Intensive cooling micro-mixing nozzle

Abstract

The invention discloses a strong-cooling micro-mixing nozzle and belongs to the technical field of advanced combustion. The high-temperature-rise burner solves the problems that an existing high-temperature-rise burner for burning hydrogen-containing fuel is high in flame temperature and high in burning speed, so that tempering is likely to happen, and safe and stable operation of the burner is seriously affected. The air-fuel mixing module is installed on an end cover of the combustor, an 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 body is installed on a fuel distribution cavity cover plate of the combustor, the connecting plug is of a stepped rod-shaped structure, and the large-diameter section of the connecting plug is fixedly connected with the other end of the rod body. The sealing cover coaxially covers the connecting plug, the opening end of the sealing cover is fixedly connected with the other end of the rod body, an annular channel is formed between the outer wall face of the small-diameter section of the connecting plug and the inner wall face of the sealing cover, and a plurality of fuel holes are formed in the sealing cover. The micro-mixing nozzle is high in flowability and enhanced in cooling and heat exchange performance, can effectively cool a sealing cover of the micro-mixing nozzle, improves the tempering resistance of the micro-mixing nozzle, and ensures safe and stable operation of a combustor.

Description

Technical Field

[0001] The invention relates to a strong cooling micro-mixing nozzle, belonging to the field of advanced combustion technology. Background Art

[0002] With the rapid development of clean energy utilization, the demand for hydrogen combustion has increased significantly. High-temperature burners that use hydrogen-containing fuels can achieve zero carbon emissions and are the preferred option for the next generation of clean burners. However, the hydrogen flame has a high temperature and a fast combustion speed, which makes it easy for high-temperature burners that use hydrogen-containing fuels to flash back. Especially under high-temperature conditions, it is very easy to cause burner burnout accidents, which will seriously affect the safe and stable operation of the burner. In addition, there is a flow stagnation zone at the closed end downstream of the fuel hole of the traditional micro-mixing nozzle. 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 it is difficult for heat to be carried away by the fuel, which further leads to accelerated burning of the nozzle when the burner flashes back, and the anti-flashback ability is poor.

[0003] Burner flashback is one of the main issues hindering the next generation of large-scale, high-power hydrogen combustion applications. Furthermore, due to the high thermal conductivity of hydrogen, approximately 6.9 times that of dry air, hydrogen is often used as a coolant to cool generators in the power generation sector.

[0004] Therefore, in order to solve the application problem of hydrogen flame combustion under high temperature rise conditions, combined with the advantages of hydrogen's high heat exchange performance, a strongly cooled hydrogen nozzle is designed. Combined with micro-mixed combustion technology, the anti-flashback ability of the micro-mixed nozzle is improved to realize large-scale combustion application of hydrogen energy. Summary of the Invention

[0005] The present invention aims to solve the problem that the existing high-temperature-rise burners burning hydrogen-containing fuels are prone to flashback due to high flame temperature and fast combustion speed, which seriously affects the safe and stable operation of the burner, and thus provides a strong cooling micro-mixing nozzle.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: A strong cooling micro-mixing nozzle includes a fuel rod and an air-fuel mixing module, wherein the air-fuel mixing module is installed on the end cover of the burner, an air-fuel mixing hole is opened on the air-fuel mixing module, and the other end of the fuel rod is inserted into the air-fuel mixing hole. The fuel rod includes a rod body, a plug joint and a cover, one end of the rod body is mounted on the fuel distribution chamber cover plate of the burner, the plug joint has a stepped rod-shaped structure and the large diameter section is fixedly connected to the other end of the rod body, the cover is coaxially covered on the plug joint and the open end of the cover is fixedly connected to the other end of the rod body, an annular channel is formed between the outer wall surface of the small diameter section of the plug joint and the inner wall surface of the cover, a plurality of fuel holes are opened on the cover, the plurality of fuel holes are distributed along the circumference of the cover and all pass through the annular channel, the rod body and the plug are not axially connected to form a fuel channel, there is a gap between the other end of the small diameter section of the plug joint and the cover, the fuel enters from one end of the fuel channel, passes through the gap between the other end of the small diameter section and the cover, the annular channel and the plurality of fuel holes, and then flows out, and after being mixed with the air cross jet in the air-fuel mixing hole, an air-fuel mixture is formed at the outlet of the air-fuel mixing hole.

[0007] Furthermore, the step surface of the plug connector is arranged on the low-temperature side of the fuel hole, and a flow stagnation area is formed between the step surface and the fuel hole.

[0008] Furthermore, the other end of the fuel rod and the other end of the air-fuel mixing module are located in the same plane.

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

[0010] Furthermore, the fuel rod is coaxially arranged with the air-fuel mixing hole.

[0011] Furthermore, the open end of the cover and the other end of the rod body are fixedly connected by welding.

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

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

[0014] Furthermore, the plurality of fuel holes are evenly distributed along the circumference of the cover.

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

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

[0017] The strong cooling micro-mixing nozzle of the present invention is structurally optimized, and the gap between the other end of the small diameter section of the plug connector and the cover is communicated with the annular channel to form a deflection area.

[0018] Air enters from one end of the air-fuel mixing module, fuel flows in from one end of the fuel channel, and flows out from the other end into the deflection zone within the cover, where it changes direction before exiting through the fuel holes. This forced flow of fuel within the deflection zone enhances fluidity and cooling and heat transfer compared to existing technologies. This effectively cools the cover of the micro-mixing nozzle, improves the nozzle's flashback resistance, and ensures safe and stable burner operation.

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

[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, the high heat transfer coefficient characteristics of hydrogen fuel itself can be utilized to achieve strong cooling of the micro-mixing nozzle, thereby realizing large-scale combustion application of hydrogen energy.

[0021] The strong cooling micro-mixing nozzle of the present invention can be applied in the fields of gas turbines, aircraft engines, aerospace engines, industrial kilns, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic main cross-sectional view of the strong cooling micro-mixing nozzle of the present invention (showing the positional relationship between the micro-mixing nozzle and the end cover of the burner and the fuel distribution cavity cover); Figure 2 for Figure 1 An enlarged schematic diagram of point P; Figure 3 is a schematic three-dimensional cross-sectional view of a strong cooling micro-mixing nozzle of the present invention; Figure 4 Schematic diagram of the three-dimensional structure of the strong cooling micro-mixing nozzle of the present invention; Figure 5 Schematic diagram of the three-dimensional structure of the fuel rod; Figure 6 is a partially enlarged schematic diagram of the other end of the fuel rod; Figure 7 It is a schematic diagram of the connection between the rod body and the plug connector; Figure 8 is a schematic three-dimensional cross-sectional view of the cover; Figure 9 This is a schematic diagram of the three-dimensional structure of the air-fuel mixing module.

[0023] In the picture: 1. Fuel rod; 11. Rod body; 11-1. Fuel channel; 12. Plug connector; 13. Cover; 13-1. Fuel hole; 13-2. Cover body; 13-3. Blind hole; 14. Annular channel; 15. Ring platform; 2. Air-fuel mixing module; 21. Air-fuel mixing hole; 3. End cover; 4. Fuel distribution chamber cover. DETAILED DESCRIPTION

[0024] Specific implementation method 1: Combination Figures 1 to 9 This embodiment is explained, and the technical solutions in the embodiment of the present invention are clearly and completely described. Obviously, the described embodiment is only a part of the embodiment of the present invention, rather than all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] It should be noted that the descriptions of the present invention regarding directions such as "front", "back", "left", "right", "inside", "outside", "left side", "right side", "upper", "lower", "top", and "bottom" are all defined based on the relationship between the orientations or positions shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure must be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0026] In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0027] A strong 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 the end cover 3 of the burner, an air-fuel mixing hole 21 is opened on the air-fuel mixing module 2, and 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 plug 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 plug connector 12 is a stepped rod structure and the large diameter section is fixedly connected to the other end of the rod body 11. The cover 13 is coaxially covered on the plug connector 12 and the open end of the cover 13 is fixedly connected to the other end of the rod body 11. An annular channel 14 is formed between the outer wall surface of the small diameter section of the plug connector 12 and the inner wall surface of the cover 13. The cover 13 is provided with a plurality of fuel holes 13-1 and a plurality of fuel holes 13-2. -1 are distributed along the circumference of the cover 13 and are all connected with the annular channel 14. The rod body 11 and the plug are not connected along the axial direction thereof. A fuel channel 11-1 is opened. There is a gap between the other end of the small-diameter section of the plug 12 and the cover 13. The fuel enters from one end of the fuel channel 11-1 and passes through the gap between the other end of the small-diameter section and the cover 13, the annular channel 14 and the plurality of fuel holes 13-1 before flowing out. After being mixed with the air cross jet in the air-fuel mixing hole 21, 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 plate 4, as well as between the air-fuel mixing module 2 and the burner end cover 3, can be a threaded connection, which facilitates disassembly. The fuel distribution chamber cover plate 4 and the burner end cover 3 described in the present invention are conventional structures of existing burners and will not be described in detail here.

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

[0030] According to the specification of the present invention Figure 1 The structural arrangement direction shown defines one end and the other end of each component structure in the present 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 mixing module 2 , an air-fuel mixing space is formed between the fuel rod 1 and the air-fuel mixing module 2 .

[0032] The strong cooling micro-mixing nozzle of the present invention is structurally optimized, so that the gap between the other end of the small diameter section of the plug connector 12 and the cover 13 is connected to the annular channel 14 to form a deflection area.

[0033] Air enters from one end of the air-fuel mixing module 2, while fuel flows in from one end of the fuel channel 11-1. It then flows out from the other end of the channel 11-1 into the deflection zone within the cover 13, where it changes direction before exiting through the fuel hole 13-1. This forced flow of fuel within the deflection zone enhances fluidity and cooling and heat exchange compared to existing technologies. This effectively cools the cover 13 of the micro-mixing nozzle, improves the nozzle's flashback resistance, and ensures safe and stable burner operation.

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

[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, the high heat transfer coefficient characteristics of the hydrogen-containing fuel itself can be utilized to achieve strong cooling of the micro-mixing nozzle, thereby realizing large-scale combustion application of hydrogen energy.

[0036] The strong cooling micro-mixing nozzle of the present invention can be applied in the fields of gas turbines, aircraft engines, aerospace engines, industrial kilns, etc.

[0037] The flow of fuel in the deflection area can be a swirl flow or a straight flow.

[0038] In the present invention, the air-fuel mixing hole 21 within 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 any other rod shape. Preferably, the outer wall of the fuel rod 1 is configured to conform to the shape of the air-fuel mixing hole 21.

[0039] The step surface of the plug connector 12 is located on the low-temperature side of the fuel hole 13-1, and a flow stagnation zone is formed between the step surface and the fuel hole 13-1. With this design, the fuel flows out of the fuel hole 13-1 and mixes with the air cross jet, forming an air-fuel mixture at the outlet of the air-fuel mixing hole 21. Through structural optimization, the flow stagnation zone is arranged upstream of the fuel hole 13-1, which makes the flow stagnation zone away from the high-temperature zone of the flame. Figure 1 In the direction shown, the left side of the fuel hole 13-1 is the high-temperature side, and the right side is the low-temperature side.

[0040] The other end of the fuel rod 1 and the other end of the air-fuel mixing module 2 are located in the same plane. Figure 1 The direction shown indicates that the other end of the fuel rod 1 and the other end of the air-fuel mixing module 2 are located in the same vertical plane. This design forms 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 mixing module 2. With the fuel rod 1 as the central bluff, a recirculating vortex is formed downstream of the fuel rod 1, further stabilizing combustion.

[0041] The cover 13 includes a cover body 13-2 and a blind hole 13-3 defined in the cover body 13-2. The plug connector 12 is inserted into the blind hole 13-3. The closed end of the blind hole 13-3 is tapered. This tapered design facilitates fuel flow. The fuel port 13-1 is defined in the cover body 13-2.

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

[0043] The open end of the cover 13 and the other end of the rod body 11 are fixedly connected by welding.

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

[0045] The corner structure between the other end of the air-fuel mixing module 2 and its inner wall is a right angle, a chamfered angle, or a rounded angle. In this design, a right angle is preferred. The air-fuel mixing module 2 can be a cylindrical structure with a cylindrical, square, or other arbitrary cross-sectional shapes.

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

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

[0048] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A strong cooling micro-mixing nozzle, characterized by: The invention comprises a fuel rod (1) and an air-fuel mixing module (2), wherein the air-fuel mixing module (2) is mounted on an end cover (3) of a burner, an air-fuel mixing hole (21) is provided on the air-fuel mixing module (2), and the other end of the fuel rod (1) is inserted into the air-fuel mixing hole (21). The fuel rod (1) comprises a rod body (11), a plug 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 plug connector (12) is a stepped rod structure and the large diameter section is fixedly connected to the other end of the rod body (11). The cover (13) is coaxially mounted on the plug connector (12) and the open end of the cover (13) is fixedly connected to the other end of the rod body (11). An annular channel (14) is formed between the outer wall surface of the small diameter section of the plug connector (12) and the inner wall surface of the cover (13). The cover (13) is provided with a plurality of fuel holes (13-1) and a plurality of fuel holes (13-2). The fuel holes (13-1) are distributed along the circumference of the cover (13) and are all connected to the annular channel (14). The rod body (11) and the plug are not connected along the axial direction thereof and are provided with a fuel channel (11-1). A gap exists between the other end of the small diameter section of the plug (12) and the cover (13). The fuel enters from one end of the fuel channel (11-1) and flows out through the gap between the other end of the small diameter section and the cover (13), the annular channel (14) and the plurality of fuel holes (13-1). The fuel is mixed with the air cross jet in the air-fuel mixing hole (21) and forms an air-fuel mixture at the outlet of the air-fuel mixing hole (21).

2. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: The step surface of the plug connector (12) is arranged on the low-temperature side of the fuel hole (13-1), and a flow stagnation zone is formed between the step surface and the fuel hole (13-1).

3. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: The other end of the fuel rod (1) and the other end of the air-fuel mixing module (2) are located in the same plane.

4. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: The sealing cover (13) comprises a cover body (13-2) and a blind hole (13-3) provided on the cover body (13-2); the plug connector (12) is inserted into the blind hole (13-3); and the closed end of the blind hole (13-3) is tapered.

5. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: The fuel rod (1) and the air-fuel mixing hole (21) are coaxially arranged.

6. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: The opening end of the cover (13) and the other end of the rod body (11) are fixedly connected by welding.

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

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

9. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: The plurality of fuel holes (13-1) are evenly distributed along the circumference of the cover (13).

10. The strong cooling micro-mixing nozzle according to claim 1, characterized in that: One end portion of the rod body (11) is coaxially and integrally machined with a ring platform (15).

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