A strongly cooled micro-mixing nozzle

Abstract

The application discloses a strong cooling micro-mixing nozzle and belongs to the field of advanced combustion technology. The application solves the problem that the existing high-temperature combustion burner using hydrogen-containing fuel is prone to backfire due to high flame temperature and fast combustion speed, and the problem that the safe and stable operation of the burner is seriously affected. The air-fuel mixing module is installed on the end cover of the burner, the air-fuel mixing hole is formed in the air-fuel mixing module, the other end of the fuel rod is inserted into the air-fuel mixing hole, one end of the rod main body is installed on the fuel distribution cavity cover plate of the burner, the plug-in connector is in a stepped rod structure, the large-diameter section is fixedly connected with the other end of the rod main body, the cover coaxial cover is arranged on the plug-in connector and the open end of the cover is fixedly connected with the other end of the rod main body, the annular channel is formed between the outer wall surface of the small-diameter section of the plug-in connector and the inner wall surface of the cover, and a plurality of fuel holes are formed in the cover. The strong flowability and the enhanced cooling and heat exchange performance can effectively cool the cover of the micro-mixing nozzle, improve the backfire resistance of the micro-mixing nozzle and ensure the safe and stable operation of the burner.

Description

Technical Field

[0001] This invention relates to a high-cooling micro-mixing nozzle, belonging to the field of advanced combustion technology. Background Technology

[0002] With the rapid development of clean energy utilization, the demand for hydrogen combustion has increased significantly. High-temperature rise burners using hydrogen-containing fuels can achieve zero carbon emissions and are the preferred solution for next-generation clean burners. However, the high temperature and fast combustion speed of hydrogen flames make high-temperature rise burners prone to backfire, especially under high-temperature rise conditions, which can easily lead to burner burnout accidents, seriously affecting the safe and stable operation of the burner. In addition, there is a flow stagnation zone at the closed end downstream of the fuel orifice of traditional micro-mixing nozzles. This flow stagnation zone is closer to the high-temperature zone of the flame. Due to the poor fluidity of the flow stagnation zone, the heat transfer coefficient is low, and heat is difficult to be carried away by the fuel. This further accelerates the burnout of the nozzle when backfire occurs, resulting in poor resistance to backfire.

[0003] Backfire burning of burners is one of the main problems restricting the large-scale, high-power application of hydrogen in the next generation. In addition, due to the high thermal conductivity of hydrogen, which is about 6.9 times that of dry air, hydrogen is often used as a cooling medium to cool generators in the power generation field.

[0004] Therefore, to address the application issues of hydrogen flame combustion under high temperature conditions, and taking advantage of hydrogen's high heat exchange performance, a hydrogen nozzle with strong cooling was designed. Combined with micro-mixing combustion technology, the anti-backfire capability of the micro-mixing nozzle was improved, enabling large-scale hydrogen energy combustion applications. Summary of the Invention

[0005] The present invention aims to solve the problem that existing high-temperature burners for burning hydrogen fuel are prone to backfire due to high flame temperature and fast combustion speed, which seriously affects the safe and stable operation of the burner. Therefore, a strong cooling micro-mixing nozzle is provided.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A high-intensity cooling micro-mixing nozzle includes a fuel rod and an air-fuel mixing module, wherein the air-fuel mixing module is mounted on the end cap of the burner, and the air-fuel mixing module has an air-fuel mixing hole, and the other end of the fuel rod is inserted into the air-fuel mixing hole. The fuel rod includes a rod body, a connector, and a cap. One end of the rod body is mounted on the fuel distribution chamber cover plate of the burner. The connector has a stepped rod structure, with its large-diameter section fixedly connected to the other end of the rod body. The cap is coaxially mounted on the connector, with its open end fixedly connected to the other end of the rod body. An annular channel is formed between the outer wall of the small-diameter section of the connector and the inner wall of the cap. Several fuel holes are provided on the cap, distributed circumferentially along the cap and communicating with the annular channel. The rod body and the connector do not have a fuel channel connected along their axial direction. There is a gap between the other end of the small-diameter section of the connector and the cap. Fuel enters from one end of the fuel channel, passes through the gap between the other end of the small-diameter section and the cap, the annular channel, and several fuel holes, and then flows out. After being mixed with air in the air-fuel mixing hole, an air-fuel mixture is formed at the outlet of the air-fuel mixing hole.

[0007] Furthermore, the stepped surface of the connector is located on the low-temperature side of the fuel hole, and a flow stagnation zone is formed between the stepped surface and the fuel hole.

[0008] Furthermore, the other end of the fuel rod is located in the same plane as the other end of the air-fuel blending module.

[0009] Furthermore, the cover includes a cover body and a blind hole opened on the cover body, the connector is inserted into the blind hole, and the closed end of the blind hole is conical.

[0010] Furthermore, the fuel rod and the air-fuel mixing hole are arranged coaxially.

[0011] Furthermore, the connection between the open end of the cap and the other end of the rod body is by welding.

[0012] Furthermore, the connector is coaxial with the main body of the rod and is integrally formed.

[0013] Furthermore, the corner structure between the other end of the air-fuel blending module and its inner wall is a right angle, a chamfer, or a rounded corner.

[0014] Furthermore, several fuel holes are evenly distributed along the circumference of the cap.

[0015] Furthermore, one end of the rod body is coaxial and integrally machined with a ring platform.

[0016] Compared with the prior art, the present invention has the following advantages: After the fuel rod is inserted into the air-fuel blending module, an air-fuel blending space is formed between the fuel rod and the air-fuel blending module.

[0017] The high-cooling micro-mixing nozzle of the present invention, through structural optimization, connects the gap between the other end of the small-diameter section of the plug and the cap with the annular channel to form a deflection zone.

[0018] Air enters from one end of the air-fuel mixing module, while fuel flows in from one end of the fuel channel and out from the other end, entering the baffle zone within the cover. Within the baffle zone, the flow direction changes, and the fuel exits through the fuel orifice. In other words, the fuel is in a forced flow state within the baffle zone. Compared to existing technologies, this results in stronger fluidity and enhanced cooling and heat exchange performance, effectively cooling the cover of the micro-mixing nozzle, improving the nozzle's resistance to backfire, and ensuring the safe and stable operation of the burner.

[0019] The connection between the open end of the cap and the other end of the rod body is far from the flame front and in a low-temperature zone, which can effectively prevent problems such as cracking at the connection point.

[0020] The strong cooling micro-mixing nozzle of the present invention has a simple structure and is easy to process. At the same time, through structural design, it can utilize the high heat transfer coefficient of hydrogen fuel itself to achieve strong cooling of the micro-mixing nozzle, realizing the large-scale combustion application of hydrogen energy.

[0021] The high-cooling micro-mixing nozzle of the present invention can be applied in fields such as gas turbines, aero engines, space engines, and industrial kilns. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view of the strong cooling micro-mixing nozzle of the present invention (the figure shows the positional relationship between the micro-mixing nozzle and the end cap of the burner and the fuel distribution chamber cover). Figure 2 for Figure 1 Enlarged schematic diagram of point P; Figure 3 This is a three-dimensional cross-sectional view of the high-cooling micro-mixing nozzle of the present invention; Figure 4 This is a three-dimensional structural schematic diagram of the high-cooling micro-mixing nozzle of the present invention; Figure 5 This is a three-dimensional structural diagram of the fuel rod; Figure 6 This is a partially enlarged schematic diagram of the other end of the fuel rod; Figure 7 A schematic diagram showing the connection between the rod body and the connector; Figure 8 A three-dimensional sectional view of the cap; Figure 9 This is a three-dimensional structural diagram of the air-fuel blending module.

[0023] In the picture: 1. Fuel rod; 11. Rod body; 11-1. Fuel channel; 12. Connector; 13. Cover; 13-1. Fuel hole; 13-2. Cover body; 13-3. Blind hole; 14. Annular channel; 15. Annular platform; 2. Air-fuel blending module; 21. Air-fuel blending hole; 3. End cover; 4. Fuel distribution chamber cover plate. Detailed Implementation

[0024] Specific implementation method one: Combining Figures 1-9 This description of embodiments provides a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the descriptions of "front," "rear," "left," "right," "inner," "outer," "left side," "right side," "upper part," "lower part," "top," and "bottom" in this invention are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] A high-intensity cooling micro-mixing nozzle includes a fuel rod 1 and an air-fuel mixing module 2, wherein the air-fuel mixing module 2 is mounted on an end cap 3 of a burner, and the air-fuel mixing module 2 has an air-fuel mixing hole 21. The other end of the fuel rod 1 is inserted into the air-fuel mixing hole 21. The fuel rod 1 includes a rod body 11, a connector 12, and a cover 13. One end of the rod body 11 is mounted on the fuel distribution chamber cover 4 of the burner. The connector 12 has a stepped rod structure, with its large-diameter section fixedly connected to the other end of the rod body 11. The cover 13 is coaxially mounted on the connector 12, with its open end fixedly connected to the other end of the rod body 11. An annular channel 14 is formed between the outer wall of the small-diameter section of the connector 12 and the inner wall of the cover 13. The cover 13 has several fuel holes 13-1. -1 is distributed circumferentially along the cap 13 and is connected to the annular channel 14. The rod body 11 and the plug are not connected along their axial direction and have fuel channels 11-1. There is a gap between the other end of the small diameter section of the plug 12 and the cap 13. Fuel enters from one end of the fuel channel 11-1, passes through the gap between the other end of the small diameter section and the cap 13, the annular channel 14 and several fuel holes 13-1 in sequence, and then flows out. After being mixed with air in the air-fuel mixing hole 21 by cross-jet, an air-fuel mixture is formed at the outlet of the air-fuel mixing hole 21.

[0028] The fixed connection between the fuel rod 1 and the fuel distribution chamber cover 4, and between the air-fuel blending module 2 and the burner end cover 3, can be a threaded connection for easy disassembly. The fuel distribution chamber cover 4 and the burner end cover 3 described in this invention are conventional structures of existing burners and will not be elaborated further here.

[0029] One end of the air-fuel blending module 2 is close to the fuel inlet 13-1, and the other end of the air-fuel blending module 2 is far away from the fuel inlet 13-1.

[0030] According to the description attached to this invention Figure 1 The structural arrangement shown defines one end and the other end of each component structure in this invention, that is, the right end of each structure is one end and the left end is the other end.

[0031] After the fuel rod 1 is inserted into the air-fuel blending module 2, an air-fuel blending space is formed between the fuel rod 1 and the air-fuel blending module 2.

[0032] The strong cooling micro-mixing nozzle of the present invention, through structural optimization, connects the gap between the other end of the small diameter section of the plug 12 and the cover 13 with the annular channel 14 to form a deflection zone.

[0033] Air enters from one end of the air-fuel mixing module 2, and fuel flows in from one end of the fuel channel 11-1 and out from the other end of the fuel channel 11-1 into the baffle zone inside the cover 13. Within the baffle zone, the flow direction changes, and the fuel flows out from the fuel hole 13-1. That is, the fuel is in a forced flow state within the baffle zone. Compared with existing technologies, this results in stronger fluidity and enhanced cooling and heat exchange performance, effectively cooling the cover 13 of the micro-mixing nozzle, improving the micro-mixing nozzle's resistance to backfire, and ensuring the safe and stable operation of the burner.

[0034] The connection between the open end of the cap 13 and the other end of the rod body 11 is far from the flame front and in a low-temperature zone, which can effectively prevent problems such as cracking at the connection.

[0035] The strong cooling micro-mixing nozzle of the present invention has a simple structure and is easy to process. At the same time, through structural design, it can utilize the high heat transfer coefficient of hydrogen fuel itself to achieve strong cooling of the micro-mixing nozzle, realizing the large-scale combustion application of hydrogen energy.

[0036] The high-cooling micro-mixing nozzle of the present invention can be applied in fields such as gas turbines, aero engines, space engines, and industrial kilns.

[0037] The flow of fuel in the deflection zone can be either swirling or direct current.

[0038] In this invention, the air-fuel mixing hole 21 inside the air-fuel mixing module 2 can be a circular hole, a rectangular hole, or a through hole of other shapes. The fuel rod 1 can be a round rod, a square rod, or other types of rods. Preferably, the shape of the outer wall surface of the fuel rod 1 is set to conform to the shape of the air-fuel mixing hole 21.

[0039] The stepped surface of the connector 12 is located on the low-temperature side of the fuel port 13-1, forming a flow stagnation zone between the stepped surface and the fuel port 13-1. With this design, after fuel flows out of the fuel port 13-1, it mixes with air in a cross-jet flow, forming an air-fuel mixture at the outlet of the air-fuel mixing port 21. Through structural optimization, the flow stagnation zone is positioned upstream of the fuel port 13-1, thus keeping it away from the high-temperature flame zone. Figure 1 As shown, the left side of fuel port 13-1 is the high-temperature side, and the right side is the low-temperature side.

[0040] The other end of fuel rod 1 and the other end of air-fuel mixing module 2 are located in the same plane. (See attached instruction manual) Figure 1 The direction shown indicates that the other end of the fuel rod 1 and the other end of the air-fuel blending module 2 are located in the same vertical plane. This design creates an annular surface between the outer wall of the other end of the fuel rod 1 and the inner wall of the other end of the air-fuel blending module 2, forming a reflux vortex downstream of the fuel rod 1 with the fuel rod 1 as the center, in order to further achieve stable combustion.

[0041] The cover 13 includes a cover body 13-2 and a blind hole 13-3 formed on the cover body 13-2. The connector 12 is inserted into the blind hole 13-3, and the closed end of the blind hole 13-3 is conical. This design, with the closed end of the blind hole 13-3 being conical, facilitates fuel flow. The fuel hole 13-1 is formed on the cover body 13-2.

[0042] The fuel rod 1 and the air-fuel mixing hole 21 are arranged coaxially.

[0043] The connection between the open end of the cover 13 and the other end of the rod body 11 is by welding.

[0044] The connector 12 is coaxial with the rod body 11 and is integrally formed.

[0045] The corner structure between the other end of the air-fuel blending module 2 and its inner wall is a right angle, a chamfer, or a rounded corner. A right angle is preferred. The air-fuel blending module 2 can be a cylindrical, square, or other cylindrical structure with any cross-sectional shape.

[0046] Several fuel holes 13-1 are evenly distributed around the circumference of the cover 13, and the number of fuel holes 13-1 is preferably six.

[0047] One end of the rod body 11 is coaxial and integrally machined with a ring platform 15. This design increases the contact area between the fuel rod 1 and the fuel distribution chamber cover plate 4 by setting the ring platform 15, thereby facilitating the installation and removal of the fuel rod 1.

[0048] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-intensity cooling micro-mixing nozzle, characterized in that: It includes a fuel rod (1) and an air-fuel mixing module (2), wherein the air-fuel mixing module (2) is installed on the end cap (3) of the burner, and the air-fuel mixing module (2) has an air-fuel mixing hole (21) opened on the air-fuel mixing module (2). The other end of the fuel rod (1) is inserted into the air-fuel mixing hole (21). The fuel rod (1) includes a rod body (11), a connector (12), and a cover (13). One end of the rod body (11) is mounted on the fuel distribution chamber cover plate (4) of the burner. The connector (12) has a stepped rod structure, and its large-diameter section is fixedly connected to the other end of the rod body (11). The cover (13) is coaxially mounted on the connector (12), and its open end is fixedly connected to the other end of the rod body (11). An annular channel (14) is formed between the outer wall of the small-diameter section of the connector (12) and the inner wall of the cover (13). The cover (13) has several fuel holes (13-1) for fuel. The holes (13-1) are distributed around the circumference of the cap (13) and are all connected to the annular channel (14). The rod body (11) and the plug (12) are connected along their axial direction by fuel channels (11-1). There is a gap between the other end of the small diameter section of the plug (12) and the cap (13). The fuel enters from one end of the fuel channel (11-1), passes through the gap between the other end of the small diameter section and the cap (13), the annular channel (14) and several fuel holes (13-1) in sequence, and then flows out. After being mixed with air in the air-fuel mixing hole (21) by cross-jet flow, an air-fuel mixture is formed at the outlet of the air-fuel mixing hole (21). The stepped surface of the connector (12) is arranged on the low-temperature side of the fuel hole (13-1), and a flow stagnation zone is formed between the stepped surface and the fuel hole (13-1).

2. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: The other end of the fuel rod (1) is located in the same plane as the other end of the air-fuel blending module (2).

3. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: The cover (13) includes a cover body (13-2) and a blind hole (13-3) opened on the cover body (13-2). The plug (12) is inserted into the blind hole (13-3), and the closed end of the blind hole (13-3) is conical.

4. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: The fuel rod (1) is arranged coaxially with the air-fuel mixing hole (21).

5. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: The connection between the open end of the cap (13) and the other end of the rod body (11) is by welding.

6. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: The connector (12) is coaxial with the rod body (11) and integrally formed.

7. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: The corner structure between the other end of the air-fuel blending module (2) and its inner wall is a right angle, a chamfer, or a rounded corner.

8. The high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: Several fuel holes (13-1) are evenly distributed around the circumference of the cap (13).

9. A high-intensity cooling micro-mixing nozzle according to claim 1, characterized in that: One end of the rod body (11) is coaxial and integrally machined with a ring platform (15).

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