenging to control, with thermal nitrogen oxides accounting for the largest proportion. Therefore, controlling combustion temperature is an effective method for reducing nitrogen oxide emissions. In recent years, the coaxial staged lean premixed combustion technology proposed by domestic and international scholars has shown great potential for achieving stable, low-pollution combustion in the combustion chamber. It effectively controls combustion zone temperature and pollutant emissions for both gaseous and liquid fuels.

[0004] In recent years, there have been many patent applications for coaxial staged burners in China. Patent 202010034769.0 discloses a centrally staged lean oil premixed low-pollution combustion chamber. The burner of this combustion chamber consists of a film-forming air atomizing nozzle of the central duty class and a two-stage swirler. The centrally staged combustion technology effectively solves the problem of low-operating-condition flame stability of fuel and the problem of high-operating-condition pollutant emissions. Patent 202110664338.7 discloses a coaxial staged burner for a low-pollution combustion chamber of a gas-fueled gas turbine. The burner consists of a duty class and a two-stage premixing stage. The fuel / air mixing and transportation are realized by a tapered swirl flow channel and a venturi structure at the flow channel outlet, which realizes stable and low-pollution combustion of gas fuel under a wide range of operating conditions and can prevent backfire. Patent 202210436239.8 discloses a low-emission dual-fuel nozzle for a gas turbine, in which the liquid fuel is diffusely burned through a duty class, and the gas fuel is premixed and burned through a two-stage axially graded swirler. The nozzle has low pollutant emissions when using gas fuel, and the liquid fuel has good combustion performance under slow running and ignition conditions. However, the liquid fuel cannot work alone under high load conditions, and can only maintain the same fuel supply state as the low operating condition during two-stage gas premixed combustion. Summary of the Invention

[0005] In response to the above-mentioned problem that the existing coaxial staged burners are difficult to achieve stable combustion using a single liquid or gas fuel under any load working conditions, the purpose of the present invention is to provide a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine to achieve stable and low-pollution combustion of gas / liquid dual fuel.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, comprising: a mounting flange 1, a main fuel sleeve 2, and a swirler 3, wherein the mounting flange 1, the main fuel sleeve 2, and the swirler 3 are sealed and connected;

[0008] The swirler 3 includes: a first-stage hub 4, first-stage full blades 7, a duty-class bluff body 10, second-stage full blades 8, a second-stage hub 5, and second-stage slit blades 9. The duty-class bluff body 10 is connected to the rear end of the main fuel sleeve 2. A liquid fuel nozzle 6 is provided in the duty-class bluff body 10. The inner periphery of the first-stage hub 4 and the outer wall of the duty-class bluff body 10 are connected by a plurality of first-stage full blades 7; the inner periphery of the second-stage hub 5 and the outer wall of the first-stage hub 4 are connected by a plurality of second-stage full blades 8; and the inner periphery of the second-stage hub 5 and the outer wall of the first-stage hub 4 are connected by a plurality of second-stage slit blades 9.

[0009] The duty class bluff body 10 and the liquid fuel nozzle 6 constitute the central duty class; the duty class bluff body 10, the first-stage hub 4 and the first-stage full blades 7 constitute the first-stage premixing stage; the first-stage hub 4, the second-stage hub 5, the second-stage full blades 8 and the second-stage slotted blades 9 constitute the second-stage premixing stage.

[0010] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein the mounting flange 1 includes: a duty-stage liquid fuel interface 11, a first-stage premixed gas fuel interface 12, a second-stage premixed gas fuel interface 13, a second-stage premixed liquid fuel interface 14 and a mounting positioning seat 15, the front end of the main fuel sleeve 2 is connected to the mounting positioning seat 15, and the front side of the mounting positioning seat 15 is installed with a duty-stage liquid fuel interface 11, a first-stage premixed gas fuel interface 12, a second-stage premixed gas fuel interface 13 and two second-stage premixed liquid fuel interfaces 14, and the duty-stage liquid fuel interface 11, the first-stage premixed gas fuel interface 12, the second-stage premixed gas fuel interface 13, the second-stage premixed liquid fuel interface 14 and the external fuel supply pipeline are threadedly connected.

[0011] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of the gas-liquid dual-fuel gas turbine, wherein the main fuel sleeve 2 is provided with a duty-stage liquid fuel pipe 21, a first-stage gas fuel annular cavity 221, a first-stage gas fuel pipe 222, a second-stage gas fuel annular cavity 231, a second-stage gas fuel pipe 232, a second-stage liquid fuel annular cavity 241, a second-stage liquid fuel pipe 242 and an oil delivery branch 243, the second-stage gas fuel pipe 232, the first-stage gas fuel pipe 222 and the second-stage liquid fuel pipe 242 are all annular pipelines, the duty-stage liquid fuel pipe 21, the second-stage gas fuel pipe 232, the first-stage The gas fuel pipe 222 and the second-stage liquid fuel pipe 242 are coaxially arranged, and the second-stage liquid fuel transition cavity 244, the second-stage gas fuel pipe 232, the first-stage gas fuel pipe 222 and the second-stage liquid fuel pipe 242 are arranged in sequence from the inside to the outside around the duty class liquid fuel pipe 21; a second-stage liquid fuel transition cavity 244 is opened on the inner wall at the rear end of the duty class liquid fuel pipe 21, and a thin wall is provided between the duty class liquid fuel pipe 21 and the second-stage liquid fuel transition cavity 244, and the second-stage liquid fuel transition cavity 244 and the second-stage liquid fuel pipe 242 are sealed and connected through a plurality of circumferentially arranged oil transfer branches 243.

[0012] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein the front end of the duty-stage liquid fuel pipe 21 is connected to the duty-stage liquid fuel interface 11; the front end of the second-stage gas fuel pipe 232 is connected to the second-stage gas fuel annular cavity 231, and the second-stage premixing stage gas fuel interface 13 is connected to the second-stage gas fuel annular cavity 231; the front end of the first-stage gas fuel pipe 222 is connected to the first-stage gas fuel annular cavity 221, and the first-stage premixing stage gas fuel interface 12 is connected to the first-stage gas fuel annular cavity 221; the front end of the second-stage liquid fuel pipe 242 is connected to the second-stage liquid fuel annular cavity 241, and the two second-stage premixing stage liquid fuel interfaces 14 are both connected to the second-stage liquid fuel annular cavity 241.

[0013] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein the liquid fuel nozzle 6 is connected to the rear end of the value class liquid fuel pipe 21, and multiple first-stage full blades 7 are arranged at equal intervals around the axis of the value class blunt body 10; each first-stage full blade 7 is provided with a first-stage blade gas fuel cavity 72, the first-stage blade gas fuel delivery pipeline 73 and the first-stage blade liquid fuel delivery pipeline 74, the first-stage blade gas fuel cavity 72 is connected to the first-stage gas fuel pipe 222, and multiple first-stage blade fuel holes 71 are provided on the outer wall of the first-stage blade gas fuel cavity 72, one end of the first-stage blade gas fuel delivery pipeline 73 is connected to the second-stage gas fuel pipe 232, and one end of the first-stage blade liquid fuel delivery pipeline 74 is connected to the second-stage liquid fuel transition cavity 244.

[0014] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein a plurality of second-stage full blades 8 are arranged at equal intervals around the axis of the class bluff body 10; a second-stage blade gas fuel cavity 82 is provided in each second-stage full blade 8, and a plurality of second-stage blade gas fuel holes 81 are provided on the outer wall of the second-stage blade gas fuel cavity 82.

[0015] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein a plurality of second-stage slit blades 9 are arranged at equal intervals around the axis of the class bluff body 10, and a second-stage slit blade 9 is provided between any two adjacent second-stage full blades 8; each second-stage slit blade 9 is provided with a second-stage blade liquid fuel cavity 92, and a plurality of second-stage blade liquid fuel holes 91 are provided on the outer wall of the second-stage blade liquid fuel cavity 92.

[0016] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein the first-stage hub 4 is a cavity structure, and a gas-liquid fuel stratification plate 42 is provided in the first-stage hub 4 to divide its interior into a first-stage hub gas fuel rectification cavity 41 and a first-stage hub liquid fuel rectification cavity 43.

[0017] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein the other end of the first-stage blade liquid fuel delivery pipeline 74 is connected to the first-stage hub liquid fuel rectification cavity 43, and the other end of the first-stage blade gas fuel delivery pipeline 73 is connected to the first-stage hub gas fuel rectification cavity 41; the second-stage blade gas fuel cavity 82 is connected to the first-stage hub gas fuel rectification cavity 41; the second-stage blade liquid fuel cavity 92 is connected to the first-stage hub liquid fuel rectification cavity 43.

[0018] The above-mentioned coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, wherein the rotation direction of the first-stage full blades 7, the second-stage full blades 8 and the second-stage slit blades 9 are the same, and the installation angle range of the second-stage full blades 8 and the second-stage slit blades 9 is 45° to 52°.

[0019] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art:

[0020] (1) In the present invention, by achieving good mixing of fuel / air in the liquid fuel nozzle of the center-stage, the first-stage premixing stage, and the second-stage premixing stage, stable combustion of a single liquid or gas fuel can be achieved under both high-load and low-load working conditions. Moreover, under high-load working conditions, by rationally arranging full blades and split blades in the second-stage premixing stage, a good evaporation and mixing process of liquid fuel can also be achieved under the same working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a structural schematic diagram of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine.

[0022] Figure 2 The present invention is a cross-sectional view of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine.

[0023] Figure 3 The present invention is a cross-sectional view of the structure of fuel casings and oil branch lines at each stage in a plane where the center line of the oil branch line in the main fuel casing of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine is located.

[0024] Figure 4 It is an enlarged cross-sectional view of the structure contained in the first-stage full blades of the first-stage premixing stage of the swirler part of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to the present invention.

[0025] Figure 5 The present invention is a circumferential cross-sectional view of the first-stage full blades of the first-stage premixing stage of the swirler part of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine.

[0026] Figure 6 The present invention is a schematic diagram of the trailing edge structure of the second-stage slotted blades of the second-stage premixing stage of the swirler part of the coaxial staged burner for the low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine.

[0027] Figure 7 The present invention is a circumferential cross-sectional view of a second-stage full blade of a second-stage premixing stage and a second-stage slotted blade of a swirler portion of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine.

[0028] Figure 8 The present invention is a structural schematic diagram of a two-stage premixing stage of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine and a venturi structure at the tail.

[0029] Figure 9 This is a diagram showing an embodiment of a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to the present invention.

[0030] Figure 10 The present invention is a test method for the installation angle of the first stage full blade, the second stage full blade and the second stage split blade of the coaxial staged burner for the low pollution combustion chamber of the gas-liquid dual fuel gas turbine. Figure 1 .

[0031] Figure 11The present invention is a test method for the installation angle of the first stage full blade, the second stage full blade and the second stage split blade of the coaxial staged burner for the low pollution combustion chamber of the gas-liquid dual fuel gas turbine. Figure 2 .

[0032] In the attached figure: 1. Mounting flange; 2. Main fuel sleeve; 3. Swirl; 4. First stage hub; 5. Second stage hub; 6. Liquid fuel nozzle; 7. First stage full blade; 8. Second stage full blade; 9. Second stage slotted blade; 10. Duty class bluff; 11. Duty class liquid fuel interface; 12. First stage premixing stage gas fuel interface; 13. Second stage premixing stage gas fuel interface; 14. Second stage premixing stage liquid fuel interface; 15. Mounting locator; 21. Duty class liquid fuel pipe; 221. First stage gas fuel annulus; 222. First stage gas fuel pipe; 231. Second stage gas fuel annulus; 232. Second stage First-stage gas fuel pipe; 241, second-stage liquid fuel annular cavity; 242, second-stage liquid fuel pipe; 243, oil branch; 244, second-stage liquid fuel transition cavity; 41, first-stage hub gas fuel rectification cavity; 42, gas-liquid fuel stratification plate; 43, first-stage hub liquid fuel rectification cavity; 71, first-stage blade fuel hole; 72, first-stage blade gas fuel cavity; 73, first-stage blade gas fuel delivery pipeline; 74, first-stage blade liquid fuel delivery pipeline; 81, second-stage blade gas fuel hole; 82, second-stage blade gas fuel cavity; 91, second-stage blade liquid fuel hole; 92, second-stage blade liquid fuel cavity. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0034] Please refer to Figures 1 to 11 As shown, a coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine is shown, which includes: a mounting flange 1, a main fuel sleeve 2 and a swirler 3, wherein the mounting flange 1, the main fuel sleeve 2 and the swirler 3 are sealed and connected;

[0035] The swirler 3 includes: a first-stage hub 4, first-stage full blades 7, a duty-class bluff body 10, second-stage full blades 8, a second-stage hub 5, and second-stage slit blades 9. The duty-class bluff body 10 is connected to the rear end of the main fuel sleeve 2. A liquid fuel nozzle 6 is provided in the duty-class bluff body 10. The inner periphery of the first-stage hub 4 and the outer wall of the duty-class bluff body 10 are connected by a plurality of first-stage full blades 7; the inner periphery of the second-stage hub 5 and the outer wall of the first-stage hub 4 are connected by a plurality of second-stage full blades 8; and the inner periphery of the second-stage hub 5 and the outer wall of the first-stage hub 4 are connected by a plurality of second-stage slit blades 9.

[0036] The duty class bluff body 10 and the liquid fuel nozzle 6 constitute the central duty class; the duty class bluff body 10, the first-stage hub 4 and the first-stage full blades 7 constitute the first-stage premixing stage; the first-stage hub 4, the second-stage hub 5, the second-stage full blades 8 and the second-stage slotted blades 9 constitute the second-stage premixing stage.

[0037] Furthermore, in a preferred embodiment, the mounting flange 1 includes: a value-class liquid fuel interface 11, a first-stage premixed gas fuel interface 12, a second-stage premixed gas fuel interface 13, a second-stage premixed liquid fuel interface 14 and a mounting positioning seat 15. The front end of the main fuel sleeve 2 is connected to the mounting positioning seat 15. The front side of the mounting positioning seat 15 is installed with a value-class liquid fuel interface 11, a first-stage premixed gas fuel interface 12, a second-stage premixed gas fuel interface 13 and two second-stage premixed liquid fuel interfaces 14. The value-class liquid fuel interface 11, the first-stage premixed gas fuel interface 12, the second-stage premixed gas fuel interface 13, the second-stage premixed liquid fuel interface 14 and the external fuel supply pipeline are threadedly connected.

[0038] Furthermore, in a preferred embodiment, the main fuel casing 2 is provided with a duty-class liquid fuel pipe 21, a first-stage gas fuel annular cavity 221, a first-stage gas fuel pipe 222, a second-stage gas fuel annular cavity 231, a second-stage gas fuel pipe 232, a second-stage liquid fuel annular cavity 241, a second-stage liquid fuel pipe 242 and an oil delivery branch 243. The second-stage gas fuel pipe 232, the first-stage gas fuel pipe 222 and the second-stage liquid fuel pipe 242 are all annular pipelines. The duty-class liquid fuel pipe 21, the second-stage gas fuel pipe 232, the first-stage gas fuel pipe 222 and The second-stage liquid fuel pipe 242 is coaxially arranged, and the second-stage liquid fuel transition cavity 244, the second-stage gas fuel pipe 232, the first-stage gas fuel pipe 222 and the second-stage liquid fuel pipe 242 are arranged in sequence from the inside to the outside around the duty class liquid fuel pipe 21; a second-stage liquid fuel transition cavity 244 is opened on the inner wall at the rear end of the duty class liquid fuel pipe 21, and a thin wall is provided between the duty class liquid fuel pipe 21 and the second-stage liquid fuel transition cavity 244, and the second-stage liquid fuel transition cavity 244 and the second-stage liquid fuel pipe 242 are sealed and connected through a plurality of circumferentially arranged oil transfer branches 243.

[0039] Furthermore, in a preferred embodiment, the front end of the duty class liquid fuel pipe 21 is connected to the duty class liquid fuel interface 11; the front end of the second-stage gas fuel pipe 232 is connected to the second-stage gas fuel annular cavity 231, and the second-stage premixing stage gas fuel interface 13 is connected to the second-stage gas fuel annular cavity 231; the front end of the first-stage gas fuel pipe 222 is connected to the first-stage gas fuel annular cavity 221, and the first-stage premixing stage gas fuel interface 12 is connected to the first-stage gas fuel annular cavity 221; the front end of the second-stage liquid fuel pipe 242 is connected to the second-stage liquid fuel annular cavity 241, and the two second-stage premixing stage liquid fuel interfaces 14 are both connected to the second-stage liquid fuel annular cavity 241.

[0040] Furthermore, in a preferred embodiment, the liquid fuel nozzle 6 is connected to the rear end of the value class liquid fuel pipe 21, and a plurality of first-stage full blades 7 are arranged at equal intervals around the axis of the value class bluff body 10; each first-stage full blade 7 is provided with a first-stage blade gas fuel cavity 72, the first-stage blade gas fuel delivery pipeline 73 and the first-stage blade liquid fuel delivery pipeline 74, the first-stage blade gas fuel cavity 72 is connected to the first-stage gas fuel pipe 222, a plurality of first-stage blade fuel holes 71 are provided on the outer wall of the first-stage blade gas fuel cavity 72, one end of the first-stage blade gas fuel delivery pipeline 73 is connected to the second-stage gas fuel pipe 232, and one end of the first-stage blade liquid fuel delivery pipeline 74 is connected to the second-stage liquid fuel transition cavity 244.

[0041] Furthermore, in a preferred embodiment, a plurality of second-stage full blades 8 are arranged at equal intervals around the axis of the class bluff body 10; a second-stage blade gas fuel cavity 82 is provided in each second-stage full blade 8, and a plurality of second-stage blade gas fuel holes 81 are provided on the outer wall of the second-stage blade gas fuel cavity 82.

[0042] Furthermore, in a preferred embodiment, a plurality of second-stage slit blades 9 are arranged at equal intervals around the axis of the value-class bluff body 10, and a second-stage slit blade 9 is provided between any two adjacent second-stage full blades 8; a second-stage blade liquid fuel cavity 92 is provided in each second-stage slit blade 9, and a plurality of second-stage blade liquid fuel holes 91 are provided on the outer wall of the second-stage blade liquid fuel cavity 92.

[0043] Furthermore, in a preferred embodiment, the first-stage hub 4 is a cavity structure, and a gas-liquid fuel stratification plate 42 is provided in the first-stage hub 4 to divide the interior into a first-stage hub gas fuel rectifying cavity 41 and a first-stage hub liquid fuel rectifying cavity 43 .

[0044] Furthermore, in a preferred embodiment, the other end of the first-stage blade liquid fuel delivery pipeline 74 is connected to the first-stage hub liquid fuel rectification cavity 43, and the other end of the first-stage blade gas fuel delivery pipeline 73 is connected to the first-stage hub gas fuel rectification cavity 41; the second-stage blade gas fuel cavity 82 is connected to the first-stage hub gas fuel rectification cavity 41; and the second-stage blade liquid fuel cavity 92 is connected to the first-stage hub liquid fuel rectification cavity 43.

[0045] In a preferred embodiment, the combustor features a compact design. It can be seen that the ends of the second-stage gas fuel pipe 232 and the first-stage gas fuel pipe 222 both directly communicate with the cavity designed within the first-stage full blade 7, occupying some circumferential space. Furthermore, due to the overall structure, the end of the second-stage liquid fuel pipe 242 cannot directly communicate with the first-stage blade liquid fuel delivery pipeline 74. Instead, a second-stage liquid fuel transition cavity 244, extending deep into the bluff body, is required to spatially connect the end with the first-stage blade liquid fuel delivery pipeline 74. The first-stage blade liquid fuel delivery pipeline 74, in turn, connects to the second-stage liquid fuel nozzle 6 through a series of structures.

[0046] There is a thin wall barrier between the duty class liquid fuel pipe 21 and the second-stage liquid fuel transition chamber 244, and they are not connected structures. In actual work, the duty class liquid fuel pipe 21 supplies the central-level fuel, while the second-stage liquid fuel transition chamber 244 supplies the second-stage liquid fuel. The amount of fuel in these two places is adjusted separately and cannot be shared.

[0047] Furthermore, in a preferred embodiment, the first-stage full blades 7, the second-stage full blades 8, and the second-stage split blades 9 have the same rotation direction, and the second-stage full blades 8 and the second-stage split blades 9 are installed at an angle ranging from 45° to 52°.

[0048] In a preferred embodiment, it is calculated that the installation angle of the first-stage full blade 7 is fixed at 40 degrees, and it is calculated that the installation angle range of the second-stage full blade 8 and the second-stage slit blade 9 is 45° to 52°. The installation angles of the second-stage full blade 8 and the second-stage slit blade 9 need to be consistent. The principle is to enhance the swirl and eliminate the angular vortex generated inside the flame tube.

[0049] In a preferred embodiment, because the swirler is an important component for generating swirl in the incoming air and mixing fuel / air, the swirl strength of the swirler must be considered when modifying the structure. The first stage must be full blades, and longer blades can generate stronger swirl.

[0050] The reason for this design of the second stage is that two different fuels need to be injected in the second stage. On the one hand, full blades can produce stronger swirl than slit blades. According to this setting method, the swirl intensity of the swirler can be controlled reasonably while realizing dual-fuel supply. On the other hand, because the slit blades are shorter, it is more difficult to design a dual-fuel supply method within this structure.

[0051] The split blades of the second-stage split blade 9 structure can provide fuel injection positions. Injecting fuel in the split can prevent the fuel from being sprayed onto the blade wall and the hub wall, avoiding the formation of fuel coking and carbon deposits; on the other hand, a backflow vortex can be generated in the trailing edge of the split, improving the atomization and evaporation mixing effect of the fuel.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the implementation and protection scope of the present invention.

[0053] The present invention also has the following implementation modes based on the above:

[0054] In a further embodiment of the present invention, a coaxial staged burner for a low-pollution combustion chamber of a gas / liquid dual-fuel gas turbine realizes stable low-pollution lean-burn premixed combustion of gas / liquid dual fuels, comprising: a mounting flange 1, a main fuel sleeve 2 and a swirler 3; a first-stage premixed gas fuel interface 11, a second-stage premixed gas fuel interface 12, a second-stage premixed gas fuel interface 13, a second-stage premixed liquid fuel interface 14 and a mounting positioning seat 15 are provided on the mounting flange 1; a first-stage premixed liquid fuel interface 11, a first-stage premixed gas fuel interface 12, a second-stage premixed gas fuel interface 13, a second-stage premixed liquid fuel interface 14 and a mounting positioning seat 15 are provided in the main fuel sleeve 2; Tube 21, first-stage gas fuel annular cavity 221, first-stage gas fuel pipe 222, second-stage gas fuel annular cavity 231, second-stage gas fuel pipe 232, second-stage liquid fuel annular cavity 241, second-stage liquid fuel pipe 242, oil delivery branch 243 and second-stage liquid fuel transition cavity 244; swirler 3 has first-stage hub 4, second-stage hub 5, first-stage full blades 7, second-stage full blades 8, second-stage slit blades 9 and duty class bluff 10; liquid fuel nozzle 6 is arranged in duty class bluff 10.

[0055] In a further embodiment of the present invention, the duty class bluff body 10 and the liquid fuel nozzle 6 constitute a central duty class; the duty class bluff body 10, the first-stage hub 4 and the first-stage full blades 7 constitute a first-stage premixing stage; and the first-stage hub 4, the second-stage hub 5, the second-stage full blades 8 and the second-stage slotted blades 9 constitute a second-stage premixing stage.

[0056] In a further embodiment of the present invention, the duty class liquid fuel interface 11, the first-stage premixing gas fuel interface 12, the second-stage premixing gas fuel interface 13 and the second-stage premixing liquid fuel interface 14 are connected to the mounting flange 1 by welding; the duty class liquid fuel interface 11, the first-stage premixing gas fuel interface 12, the second-stage premixing gas fuel interface 13, the second-stage premixing liquid fuel interface 14 and the external fuel supply pipeline are threadedly connected; the mounting flange 1, the main fuel sleeve 2 and the swirler 3 are sealed and the processing method is additive manufacturing.

[0057] In a further embodiment of the present invention, the first-stage hub 4 contains a first-stage hub gas fuel rectifying cavity 41, a gas / liquid fuel stratification plate 42 and a first-stage hub liquid fuel rectifying cavity 43, and the second-stage hub 5 is placed as a whole on the outside of the first-stage hub 4 and is a solid shell.

[0058] In a further embodiment of the present invention, the first-stage full blades 7 and the second-stage full blades 8 are both NACA blade-shaped blades, the first-stage full blades 7, the second-stage full blades 8 and the second-stage slit blades 9 have the same rotation direction, the installation angle range of the second-stage full blades 8 and the second-stage slit blades 9 is 45° to 52°, and the second-stage full blades 8 and the second-stage slit blades 9 are evenly staggered; the proportion of the number of second-stage slit blades 9 to the total number of second-stage premixed stage blades is less than or equal to 50%, that is, the number of second-stage slit blades 9 shall not exceed the number of second-stage full blades 8, to ensure the combustion effect of gaseous (natural gas) fuel and liquid (fuel) fuel, and the best effect is achieved when the number of second-stage full blades 8 and second-stage slit blades 9 is 1:1.

[0059] In a further embodiment of the present invention, the value-class liquid fuel pipe 21, the first-stage gas fuel pipe 222, the second-stage gas fuel pipe 232, and the second-stage liquid fuel pipe 242 in the main fuel pipe are coaxially nested and are not connected to each other. A second-stage liquid fuel transition cavity 244 is opened in the wall of the value-class liquid fuel pipe 21, and the oil delivery branch 243 is a number of 2 to 8 pipes uniformly arranged along the circumferential direction. The oil delivery branch 243 passes through the first-stage gas fuel pipe 222 and the second-stage gas fuel pipe 232, so that the second-stage liquid fuel pipe 242 is connected to the second-stage liquid fuel transition cavity 244.

[0060] In a further embodiment of the present invention, the first-stage full blade 7 includes a first-stage blade fuel hole 71 , a first-stage blade gas fuel cavity 72 , a first-stage blade gas fuel delivery pipeline 73 and a first-stage blade liquid fuel delivery pipeline 74 .

[0061] In a further embodiment of the present invention, the second-stage full blade 8 includes a second-stage blade gas fuel hole 81 and a second-stage blade gas fuel cavity 82 ; the second-stage slit blade 9 includes a second-stage blade liquid fuel hole 91 and a second-stage blade liquid fuel cavity 92 .

[0062] In a further embodiment of the present invention, the first-stage blade gas fuel delivery pipeline 73, the first-stage hub gas fuel rectifying cavity 41, the second-stage blade gas fuel cavity 82 and the second-stage blade gas fuel hole 81 are connected, and the first-stage blade liquid fuel delivery pipeline 74, the first-stage hub liquid fuel rectifying cavity 43, the second-stage blade liquid fuel cavity 92 and the second-stage blade liquid fuel hole 91 are connected.

[0063] In a further embodiment of the present invention, the second-stage liquid fuel holes 91 on the second-stage slit blades 9 have a diameter of 0.2 to 1 mm and are 1 to 4 in number. Regardless of the blade size, the liquid fuel hole diameter must not exceed a minimum of 0.2 mm. If the diameter is too small, the fuel will clog the hole after passing through it. If the diameter is too large, the fuel injection velocity will be too low under operating conditions, resulting in poor atomization.

[0064] In a further embodiment of the present invention, the maximum diameter of the mounting locator 15 on the mounting flange 1 and the second-stage hub 5 on the swirler 3 does not exceed 140 mm. Due to process limitations for inserting the swirler into the casing, diameters exceeding 140 mm are not possible. The thread specifications of the duty-stage liquid fuel interface 11, the first-stage premixing gas fuel interface 12, the second-stage premixing gas fuel interface 13, and the second-stage premixing liquid fuel interface 14 range from 16 mm to 20 mm. The maximum diameter of the main fuel sleeve 2 does not exceed 45 mm. Since the maximum diameter of the main fuel pipe determines the size of the duty-stage bluff, exceeding 45 mm may result in the duty-stage bluff being too large, reducing the air intake of the swirler and affecting performance.

[0065] In a further embodiment of the present invention, a coaxial staged burner for a low-pollution combustion chamber of a gas / liquid dual-fuel gas turbine of the present invention achieves stable combustion of a single liquid or gas fuel under both high-load and low-load working conditions through good mixing of fuel / air in the liquid fuel nozzle of the center value class, the first-stage premixing stage, and the second-stage premixing stage. Moreover, under high-load working conditions, the full blades and split blades are reasonably arranged in the second-stage premixing stage, so that the liquid fuel can also achieve a good evaporation mixing process under the same working conditions.

[0066] In a further embodiment of the present invention, the air intake temperature of the working environment of the model combustion chamber of this type is 770K, which has reached the evaporation temperature of the fuel, but the temperature of the fuel in the burner is 300K, and it is supplied to the flame tube at room temperature. The temperature inside the pipeline close to the combustion zone of the flame tube may increase slightly due to heat convection and heat radiation, but the fuel will not evaporate in the pipeline. When it is sprayed into the flame tube from the burner nozzle, it gradually evaporates from liquid to gas, but the process is very short. Good atomization in the liquid state can make the evaporation and mixing more uniform.

[0067] In a further embodiment of the present invention, the central duty class specifically refers to a structure consisting of a duty class bluff body 10 and a liquid fuel nozzle 6; in an embodiment of the present invention, the first-stage premixing stage specifically refers to a structure consisting of a duty class bluff body 10, a first-stage hub 4 and a first-stage full blade 7; in an embodiment of the present invention, the second-stage premixing stage specifically refers to a structure consisting of a first-stage hub 4, a second-stage hub 5, a second-stage full blade 8 and a second-stage slit blade 9. The structure inside the first-stage hub 4 is reasonably arranged to allow the fuel to be supplied to the designated position, which can play a certain rectifying role within the structure. Otherwise, if the channel is directly connected to the designated nozzle position of the second stage, the fuel injection may fluctuate.

[0068] In a further embodiment of the present invention, the coaxial staged burner has four operating states: liquid fuel low load operating state; liquid fuel high load operating state; gas fuel low load operating state; gas fuel high load operating state.

[0069] In a further embodiment of the present invention, when in a low-load working state of liquid fuel, the duty class liquid fuel interface 11 is connected to the duty class liquid fuel external supply structure, the liquid fuel enters the duty class liquid fuel pipe 21, and is finally sprayed into the combustion chamber through the liquid fuel nozzle 6 at the end of the duty class liquid fuel pipe 21 for atomization, and enters the swirling air for diffusion and combustion.

[0070] In a further embodiment of the present invention, when in a high-load working state of liquid fuel, the value-class liquid fuel interface 11 and the second-stage premixing-class liquid fuel interface 14 are respectively connected to the external supply structure of the value-class liquid fuel and the second-stage premixing-class liquid fuel, and the two liquid fuels through the value-class liquid fuel interface 11 and the second-stage premixing-class liquid fuel interface 14 can independently adjust the flow without affecting each other. The value-class liquid fuel enters the value-class liquid fuel pipe 21, is sprayed into the combustion chamber through the liquid fuel nozzle 6 at the end of the value-class liquid fuel pipe 21 for atomization, and finally enters the combustion chamber for diffusion combustion. At the same time, the second-stage premixing-class liquid fuel passes through the second-stage liquid fuel annular cavity 241, the second-stage liquid fuel pipe 242, the oil delivery branch 243, the second-stage liquid fuel transition cavity 244, the first-stage blade liquid fuel delivery pipeline 74, and the first-stage hub liquid fuel rectifying cavity 43 into the second-stage blade liquid fuel cavity 92, enters the swirl air downstream through the second-stage blade liquid fuel hole 91 for premixing and evaporation process, and enters the combustion chamber for lean burn premixed combustion.

[0071] In a further embodiment of the present invention, when the gas fuel is in a low-load working state, the first-stage premixing gas fuel interface 12 is connected to the first-stage premixing gas fuel external supply structure, and the first-stage premixing gas fuel enters the first-stage gas fuel annular cavity 221, the first-stage gas fuel pipe 222, and the first-stage blade gas fuel cavity 72, and enters the swirling air through the first-stage blade fuel hole 71 for premixing, and performs lean-burn premixed combustion in the combustion chamber.

[0072] In a further embodiment of the present invention, when the gas fuel is in a high-load working state, the first-stage premixing gas fuel interface 12 and the second-stage premixing gas fuel interface 13 are respectively connected to the external supply structure of the first-stage premixing gas fuel and the second-stage premixing gas fuel, and the two gas fuels through the first-stage premixing gas fuel interface 12 and the second-stage premixing gas fuel interface 13 can independently adjust the flow without affecting each other. The first-stage gas fuel enters the first-stage gas fuel annular cavity 221, the first-stage gas fuel pipe 222, and the first-stage blade gas fuel cavity 72, enters the swirl air through the first-stage blade fuel hole 71 for premixing, and performs lean premixed combustion in the combustion chamber. At the same time, the second-stage premixing gas fuel enters the second-stage blade gas fuel cavity 82 through the second-stage gas fuel annular cavity 231, the second-stage gas fuel pipe 232, the first-stage blade gas fuel delivery pipeline 73, and the first-stage hub gas fuel rectifying cavity 41, enters the swirl air through the second-stage blade gas fuel hole 81 for premixing, and enters the combustion chamber for lean premixed combustion.

[0073] In a further embodiment of the present invention, a coaxial staged burner comprises: a mounting flange 1, a main fuel sleeve 2, and a swirler 3; the mounting flange 1 has a fuel supply interface; the main fuel sleeve 2 contains a coaxially nested four-stage fuel sleeve; the swirler 3 comprises a central stage, a first premixing stage, a second premixing stage, a first hub 4, and a second hub 5; the first premixing stage blades are all first-stage full blades 7, and the second premixing stage blades are second-stage full blades 8 and second-stage slit blades 9, arranged evenly and staggered; when liquid fuel is operating alone, the fuel enters the swirl channel through the stage liquid fuel nozzle 6 and the second-stage blade liquid fuel hole 91 to achieve premixing and evaporation; when gas fuel is operating alone, the fuel enters the swirl channel through the first-stage blade fuel hole 71 and the second-stage blade gas fuel hole 81 to achieve mixing. The present invention achieves stable, low-pollution, lean-burn premixed combustion of gas / liquid dual fuels through the tapered swirl channel of the two premixing stages and the tail venturi structure, and the evenly staggered arrangement of the second-stage full blades 8 and the second-stage slit blades 9.

[0074] In a further embodiment of the present invention, a two-stage premixing stage tapered swirl channel is formed by the outer wall of the duty class bluff body 10 and the inner wall of the first-stage hub 4, and the outer wall of the first-stage hub 4 and the inner wall of the second-stage hub 5. The ends of the first-stage hub 4 and the second-stage hub 5 are venturi structures.

[0075] In a further embodiment of the present invention, the structure is improved from a single gaseous fuel burner to a dual-fuel burner. This gaseous fuel structure already has a well-established body of papers and patents. The specific difference is that this structure, while maintaining the same air supply scheme and structure, can achieve a dual-fuel combustion mechanism with a head intake exceeding 70%.

[0076] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine, characterized in that: include: The mounting flange (1), the main fuel sleeve (2) and the cyclone (3) are sealed and connected to each other; The swirler (3) comprises: a first-stage hub (4), first-stage full blades (7), a duty class bluff body (10), second-stage full blades (8), a second-stage hub (5) and second-stage slit blades (9); the duty class bluff body (10) is connected to the rear end of the main fuel sleeve (2); a liquid fuel nozzle (6) is provided in the duty class bluff body (10); the inner periphery of the first-stage hub (4) and the outer wall of the duty class bluff body (10) are connected through a plurality of first-stage full blades (7); the inner periphery of the second-stage hub (5) and the outer wall of the first-stage hub (4) are connected through a plurality of second-stage full blades (8); and the inner periphery of the second-stage hub (5) and the outer wall of the first-stage hub (4) are connected through a plurality of second-stage slit blades (9); The duty class bluff body (10) and the liquid fuel nozzle (6) constitute a central duty class; the duty class bluff body (10), the first stage hub (4) and the first stage full blades (7) constitute a first stage premixing stage; the first stage hub (4), the second stage hub (5), the second stage full blades (8) and the second stage slotted blades (9) constitute a second stage premixing stage; A plurality of second-stage full blades (8) are arranged at equal intervals around the axis of the class bluff body (10); a second-stage blade gas fuel cavity (82) is provided in each second-stage full blade (8), and a plurality of second-stage blade gas fuel holes (81) are provided on the outer wall of the second-stage blade gas fuel cavity (82); A plurality of second-stage slit blades (9) are arranged at equal intervals around the axis of the class blunt body (10), and a second-stage slit blade (9) is provided between any two adjacent second-stage full blades (8); a second-stage blade liquid fuel cavity (92) is provided in each second-stage slit blade (9), and a plurality of second-stage blade liquid fuel holes (91) are provided on the outer wall of the second-stage blade liquid fuel cavity (92).

2. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 1, characterized in that: The mounting flange (1) comprises: a duty class liquid fuel interface (11), a first-stage premixing gas fuel interface (12), a second-stage premixing gas fuel interface (13), a second-stage premixing liquid fuel interface (14) and a mounting positioning seat (15); the front end of the main fuel sleeve (2) is connected to the mounting positioning seat (15); a duty class liquid fuel interface (11), a first-stage premixing gas fuel interface (12), a second-stage premixing gas fuel interface (13) and two second-stage premixing liquid fuel interfaces (14) are mounted on the front side of the mounting positioning seat (15); the duty class liquid fuel interface (11), the first-stage premixing gas fuel interface (12), the second-stage premixing gas fuel interface (13) and the second-stage premixing liquid fuel interface (14) are threadedly connected to a pipeline for supplying external fuel.

3. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 2, characterized in that: The main fuel casing (2) is provided with a duty class liquid fuel pipe (21), a first-stage gas fuel annular cavity (221), a first-stage gas fuel pipe (222), a second-stage gas fuel annular cavity (231), a second-stage gas fuel pipe (232), a second-stage liquid fuel annular cavity (241), a second-stage liquid fuel pipe (242) and an oil delivery branch (243). The second-stage gas fuel pipe (232), the first-stage gas fuel pipe (222) and the second-stage liquid fuel pipe (242) are all annular pipes. The duty class liquid fuel pipe (21), the second-stage gas fuel pipe (232), the first-stage gas fuel pipe (222) and the second-stage liquid fuel pipe (242) are The fuel pipe (242) is coaxially arranged, and the second-stage liquid fuel transition cavity (244), the second-stage gas fuel pipe (232), the first-stage gas fuel pipe (222) and the second-stage liquid fuel pipe (242) are arranged in sequence from the inside to the outside around the duty class liquid fuel pipe (21); a second-stage liquid fuel transition cavity (244) is opened on the rear end inner wall of the duty class liquid fuel pipe (21), a thin wall is provided between the duty class liquid fuel pipe (21) and the second-stage liquid fuel transition cavity (244), and the second-stage liquid fuel transition cavity (244) and the second-stage liquid fuel pipe (242) are sealed and connected through a plurality of circumferentially arranged oil delivery branches (243).

4. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 3, characterized in that: The front end of the duty class liquid fuel pipe (21) is in communication with the duty class liquid fuel interface (11); the front end of the second-stage gas fuel pipe (232) is in communication with the second-stage gas fuel annular cavity (231), and the second-stage premixing stage gas fuel interface (13) is in communication with the second-stage gas fuel annular cavity (231); the front end of the first-stage gas fuel pipe (222) is in communication with the first-stage gas fuel annular cavity (221), and the first-stage premixing stage gas fuel interface (12) is in communication with the first-stage gas fuel annular cavity (221); the front end of the second-stage liquid fuel pipe (242) is in communication with the second-stage liquid fuel annular cavity (241), and both second-stage premixing stage liquid fuel interfaces (14) are in communication with the second-stage liquid fuel annular cavity (241).

5. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 4, characterized in that: The liquid fuel nozzle (6) is connected to the rear end of the duty class liquid fuel pipe (21), and a plurality of first-stage full blades (7) are arranged at equal intervals around the axis of the duty class bluff body (10); each first-stage full blade (7) is provided with a first-stage blade gas fuel cavity (72), a first-stage blade gas fuel delivery pipeline (73) and a first-stage blade liquid fuel delivery pipeline (74); the first-stage blade gas fuel cavity (72) is connected to the first-stage gas fuel pipe (222); a plurality of first-stage blade fuel holes (71) are provided on the outer wall of the first-stage blade gas fuel cavity (72); one end of the first-stage blade gas fuel delivery pipeline (73) is connected to the second-stage gas fuel pipe (232), and one end of the first-stage blade liquid fuel delivery pipeline (74) is connected to the second-stage liquid fuel transition cavity (244).

6. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 1, characterized in that: The first-stage hub (4) is a cavity structure. A gas-liquid fuel stratification plate (42) is provided in the first-stage hub (4) to divide the interior of the first-stage hub into a first-stage hub gas fuel rectification cavity (41) and a first-stage hub liquid fuel rectification cavity (43).

7. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 6, characterized in that: The other end of the first-stage blade liquid fuel delivery pipeline (74) is in communication with the first-stage hub liquid fuel rectification cavity (43), and the other end of the first-stage blade gas fuel delivery pipeline (73) is in communication with the first-stage hub gas fuel rectification cavity (41); the second-stage blade gas fuel cavity (82) is in communication with the first-stage hub gas fuel rectification cavity (41); and the second-stage blade liquid fuel cavity (92) is in communication with the first-stage hub liquid fuel rectification cavity (43).

8. The coaxial staged burner for a low-pollution combustion chamber of a gas-liquid dual-fuel gas turbine according to claim 1, characterized in that: The first-stage full blades (7), the second-stage full blades (8) and the second-stage split blades (9) have the same rotation direction, and the second-stage full blades (8) and the second-stage split blades (9) have an installation angle range of 45° to 52°.

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