A combustion chamber nozzle

Abstract

The present invention relates to the technical field of gas turbines, and in particular to a combustion chamber nozzle, comprising: a central cone structure; a rear section of a first fuel supply cavity penetrates the central cone structure, and a fuel jet channel is provided near the end of the first fuel supply cavity; a first intermediate annular cavity is provided on the central cone structure and surrounds the rear section of the first fuel supply cavity; a first fuel jet hole is provided at the end of the first intermediate annular cavity; the first fuel supply cavity is connected to the first intermediate annular cavity through a fuel distribution hole; a first CO2 annular cavity is sleeved on the outer periphery of the front section of the first fuel supply cavity; an air annular cavity is sleeved on the outer periphery of the first CO2 annular cavity and the central cone structure, the first CO2 annular cavity is connected to the air annular cavity through a first delivery hole provided near the end; the front section of the first intermediate annular cavity is connected to the air annular cavity through a second delivery hole; the present application adds CO2 to air and fuel by providing the first CO2 annular cavity, thereby suppressing the increase speed of the flame radius, reducing the flame propagation speed and the risk of backfire.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and in particular to a combustion chamber nozzle. Background Art

[0002] Currently, most heavy-duty gas turbines use premixed combustion technology to reduce pollutant emissions. This technology thoroughly mixes the fuel and oxidizer before entering the flame tube. By controlling the fuel-oxidizer ratio and lowering the flame temperature, pollutant emissions are reduced. However, premixed combustion technology carries the risk of flashback, particularly with the recent introduction of hydrogen-infused natural gas combustion. This risk is exacerbated, and in severe cases, can damage combustion chamber components and even turbine blades. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects of high risk of flashback, easy burning of combustion chamber components, and even damage to gas turbine blades when natural gas mixed with hydrogen is burned.

[0004] In order to achieve the above object, the present invention provides a combustion chamber nozzle, comprising:

[0005] A central cone structure, consisting of a cylindrical segment and a conical segment connected to each other, wherein the axis of the central cone structure is arranged along the axial direction of the combustion chamber nozzle;

[0006] A first fuel supply cavity, the rear section of which penetrates the central cone structure along the axial direction of the combustion chamber nozzle, and a fuel jet channel is provided near the end of the first fuel supply cavity; the fuel jet channel is adapted to communicate with the flame tube; the first fuel supply cavity is adapted to supply fuel;

[0007] A first intermediate annular cavity is provided on the central cone structure and surrounds the rear section of the first fuel supply cavity. A plurality of first fuel jet holes are circumferentially provided at the distal end of the first intermediate annular cavity. The first fuel jet holes are adapted to communicate with the flame tube. The first fuel supply cavity communicates with the first intermediate annular cavity via a plurality of fuel distribution holes.

[0008] A first CO2 annular cavity is arranged on the outer periphery of the front section of the first fuel supply cavity; the first CO2 annular cavity is suitable for providing CO2;

[0009] An air ring cavity is arranged on the outer circumference of the first CO2 ring cavity and the central cone structure. The first CO2 ring cavity is connected to the air ring cavity through a plurality of first delivery holes arranged near the end; the front section of the first intermediate ring cavity is connected to the air ring cavity through a plurality of second delivery holes; the end of the air ring cavity is suitable for connecting with the flame tube; and the air ring cavity is suitable for providing air.

[0010] Optionally, a swirler is provided circumferentially at a position near the end of the air ring cavity; the swirler is provided with a plurality of hollow blades circumferentially; the first intermediate ring cavity is connected to the plurality of blades of the swirler through a plurality of second delivery holes; the blades are connected to the air ring cavity through supply holes.

[0011] Optionally, in the first fuel supply cavity, a transitional convergent section cavity is provided near the fuel jet channel.

[0012] Optionally, the first intermediate annular cavity is a streamlined annular cavity in a transitional form.

[0013] Optionally, the plurality of first delivery holes are divided into a plurality of groups; the first delivery holes in each group are arranged at intervals along the axial direction of the first CO2 annular cavity, the number of first delivery holes in each group is the same, and the first delivery holes in adjacent groups are arranged in a staggered manner.

[0014] Optionally, it also includes:

[0015] A second intermediate annular cavity is provided on the cone section of the central cone structure and surrounds the first intermediate annular cavity; a second injection annular slit is circumferentially provided at the end of the second intermediate annular cavity; the second injection annular slit is adapted to communicate with the flame tube; and the end of the first CO2 annular cavity communicates with the second intermediate annular cavity via a plurality of delivery channels;

[0016] A second CO2 annular cavity is sleeved on the outer periphery of the air annular cavity; a first injection annular slit is circumferentially provided at the end of the second CO2 annular cavity, the jet direction of the first injection annular slit being toward the axis of the central cone structure and perpendicular to the axis of the central cone structure; the second CO2 annular cavity is suitable for providing CO2;

[0017] The second fuel supply cavity is sleeved on the outer circumference of the second CO2 annular cavity; a plurality of third fuel jet holes are circumferentially provided at the end of the second fuel supply cavity, and the third fuel jet holes are suitable for communicating with the flame tube; the second fuel supply cavity is suitable for providing fuel.

[0018] Optionally, the rear section of the second CO2 annular cavity is provided with an annular cavity in an expanded form corresponding to the cone section.

[0019] Optionally, it also includes:

[0020] A fairing connected to the outer wall of the second fuel supply cavity, the fairing being arranged beyond the central cone structure, and the cavity enclosed by the fairing being suitable for communicating with the flame tube;

[0021] In the air annulus, the first portion of CO2 in the first CO2 annulus mixes with the air in the air annulus to form an initial mixing zone;

[0022] In the space near the second delivery hole in the air annulus, the CO2 and air delivered from the initial mixing zone are mixed with the first portion of the fuel in the first fuel supply chamber to form a main mixing zone;

[0023] In the space near the first injection annular gap in the air annulus, CO2, air and fuel delivered from the main mixing zone are mixed with CO2 from the second CO2 annular cavity to form a fluid nozzle mixing zone;

[0024] Inside the fairing, the CO2, air, and fuel delivered by the fluid nozzle mixing zone are mixed with the second portion of the fuel in the first fuel supply cavity, the second portion of the CO2 in the first CO2 annular cavity, and the fuel in the second fuel supply cavity to form a final mixing zone;

[0025] The proportion of fuel increases gradually in the order of the initial mixing zone, the main mixing zone, the fluid nozzle mixing zone and the final mixing zone. In the final mixing zone, the proportion of fuel reaches the design equivalence ratio of premixed combustion.

[0026] Optionally, the fairing is provided with an arc-shaped inner wall, and the jet direction of the third fuel jet hole is arranged parallel to the axis of the central cone structure; the arc-shaped inner wall is suitable for refracting the jet of the third fuel jet hole and approaching the axis direction of the combustion chamber nozzle.

[0027] Optionally, the second fuel supply cavity is arranged beyond the second CO2 annular cavity, and a plurality of second fuel jet holes are circumferentially provided on the inner wall of the second fuel supply cavity near the end, and the jet direction of the first fuel jet hole and the jet direction of the second fuel jet hole intersect on the center line of the annular outlet of the air annular cavity.

[0028] The above technical solution of the present invention has the following advantages over the prior art:

[0029] 1. The combustion chamber nozzle provided by the present invention comprises: a central cone structure, which is composed of a cylindrical section and a cone section that are connected and arranged, and the axis of the central cone structure is arranged along the axial direction of the combustion chamber nozzle; a first fuel supply cavity, the rear section of which passes through the central cone structure along the axial direction of the combustion chamber nozzle, and a fuel jet channel is provided near the end of the first fuel supply cavity; the fuel jet channel is suitable for communicating with the flame tube; the first fuel supply cavity is suitable for providing fuel; a first intermediate annular cavity, which is arranged on the central cone structure, and the first intermediate annular cavity is arranged around the rear section of the first fuel supply cavity; a plurality of first fuel jet holes are provided at the end of the first intermediate annular cavity along the circumferential direction; the first fuel jet hole is suitable for communicating with the flame tube; the first fuel supply cavity is connected to the first intermediate annular cavity through a plurality of fuel distribution holes; a first CO2 annular cavity is sleeved on the outer periphery of the front section of the first fuel supply cavity; the first CO2 annular cavity Suitable for providing CO2; an air ring cavity, which is sleeved on the outer periphery of the first CO2 ring cavity and the central cone structure, and the first CO2 ring cavity is connected to the air ring cavity through a plurality of first delivery holes arranged near the end; the front section of the first intermediate ring cavity is connected to the air ring cavity through a plurality of second delivery holes; the end of the air ring cavity is suitable for communicating with the flame tube; the air ring cavity is suitable for providing air; the present application adopts the above technical solution, by arranging a first CO2 ring cavity in the combustion chamber nozzle, adding an appropriate amount of CO2 to the air and fuel, the specific heat of CO2 is relatively high, which increases the average specific heat of the mixture, resulting in a decrease in the temperature of the combustible mixture, inhibiting the increase rate of the flame radius, thereby reducing the flame propagation speed and the risk of backfire; at the same time, the dilution effect of CO2 can effectively reduce the flame temperature, thereby reducing the generation of thermal nitrogen oxides, which is conducive to achieving high-efficiency and low-pollution combustion, reducing pollutant emissions, and having significant environmental benefits.

[0030] 2. The present invention provides a swirler circumferentially disposed near the end of the air annular cavity; the swirler is circumferentially provided with a plurality of hollow blades; the first intermediate annular cavity is connected to the plurality of blades of the swirler through a plurality of second delivery holes; the blades are connected to the air annular cavity through supply holes; the present application adopts the above-mentioned technical solution, and by providing the swirler, the mixing of fuel and air is more uniform, and a stable recirculation zone is formed.

[0031] 3. In the present invention, a transitional convergent section cavity is provided near the fuel jet channel in the first fuel supply cavity; the present application adopts the above technical solution to generate a high-speed jet through the fuel jet channel, which is directly injected into the flame tube from the center position of the combustion chamber nozzle. Based on the Bernoulli principle, the average propagation speed of the mixed gas can be increased.

[0032] 4. The first intermediate annular cavity of the present invention is a streamlined annular cavity of transitional form; this application adopts the above technical solution to reduce the resistance during CO2 transmission and increase the transmission speed of CO2 by setting a streamlined annular cavity.

[0033] 5. The multiple first delivery holes described in the present invention are divided into multiple groups; the first delivery holes in each group are arranged at intervals along the axial direction of the first CO2 annular cavity, the number of first delivery holes in each group is the same, and the first delivery holes in adjacent groups are arranged in a staggered manner; this application adopts the above technical solution, and through the provision of multiple first delivery holes, the uniformity of mixing of CO2 and air is improved.

[0034] 6. The combustion chamber nozzle provided by the present invention also includes: a second intermediate annular cavity, which is arranged on the cone section of the central cone structure, and the second intermediate annular cavity is arranged around the first intermediate annular cavity; a second injection annular slit is circumferentially provided at the end of the second intermediate annular cavity; the second injection annular slit is suitable for communicating with the flame tube; the end of the first CO2 annular cavity is connected to the second intermediate annular cavity through a plurality of delivery channels; a second CO2 annular cavity is sleeved on the outer circumference of the air annular cavity; a first injection annular slit is circumferentially provided at the end of the second CO2 annular cavity, and the jet direction of the first injection annular slit is toward the axis of the central cone structure and perpendicular to the axis of the central cone structure; the second CO2 annular cavity is suitable for providing CO2; a second fuel supply A fuel supply cavity is provided on the outer periphery of the second CO2 annular cavity; a plurality of third fuel jet holes are provided circumferentially at the end of the second fuel supply cavity, and the third fuel jet holes are suitable for communicating with the flame tube; the second fuel supply cavity is suitable for providing fuel; the present application adopts the above technical solution, by setting a first injection annular gap, and utilizing the jet of CO2 gas to form a fluid nozzle, on the one hand, it can adjust the effective area ratio of the fluid nozzle and increase the average propagation speed of the mixed gas, and on the other hand, it can increase the average specific heat of the mixed gas, reduce the temperature of the mixed gas, inhibit the increase rate of the flame radius, and reduce the flame propagation speed; in addition, the dilution effect and physical barrier effect of the CO2 ejected from the first injection annular gap prevent backfire and protect the safety of the gas turbine components.

[0035] 7. The rear section of the second CO2 annular cavity of the present invention is provided with an expanded annular cavity corresponding to the conical section; the present application adopts the above technical solution, and by setting the expanded annular cavity and the first injection annular gap, a fluid nozzle is formed to increase the gas flow rate, adjust the effective area ratio of the nozzle, and prevent backfire.

[0036] 8. The combustion chamber nozzle provided by the present invention also includes: a fairing connected to the outer wall of the second fuel supply cavity, and the fairing is arranged beyond the central cone structure, and the cavity surrounded by the fairing is suitable for communicating with the flame tube; in the air annulus, the first part of the CO2 of the first CO2 annulus is mixed with the air of the air annulus to form an initial mixing zone; in the space near the second delivery hole in the air annulus, the CO2 and air delivered by the initial mixing zone are mixed with the first part of the fuel of the first fuel supply cavity to form a main mixing zone; in the space near the first injection annular gap in the air annulus, the CO2, air and fuel delivered by the main mixing zone are mixed with the CO2 of the second CO2 annulus to form a fluid nozzle mixing zone; inside the fairing The CO2, air, and fuel delivered by the fluid nozzle mixing zone are mixed with the second portion of the fuel in the first fuel supply chamber, the second portion of the CO2 in the first CO2 annular chamber, and the fuel in the second fuel supply chamber to form a final mixing zone. The fuel ratio gradually increases in the order of the initial mixing zone, the main mixing zone, the fluid nozzle mixing zone, and the final mixing zone. In the final mixing zone, the fuel ratio reaches the design equivalence ratio for premixed combustion. The present application adopts the above-mentioned technical solution by providing four dispersed mixing zones, gradually increasing the fuel amount to the design equivalence ratio for premixed combustion until the design equivalence ratio for premixed combustion is reached in the final mixing zone. This allows the combustion flame to stably settle and burn downstream of the combustor nozzle outlet, preventing flashback. Even if a brief flashback occurs due to some uncontrollable reason, it will cease due to the equivalence ratio of the mixed gas upstream of the final mixing zone not meeting the combustion requirements, as well as the dilution and physical barrier effects of the CO2 ejected from the first injection annular gap, thereby protecting the safety of the gas turbine components.

[0037] 9. The fairing described in the present invention is provided with an arc-shaped inner wall, and the jet direction of the third fuel jet hole is arranged parallel to the axis of the central cone structure; the arc-shaped inner wall is suitable for refracting the jet of the third fuel jet hole and approaching the axis direction of the combustion chamber nozzle; the present application adopts the above-mentioned technical solution, and the fuel jet transmitted through the third fuel jet hole is directly transmitted to the arc-shaped fairing, and the flow direction is changed here, and in the final mixing zone, it is quickly and evenly mixed with the air, CO2 and fuel delivered from the fluid nozzle mixing zone, as well as the fuel delivered from the first fuel jet hole and the CO2 delivered from the second injection ring gap, and ignites and burns under the action of the igniter, and the flame is stably stationed in the downstream area of ​​the combustion chamber nozzle outlet to prevent backfire.

[0038] 10. The second fuel supply cavity of the present invention is arranged beyond the second CO2 annular cavity, and a plurality of second fuel jet holes are circumferentially provided on the inner wall of the second fuel supply cavity near the end, and the jet direction of the first fuel jet hole and the jet direction of the second fuel jet hole intersect on the center line of the annular outlet of the air annular cavity; the present application adopts the above technical solution, and the fuel jetted through the first fuel jet hole and the fuel jetted through the second fuel jet hole collide and mix at the outlet of the combustion chamber nozzle, and the mixing position is in the middle area of ​​the annular outlet of the air annular cavity to improve the mixing uniformity and mixing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A schematic diagram of the three-dimensional structure of a combustion chamber nozzle provided in an embodiment of the present invention;

[0041] Figure 2 It is a right side structural schematic diagram of the combustion chamber nozzle provided in an embodiment of the present invention;

[0042] Figure 3 for Figure 2 A-A cross-sectional structural diagram;

[0043] Figure 4 This is a schematic diagram of the main structure of the combustion chamber nozzle provided in an embodiment of the present invention;

[0044] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure of B-B in the middle;

[0045] Figure 6 for Figure 4 Schematic diagram of the cross-sectional structure of C-C in the middle;

[0046] Figure 7 Schematic diagram of the mixing zone structure of the combustion chamber nozzle provided in an embodiment of the present invention.

[0047] Description of reference numerals:

[0048] 1. Central cone structure; 2. First fuel supply cavity; 3. First CO2 annular cavity; 4. Air annular cavity; 5. Second CO2 annular cavity; 6. Second fuel supply cavity; 7. First delivery hole; 8. Delivery channel; 9. Second intermediate annular cavity; 10. Fuel distribution hole; 11. First intermediate annular cavity; 12. Second delivery hole; 13. Swirl; 14. Supply hole; 15. First injection annular gap; 16. First fuel jet hole; 17. Second fuel jet hole; 18. Third fuel jet hole; 19. Fuel jet channel; 20. Second injection annular gap; 21. Fairing; 22. Initial mixing zone; 23. Main mixing zone; 24. Fluid nozzle mixing zone; 25. Final mixing zone. DETAILED DESCRIPTION

[0049] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] like Figures 1 to 7A specific embodiment of the combustion chamber nozzle shown is suitable for the combustion of gaseous fuels, especially for the combustion of natural gas mixed with hydrogen. The combustion chamber nozzle includes: a central cone structure 1, a first fuel supply cavity 2 passing through the central cone structure 1, a first intermediate ring cavity 11 and a second intermediate ring cavity 9 arranged on the central cone structure 1, a first CO2 ring cavity 3 sleeved on the outer periphery of the first fuel supply cavity 2, an air ring cavity 4 sleeved on the outer peripheries of the first CO2 ring cavity 3 and the central cone structure 1, a second CO2 ring cavity 5 sleeved on the outer periphery of the air ring cavity 4, a second fuel supply cavity 6 sleeved on the outer periphery of the second CO2 ring cavity 5, and a fairing 21 connected to the outer wall of the second fuel supply cavity 6.

[0054] like Figures 1 to 6 As shown, the central cone structure 1 is composed of a cylindrical section and a conical section that are connected; the front end is cylindrical, and the tail gradually shrinks into a cone. The axis of the central cone structure 1 is arranged along the axial direction of the combustion chamber nozzle. The rear section of the first fuel supply cavity 2 passes through the center of the central cone structure 1 along the axial direction of the combustion chamber nozzle, and a fuel jet channel 19 is provided near the center of the end of the first fuel supply cavity 2. Specifically, the cross-section of the first fuel supply cavity 2 is circular; the diameter of the fuel jet channel 19 is 2-6 mm, and the axial length of the fuel jet channel 19 is 2 / 5 to 4 / 5 of the axial length of the conical section of the central cone structure 1.

[0055] Furthermore, in the first fuel supply chamber 2, a transitional convergent section cavity is provided near the fuel jet channel 19. The fuel jet channel 19 is suitable for communicating with the flame tube; the first fuel supply chamber 2 is suitable for providing fuel. The first intermediate annular cavity 11 is provided on the central cone structure 1, and the first intermediate annular cavity 11 is provided around the rear section of the first fuel supply chamber 2; specifically, the first intermediate annular cavity 11 is a transitional streamlined annular cavity. Twelve first fuel jet holes 16 are evenly spaced along the circumferential direction at the end of the first intermediate annular cavity 11; the first fuel jet holes 16 are suitable for communicating with the flame tube; the first fuel supply chamber 2 is connected to the first intermediate annular cavity 11 through six evenly spaced fuel distribution holes 10 provided near the downstream. The first CO2 annular cavity 3 is sleeved on the outer periphery of the front section of the first fuel supply chamber 2; the first CO2 annular cavity 3 is suitable for providing CO2. The air annular cavity 4 is nestled around the outer periphery of the first CO2 annular cavity 3 and the central cone structure 1. The first CO2 annular cavity 3 communicates with the air annular cavity 4 via a plurality of first delivery holes 7 disposed near the distal end. Specifically, the first CO2 annular cavity 3 has a circular cross-section. The plurality of first delivery holes 7 are divided into three to five groups. Each group of first delivery holes 7 is equidistantly spaced along the axial direction of the first CO2 annular cavity 3 at intervals of 10-15 times the diameter of the first delivery holes 7. Each group of first delivery holes 7 has the same number of first delivery holes 7, and adjacent groups of first delivery holes 7 are staggered. More specifically, the first delivery holes 7 are divided into three groups. The front section of the first intermediate annular cavity 11 communicates with the air annular cavity 4 via fifteen evenly spaced second delivery holes 12. The distal end of the air annular cavity 4 is adapted to communicate with the flame tube. The air annular cavity 4 is adapted to provide air. Furthermore, a swirler 13 is provided along the circumferential direction at a position near the end of the air ring cavity 4; the swirler 13 is provided with fifteen hollow blades along the circumferential direction; the first intermediate ring cavity 11 is connected to the fifteen blades respectively through fifteen second delivery holes 12; the blades are connected to the air ring cavity 4 through supply holes 14.

[0056] The second intermediate annular cavity 9 is disposed on the cone section of the central cone structure 1 and surrounds the first intermediate annular cavity 11. A second injection annular slit 20 is circumferentially provided at the end of the second intermediate annular cavity 9. The second injection annular slit 20 is adapted to communicate with the flame tube. Specifically, the size of the second injection annular slit 20 is 2-6 mm, and its jet direction is parallel to the central axis of the central cone structure 1. The end of the first CO2 annular cavity 3 communicates with the second intermediate annular cavity 9 via fifteen evenly spaced delivery channels 8. The swirler 13 has an equal number of blades, second delivery holes 12, and delivery channels 8; the second delivery holes 12 and delivery channels 8 are spaced apart. A first injection annular gap 15 is circumferentially defined at the end of the second CO2 annular cavity 5. The jet direction of the first injection annular gap 15 is oriented toward and perpendicular to the axis of the central cone structure 1. Specifically, the size of the first injection annular gap 15 is 2-6 mm. The distance between the blade tips of the swirler 13 and the first injection annular gap 15 is greater than twice the axial length of the swirler 13 blades. The second CO2 annular cavity 5 has a circular cross-section and is suitable for supplying CO2. The rear section of the second CO2 annular cavity 5 is provided with an expanded annular cavity corresponding to the cone section. The second injection annular gap 20 is positioned beyond the rear section of the second CO2 annular cavity 5. A plurality of third fuel injection holes 18 are circumferentially spaced and evenly spaced at intervals at the end of the second fuel supply cavity 6. These third fuel injection holes 18 are suitable for communicating with the flame tube. The second fuel supply cavity 6 is suitable for supplying fuel and has a circular cross-section. The first fuel supply cavity 2, first CO2 annular cavity 3, first intermediate annular cavity 11, second intermediate annular cavity 9, fuel jet channel 19, air annular cavity 4, second CO2 annular cavity 5, and second fuel supply cavity 6 are all coaxially arranged. The first injection annular slit 15, second injection annular slit 20, and the rear section of the second CO2 annular cavity 5 form a fluid nozzle, which is used to increase gas flow rate and prevent backfire.

[0057] like Figure 2 、 Figure 3 and Figure 7As shown, the fairing 21 extends beyond the central cone structure 1, and the cavity enclosed by the fairing 21 is suitable for communicating with the flame tube. The second fuel supply chamber 6 extends beyond the second CO2 annular chamber 5. Thirty-six second fuel jet holes 17 are evenly spaced circumferentially along the inner wall near the end of the second fuel supply chamber 6. The jet directions of the first fuel jet holes 16 and the second fuel jet holes 17 intersect at the centerline of the annular outlet of the air annular chamber 4. In the air annular chamber 4, the first portion of CO2 in the first CO2 annular chamber 3 mixes with the air in the air annular chamber 4, forming an initial mixing zone 22. In the space near the second delivery hole 12 in the air annular chamber 4, the CO2 and air delivered from the initial mixing zone 22 mix with the first portion of fuel in the first fuel supply chamber 2, forming a primary mixing zone 23. In the space near the first injection annular gap 15 in the air annular chamber 4, the CO2, air, and fuel delivered from the primary mixing zone 23 mix with the CO2 in the second CO2 annular chamber 5, forming a fluid nozzle mixing zone 24. Inside the fairing 21, CO2, air, and fuel delivered by the fluid nozzle mixing zone 24 mix with the second portion of fuel from the first fuel supply chamber 2, the second portion of CO2 from the first CO2 annular chamber 3, and the fuel from the second fuel supply chamber 6, forming a final mixing zone 25. The fuel ratio gradually increases in the order of the initial mixing zone 22, the main mixing zone 23, the fluid nozzle mixing zone 24, and the final mixing zone 25. In the final mixing zone 25, the fuel ratio reaches the design equivalence ratio for premixed combustion. Specifically, the first portion of fuel flow provided by the supply hole 14, the fuel flow provided by the first fuel injection hole 16, the fuel flow provided by the second fuel injection hole 17, the fuel flow provided by the third fuel injection hole 18, and the fuel flow provided by the fuel injection channel 19 account for 40%, 15%, 15%, 20%, and 10% of the total fuel flow, respectively. The second portion of fuel in the first fuel supply chamber 2 includes the fuel provided by the first fuel injection hole 16 and the fuel provided by the fuel injection channel 19. The first portion of the CO2 flow provided through the first delivery hole 7, the first injection annular slit 15, and the second portion of the CO2 flow provided through the second injection annular slit 20 account for 50%, 35%, and 15% of the total CO2 flow, respectively. Furthermore, the fairing 21 has a curved inner wall, and the jet direction of the third fuel jet hole 18 is arranged parallel to the axis of the central cone structure 1. The curved inner wall is suitable for deflecting the jet from the third fuel jet hole 18 toward the axis of the combustion chamber nozzle. During gas turbine operation, when the fuel is natural gas, the volume ratio of CO2 in the first gas mixture should be less than 30%. The first gas mixture consists of air, natural gas, CO2, and hydrogen. When the fuel is natural gas mixed with hydrogen, the volume ratio of CO2 in the second gas mixture should be less than 10%. The second gas mixture consists of air, natural gas, CO2, and hydrogen.

[0058] The working process of the combustion chamber nozzle described in this application is briefly described as follows:

[0059] Fuel is supplied to the first fuel supply cavity 2 and the second fuel supply cavity 6 by the upstream component, and CO2 is supplied to the first CO2 annular cavity 3 and the second CO2 annular cavity 5 by the upstream component; at the same time, air is transmitted from the compressor outlet and enters the air annular cavity 4.

[0060] The first part of the CO2 in the first CO2 annular cavity 3 enters the air annular cavity 4 through the first delivery hole 7 and is mixed with the air in the initial mixing area 22. The second part of the CO2 in the first CO2 annular cavity 3 enters the second intermediate annular cavity 9 through the delivery channel 8 and is ejected from the second injection annular gap 20.

[0061] The first portion of fuel in the first fuel supply chamber 2 enters the first intermediate annular chamber 11 through the fuel distribution holes 10. The second portion of fuel is directly discharged into the flame tube through the fuel jet channel 19. The fuel in the first intermediate annular chamber 11 is divided into two paths. One path enters the chamber of the swirler 13 blades through the second delivery hole 12. From there, it is transferred through the supply holes 14 on the blades to the air annular chamber 4. In the primary mixing zone 23, it mixes with the air and CO2 transmitted from the initial mixing zone 22 and flows downstream. The other path exits through the first fuel jet hole 16 at the end of the first intermediate annular chamber 11.

[0062] All the CO2 in the second CO2 annular cavity 5 is discharged from the first injection annular gap 15 at its end, mixed with the air, CO2 and fuel from the main mixing zone 23 in the fluid nozzle mixing zone 24, and flows downstream.

[0063] A portion of the fuel in the second fuel supply chamber 6 is discharged through the second fuel jet orifice 17 at the distal end, while the remainder is discharged through the third fuel jet orifice 18 at the distal end. The fuel from the second fuel jet orifice 17 collides and mixes with the fuel from the first fuel jet orifice 16 at the combustor nozzle outlet. The mixing location is in the middle of the annular outlet of the air annulus 4, enhancing mixing uniformity. Simultaneously, the fuel jet from the third fuel jet orifice 18 is directly transmitted to the fairing 21, where it changes direction. In the final mixing zone 25, it is rapidly and evenly mixed with the air, CO2, and fuel from the fluid nozzle mixing zone 24, the fuel from the second fuel jet orifice 17 and the first fuel jet orifice 16, and the CO2 from the second injection annular gap 20. The fuel is then ignited and burned by the igniter, resulting in a flame located downstream of the combustor nozzle outlet.

[0064] The fuel jet channel 19 injects directly into the flame tube from the center of the combustion chamber nozzle. Based on the Bernoulli principle, this increases the average propagation velocity of the mixed gas. The first injection annular slit 15 utilizes a CO2 gas jet to form a fluid nozzle. This not only adjusts the effective area ratio of the nozzle and increases the average propagation velocity of the mixed gas, but also increases the average specific heat of the mixed gas, lowering the temperature of the combustible mixed gas, suppressing the rate of increase in the flame radius, and reducing the flame propagation velocity. Similarly, because the second injection annular slit 20 is located in the expansion portion of the convergent section, i.e., the rear section of the second CO2 annular cavity 5 is provided with an expansion-shaped annular cavity corresponding to the conical section, it can both increase the average propagation velocity of the mixed gas and adjust the effective area ratio of the nozzle. The distributed mixing zone can gradually increase the ratio of fuel and CO2 in the mixed gas until the designed equivalence ratio of premixed combustion is reached in the final mixing zone 25, thereby causing the flame to settle in the downstream area of ​​the nozzle outlet. Therefore, the invention can increase the average propagation speed of the mixed gas in the combustion chamber nozzle to make it higher than the flame propagation speed, prevent backfire, and at the same time station the flame downstream of the nozzle outlet to make it burn stably. Even if a short backfire occurs due to some uncontrollable reasons, the backfire will be stopped because the equivalence ratio of the mixed gas upstream of the last-stage mixing zone 25 does not meet the combustion requirements and the dilution effect and physical barrier effect of the CO2 ejected from the first injection annular gap 15, thereby protecting the safety of the gas turbine components.

[0065] The present invention, based on a combination of CO2 blending, fluid nozzle regulation, and dispersed blending zones, enables gas turbines to safely and stably premix and combust gaseous fuels. The principle is that CO2 has a high specific heat, which increases the average specific heat of the mixture, resulting in a decrease in the temperature of the combustible mixture, inhibiting the rate of increase in the flame radius and reducing the flame propagation speed. The use of a fluid nozzle adjusts the effective area ratio of the nozzle, increasing the average propagation speed of the mixture. The dispersed blending zones gradually increase the fuel ratio in the mixture, achieving the designed equivalence ratio for premixed combustion in the final blending zone, and allowing the combustion flame to settle downstream of the nozzle outlet. Therefore, the above provides a triple guarantee for gas turbine combustion, preventing backfire and ensuring safe and stable operation of the gas turbine. Furthermore, the dilution effect of CO2 effectively reduces flame temperature, reduces the generation of thermal nitrogen oxides, and protects the environment.

[0066] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A combustion chamber nozzle, characterized in that: include: A central cone structure (1) is composed of a cylindrical segment and a cone segment that are connected to each other, and the axis of the central cone structure (1) is arranged along the axial direction of the combustion chamber nozzle; A first fuel supply cavity (2), the rear section of which penetrates the central cone structure (1) along the axial direction of the combustion chamber nozzle, and a fuel jet channel (19) is provided near the end of the first fuel supply cavity (2); the fuel jet channel (19) is suitable for communicating with the flame tube; the first fuel supply cavity (2) is suitable for providing fuel; A first intermediate annular cavity (11) is provided on the central cone structure (1), and the first intermediate annular cavity (11) is provided around the rear section of the first fuel supply cavity (2); a plurality of first fuel jet holes (16) are provided at the end of the first intermediate annular cavity (11) along the circumferential direction; the first fuel jet holes (16) are suitable for communicating with the flame tube; the first fuel supply cavity (2) is communicated with the first intermediate annular cavity (11) through a plurality of fuel distribution holes (10); A first CO2 annular cavity (3) is sleeved on the outer periphery of the front section of the first fuel supply cavity (2); the first CO2 annular cavity (3) is suitable for providing CO2; An air ring cavity (4) is sleeved on the outer periphery of the first CO2 ring cavity (3) and the central cone structure (1); the first CO2 ring cavity (3) is connected to the air ring cavity (4) through a plurality of first delivery holes (7) arranged near the end; the front section of the first intermediate ring cavity (11) is connected to the air ring cavity (4) through a plurality of second delivery holes (12); the end of the air ring cavity (4) is suitable for being connected to the flame tube; and the air ring cavity (4) is suitable for providing air.

2. The combustion chamber nozzle according to claim 1, characterized in that A swirler (13) is provided along the circumference of the air annular cavity (4) near the end thereof; the swirler (13) is provided with a plurality of hollow blades along the circumference; the first intermediate annular cavity (11) is respectively connected to the plurality of blades of the swirler (13) through a plurality of second delivery holes (12); and the blades are connected to the air annular cavity (4) through supply holes (14).

3. The combustion chamber nozzle according to claim 1, characterized in that In the first fuel supply cavity (2), a transitional convergent cavity is provided near the fuel jet channel (19).

4. The combustion chamber nozzle according to claim 1, characterized in that The first intermediate annular cavity (11) is a streamlined annular cavity in a transitional form.

5. The combustion chamber nozzle according to claim 1, characterized in that The plurality of first delivery holes (7) are divided into a plurality of groups; the first delivery holes (7) in each group are arranged at intervals along the axial direction of the first CO2 annular cavity (3); the number of the first delivery holes (7) in each group is the same, and the first delivery holes (7) in adjacent groups are arranged in a staggered manner.

6. The combustion chamber nozzle according to any one of claims 1 to 5, characterized in that: Also includes: A second intermediate annular cavity (9) is provided on the cone section of the central cone structure (1), and the second intermediate annular cavity (9) is arranged around the first intermediate annular cavity (11); a second injection annular slit (20) is provided at the end of the second intermediate annular cavity (9) along the circumferential direction; the second injection annular slit (20) is suitable for communicating with the flame tube; the end of the first CO2 annular cavity (3) is communicated with the second intermediate annular cavity (9) through a plurality of delivery channels (8); A second CO2 annular cavity (5) is sleeved on the outer circumference of the air annular cavity (4); a first injection annular slit (15) is provided at the end of the second CO2 annular cavity (5) along the circumferential direction, and the jet direction of the first injection annular slit (15) is toward the axis of the central cone structure (1) and is perpendicular to the axis of the central cone structure (1); the second CO2 annular cavity (5) is suitable for providing CO2; A second fuel supply cavity (6) is sleeved on the outer circumference of the second CO2 annular cavity (5); a plurality of third fuel jet holes (18) are circumferentially provided at the end of the second fuel supply cavity (6); the third fuel jet holes (18) are suitable for communicating with the flame tube; the second fuel supply cavity (6) is suitable for supplying fuel.

7. The combustion chamber nozzle according to claim 6, characterized in that The rear section of the second CO2 annular cavity (5) is provided with an annular cavity in an expanded form corresponding to the cone section.

8. The combustion chamber nozzle according to claim 6, characterized in that Also includes: A fairing (21) is connected to the outer wall of the second fuel supply cavity (6), and the fairing (21) is arranged beyond the central cone structure (1), and the cavity enclosed by the fairing (21) is suitable for communicating with the flame tube; In the air annular cavity (4), the first portion of CO2 in the first CO2 annular cavity (3) is mixed with the air in the air annular cavity (4) to form an initial mixing zone (22); In the space near the second delivery hole (12) in the air annular cavity (4), CO2 and air delivered by the initial mixing zone (22) are mixed with the first portion of the fuel in the first fuel supply cavity (2) to form a main mixing zone (23); In the space near the first injection annular gap (15) in the air annular cavity (4), CO2, air and fuel delivered by the main mixing zone (23) are mixed with CO2 from the second CO2 annular cavity (5) to form a fluid nozzle mixing zone (24); Inside the fairing (21), CO2, air and fuel delivered by the fluid nozzle mixing zone (24) are mixed with the second portion of the fuel in the first fuel supply cavity (2), the second portion of the CO2 in the first CO2 annular cavity (3) and the fuel in the second fuel supply cavity (6) to form a final mixing zone (25); The proportion of fuel increases gradually in the order of the initial mixing zone (22), the main mixing zone (23), the fluid nozzle mixing zone (24) and the final mixing zone (25). In the final mixing zone (25), the proportion of fuel reaches the design equivalence ratio of premixed combustion.

9. The combustion chamber nozzle according to claim 8, characterized in that The fairing (21) is provided with an arc-shaped inner wall, and the jet direction of the third fuel jet hole (18) is arranged parallel to the axis of the central cone structure (1); the arc-shaped inner wall is suitable for refracting the jet of the third fuel jet hole (18) and approaching the axis direction of the combustion chamber nozzle.

10. The combustion chamber nozzle according to claim 6, characterized in that The second fuel supply cavity (6) is arranged beyond the second CO2 annular cavity (5), and a plurality of second fuel jet holes (17) are circumferentially arranged on the inner wall of the second fuel supply cavity (6) near the end thereof, and the jet directions of the first fuel jet holes (16) and the second fuel jet holes (17) intersect on the center line of the annular outlet of the air annular cavity (4).

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