Mutual impact type coaxial shear gas-gas injector

Abstract

The invention discloses a mutual-striking type coaxial shear gas-gas injector. The problem that an existing coaxial shear injector is poor in mixing efficiency when the momentum ratio of two gas flows is small is solved. The device comprises an oxidant main flow pipe and a fuel pipe which are coaxially connected, the oxidant main flow pipe is of a hollow tubular structure, and the output end is connected with the oxidant divergent nozzle; the fuel pipe is of a hollow tubular structure, the inner wall of one end of the fuel pipe is integrally connected with a supporting plate, the inner wall of the other end of the fuel pipe is connected with an injection panel, the injection panel is provided with a fuel gradually-shrinking nozzle, the middle of the supporting plate is connected with the outer wall of the oxidizing agent main flow pipe in a sleeved mode, and the oxidizing agent gradually-expanding nozzle extends into the fuel gradually-shrinking nozzle. A fuel cavity is formed between the oxidant main flow pipe and the fuel pipe; the end, close to the supporting plate, of the fuel pipe is connected with a fuel conveying pipe which is communicated with the fuel pipe. The oxidant and the fuel enter the combustion chamber at an angle respectively, so that the mutual impact effect is formed, and the mixing of the oxidant and the fuel is enhanced.

Description

Technical Field

[0001] The invention relates to a shear gas injector of a liquid rocket engine, in particular to a mutual impact type coaxial shear gas injector. Background Art

[0002] Liquid rocket engines are currently the predominant propulsion system for launch vehicles and are crucial for space launches and deep space exploration missions. In liquid rocket engines, if thermal protection measures such as regenerative cooling are employed, the propellant may be in a gaseous state upon entering the combustion chamber. For gaseous propellants, combustion involves no atomization or evaporation, requiring only the mixing efficiency of the two propellants, which directly determines the engine's combustion efficiency. Therefore, improving the mixing efficiency of bipropellants, and thereby ensuring combustion efficiency, is a matter of considerable concern.

[0003] Existing gas-gas injectors typically employ coaxial shear or coaxial direct injection, with coaxial dual-shear injectors also being a derivative. Coaxial shear injectors are currently the preferred injection method for liquid rocket engine combustion chambers, primarily achieving efficient propellant mixing through the shearing action of the inner and outer jets. However, when the momentum ratio of the two gas-gas injectors is relatively small, the mixing efficiency of coaxial shear injection is suboptimal. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of poor mixing efficiency of the existing coaxial shear injector when the momentum ratio of the two air flows is relatively small, and to provide a mutual impact coaxial shear gas injector.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A mutual impact coaxial shear gas injector is special in that it comprises a coaxially connected oxidant main flow pipe and a fuel pipe;

[0007] The oxidant main flow pipe is a hollow tubular structure for conveying oxidant, and the output end is connected to the oxidant gradually diverging nozzle;

[0008] The fuel pipe is a hollow tubular structure, with a support plate integrally connected to the inner wall of one end and an injection panel connected to the inner wall of the other end. The injection panel is coaxially provided with a fuel convergent nozzle. The input end of the oxidant main flow pipe passes through the middle of the support plate and is connected to the external oxidant supply system, and the oxidant divergent nozzle at the output end extends into the interior of the fuel convergent nozzle.

[0009] A fuel cavity is formed between the oxidant main flow pipe and the fuel pipe; a gap is formed between the end of the oxidant gradually diverging nozzle away from the oxidant main flow pipe and the inner wall of the fuel gradually converging nozzle, forming a fuel channel, and the fuel channel is connected to the fuel cavity;

[0010] One end of the fuel pipe close to the support plate is connected to a fuel delivery pipe, which is communicated with the fuel pipe and is used to deliver fuel to the fuel cavity; the other end of the fuel pipe is used to connect to the combustion chamber.

[0011] In the gas-gas injector, the oxidizer and fuel are ejected at high speeds from the circular tube and the annular gap respectively, generating a shearing effect at the interface between the two, so that the oxidizer and fuel are mixed; by combining the internal oxidizer gradually diverging nozzle with the fuel gradually convergent nozzle nested outside the oxidizer gradually diverging nozzle, the oxidizer and fuel can enter the combustion chamber at different angles respectively, forming a mutual impact effect after the injection panel, which greatly enhances the mixing of the oxidizer and fuel, and is beneficial to the subsequent combustion and heat release in the combustion chamber.

[0012] Furthermore, the inner wall of the fuel pipe is connected to a rectifying plate;

[0013] The rectifying plate divides the fuel cavity into a fuel cavity I and a fuel cavity II; the fuel cavity I and the fuel cavity II are coaxial and cylindrical, and the flow rate and flow direction of the fuel become uniform after passing through the rectifying plate.

[0014] The fuel delivery pipe is communicated with the fuel cavity I, and the fuel cavity II is communicated with the fuel channel.

[0015] Furthermore, the rectifier plate is an annular plate body, and a plurality of through holes are provided on the annular plate body. The plurality of through holes are arranged at equal intervals in the circumferential direction and at equal intervals in the radial direction to form a plurality of concentric circular through holes.

[0016] Furthermore, the oxidizer diverging nozzle extends to the interior of the fuel convergent nozzle, and the output end of the oxidizer diverging nozzle is retracted by 1 / 4 to 1 / 3 of the thickness of the injection panel relative to the output end of the fuel convergent nozzle. The inner wall of the fuel convergent nozzle limits the ejection of the oxidizer, which can promote efficient mixing with the fuel.

[0017] Furthermore, a plurality of direct fuel nozzles are provided along the circumference of the outer edge of the injection panel, which can form a protective layer with a lower temperature on the inner wall of the downstream combustion chamber, reduce the heat transferred to the chamber wall, and play a role in thermal protection.

[0018] Furthermore, the fuel pipe is integrally connected to the support plate.

[0019] Furthermore, the oxidant diverging nozzle has a constant outer diameter and a trumpet-shaped expansion structure with an inner diameter, and the end with a smaller opening of the oxidant diverging nozzle is connected to the oxidant main flow pipe, and there is a gap between the outer wall of the other end and the inner wall of the fuel convergent nozzle to form a fuel channel.

[0020] Furthermore, the fuel convergent nozzle is a trumpet-shaped contraction structure, and the end with a larger opening is close to the fuel chamber II.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) An impact-type coaxial shear gas-gas injector provided by the present invention sets the inner hole of the oxidizer expansion nozzle at the end of the oxidizer main pipe as an expansion structure, and opens a fuel contraction nozzle on the injection panel connected to the end of the fuel pipe. This fuel contraction nozzle is a contraction structure, enabling the oxidizer and fuel to enter the combustion chamber at an angle respectively, forming an impact effect, greatly enhancing the mixing of the oxidizer and fuel, and being beneficial to subsequent heat release by combustion in the combustion chamber.

[0023] (2) An impact-type coaxial shear gas-gas injector provided by the present invention opens a plurality of fuel direct injection nozzles along the circumference at the outer edge of the injection panel, injecting the fuel parallel to the inner wall of the combustion chamber, ensuring a large surplus of fuel near the chamber wall, forming a temperature-lower protective layer to separate the high-temperature gas from the wall surface, reducing the heat transferred to the chamber wall, and playing a role in thermal protection. This cooling method has a simple structure and can ensure reliable cooling efficiency with a relatively small specific impulse loss.

[0024] (3) An impact-type coaxial shear gas-gas injector provided by the present invention has the oxidizer expansion nozzle retracted by 1 / 4 to 1 / 3 relative to the fuel contraction nozzle, which can greatly reduce the ablation degree of the tip of the oxidizer pipe, thus being beneficial to the reliable operation of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a three-dimensional sectional view of an embodiment of an impact-type coaxial shear gas-gas injector provided by the present invention;

[0026] Figure 2 is a front sectional view of an embodiment of an impact-type coaxial shear gas-gas injector provided by the present invention.

[0027] In the figure, 1 - oxidizer main pipe; 2 - fuel pipe; 3 - fuel chamber I; 4 - rectifying plate; 5 - fuel chamber II; 6 - fuel direct injection nozzle; 7 - fuel contraction nozzle; 8 - oxidizer expansion nozzle; 9 - fuel delivery pipe; 10 - support plate; 11 - injection panel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To make the objectives, advantages, and features of the present invention clearer, the following further elaborates on an impact-type coaxial shear gas-gas injector proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following detailed description, the advantages and features of the present invention will be clearer.

[0029] An impact-type coaxial shear gas-gas injector in this embodiment, as Figure 1 and Figure 2As shown in the figure, it includes an oxidizer main pipe 1 and a fuel pipe 2 connected coaxially. The oxidizer main pipe 1 is a hollow tubular structure for transporting oxidizer. One end is connected to an external oxidizer supply system through a welded straight-through joint, and the other end is connected to an oxidizer expanding nozzle 8. The oxidizer is ejected through the oxidizer expanding nozzle 8. The fuel pipe 2 is a hollow tubular structure for transporting fuel. One end is integrally connected with a support plate 10 on the inner wall, and is connected to an external supply system through a welded straight-through joint. The other end is connected with an injection panel 11 on the inner wall. A fuel reducing nozzle 7 is provided on the injection panel 11. The oxidizer expanding nozzle 8 extends into the fuel reducing nozzle 7, and the oxidizer expanding nozzle 8 is indented into the panel thickness by 1 / 4 to 1 / 3 relative to the inner wall of the fuel reducing nozzle 7, which can greatly reduce the ablation degree of the tip of the oxidizer pipe, thus being beneficial to the reliable operation of the engine.

[0030] In this embodiment, a fuel chamber is formed between the oxidizer main pipe 1 and the fuel pipe 2. A flow rectifying plate 4 is arranged in the fuel chamber 2 to divide the fuel chamber into a fuel chamber I 3 and a fuel chamber II 5. Among them, the flow rectifying plate 4 is an annular plate body. A plurality of through holes are provided on the annular plate body. The plurality of through holes are arranged at equal intervals circumferentially and at equal intervals radially to form a plurality of concentric circular through holes. After the fuel enters the fuel chamber I 3, it enters the fuel chamber II 5 through the flow rectifying plate 4. The flow rectifying plate can adjust the fuel in the fuel chamber I 3 to make the flow rate and flow direction of the fuel uniform.

[0031] In this embodiment, a gap is formed between the end of the oxidizer expanding nozzle 8 far from the oxidizer main pipe 1 and the inner wall of the fuel reducing nozzle 7 to form a fuel passage. The fuel passage communicates with the fuel chamber II, and can eject the fuel with uniform flow rate and flow direction in the fuel chamber II.

[0032] The oxidizer expanding nozzle 8 is coaxial with and communicates with the oxidizer main pipe 1. The oxidizer expanding nozzle 8 has a constant outer diameter and an inner diameter with a flared expansion structure. The end with a small opening of the oxidizer expanding nozzle 8 is connected to the oxidizer main pipe 1, and a gap is formed between the outer wall of the other end and the inner wall of the fuel reducing nozzle 7 to form a fuel passage, which can make the oxidizer eject in a conical shape at a certain angle from the outlet of the oxidizer expanding nozzle 8.

[0033] In this embodiment, the fuel reducing nozzle 7 communicates with the fuel chamber II, and the fuel reducing nozzle 7 is a flared contraction structure, and the end with a large opening is close to the fuel chamber II, which can make the fuel eject in a contracted shape.

[0034] In this embodiment, the inner hole of the oxidizer expansion nozzle 8 at the end of the oxidizer main pipe 1 is set to an expansion structure, and a fuel contraction nozzle 7 is provided on the injection panel 11 connected to the end of the fuel pipe 2. The fuel contraction nozzle 7 is a contraction structure, so that the oxidizer and the fuel enter the combustion chamber at an angle respectively, and an impact effect is formed behind the injection panel 11, greatly enhancing the mixing of the oxidizer and the fuel, which is beneficial to subsequent heat release by combustion in the combustion chamber.

[0035] In this embodiment, one end of the fuel pipe 2 close to the support plate 10 is connected to the fuel delivery pipe 9. The fuel delivery pipe 9 is communicated with the fuel pipe 2 and is used for delivering fuel to the fuel chamber.

[0036] In this embodiment, a plurality of fuel straight-through nozzles 6 are provided along the circumference at the outer edge of the injection panel 11, and the fuel is injected parallel to the inner wall of the combustion chamber, ensuring that there is a large surplus of fuel near the chamber wall, forming a temperature-lower protective layer to separate the high-temperature gas from the wall surface, reducing the heat transferred to the chamber wall and playing a role in thermal protection; the cooling method adopted in this embodiment has a simple structure and can ensure reliable cooling efficiency with a small specific impulse loss.

[0037] During use, when the injector works, one end of the outer wall of the fuel pipe 2 close to the fuel contraction nozzle 7 is connected to the combustion chamber; the oxidizer flows into the oxidizer main pipe 1 from the external supply system through the pipeline and then sprays out in an expanding shape from the oxidizer expansion nozzle 8. The fuel flows into the fuel pipe 2 from the external supply system through the pipeline, and then sequentially passes through the fuel chamber I3, the rectifying plate 4, and the fuel chamber II5. Finally, a part of the fuel sprays out in a converging shape from the fuel contraction nozzle 7 and is efficiently mixed with the conically sprayed oxidizer; another part of the fuel sprays out from the plurality of fuel straight-through nozzles 6 and forms a temperature-lower protective layer on the inner wall of the downstream combustion chamber, reducing the heat transferred to the chamber wall and playing a role in thermal protection.

[0038] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application.

Claims

1. An impact-type coaxial shear gas-gas injector, characterized in that: It comprises an oxidant main flow pipe (1) and a fuel pipe (2) coaxially connected from inside to outside; The oxidant main flow pipe (1) is a hollow tubular structure for conveying the oxidant, and the output end is connected to an oxidant gradually diverging nozzle (8); The fuel pipe (2) is a hollow tubular structure, the inner wall of one end of which is connected to a support plate (10), and the inner wall of the other end of which is connected to an injection panel (11), and a fuel convergent nozzle (7) is coaxially provided on the injection panel (11), the input end of the oxidant main flow pipe (1) passes through the middle of the support plate (10) and is connected to an external oxidant supply system, and the oxidant divergent nozzle (8) at the output end extends to the interior of the fuel convergent nozzle (7); A fuel cavity is formed between the oxidant main flow pipe (1) and the fuel pipe (2); a gap exists between the end of the oxidant gradually diverging nozzle (8) away from the oxidant main flow pipe (1) and the inner wall of the fuel gradually converging nozzle (7), forming a fuel channel, and the fuel channel is communicated with the fuel cavity; One end of the fuel pipe (2) close to the support plate (10) is connected to a fuel delivery pipe (9), which is in communication with the fuel pipe (2) and is used to deliver fuel to the fuel cavity; the other end of the fuel pipe (2) is used to connect to the combustion chamber.

2. The mutual impact type coaxial shear gas-gas injector according to claim 1, characterized in that: The inner wall of the fuel pipe (2) is connected to a rectifying plate (4); The rectifying plate (4) divides the fuel cavity into a fuel cavity I (3) and a fuel cavity II (5); The fuel delivery pipe (9) is connected to the fuel cavity I (3); the fuel cavity II (5) is connected to the fuel channel.

3. The mutual-impact coaxial shear gas-gas injector according to claim 2, wherein: The rectifying plate (4) is an annular plate body, and a plurality of through holes are opened on the annular plate body. The plurality of through holes are arranged at equal intervals in the annular direction and at equal intervals in the radial direction to form a plurality of concentric circles.

4. The mutual-impact type coaxial shear gas-gas injector according to claim 1, characterized in that: The oxidant diverging nozzle (8) extends into the interior of the fuel convergent nozzle (7), and the output end of the oxidant diverging nozzle (8) is retracted relative to the output end of the fuel convergent nozzle (7) by a distance of 1 / 4 to 1 / 3 of the thickness of the injection panel.

5. The mutual-impact coaxial shear gas-gas injector according to claim 1, characterized in that: The outer edge of the injection panel (11) is provided with a plurality of fuel direct current nozzles (6) along the circumference.

6. The air-air injector with mutual impact and coaxial shearing according to claim 1, wherein: The fuel pipe (2) is integrally connected to the support plate (10).

7. The mutual-impact type coaxial shear gas-gas injector according to claim 1, wherein: The oxidant diverging nozzle (8) has a constant outer diameter and a trumpet-shaped inner diameter. The end of the oxidant diverging nozzle (8) with a smaller opening is connected to the oxidant main flow pipe (1), and a gap exists between the outer wall of the end with a larger opening and the inner wall of the fuel convergent nozzle (7) to form the fuel channel.

8. The mutual-impact type coaxial shear gas-gas injector according to claim 1, wherein: The fuel converging nozzle (7) is a trumpet-shaped contraction structure, and the end with a larger opening is close to the fuel chamber II (5).

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