Combustion chamber and nozzle thereof

By using multiple slope blocks in the nozzle to form a recirculation zone, the problems of uneven mixing and high cost in the existing micro-mixed combustion technology are solved, and efficient mixing of fuel and air and low-cost production are achieved.

CN120402932BActive Publication Date: 2025-09-05AECC CHINA GAS TURBINE ESTAB
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Patent Information

Application Number
CN202510898726.X
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2025-07-01
Publication Date
2025-09-05
Estimated Expiration
2045-07-01

AI Technical Summary

Technical Problem

The existing nozzle structure based on micro-mix combustion technology is relatively complex, resulting in uneven mixing of hydrogen and air, large power loss, and high manufacturing costs.

Method used

The nozzle structure is designed with multiple slope blocks, and the slope blocks form a recirculation zone to achieve effective mixing of fuel and air, simplifying the flow channel design.

Benefits of technology

The uniform mixing of fuel and air is achieved, the power loss of the mixed gas is reduced, and the manufacturing cost of the nozzle is reduced.

✦ Generated by Eureka AI based on patent content.

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Abstract

The present application discloses a combustion chamber and its nozzle, which relate to the field of nozzle technology. The nozzle includes: a tube body; an air flow channel is formed inside the tube body; a plurality of ramp blocks; each ramp block is arranged on the inner wall of the tube body, and each ramp block is distributed around the circumference of the tube body; each ramp block has a ramp surface, and the distance between the ramp surface and the inner wall of the tube body increases along a first direction; a fuel flow channel is arranged on the ramp block; the input end of the fuel flow channel extends through the tube body, and the output end of the fuel flow channel extends through the corresponding ramp block. The present application can enable air and fuel to form an effective micro-mixing inside the nozzle simply by designing a plurality of ramp blocks. Its overall structure is simple, which not only does not significantly reduce the power of the mixture formed by the air and fuel, but also can reduce the production cost of the nozzle.
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Description

Technical Field

[0001] The present application relates to the field of nozzle technology, and in particular to a combustion chamber and a nozzle thereof. Background Art

[0002] Gas turbines are a key component of the energy and power sector. Traditional gas turbines primarily use natural gas as fuel. However, with increasing environmental protection demands, flexible combustion of fuels primarily hydrogen mixed with other fuels (such as carbon monoxide or methane) is a key approach to achieving low-carbon or even zero-carbon power generation in future low-carbon clean energy ecosystems. However, the combustion characteristics of hydrogen fuel differ significantly from those of traditional hydrocarbon fuels. Hydrogen has a wider combustion limit, faster flame propagation speed, and higher adiabatic flame temperature. To address these technical challenges, those skilled in the art have designed nozzles based on micro-mixing combustion technology. Micro-mixing combustion achieves ultra-low emissions by reducing the mixing scale of fuel (e.g., pure hydrogen or hydrogen-enriched fuel) and air without significantly reducing gas flow rate. Because the mixture formed by mixing the fuel and oxidizer has minimal power loss, the mixture can maintain a high flow rate. This high flow rate offers strong flashback resistance and fuel flexibility. Existing nozzles based on micro-mixing combustion technology have relatively complex internal flow channel designs to ensure uniform mixing of hydrogen and air. For example, similar nozzles are disclosed in patent documents with publication number: CN116642204A, entitled: A Micro-mixing Nozzle and Combustion Chamber with Swirl Mixer; and CN116697405A, entitled: A Premixed Swirl Micro-mixing Nozzle and Combustion Chamber. Although nozzles with more complex flow channel designs can improve the uniformity of mixing hydrogen and air, the resulting mixed gas suffers from significant power losses, which reduces the nozzle's anti-flashback and flexible fuel adaptability. Furthermore, the more complex the nozzle design, the higher the manufacturing cost. Summary of the Invention

[0003] The purpose of this application is to provide a combustion chamber and a nozzle thereof to solve the technical problem that the nozzle structure based on the existing micro-mixing combustion technology is relatively complex.

[0004] To achieve the above objectives, this application provides the following technical solutions:

[0005] In a first aspect, the present application proposes a technical solution for a nozzle, the nozzle comprising:

[0006] A tube body; an air flow channel is formed inside the tube body;

[0007] a plurality of ramp blocks; each ramp block is disposed on the inner wall of the tube body and is distributed circumferentially around the tube body; each ramp block has a ramp surface, the ramp surface increasing in distance from the inner wall of the tube body along a first direction; the first direction is parallel to the axis of the tube body and points from the input end to the output end of the air flow channel;

[0008] A fuel flow channel is provided on the slope block; the input end of the fuel flow channel extends through the tube body, and the output end of the fuel flow channel extends through the corresponding slope block.

[0009] As a specific solution in the technical solution of the present application, the tube body includes a contraction tube section and a premixing tube section sequentially connected along a first direction; the inner diameter of the contraction tube section decreases along the first direction.

[0010] As a specific solution in the technical solution of this application, the slope surface is a plane or a curved surface.

[0011] As a specific solution in the technical solution of the present application, each fuel flow channel is arrayed around the axis line of the tube body; the fuel jet ejected from each fuel flow channel can form a swirl between each slope block.

[0012] As a specific solution in the technical solution of the present application, the opening of the fuel flow channel output end is located on the side of the slope block; the angle between the direction of the fuel jet and the side is greater than or equal to 45° and less than or equal to 75°.

[0013] As a specific solution in the technical solution of the present application, the spatial angle between the direction of the fuel jet and the first direction is greater than or equal to 30° and less than or equal to 60°.

[0014] In a second aspect, the present application proposes a technical solution for a combustion chamber, which includes a nozzle as described in any one of the first aspects.

[0015] As a specific solution in the technical solution of this application, it includes:

[0016] flame tube;

[0017] A nozzle plate is disposed in the flame tube; the nozzle plate has a fuel cavity therein;

[0018] A plurality of nozzles; each nozzle is disposed on a nozzle plate, and each nozzle penetrates the nozzle plate along the axial direction of the flame tube; an input end of a fuel flow channel in each nozzle is connected to the fuel cavity;

[0019] a fuel delivery pipe, disposed on the nozzle plate and communicating with the fuel cavity;

[0020] Igniter; the igniter passes through the nozzle plate.

[0021] As a specific solution in the technical solution of the present application, a partition is also provided inside the nozzle disk; the partition divides the fuel cavity into a main combustion stage fuel cavity and a secondary combustion stage fuel cavity; the fuel delivery pipe includes a main combustion stage fuel pipe and a secondary combustion stage fuel pipe; the main combustion stage fuel pipe is connected to the main combustion stage fuel cavity, and the secondary combustion stage fuel pipe is connected to the secondary combustion stage fuel cavity.

[0022] As a specific solution in the technical solution of the present application, the fuel delivery pipe also includes a duty class fuel pipe; the duty class fuel pipe passes through the nozzle plate, and the duty class fuel pipe is close to the igniter.

[0023] As a specific solution in the technical solution of the present application, the nozzle disk is further provided with a plurality of cooling structures, each cooling structure being used to cool the nozzle disk.

[0024] As a specific solution in the technical solution of the present application, the cooling structure includes an air inlet, a cooling cavity and an air outlet arranged in sequence on the nozzle disk along a first direction; the air inlet and the air outlet are both connected to the cooling cavity; the axial lines of the air inlet and the air outlet are both parallel to the first direction, and the projections of the air inlet and the air outlet along the first direction do not overlap.

[0025] As a specific solution in the technical solution of this application, there are multiple air outlet holes, and each air outlet hole is distributed around the axis of the air inlet hole; the sum of the cross-sectional areas of each air outlet hole is greater than the cross-sectional area of ​​the air inlet hole, and the cross section is perpendicular to the first direction.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The present application only uses the design of multiple slope blocks to enable the air and fuel to form an effective micro-mixing inside the nozzle. Its overall structure is simple, which not only does not significantly reduce the power of the mixture formed by the air and fuel, but also can reduce the production cost of the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A three-dimensional schematic diagram of a nozzle proposed in an embodiment of the present application;

[0029] Figure 2 for Figure 1 A longitudinal cross-sectional diagram of the middle nozzle;

[0030] Figure 3 A cross-sectional schematic diagram of a nozzle proposed in an embodiment of the present application;

[0031] Figure 4A schematic cross-sectional view of a combustion chamber proposed in an embodiment of the present application;

[0032] Figure 5 A schematic three-dimensional diagram of a combustion chamber proposed in an embodiment of the present application;

[0033] Figure 6 for Figure 5 A three-dimensional schematic diagram of the combustion chamber from another direction;

[0034] Figure 7 A three-dimensional schematic diagram of a nozzle plate proposed in an embodiment of the present application;

[0035] Figure 8 for Figure 7 A three-dimensional schematic diagram of the nozzle plate from another direction;

[0036] Figure 9 A schematic structural diagram of a fuel chamber proposed in an embodiment of the present application;

[0037] Figure 10 This is a schematic structural diagram of a cooling structure proposed in an embodiment of the present application.

[0038] In the figure: 1. Nozzle plate; 11. Fuel chamber; 111. Partition; 112. Primary combustion stage fuel chamber; 113. Secondary combustion stage fuel chamber; 2. Flame tube; 3. Nozzle; 31. Pipe body; 311. Contraction pipe section; 312. Premixing pipe section; 32. Slope block; 321. Slope surface; 33. Fuel flow channel; 34. Air flow channel; 4. Fuel delivery pipe; 41. Primary combustion stage fuel pipe; 42. Secondary combustion stage fuel pipe; 43. Duty class fuel pipe; 5. Igniter; 61. Air inlet; 62. Air outlet; 63. Cooling chamber. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0040] It should be noted that, in the description of this application, the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on this application.

[0041] Furthermore, it should be understood that for the sake of ease of description, the sizes of the various components shown in the drawings are not drawn according to actual proportions. For example, the thickness or width of certain layers may be exaggerated relative to other layers.

[0042] It should be noted that like numbers and letters represent similar items in the following figures, so once an item is defined or described in one figure, it will not need to be further discussed and described in detail in the description of the subsequent figures.

[0043] Before understanding the embodiments of the present application, it should be understood that the components or structures used to guide fluids in a nozzle or combustion chamber (e.g., the fuel flow channel 33, the air flow channel 34, the main combustion stage fuel pipe 41, and the duty class fuel pipe 43, etc.) all have an input end and an output end, wherein the input end refers to the end where the fluid (e.g., fuel, air, or a mixture, etc.) flows into the component or structure, and the output end refers to the end where the fluid flows out of the component or structure. In other words, in the nozzle or combustion chamber proposed in the embodiments of the present application, the flow direction of the fluid during use is always from the input end of a component or structure to the output end.

[0044] In order to solve the technical problem of the relatively complex structure of the existing nozzle based on the micro-mixing combustion technology mentioned in the background art, this application proposes an embodiment of a nozzle. The nozzle 3 includes a tube body 31, a plurality of slope blocks 32, and a fuel flow channel 33 provided on the slope blocks 32. Figure 1 As shown, each ramp block 32 is provided on the inner wall of the pipe body 31, and each ramp block 32 is distributed around the circumference of the pipe body 31. Figure 2 As shown, each slope block 32 has a slope surface 321, and the slope surface 321 is along the first direction (ie, as shown in FIG. Figure 2 The distance from the inner wall of the tube body 31 increases in the direction A) shown. The first direction is parallel to the axis of the tube body 31 and points from the input end of the air flow channel 34 to the output end. The air flow channel 34 is formed inside the tube body 31. The input end of the fuel flow channel 33 extends through the tube body 31, and the output end of the fuel flow channel 33 extends through the corresponding ramp block 32.

[0045] When in use, the air outside the tube body 31 enters the interior of the air flow channel 34 from the input end of the air flow channel 34; after the air encounters the slope block 32, the slope surface 321 and the slope block 32 will disturb the flow direction of the air, so that the air flowing through the slope block 32 forms a slope behind the slope block 32. Figure 2The recirculation zone B shown. Furthermore, fuel located outside the tube body 31 (hereinafter referred to as the fuel cavity 11) enters the fuel flow channel 33 from its input end. Because the output end of the fuel flow channel 33 extends through the corresponding ramp block 32, the fuel flowing out of the output end of the fuel flow channel 33 will inevitably flow through the recirculation zone B. If the fuel flows near the recirculation zone B, it will be drawn into the recirculation zone B. Furthermore, the air and fuel in the recirculation zone B can be strongly mixed. It should be understood that the more uniform the mixing of air and fuel, the fewer pollutants (e.g., nitrogen oxides) produced by subsequent combustion.

[0046] In this embodiment, if Figure 2 As shown, after air flows through the ramp block 32, a shedding vortex is generated at the edge of the ramp block 32, which in turn forms a recirculation zone at the bottom of the ramp block 32. When hydrogen is ejected directly from the bottom of the ramp block 32 along the axial direction of the tube body 31, it enters the recirculation zone at the bottom of the ramp block 32. The recirculation zone entrains the fuel located at the center of the vortex, causing intense mixing of the fuel and air. This improves the uniformity of the fuel-air mixing, improves the uneven distribution of combustion temperature, and enhances the emission reduction effect.

[0047] The nozzle proposed in this embodiment can effectively form a micro-mixing of air and fuel inside the nozzle simply by designing multiple slope blocks. Its overall structure is simple, which not only does not significantly reduce the power of the mixture formed by air and fuel, but also can reduce the manufacturing cost of the nozzle.

[0048] In the embodiment of the present application, there are no excessive restrictions on the shape and structure of the slope block 32. It is only necessary that the slope block 32 can form a recirculation zone B behind the slope block 32 for the air flowing in the first direction. For example, the slope block 32 can be a triangular block or a Figure 1 Trapezoidal block shown.

[0049] In the embodiment of the present application, there are no excessive restrictions on the slope surface 321, as long as the distance between the slope surface 321 and the inner wall of the tube body 31 increases gradually along the first direction. For example, the slope surface 321 can be a flat surface or a curved surface.

[0050] In the embodiment of the present application, there is no limit to the number of ramp blocks 32, as long as the recirculation zone formed by each ramp block 32 meets the mixing requirements of air and fuel. It is easy to understand that the more ramp blocks 32 there are, the more recirculation zones are formed. If the number of recirculation zones formed is more, although the mixing of air and fuel is more uniform, the power loss of the formed mixture is also greater. Based on this, in order to avoid a large number of ramp blocks 32 resulting in a large power loss of the formed mixture, and to avoid a small number of ramp blocks 32 resulting in uneven mixing of air and fuel, in a specific embodiment of the present application, the number of ramp blocks 32 can be as follows: Figure 1 4, or as Figure 3 3 shown.

[0051] As known from the background art, if the speed of the mixed gas (i.e. the gas formed by the mixture of air and fuel) ejected from the nozzle is greater, the probability of the nozzle flashing is smaller, and the nozzle is more adaptable to various flexible fuels. In order to increase the speed of the mixed gas ejected from the nozzle, in one embodiment of the present application, Figure 2 As shown, the pipe body 31 includes a first direction (ie, Figure 2 The converging pipe section 311 and the premixing pipe section 312 are connected in sequence along the first direction (as shown). The inner diameter of the converging pipe section 311 decreases along the first direction. Because the inner diameter of the converging pipe section 311 decreases along the first direction, the velocity of air flowing through the converging pipe section 311 increases. If the air velocity in the air flow channel 34 increases, the velocity of the mixed air formed in the air flow channel 34 will also increase.

[0052] In order to avoid forming a step between the contraction pipe section 311 and the premixing pipe section 312, thereby reducing the flow velocity of the air in the air flow channel 34, in one embodiment of the present application, as shown in FIG. Figure 2 As shown, the inner diameters of the premixing tube section 312 are uniform throughout, and the minimum inner diameter of the convergent tube section 311 is equal to the inner diameter of the premixing tube section 312. Because the minimum inner diameter of the convergent tube section 311 is equal to the inner diameter of the premixing tube section 312, the junction between the convergent tube section 311 and the premixing tube section 312 is smooth and step-free, meaning that the flow velocity of the air in the air flow channel 34 is not reduced by the step.

[0053] In order to further improve the uniformity of the mixing of air and fuel in the air flow passage 34, in one embodiment of the present application, the mixed air in the air flow passage 34 can also be caused to form a swirl. If the mixed air in the air flow passage 34 forms a swirl, the uniformity of the mixing of air and fuel can be further improved, that is, the emission of pollutants can be further reduced.

[0054] In the embodiment of the present application, any reasonable method can be used to make the mixed gas in the air flow channel 34 form a swirl. For example, a swirler is provided in the air flow channel 34. If a swirler is provided in the air flow channel 34, the complexity of the nozzle will increase, and the swirler will greatly reduce the flow velocity of the mixed gas. In order not to increase the complexity of the nozzle and not to greatly reduce the flow velocity of the mixed gas, in one embodiment of the present application, each fuel flow channel 33 can be arranged around the axis of the tube body 31, and the fuel jet ejected by each fuel flow channel 33 can form a swirl between each slope block 32 (that is, as shown in FIG. Figure 3 Swirl D) shown.

[0055] In this embodiment, the meaning of "array" is equivalent to the meaning of "array" in the field of three-dimensional design. In other words, an array refers to the linear or circumferential arrangement of an object (for example, the fuel flow channel 33 described above) in three-dimensional space according to certain rules and regulations.

[0056] In this embodiment, a swirling flow can be formed in the mixed gas in the air flow channel 34 without providing a swirler. In other words, this embodiment neither increases the complexity of the nozzle nor significantly reduces the flow speed of the mixed gas.

[0057] In this embodiment, there is no restriction on the shape of the fuel flow channel 33, as long as the fuel flow channels 33 of each array can form a swirl of the ejected fuel jet. It should be clear that for the fluid (i.e., the fuel), the jet direction formed must be parallel to the axis of the output end of the flow channel. For example, Figure 2 As shown, if the axis of the output end of the fuel flow channel 33 is parallel to the first direction (i.e., Figure 2 If the direction A shown in FIG. 3 is the same as the direction A shown in FIG. 3 ), the direction of the fuel jet ejected from the fuel flow channel 33 is also parallel to the first direction. It should be noted that since the fuel flow channels 33 are arranged around the axis of the tube body 31, as long as the axis of the output end of the fuel flow channel 33 is not aligned with the axis of the tube body 31, each fuel jet will inevitably form a swirl. In other words, in this embodiment, the fuel jet ejected from each fuel flow channel 33 can form a swirl between each ramp block 32 when the axis of the output end of the fuel flow channel 33 is aligned with the axis of the tube body 31.

[0058] In this embodiment, the size of the swirl formed by each fuel jet is closely related to the jet direction formed by each fuel jet. If the swirl formed is small, it is difficult to mix the air and fuel evenly, which means that more pollutants are generated during subsequent combustion; if the swirl formed is large, the power loss of the mixed gas is large, which means that it is easy to cause backfire during subsequent combustion. In order to avoid the swirl formed by each fuel jet being too large or too small, in one embodiment of the present application, Figure 3 As shown, the opening of the output end of the fuel flow channel 33 is located on the side of the ramp block 32, and the direction of the fuel jet (i.e. Figure 3 The angle between the direction C shown in FIG. Figure 3 The angle θ shown in FIG2 is greater than or equal to 45° and less than or equal to 75°. Specifically, in this embodiment, the angle θ can be any one of 45°, 50°, 55°, 60°, 65°, 70°, and 75°, or any degree between two adjacent degrees mentioned above.

[0059] In this embodiment, if Figure 3 As shown, hydrogen is ejected from the fuel flow channel 33 on the side of the slope block 32, and the injection angle θ is greater than or equal to 45° and less than or equal to 75°, forming a certain angle with the air flow direction. The fuel forms a small vortex in the center of the tube body 31 and mixes with the central air, and then enters the recirculation area at the bottom of the slope block 32, which can effectively improve the mixing uniformity of the fuel and air.

[0060] In this embodiment, if the swirl flow and the main flow in the air flow channel 34 collide, the flow velocity of the mixed gas in the air flow channel 34 will be reduced. To prevent the swirl flow from colliding with the main flow in the air flow channel 34, in one embodiment of the present application, the spatial angle between the direction of the fuel jet and the first direction can be greater than or equal to 30° and less than or equal to 60°. Specifically, the spatial angle can be any one of 30°, 35°, 40°, 45°, 50°, 55°, and 60°, or any degree between two adjacent degrees mentioned above.

[0061] In the embodiment of the present application, there are no excessive restrictions on the size of each component of the nozzle 3, as long as the size of each component can meet the requirements of uniform mixing of air and fuel. For example, in a specific embodiment of the present application, the diameter of the air flow channel 34 (i.e., Figure 2 The diameter d) shown in FIG can be greater than or equal to 5 mm and less than or equal to 7 mm; the height of the ramp block 32 (ie, Figure 2 The height H shown in FIG) can be greater than or equal to 1.5 mm and less than or equal to 2.0 mm; the distance between the end of the ramp block 32 and the output end of the air flow channel 34 (ie, Figure 2The distance S shown can be greater than or equal to 1 mm and less than or equal to 3 mm; the length of the contraction tube section 311 along the first direction can be greater than or equal to 2 mm and less than or equal to 4 mm; the diameter of the fuel flow channel 33 can be greater than or equal to 0.4 mm and less than or equal to 0.8 mm, etc. Of course, in other embodiments of the present application, the above dimensions can be designed according to needs.

[0062] The nozzle proposed in the embodiment of the present application can enable the air and fuel to form an effective micro-mixing inside the nozzle simply by designing multiple slope blocks. Its overall structure is simple, which not only does not significantly reduce the power of the mixture formed by the air and fuel, but also can reduce the manufacturing cost of the nozzle.

[0063] After introducing the nozzles proposed in the embodiments of the present application, the following describes an embodiment of a combustion chamber proposed in the present application. The combustion chamber includes the nozzle 3 proposed in any one of the above embodiments.

[0064] The combustion chamber proposed in the embodiment of the present application has a nozzle that can effectively form a micro-mixing of air and fuel inside the nozzle simply by designing multiple slope blocks. Its overall structure is simple, which not only does not significantly reduce the power of the mixture formed by the air and fuel, but also can reduce the manufacturing cost of the nozzle.

[0065] In a specific embodiment of the present application, the combustion chamber may include a nozzle plate 1, a flame tube 2, a fuel delivery pipe 4, an igniter 5 and a plurality of nozzles 3. Figure 4 As shown, a nozzle disk 1 is disposed within a flame tube 2 and defines a fuel chamber 11. A fuel delivery pipe 4 is disposed within the nozzle disk 1 and communicates with the fuel chamber 11. An igniter 5 is disposed within the nozzle disk 1 and extends through the nozzle disk 1. Each nozzle 3 is disposed within the nozzle disk 1 and extends axially through the nozzle disk 1 along the flame tube 2. The input end of the fuel flow channel 33 in each nozzle 3 communicates with the fuel chamber 11.

[0066] During use, fuel (which can be pure hydrogen or hydrogen-rich fuel) is injected into the fuel chamber 11 through the fuel delivery pipe 4. Since the input end of the fuel flow channel 33 in each nozzle 3 is connected to the fuel chamber 11, the fuel in the fuel chamber 11 can enter the air flow channel 34 of each nozzle 3 through the fuel flow channel 33. Since each nozzle 3 passes through the nozzle disk 1 along the axial direction of the flame tube 2, the air outside the flame tube 2 can enter the air flow channel 34 through the input end of the air flow channel 34 in the nozzle 3. Furthermore, the air and fuel entering the air flow channel 34 can produce the mixing described above, thereby forming a mixed gas. Furthermore, the formed mixed gas can enter the flame tube 2 through the output end of the air flow channel 34 in each nozzle 3, and then participate in subsequent combustion.

[0067] It's important to note that the operating condition of a gas turbine is positively correlated with the amount of fuel injected into the combustion chamber. That is, the greater the amount of fuel injected into the combustion chamber, the higher the operating condition of the gas turbine; the less fuel injected into the combustion chamber, the lower the operating condition of the gas turbine. It's important to understand that when the gas turbine is operating at low conditions, the amount of fuel required, and therefore the amount of fuel entering each nozzle 3, is less. While the amount of air entering each nozzle 3 remains essentially unchanged during the operation of the gas turbine, the fuel equivalence of the mixture formed by each nozzle 3 is relatively low when the gas turbine is operating at low conditions. If the fuel equivalence ratio of the mixture is too low, the combustion chamber is very susceptible to flameout or unstable combustion.

[0068] In order to avoid flameout or unstable combustion in the combustion chamber when the gas turbine is in low operating conditions, in one embodiment of the present application, a partition 111 is further provided inside the nozzle disc 1. The partition 111 divides the fuel chamber 11 into a primary combustion stage fuel chamber 112 and a secondary combustion stage fuel chamber 113. Figure 5 and Figure 6 As shown, the fuel delivery pipe 4 includes a primary fuel pipe 41 and a secondary fuel pipe 42. The primary fuel pipe 41 is connected to the primary fuel cavity 112, and the secondary fuel pipe 42 is connected to the secondary fuel cavity 113.

[0069] During operation, fuel can be delivered to the primary and secondary fuel chambers 112 and 113, respectively, through the primary and secondary fuel pipes 41 and 42. If the gas turbine is operating at a low operating condition, a majority of the fuel can be delivered to the secondary fuel chamber 113 through the secondary fuel pipe 42, so that the mixture produced by the nozzles 3 in the secondary fuel chamber 113 has a higher fuel equivalence ratio, thereby preventing flame extinguishment or unstable combustion in the combustion chamber due to excessively low fuel equivalence ratio in the mixture. If the gas turbine is operating at a high operating condition, fuel can be evenly delivered to the primary and secondary fuel chambers 112 and 113 through the primary and secondary fuel pipes 41 and 42, thereby preventing an increase in the content of pollutants (i.e., nitrogen oxides) caused by different fuel equivalence ratios of the mixtures produced by the various nozzles 3 (i.e., uneven mixing of the mixtures).

[0070] In the embodiment of the present application, uniformly delivering fuel to the primary fuel chamber 112 and the secondary fuel chamber 113 means delivering fuel to the primary fuel chamber 112 and the secondary fuel chamber 113 in equal proportions according to the ratio of the number of nozzles 3 connected to the primary fuel chamber 112 and the secondary fuel chamber 113. For example, if the number of nozzles 3 connected to the primary fuel chamber 112 is x, and the number of nozzles 3 connected to the secondary fuel chamber 113 is y; where x is greater than or equal to y, and both x and y are positive integers greater than or equal to 1; then, when the gas turbine is in a high operating condition, fuel in a ratio of x ÷ (x + y) × 100% can be delivered to the primary fuel chamber 112 through the primary fuel pipe 41; and fuel in a ratio of y ÷ (x + y) × 100% can be delivered to the secondary fuel chamber 113 through the secondary fuel pipe 42. Of course, in other embodiments of the present application, other reasonable methods may also be used to distribute fuel to the primary combustion stage fuel cavity 112 and the secondary combustion stage fuel cavity 113 .

[0071] In the embodiment of the present application, there is no limitation on the division method of the primary combustion stage fuel cavity 112 and the secondary combustion stage fuel cavity 113. For example, the fuel cavity 11 can be divided into the primary combustion stage fuel cavity 112 and the secondary combustion stage fuel cavity 113; or Figure 9 As shown in FIG, the fuel chamber 11 is divided into a primary combustion stage fuel chamber 112 and a secondary combustion stage fuel chamber 113. Figure 9 The divided primary combustion stage fuel cavity 112 and secondary combustion stage fuel cavity 113 can make the temperature field in the combustion chamber tend to be uniform no matter how the fuel amount is adjusted.

[0072] It should be noted that most gas turbines use lean premixed combustion technology. Lean premixed combustion involves premixing fuel and air to form a mixture where the stoichiometric ratio of the fuel in the resulting mixture is lower than the stoichiometric ratio required for combustion. The advantage of lean premixed combustion is that the air content in the mixture is relatively high, allowing the fuel to burn fully while also keeping the combustion temperature low. If the fuel burns fully and the combustion temperature is low, the pollutants produced by combustion (such as nitrogen oxides) can be minimized. It should be noted that if a gas turbine uses lean premixed combustion technology, the low stoichiometric ratio of the fuel in the mixture makes it difficult to ignite, which in turn makes it difficult to start the gas turbine.

[0073] In order to make the combustion chamber proposed in the embodiment of the present application applicable to the gas turbine based on the lean premixed combustion technology, in one embodiment of the present application, as shown in FIG. Figure 5 and Figure 6 As shown, the fuel delivery pipe 4 further includes a duty class fuel pipe 43. The duty class fuel pipe 43 passes through the nozzle plate 1, and the duty class fuel pipe 43 is close to the igniter 5.

[0074] During operation, fuel can be delivered directly to the interior of the flame tube 2 via the duty-stage fuel pipe 43. That is, in this embodiment, the fuel entering the flame tube 2 via the primary-stage fuel pipe 41 and the secondary-stage fuel pipe 42 can form premixed combustion, while the fuel entering the flame tube 2 via the duty-stage fuel pipe 43 can form diffusion combustion. Compared to premixed combustion, diffusion combustion is more stable and easier to ignite.

[0075] In this embodiment, the duty class fuel pipe 43 being close to the igniter 5 means that the distance between the duty class fuel pipe 43 and the igniter 5 is close enough so that the fuel ejected from the duty class fuel pipe 43 can be easily ignited by the igniter 5. For example, in a certain type of gas turbine, the duty class fuel pipe 43 being close to the igniter 5 means that the distance between the axis of the igniter 5 and the axis of the duty class fuel pipe 43 is less than 5 centimeters or less than 6 centimeters.

[0076] It should be noted that the nozzle disc 1 is used in a high-temperature environment for a long time. In order to reduce the temperature of the nozzle disc 1 during use and thereby increase the service life of the nozzle disc 1, in one embodiment of the present application, the nozzle disc 1 is also provided with multiple cooling structures, each cooling structure being used to cool the nozzle disc 1.

[0077] In this embodiment, the cooling structure may be any suitable structure capable of cooling the nozzle disk 1. For example, the cooling structure may be the cooling wall structure disclosed in the patent application publication number CN117570471A, entitled "Combustion Chamber Flame Liner Cooling Wall Structure and Flame Liner with Integrated Impingement Cooling," or the double-layer composite wall cooling structure disclosed in the patent application publication number CN116357999A, entitled "A Gas Turbine Combustion Chamber Flame Liner Wall Double-layer Composite Cooling Structure."

[0078] In a specific embodiment of the present application, the cooling structure may include an air inlet 61, a cooling cavity 63, and an air outlet 62 sequentially arranged on the nozzle plate 1 along the first direction. The air inlet 61 and the air outlet 62 are both connected to the cooling cavity 63. When in use, the air outside the nozzle plate 1 will pass through the cooling cavity 63. Figure 7 The air inlet 61 shown enters the cooling cavity 63, and the air in the cooling cavity 63 is then Figure 8 The air is ejected from the air outlet holes 62. Since the temperature of the air is much lower than the temperature of the flame during combustion, the air circulating in the cooling structure can reduce the temperature of the nozzle plate 1.

[0079] In this embodiment, the higher the speed of the air ejected from the air outlet 62, the more likely it is that the combustion of the mixed gas ejected from the nozzle 3 will become unstable, that is, flame separation will occur. In order to reduce the speed of the air ejected from the air outlet 62 and thereby avoid the phenomenon of flame separation, in one embodiment of the present application, the axis of the air inlet 61 and the air outlet 62 are parallel to the first direction, and the projections of the air inlet 61 and the air outlet 62 along the first direction do not overlap. If the projections of the air inlet 61 and the air outlet 62 along the first direction do not overlap, the air entering the cooling chamber 63 through the air inlet 61 will inevitably impact the inner wall of the cooling chamber 63. If the air entering the cooling chamber 63 impacts the inner wall of the cooling chamber 63, the kinetic energy of the air will be consumed, that is, the speed of the air flowing out of the air outlet 62 will be reduced.

[0080] To further reduce the velocity of air flowing out of the outlet 62, in one embodiment of the present application, the cross-sectional area of ​​the outlet 62 can be larger than that of the inlet 61, with the cross-sectional area perpendicular to the first direction. Based on the principle of conservation of flow, as the runoff area increases, the flow velocity decreases. In other words, if the cross-sectional area of ​​the outlet 62 is larger than that of the inlet 61, the velocity of air flowing through the outlet 62 will also decrease.

[0081] It should be clear that in Figure 8 The nozzle plate 1 shown is provided with dense nozzles 3 and air outlet holes 62. That is, the space for the air outlet holes 62 in the nozzle plate 1 is relatively narrow. If the cross-sectional area of ​​the air outlet holes 62 is larger than the cross-sectional area of ​​the air inlet holes 61, it is difficult to achieve that the projections of the air inlet holes 61 and the air outlet holes 62 along the first direction do not overlap. If the projections of the air inlet holes 61 and the air outlet holes 62 along the first direction overlap, it is difficult to reduce the speed of the air flowing out of the air outlet holes 62. In order to achieve that the cross-sectional area of ​​the air outlet holes 62 is larger than the cross-sectional area of ​​the air inlet holes 61 in a narrow space, and that the projections of the air inlet holes 61 and the air outlet holes 62 along the first direction do not overlap, in one embodiment of the present application, Figure 10 As shown, there may be multiple air outlet holes 62, each of which is distributed around the axis of the air inlet hole 61. The sum of the cross-sectional areas of each air outlet hole 62 is greater than the cross-sectional area of ​​the air inlet hole 61, and the cross-sectional area is perpendicular to the first direction.

[0082] The combustion chamber proposed in the embodiment of the present application has a nozzle that can effectively form a micro-mixing of air and fuel inside the nozzle simply by designing multiple slope blocks. Its overall structure is simple, which not only does not significantly reduce the power of the mixture formed by the air and fuel, but also can reduce the manufacturing cost of the nozzle.

[0083] It should be understood that the embodiments of the present application illustrate the nozzle and combustion chamber proposed in this application only through the application scenario of a gas turbine, and do not imply that the nozzle and combustion chamber proposed in this application are only applicable to gas turbine applications. In other words, there is no limitation on the application scenarios of the nozzle and combustion chamber proposed in this application. For example, the nozzle and combustion chamber proposed in this application can also be applied to aircraft engines or automobile engines, etc., and no further details are given here.

[0084] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A nozzle (3), characterized in that: include: A tube body (31); an air flow channel (34) is formed inside the tube body (31); A plurality of slope blocks (32); each slope block (32) is arranged on the inner wall of the tube body (31), and each slope block (32) is distributed around the circumference of the tube body (31); each slope block (32) has a slope surface (321), and the distance between the slope surface (321) and the inner wall of the tube body (31) increases along a first direction; the first direction is parallel to the axis of the tube body (31) and points from the input end to the output end of the air flow channel (34); A fuel flow channel (33) is provided on the slope block (32); the input end of the fuel flow channel (33) extends through the tube body (31), and the output end of the fuel flow channel (33) extends through the corresponding slope block (32).

2. The nozzle (3) according to claim 1, characterized in that The tube body (31) comprises a contraction tube section (311) and a premixing tube section (312) connected in sequence along a first direction; the inner diameter of the contraction tube section (311) decreases gradually along the first direction.

3. The nozzle (3) according to claim 1, characterized in that The slope surface (321) is a plane or a curved surface.

4. The nozzle (3) according to any one of claims 1 to 3, characterized in that The fuel flow channels (33) are arranged in an array around the axis of the tube body (31); the fuel jets ejected from the fuel flow channels (33) can form swirls between the slope blocks (32).

5. The nozzle (3) according to claim 4, characterized in that The opening of the output end of the fuel flow channel (33) is located on the side of the slope block (32); the angle between the direction of the fuel jet and the side is greater than or equal to 45° and less than or equal to 75°.

6. The nozzle (3) according to claim 5, characterized in that The spatial angle between the direction of the fuel jet and the first direction is greater than or equal to 30° and less than or equal to 60°.

7. A combustion chamber, characterized in that: Comprising a nozzle (3) as claimed in any one of claims 1 to 6.

8. The combustion chamber according to claim 7, characterized in that include: Flame tube (2); A nozzle plate (1) is arranged in the flame tube (2); The nozzle plate (1) has a fuel cavity (11) therein; A plurality of nozzles (3); each nozzle (3) is disposed on a nozzle disk (1), and each nozzle (3) penetrates the nozzle disk (1) along the axial direction of the flame tube (2); an input end of a fuel flow channel (33) in each nozzle (3) is connected to the fuel cavity (11); A fuel delivery pipe (4) is provided on the nozzle plate (1), and the fuel delivery pipe (4) is in communication with the fuel cavity (11); Igniter (5); the igniter (5) passes through the nozzle disc (1).

9. The combustion chamber according to claim 8, characterized in that A partition (111) is further provided inside the nozzle disc (1); the partition (111) divides the fuel cavity (11) into a main combustion stage fuel cavity (112) and a secondary combustion stage fuel cavity (113); the fuel delivery pipe (4) includes a main combustion stage fuel pipe (41) and a secondary combustion stage fuel pipe (42); the main combustion stage fuel pipe (41) is connected to the main combustion stage fuel cavity (112), and the secondary combustion stage fuel pipe (42) is connected to the secondary combustion stage fuel cavity (113).

10. The combustion chamber according to claim 9, characterized in that The fuel delivery pipe (4) further includes a duty class fuel pipe (43); the duty class fuel pipe (43) passes through the nozzle plate (1), and the duty class fuel pipe (43) is close to the igniter (5).

11. The combustion chamber according to claim 8, characterized in that The nozzle disc (1) is further provided with a plurality of cooling structures, each cooling structure being used to cool the nozzle disc (1).

12. The combustion chamber according to claim 11, characterized in that The cooling structure comprises an air inlet (61), a cooling cavity (63) and an air outlet (62) sequentially arranged on the nozzle disk (1) along a first direction; the air inlet (61) and the air outlet (62) are both connected to the cooling cavity (63); the axis lines of the air inlet (61) and the air outlet (62) are both parallel to the first direction, and the projections of the air inlet (61) and the air outlet (62) along the first direction do not overlap.

13. The combustion chamber according to claim 12, characterized in that There are a plurality of air outlet holes (62), each of which is distributed around the axis of the air inlet hole (61); the sum of the cross-sectional areas of each of the air outlet holes (62) is greater than the cross-sectional area of ​​the air inlet hole (61), and the cross-sectional area is perpendicular to the first direction.

Citation Information

Patent Citations

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    CN116357999A

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