A nozzle with a central blunt body to suppress combustion oscillation

Abstract

The invention relates to the technical field of burners and provides a nozzle with a central blunt body for suppressing combustion oscillation, comprising a feed pipe, a micro-mixing tube and an oscillation suppression component, wherein the first end of the micro-mixing tube is connected to the discharge end of the feed pipe, and an air intake micro-hole is opened on the outer side of the micro-mixing tube to allow air to enter; the oscillation suppression component is arranged at the second end of the micro-mixing tube, and comprises a DC blade, a guide member and a shell, the guide member comprises a support rod and a shower-type blunt body, the support rod is axially arranged at the center of the shell, the DC blade is arranged in the shell, and the DC blade is rotatably arranged at the first end of the support rod, the shower-type blunt body is arranged at the second end of the support rod, the shower-type blunt body and the second end of the support rod are connected in an arc-shaped smooth transition, and one end of the shell corresponding to the shower-type blunt body is folded outward to form a flared structure; the invention has a simple structure and low cost, and after the fuel is fed into the micro-mixing tube through the feed pipe and mixed with the air entering through the air intake micro-hole, the combustion oscillation can be effectively suppressed by the oscillation suppression component.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, in particular to a nozzle with a central blunt body for suppressing combustion oscillation. Background Art

[0002] In the field of jet propulsion, fuel and oxidizer are mixed and burned in the combustion chamber to provide high-temperature combustion gas as power for the aircraft. Traditional technology mainly uses hydrocarbon fuels as the main raw materials, while hydrogen, as an efficient and clean energy source, has become an important trend in future fuels.

[0003] Micro-mixed combustion technology achieves ultra-low emissions by reducing the mixing scale of fuel and air and enhancing outlet uniformity. At the same time, the high-speed jet at the outlet has strong anti-backfire ability and flexible fuel adaptability. However, due to the fast combustion speed of hydrogen, short flame length, high adiabatic flame temperature and large heat release rate, the risk of combustion instability of the micro-mixing scheme is greatly increased, and combustion oscillations are very likely to occur.

[0004] The existing methods for suppressing oscillations can be divided into active control and passive control. However, no matter which method is used, the design is difficult, the cost is high, and the implementation is also very difficult. Summary of the Invention

[0005] The present invention provides a nozzle with a central blunt body for suppressing combustion oscillation, so as to solve the defects in the prior art that hydrogen fuel burners are prone to combustion oscillation and have high suppression costs.

[0006] The present invention provides a nozzle with a central blunt body for suppressing combustion oscillation, comprising:

[0007] a feed pipe for supplying fuel;

[0008] A micro-mixing tube, wherein a first end of the micro-mixing tube is connected to the discharge end of the feed tube, and an air inlet micro-hole is provided on the outer side of the micro-mixing tube for allowing air to enter;

[0009] An oscillation suppression assembly is provided at the second end of the micro-mixing tube and includes a DC blade, a flow guide and a shell. The flow guide includes a support rod and a shower-type blunt body. The support rod is axially arranged at the center of the shell. The DC blade is arranged in the shell and is rotatably arranged at the first end of the support rod. The shower-type blunt body is arranged at the second end of the support rod. The shower-type blunt body is connected to the second end of the support rod in an arc-shaped smooth transition. The shell is folded outward at one end corresponding to the shower-type blunt body to form a flared structure.

[0010] The nozzle with a central blunt body for suppressing combustion oscillation provided by the present invention further includes a fuel buffer chamber, the discharge end of the feed pipe is connected to the fuel buffer chamber, and the first end of the micro-mixing tube is connected to the fuel buffer chamber.

[0011] According to the nozzle with a central blunt body for suppressing combustion oscillations provided by the present invention, a plurality of micro-mixing tubes are provided, and the plurality of micro-mixing tubes are arranged in an array. The first ends of the plurality of micro-mixing tubes are all connected to the fuel buffer chamber, and the second end of each of the micro-mixing tubes is provided with the oscillation suppression component.

[0012] The nozzle with a central blunt body for suppressing combustion oscillations provided by the present invention also includes a closed box, which is provided with an air inlet, and the fuel buffer chamber and the micro-mixing tube are both arranged in the closed box, the discharge end of the feed pipe extends into the closed box and is connected to the fuel buffer chamber, and the shell is arranged outside the closed box and is connected to the second end of the micro-mixing tube.

[0013] According to the nozzle with a central blunt body for suppressing combustion oscillation provided by the present invention, the top of the closed box is also connected to a flame tube, and the shell is located in the flame tube.

[0014] According to the nozzle with a central blunt body for suppressing combustion oscillation provided by the present invention, the direct current blade is in a clover shape, a cross shape, a snowflake shape, a crisscross shape, and a nine-square grid shape.

[0015] According to the nozzle with a central blunt body for suppressing combustion oscillations provided by the present invention, a nozzle mounting plate is provided on the top of the closed box, and the nozzle mounting plate is provided with a plurality of connection holes. The number of the connection holes is the same as that of the micro-mixing tubes and the positions correspond one-to-one. The lower ends of the connection holes are connected to the second ends of the micro-mixing tubes, and the upper ends of the connection holes are connected to the housing.

[0016] According to the nozzle with a central blunt body for suppressing combustion oscillation provided by the present invention, the shell is cylindrical, and the inner diameter D0 of the shell is in the range of 3-20 mm.

[0017] According to the nozzle with a central blunt body for suppressing combustion oscillation provided by the present invention, the maximum inner diameter D2 of the expansion structure is in the range of: D0<D2≤1.4D0, and the angle α between the expansion structure and the horizontal plane is 0-90°.

[0018] According to the nozzle with a central blunt body for suppressing combustion oscillation provided by the present invention, the expansion angle β of the shower-type blunt body is 15-75°, the diameter D1 of the shower-type blunt body is in the range of: 0.3D0≤D1≤0.8D0, the thickness T1 of the shower-type blunt body is: 0.1D0≤T1≤0.5D0, and the vertical distance H1 between the top of the shower-type blunt body and the flared structure is 0.2D0≤H1≤0.6D0.

[0019] The present invention provides a nozzle with a central blunt body for suppressing combustion oscillations, comprising a feed pipe, a micro-mixing tube, and an oscillation suppression assembly. The feed pipe is used to supply fuel. The first end of the micro-mixing tube is connected to the discharge end of the feed pipe, and an air intake micro-hole is opened on the outer side of the micro-mixing tube to allow air to enter. The oscillation suppression assembly is arranged at the second end of the micro-mixing tube, and comprises a direct current blade, a flow guide, and a shell. The flow guide comprises a support rod and a shower-type blunt body. The support rod is axially arranged at the center of the shell. The direct current blade is arranged in the shell and is rotatably arranged at the first end of the support rod. The shower-type blunt body is arranged at the second end of the support rod. The shower-type blunt body and the second end of the support rod are connected in an arc-shaped smooth transition. One end of the shell corresponding to the shower-type blunt body is folded outward to form a flared structure. With such an arrangement, the present invention has a simple structure and low cost. After the fuel is fed into the micro-mixing tube through the feed pipe and mixed with the air entering through the air intake micro-hole, it passes through the direct current blade, the shower-type blunt body, and the flared structure of the oscillation suppression assembly in sequence, thereby effectively achieving the effect of suppressing combustion oscillations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic structural diagram of a nozzle with a central blunt body for suppressing combustion oscillations provided by an embodiment of the present invention.

[0022] Figure 2 It is a cross-sectional view of a nozzle with a central blunt body for suppressing combustion oscillations provided by an embodiment of the present invention.

[0023] Figure 3 Schematic diagram of the structure of the oscillation suppression component provided by an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1. Feed pipe; 2. Micro-mixing tube; 3. DC blade; 4. Guide piece; 41. Support rod; 42. Shower-type blunt body; 5. Shell; 6. Fuel buffer chamber; 7. Sealed box; 8. Flame tube; 9. Nozzle mounting plate; 10. Cover plate; 11. Inlet pipe. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0027] The following combination Figure 1-Figure 3 The nozzle of the present invention is described with a central bluff body to suppress combustion oscillations.

[0028] like Figures 1 to 3 As shown, this embodiment provides a nozzle with a guide member 4 for suppressing combustion oscillation, including: a feed pipe 1, a micro-mixing pipe 2 and an oscillation suppression component.

[0029] Among them, the feeding pipe 1 is used to provide fuel; the first end of the micro-mixing tube 2 is connected to the discharge end of the feeding tube 1, and an air intake microhole for allowing air to enter is opened on the outside of the micro-mixing tube 2; the oscillation suppression component is arranged at the second end of the micro-mixing tube 2, including a DC blade 3, a guide member 4 and a shell 5, the guide member 4 includes a support rod 41 and a shower-type blunt body 42, the support rod 41 is axially arranged at the center of the shell 5, the DC blade 3 is arranged in the shell 5, and the DC blade 3 is rotatably arranged at the first end of the support rod 41, the shower-type blunt body 42 is arranged at the second end of the support rod 41, the shower-type blunt body 42 and the second end of the support rod 41 are connected in an arc-shaped smooth transition, and the end of the shell 5 corresponding to the shower-type blunt body 42 is folded outward to form a flared structure.

[0030] During operation, pure hydrogen, hydrogen-doped methane and other fuels are fed into the micro-mixing tube 2 through the feed pipe 1, mixed with the air entering through the air inlet micropores, and then pass through the DC blades 3, the shower-type blunt body 42 and the flared structure in the oscillation suppression component in sequence to achieve the effect of suppressing combustion oscillations.

[0031] Reference Figure 3 In this embodiment, the design dimensions of each part of the oscillation suppression component are:

[0032] The inner diameter D0 of the shell 5 is in the range of 3-20 mm, the wall thickness is T2, the maximum inner diameter D2 of the flared structure is in the range of D0<D2≤1.4D0, and the angle α between the flared structure and the horizontal plane is 0-90°; the diameter d of the support rod 41 and the expansion angle β of the showerhead bluff body 42 are in the range of 15-75°, the diameter D1 of the showerhead bluff body 42 is in the range of 0.3D0≤D1≤0.8D0, the thickness T1 of the showerhead bluff body 42 is in the range of 0.1D0≤T1≤0.5D0, and the vertical distance H1 between the top of the showerhead bluff body 42 and the flared structure is 0.2D0≤H1≤0.6D0.

[0033] like Figure 3 As shown, in order to optimize the flow field, the straight edge connections are all designed with arc transition connections. The transition arc radius between the vertical section of the showerhead bluff body 42 and the expanded portion of the showerhead bluff body 42 is R1, the transition arc radius between the inner wall of the flared structure and the vertical section of the shell 5 is R2, and the transition arc radius between the support rod 41 and the showerhead bluff body 42 is R3.

[0034] Among them, D0, D1, D2, H1, T1 and β are the main constraints and can be adjusted according to the actual fuel type, air flow, equivalence ratio, etc.

[0035] In some embodiments, the DC blades 3 are shaped like a clover leaf, a cross, a snowflake, a 'P' shape, or a grid. The specific shape can be adjusted according to the inner diameter D0 of the housing 5. When D0 ≤ 6 mm, the DC blades 3 are preferably shaped like a clover leaf. When D0 ≥ 14 mm, the DC blades 3 are preferably shaped like a grid. When 6 < D0 < 14 mm, the DC blades can be shaped like a cross, a snowflake, or a 'P' shape.

[0036] like Figure 1 and Figure 2 As shown, the fuel buffer chamber 6 is further included. The discharge end of the feed pipe 1 is connected to the fuel buffer chamber 6, and the first end of the micro-mixing tube 2 is connected to the fuel buffer chamber 6. With this arrangement, the fuel buffer chamber 6 can reduce pressure pulsation for fuels such as hydrogen and suppress combustion instability.

[0037] In this embodiment, multiple micro-mixing tubes 2 are provided, arranged in an array. The first ends of each of the micro-mixing tubes 2 are connected to the fuel buffer chamber 6, and the second end of each micro-mixing tube 2 is provided with an oscillation suppression assembly. The size of the fuel buffer chamber 6 can be designed based on specific operating conditions and the number of nozzle arrays.

[0038] like Figure 1 and Figure 2 As shown, in this embodiment, a closed box 7 is further included. The closed box 7 is provided with an air inlet, which may be connected to an air inlet pipe 11. The fuel buffer chamber 6 and the micro-mixing tube 2 are both arranged in the closed box 7. The discharge end of the feed pipe 1 extends into the closed box 7 and is connected to the fuel buffer chamber 6. The shell 5 is arranged outside the closed box 7 and is connected to the second end of the micro-mixing tube 2.

[0039] like Figure 1 As shown, the top of the sealed box 7 is also connected to the flame tube 8, and the shell 5 is located in the flame tube 8. Fuels such as pure hydrogen and hydrogen-doped methane are introduced into the fuel buffer chamber 6 through the feed pipe 1, and then enter the micro-mixing tube 2 and are evenly mixed with the air entering through the air inlet micropores. They are then ejected through the DC blades 3, the shower-type blunt body 42 and the flared structure in the oscillation suppression component in sequence, and finally burn in the flame tube 8 to achieve the effect of suppressing combustion oscillation.

[0040] In some embodiments, an observation port is provided on one side of the sealed box 7, and the observation port is detachably connected to a sealing plate. For example, the sealing plate is connected to one side of the sealed box 7 by bolts. After the sealing plate is removed, the situation in the sealed box 7 can be detected by a thermocouple and a pressure sensor.

[0041] In this embodiment, a nozzle mounting plate 9 is provided on the top of the sealed box 7. The nozzle mounting plate 9 is provided with multiple connection holes. The number of connection holes is the same as that of the micro-mixing tubes 2 and the positions correspond one to one. The lower ends of the connection holes are connected to the second ends of the micro-mixing tubes 2, and the upper ends of the connection holes are connected to the housing 5, thereby achieving the connection between the oscillation suppression assembly and the micro-mixing tubes 2 through the nozzle mounting plate 9.

[0042] Furthermore, a cover plate 10 is provided on the top of the sealed box 7, and a mounting hole is provided on the cover plate 10. A nozzle mounting plate 9 is detachably connected to the mounting hole, and a gasket can be provided at the connection between the nozzle mounting plate 9 and the cover plate 10 to ensure the sealing effect of the sealed box 7.

[0043] The present invention provides a nozzle with a central bluff body for suppressing combustion oscillations. The nozzle can suppress combustion oscillations of fuels such as pure hydrogen and hydrogen-doped methane at a pressure drop of 1.5%-5% and an equivalence ratio of 0.3-0.9 (the equivalence ratio is the ratio of the amount of air theoretically required for complete combustion to the actual amount of air supplied during fuel combustion). The combustion oscillation suppression effect is achieved through the DC blades 3, the guide member 4, and the housing 5. The DC blades 3, the shower-like bluff body 42, and the flared structure of the housing 5 can be adjusted to achieve combustion oscillation suppression for different fuels, different air flow rates, and different inlet temperatures. The form of the DC blades 3 can be adjusted and selected based on the inner diameter D0 of the housing 5. The angle α between the flared structure and the horizontal plane and the expansion angle β of the shower-like bluff body 42 can adjust the flame shape. At the same time, by adjusting the diameter D1 of the shower-like bluff body 42 and the vertical distance H1 between the top of the shower-like bluff body 42 and the flared structure, oscillations of various frequencies can be effectively suppressed. The present invention utilizes a passive control method to achieve combustion oscillation suppression under different fuels, different air flows, and different inlet temperatures at a relatively low cost.

[0044] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or modes and features of different embodiments or modes described in this specification without contradiction.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A nozzle with a central blunt body to suppress combustion oscillation, characterized in that: include: A feed pipe (1) for supplying fuel; A micro-mixing tube (2), wherein a first end of the micro-mixing tube (2) is connected to the discharge end of the feed tube (1), and an air inlet micro-hole for allowing air to enter is provided on the outer side of the micro-mixing tube (2); An oscillation suppression component is arranged at the second end of the micro-mixing tube (2), comprising a DC blade (3), a flow guide (4) and a housing (5); the flow guide (4) comprises a support rod (41) and a shower-type blunt body (42); the support rod (41) is axially arranged at the center of the housing (5); the DC blade (3) is arranged in the housing (5), and the DC blade (3) is rotatably arranged at the first end of the support rod (41); the shower-type blunt body (42) is arranged at the second end of the support rod (41); the shower-type blunt body (42) and the second end of the support rod (41) are connected in an arc-shaped smooth transition; one end of the housing (5) corresponding to the shower-type blunt body (42) is folded outward to form a flared structure.

2. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 1, characterized in that: It also includes a fuel buffer chamber (6), the discharge end of the feed pipe (1) is in communication with the fuel buffer chamber (6), and the first end of the micro-mixing tube (2) is in communication with the fuel buffer chamber (6).

3. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 2, characterized in that: A plurality of the micro-mixing tubes (2) are provided, and the plurality of micro-mixing tubes (2) are arranged in an array. The first ends of the plurality of micro-mixing tubes (2) are all in communication with the fuel buffer chamber (6), and the second end of each micro-mixing tube (2) is provided with the oscillation suppression component.

4. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 2, characterized in that: The invention also comprises a sealed box (7), wherein the sealed box (7) is provided with an air inlet, the fuel buffer chamber (6) and the micro-mixing tube (2) are both arranged in the sealed box (7), the discharge end of the feed pipe (1) extends into the sealed box (7) and is in communication with the fuel buffer chamber (6), and the shell (5) is arranged outside the sealed box (7) and is in communication with the second end of the micro-mixing tube (2).

5. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 4, characterized in that: The top of the sealed box (7) is also connected to a flame tube (8), and the shell (5) is located in the flame tube (8).

6. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 1, characterized in that: The DC blades (3) are in the shape of a clover, a cross, a snowflake, a rice cake, or a nine-square grid.

7. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 4, characterized in that: A nozzle mounting plate (9) is provided on the top of the sealed box (7), and the nozzle mounting plate (9) is provided with a plurality of connection holes, the number of the connection holes being the same as that of the micro-mixing tubes (2) and the positions being in one-to-one correspondence, the lower ends of the connection holes being connected to the second ends of the micro-mixing tubes (2), and the upper ends of the connection holes being connected to the housing (5).

8. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 1, characterized in that: The shell (5) is cylindrical, and the inner diameter D0 of the shell (5) is in the range of 3-20 mm.

9. The nozzle with a central blunt body for suppressing combustion oscillation according to claim 8, characterized in that: The maximum inner diameter D2 of the flared structure is in the range of D0<D2≤1.4D0, and the angle α between the flared structure and the horizontal plane is 0-90°.

10. The nozzle with a central bluff body for suppressing combustion oscillation according to claim 8, characterized in that: The expansion angle β of the shower type bluff body (42) is 15-75°, the diameter D1 of the shower type bluff body (42) is in the range of 0.3D0≤D1≤0.8D0, the thickness T1 of the shower type bluff body (42) is in the range of 0.1D0≤T1≤0.5D0, and the vertical distance H1 between the top of the shower type bluff body (42) and the flared structure is in the range of 0.2D0≤H1≤0.6D0.

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