Liquid oxygen-methane pin-type hypergolic gas generator and starting control method thereof

Abstract

The present application belongs to the technical field of liquid rocket engine, and particularly relates to a liquid oxygen and methane needle bolt type rich combustion gas generator and a starting control method thereof, which comprises a needle bolt type injector, a generator shell, an igniter and a methane flow passage, the needle bolt type injector comprises a center cylinder, the center cylinder is a cavity structure with a liquid oxygen radial injection groove, and a liquid oxygen flow channel is formed, when the present application is used, methane is divided into three paths: one path is ignited by a torch after being impacted and atomized by liquid oxygen through an injection ring gap; the other two paths are heated through a body regenerative cooling passage, and liquid films are formed by being sprayed from a ring belt straight flow hole, wall surface cooling and main stream temperature control are considered. Advantage: relying on the wide range adjustment characteristics of the needle bolt injector to suppress oscillating combustion, the secondary injection is suitable for large flow of methane, reliable ignition at low mixing ratio and multiple starts are realized; the structure is compact, the cost is low, reuse is supported, and combustion stability and heat protection efficiency are considered.

Description

Technical Field

[0001] This invention belongs to the field of liquid rocket engine technology, specifically a liquid oxygen-methane needle-type fuel-rich gas generator and its start-up control method. Background Technology

[0002] Open-cycle liquid oxygen-methane liquid rocket engines possess advantages such as simple structure, high system maturity, low cost, and rapid development, making them promising candidates for application in the commercial aerospace sector. The fuel-rich gas generator is a crucial component of this type of engine. It organizes the ignition and combustion of liquid oxygen and methane to generate high-temperature, high-pressure fuel-rich gas, which drives the turbopump to supply propellant to the thrust chamber and generator.

[0003] Liquid oxygen-methane rich gas generators have problems such as low mixing ratio, large difference in volumetric flow rate between fuel and oxidant, difficulty in ignition, and difficulty in combustion organization. Traditionally, rich gas generators mostly adopt centrifugal or direct-flow injection schemes. However, this type of generator is prone to oscillating combustion problems, and measures need to be taken to suppress oscillating combustion. At present, there is no reliable method in engineering to predict oscillating combustion.

[0004] Needle-type injectors offer advantages such as low cost, high combustion stability margin, and strong wide-range flow rate adjustment capability. Currently, they are mainly used in the thrust chambers of liquid rocket engines, with limited application in fuel-rich gas generators. While needle-type injectors can fundamentally avoid oscillating combustion problems in fuel-rich gas generators, they also require addressing issues such as high methane volumetric flow rate, difficulty in reliable ignition and combustion, reliable cooling of the generator body, and poor gas temperature uniformity.

[0005] Therefore, the present invention provides a liquid oxygen methane needle-type rich gas generator and its start-up control method. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a liquid oxygen methane needle-type rich gas generator, comprising a needle-type injector, a generator housing, an igniter, and a methane flow channel.

[0008] The needle-type injector includes a central cylinder, which is a cavity structure with a radial injection groove for liquid oxygen, forming a flow channel for liquid oxygen. A liquid oxygen inlet is provided on the side of the central cylinder, and the radial injection groove for liquid oxygen is designed with a structure in which the main groove and the auxiliary groove are arranged alternately.

[0009] The generator housing includes a generator housing head and a generator housing body. The generator housing head is provided with a needle-type injector and igniter mounting interface, and also includes a methane inlet collection chamber, a diversion chamber and an injection chamber. The generator housing body includes a body atomizing and mixing zone, a body cylindrical section and a body converging section. A body pressure measuring hole is opened on the outer side of the body cylindrical section. A methane inlet is opened on the generator housing head and a pressure measuring connector is installed.

[0010] The igniter is a gaseous oxygen or gaseous methane igniter. The distance between the igniter installation channel outlet and the central cylinder is 25mm to 35mm. The angle between the igniter axis and the generator axis is 20° to 45°.

[0011] The methane flow channel includes a methane inlet collection chamber, a methane distribution chamber and a methane injection chamber located at the head of the generator housing, a regeneration cooling channel located in the front half of the generator housing body, a first-ring collector, a second-ring collector, and a methane injection annular gap located between the head of the generator housing and the central cylinder.

[0012] The liquid oxygen ejected from the radial liquid oxygen injection tank collides with the methane ejected from the methane injection ring to form a spray fan. The angle between the spray fan and the generator axis is 50°~80°. The main tank and the auxiliary tank form spray fans at different angles, while also taking into account the downward leakage of methane.

[0013] Preferably, the methane flow channel further includes a pressure measuring nozzle disposed at the generator head for measuring the pressure of the methane inlet collecting chamber.

[0014] Preferably, the first annular belt collector includes an annular belt spray front chamber, and the generator housing body has an annular belt axial DC hole. The annular belt spray front chamber communicates with the annular belt axial DC hole, and the axis of the annular belt axial DC hole is parallel to the axis of the generator housing body. The second annular belt collector includes two annular belt spray front chambers, and the generator housing body has two annular belt axial DC holes. The two annular belt axial DC holes communicate with the two annular belt spray front chambers, and the axes of the two annular belt DC holes are parallel to the axis of the generator housing body.

[0015] Preferably, the two-ring collector is connected to the one-ring collector through the regeneration cooling channel of the generator housing body, and the one-ring collector is connected to the methane distribution chamber at the head of the generator housing through the regeneration cooling channel; according to the above structure, the generator housing body realizes a cooling scheme of regeneration cooling in the first half and liquid film cooling in the second half of the side area.

[0016] Preferably, the characteristic length of the gas generator is 1.5m to 3.0m. As the liquid film in the edge area moves downstream, it continuously evaporates and mixes with the mainstream gas, thereby reducing the temperature of the main gas and improving the uniformity of the gas temperature.

[0017] Preferably, the methane splitting chamber is connected to both the regeneration cooling channel of the generator housing and the methane injection chamber. The flow distribution between the two is achieved by designing the flow resistance of the regeneration cooling channel and the methane injection chamber. The flow rates of the first and second annular coolants account for 25% to 35% of the total methane flow rate.

[0018] The number of ring belts is not limited to two ring belts; it can be designed as one ring belt or three or more ring belts, with the ring belts connected by a regenerative cooling channel.

[0019] Preferably, the impact point between the liquid oxygen methane spray fan and the generator housing body is located in front of the DC outlet of the ring belt, and the distance between the two is 10mm to 30mm. The generator housing is integrally formed based on additive manufacturing process.

[0020] Preferably, a circular plate is fixedly connected to the side of the generator housing away from the head of the generator housing, a sleeve plate is sleeved on the outer side of the circular plate, an annular groove is formed on the inner wall of the sleeve plate, and a plurality of limiting blocks adapted to the annular groove are fixedly connected to the outer side of the circular plate.

[0021] An arc-shaped cover is fixedly connected to the side of the socket plate. A telescopic block is movably inserted inside the arc-shaped cover. An air pump and a start / stop controller are installed inside the arc-shaped cover. Insertion blocks are fixedly connected to a pair of sides of the telescopic block. Insertion grooves that are adapted to the insertion blocks are opened on a pair of inner side walls of the arc-shaped cover. A rubber extrusion block is fixedly connected between the insertion groove and the insertion block. Sealing blocks are provided between the socket plate and the arc-shaped cover, as well as on a pair of inner side walls and the inner top wall of the arc-shaped cover. The sealing blocks abut against the outer side of the telescopic block.

[0022] A start-up control method for a liquid oxygen-methane needle-type rich gas generator, applicable to the aforementioned liquid oxygen-methane needle-type rich gas generator, includes the following steps:

[0023] S1: The oxygen and methane igniters are working, forming a stable torch inside the gas generator;

[0024] S2: Methane enters from the head inlet of the generator shell, and is divided into three paths through the methane inlet collection chamber and the distribution chamber: one path is sprayed out through the head methane injection ring slit; the other two paths enter the body regeneration cooling channel, and are divided into the first and second ring collectors, and are sprayed out through the direct flow hole to form a liquid film, which cools the wall surface and mixes to reduce the temperature of the mainstream fuel gas and improve temperature uniformity.

[0025] S3: Liquid oxygen enters from the liquid oxygen inlet of the central cylinder and is injected into the liquid oxygen radial injection groove. It collides with the methane injected backward from the methane injection ring to form a spray fan. The impact point of the spray fan with the generator housing body is located in front of the DC outlet of the ring. After the liquid oxygen and methane are atomized and mixed, they are ignited by the torch of the igniter.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. This invention utilizes the advantages of needle-type injectors, such as high combustion stability margin and strong wide-range flow rate adjustment capability, to avoid the oscillating combustion problem that may occur in gas generators using centrifugal or direct-flow injectors, thereby improving the stability margin of the generator.

[0028] 2. Under extremely low mixing ratio conditions, the present invention sets up a secondary injection of methane, and rationally designs the mixing ratio distribution near the ignition zone for the spray field structure of the needle-type injector, which can achieve reliable ignition and multiple start-up ignition of the needle-type injector.

[0029] 3. This invention solves the problem of large methane volume flow rate by secondary injection of methane. At the same time, it adopts a regeneration cooling scheme in the front half of the body and a double-ring liquid film cooling scheme in the rear half of the body. This improves the reliability of body cooling and enables the mixing of secondary injected methane with mainstream fuel gas, thereby reducing the temperature of mainstream fuel gas and improving the uniformity of fuel gas temperature.

[0030] 4. Compared with gas generators using centrifugal or direct-flow injectors, the present invention has the advantages of simple structure, low cost, high reliability, and the ability to be reused multiple times.

[0031] 5. In use, the igniter is activated first, forming a stable high-temperature torch inside the generator. Methane enters from the head inlet and is divided into three paths through the methane inlet collection chamber and the diversion chamber. One path flows into the head injection chamber and is ejected backward from the methane injection annular seam between the shell and the central cylinder. It collides with the liquid oxygen ejected from the radial main and auxiliary channels of the central cylinder to form a spray fan, which also covers the methane leakage. After being mixed evenly, it is ignited by the igniter. The other two paths enter the regeneration cooling channel in the first half of the body, absorb heat, and then converge into the first and second annular collectors, respectively. They are ejected through the direct current hole to form a liquid film, which cools the body wall and mixes with the mainstream combustion gas downstream, reducing the mainstream temperature and improving temperature uniformity. This scheme relies on the high stability and wide flow rate adjustment advantages of the needle-type injector to avoid the risk of oscillating combustion. By adapting the high flow rate characteristics of methane through secondary injection, it achieves reliable ignition and multiple starts under low mixing ratios. The structure is simple, the cost is low, and it supports repeated use.

[0032] 6. In use, after fixing the connecting plate with bolts, the ignition angle can be steplessly adjusted by charging / drawing air into the arc-shaped cover using the air pump: during charging, the telescopic block moves outward, the plug-in block squeezes the rubber extrusion block to store energy, and simultaneously drives the circular plate and generator to rotate clockwise; negative pressure suction drives counterclockwise rotation. Its advantages are that it replaces the rigid connecting rod with a pneumatic flexible drive, completely eliminating mechanical backlash; the rubber extrusion block has sealing, damping and self-locking functions, and the angle is stable and does not drift after the gas is stopped; the fully enclosed structure is resistant to high temperature and dust, greatly improving the pointing accuracy of the igniter and the long-term operational reliability. Attached Figure Description

[0033] The invention will now be further described with reference to the accompanying drawings.

[0034] Figure 1 This is a perspective view of the present invention;

[0035] Figure 2 This is a partial schematic diagram of the central cylinder in this invention;

[0036] Figure 3 This is a schematic diagram of the socket plate in this invention;

[0037] Figure 4 This is a schematic diagram of the circular plate in this invention;

[0038] Figure 5 This is the present invention. Figure 4 Enlarged view of point A in the middle;

[0039] Figure 6 This is a schematic diagram of the plug-in block in this invention;

[0040] Figure 7 This is a schematic diagram of the arc-shaped cover in this invention;

[0041] Figure 8 This is the present invention. Figure 7 Enlarged view of point B in the middle;

[0042] Figure 9 This is a schematic diagram of the method in this invention.

[0043] In the diagram: 1. Liquid oxygen radial injection channel; 2. Central cylinder; 3. Methane inlet collection chamber; 4. Injection chamber; 5. Generator housing body; 51. Body atomization and mixing zone; 52. Body cylindrical section; 53. Body converging section; 6. Liquid oxygen inlet; 7. Needle-type injector; 8. Methane injection annular seam; 9. Pressure measuring nozzle; 10. Methane inlet; 11. Generator housing head; 1101. Ignition device; 12. Diverter chamber; 13. First-ring collector; 14. Second-ring collector; 15. Body pressure measuring hole; 16. Circular plate; 17. Socket plate; 18. Annular groove; 19. Limiting block; 20. Arc-shaped cover; 21. Telescopic block; 22. Insertion block; 23. Insertion groove; 24. Rubber extrusion block; 25. Sealing block; 26. Regeneration cooling channel. Detailed Implementation

[0044] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0045] Example 1: As Figure 1 and Figure 2 As shown in the embodiment of the present invention, a liquid oxygen methane needle-type rich gas generator includes a needle-type injector 7, a generator housing, an igniter 1101, and a methane flow channel.

[0046] The needle-type injector 7 includes a central cylinder 2, which is a cavity structure with a liquid oxygen radial injection groove 1 to form a liquid oxygen flow channel. A liquid oxygen inlet 6 is provided on the side of the central cylinder 2. The liquid oxygen radial injection groove 1 is designed with a structure in which the main groove and the auxiliary groove are arranged alternately.

[0047] The generator housing includes a generator housing head 11 and a generator housing body 5. The generator housing head 11 is provided with a needle-type injector 7 and an igniter 1101 mounting interface, and also includes a methane inlet collection chamber 3, a diversion chamber 12 and an injection chamber 4. The generator housing body 5 includes a body atomizing and mixing zone 51, a body cylindrical section 52 and a body converging section 53. A body pressure measuring hole 15 is opened on the outer side of the body cylindrical section 52. A methane inlet 10 is opened on the generator housing head 11 and a pressure measuring connector 9 is installed.

[0048] The igniter 1101 is a gaseous oxygen or gaseous methane igniter 1101. The distance between the outlet of the igniter 1101 installation channel and the central cylinder 2 is 25mm to 35mm. The angle between the axis of the igniter 1101 and the axis of the generator is 20° to 45°.

[0049] The methane flow channel includes a methane inlet collection chamber 3, a methane diversion chamber 12 and a methane injection chamber 4 located at the head 11 of the generator housing, a regeneration cooling channel 26 located in the front half of the body 5 of the generator housing, a first ring collector 13, a second ring collector 14, and a methane injection annular seam 8 located between the head 11 of the generator housing and the central cylinder 2.

[0050] The liquid oxygen ejected from the radial liquid oxygen injection tank 1 and the methane ejected from the methane injection annular seam 8 collide with each other to form a spray fan. The angle between the spray fan and the generator axis is 50°~80°. The main tank and the auxiliary tank form spray fans at different angles, while also taking into account the downward leakage of methane.

[0051] The methane flow channel also includes a pressure measuring nozzle 9 located at the generator head for measuring the pressure of the methane inlet collection chamber 3.

[0052] The first annular belt collector 13 includes an annular belt spray front chamber. An annular belt axial direct current hole is formed on the generator housing body 5. The annular belt spray front chamber communicates with the annular belt axial direct current hole. The axis of the annular belt axial direct current hole is parallel to the axis of the generator housing body 5. The second annular belt collector 14 includes two annular belt spray front chambers. Two annular belt axial direct current holes are formed on the generator housing body 5. The two annular belt axial direct current holes communicate with the two annular belt spray front chambers. The axis of the two annular belt direct current holes is parallel to the axis of the generator housing body 5.

[0053] The two-ring collector 14 is connected to the one-ring collector 13 through the regeneration cooling channel 26 of the generator housing body 5. The one-ring collector 13 is connected to the methane distribution chamber 12 of the generator housing head 11 through the regeneration cooling channel 26. According to the above structure, the generator housing body 5 realizes a cooling scheme of regeneration cooling in the first half and liquid film cooling in the second half of the side area.

[0054] The gas generator has a characteristic length of 1.5m to 3.0m. As the liquid film in the edge region moves downstream, it continuously evaporates and mixes with the mainstream gas, thereby reducing the temperature of the main gas and improving the uniformity of the gas temperature.

[0055] The methane splitting chamber 12 is simultaneously connected to the regeneration cooling channel 26 of the generator housing body 5 and the methane injection chamber 4. The flow distribution between the two is achieved by designing the flow resistance of the regeneration cooling channel 26 and the methane injection chamber 4. The flow rates of the first and second ring coolants account for 25% to 35% of the total methane flow rate.

[0056] The number of ring belts is not limited to two ring belts; it can be designed as one ring belt or three or more ring belts, with the ring belts connected by a regeneration cooling channel 26.

[0057] The point of impact between the liquid oxygen methane spray fan and the generator housing body 5 is located in front of the DC outlet of the ring belt, and the distance between the two is 10mm to 30mm. The generator housing is integrally formed based on additive manufacturing process.

[0058] In use, the igniter 1101 is activated first, forming a stable high-temperature torch inside the generator. Methane enters from the head inlet and is divided into three paths through the methane inlet collection chamber 3 and the diversion chamber 12. One path flows into the head injection chamber 4 and is ejected backward from the methane injection annular seam 8 between the shell and the central cylinder 2. It collides with the liquid oxygen ejected from the radial main and auxiliary channels of the central cylinder 2 to form a 50°~80° spray fan, which also covers the methane leakage. After being mixed evenly, it is ignited by the igniter 1101. The other two paths enter the regeneration cooling channel 26 in the front half of the body, absorb heat, and then flow into the first ring collector 13 and the second ring collector 14, respectively. They are ejected through the direct current hole to form a liquid film, which cools the body wall and mixes with the mainstream combustion gas downstream, reducing the mainstream temperature and improving temperature uniformity. This solution leverages the high stability and wide flow rate adjustment of the needle-type injector to avoid the risk of oscillating combustion. By adapting to the high flow rate characteristics of methane through secondary injection, it achieves reliable ignition and multiple starts under low mixing ratios. It has a simple structure, low cost, and supports repeated use.

[0059] Example 2: Figure 3-8 As shown in the comparative embodiment one, another embodiment of the present invention is as follows: a circular plate 16 is fixedly connected to the side of the generator housing body 5 away from the generator housing head 11, a sleeve plate 17 is sleeved on the outer side of the circular plate 16, an annular groove 18 is formed on the inner wall of the sleeve plate 17, and a plurality of limiting blocks 19 adapted to the annular groove 18 are fixedly connected to the outer side of the circular plate 16.

[0060] An arc-shaped cover 20 is fixedly connected to the side of the socket plate 17. A telescopic block 21 is movably inserted inside the arc-shaped cover 20. An air pump body and a start / stop controller are provided inside the arc-shaped cover 20. Insertion blocks 22 are fixedly connected to a pair of sides of the telescopic block 21. Insertion grooves 23 adapted to the insertion blocks 22 are provided on a pair of inner sidewalls of the arc-shaped cover 20. A rubber extrusion block 24 is fixedly connected between the insertion groove 23 and the insertion block 22. Sealing blocks 25 are provided between the socket plate 17 and the arc-shaped cover 20, as well as on a pair of inner sidewalls and the inner top wall of the arc-shaped cover 20. The sealing blocks 25 abut against the outer side of the telescopic block 21.

[0061] When using this invention, the socket plate 17 needs to be installed and fixed on a plane at a certain height using bolts. During use, the air pump body can be started to inflate or draw air into the arc-shaped cover 20 from its outlet end.

[0062] When air is injected into the arc-shaped cover 20, under the action of gas thrust, the telescopic block 21 will pull the rubber extrusion block 24 to move outward together. When the telescopic block 21 moves outward, it will drive a pair of plug-in blocks 22 to move in the plug-in groove 23 and squeeze the rubber extrusion block 24 to shrink in the plug-in groove 23. At the same time, the side of the telescopic block 21 away from the arc-shaped cover 20 will drive the circular plate 16 and all its mechanisms to rotate clockwise together, thereby adjusting the angle of the igniter 1101.

[0063] When the arc-shaped cover 20 is subjected to negative pressure, the telescopic block 21 will drive the circular plate 16 and all its mechanisms to rotate counterclockwise, thereby adjusting the angle of the igniter 1101.

[0064] In summary, when using this invention, after the connecting plate 17 is fixed with bolts, the ignition angle can be steplessly adjusted by inflating / inhaling air into the arc-shaped cover 20 using the air pump: during inflation, the telescopic block 21 moves outward, the plug block 22 squeezes the rubber extrusion block 24 to store energy, and simultaneously drives the circular plate 16 and the generator to rotate clockwise; negative pressure intake drives counterclockwise rotation. Its advantages are that it replaces the rigid connecting rod with a pneumatic flexible drive, completely eliminating mechanical backlash; the rubber extrusion block 24 has sealing, damping and self-locking functions, and the angle is stable and does not drift after the air supply stops; the fully enclosed structure is resistant to high temperature and dust, greatly improving the pointing accuracy and long-term operational reliability of the igniter 1101.

[0065] like Figure 9 As shown, a start-up control method for a liquid oxygen-methane needle-type rich gas generator is described. This method is applicable to the aforementioned liquid oxygen-methane needle-type rich gas generator and includes the following steps:

[0066] S1: The oxygen and methane igniter 1101 is working, forming a stable torch inside the gas generator;

[0067] S2: Methane enters from the inlet 11 at the head of the generator shell, and is divided into three paths through the methane inlet collection chamber 3 and the diversion chamber 12: one path is sprayed out through the head methane injection annular slit 8; the other two paths enter the body regeneration cooling channel 26, and are divided into the first annular collector 13 and the second annular collector 14, and are sprayed out through the direct flow hole to form a liquid film, which cools the wall surface and mixes to reduce the temperature of the mainstream combustion gas and improve temperature uniformity.

[0068] S3: Liquid oxygen enters from the liquid oxygen inlet 6 of the central cylinder 2 and is injected into the liquid oxygen radial injection groove 1. It collides with the methane sprayed backward from the methane injection annular slit 8 to form a spray fan. The impact point of the spray fan and the generator housing body 5 is located in front of the DC outlet of the ring. After the liquid oxygen and methane are atomized and mixed, they are ignited by the torch of the igniter 1101.

[0069] The terms "front," "back," "left," "right," "top," and "bottom" all refer to the figures in the accompanying drawings. Figure 1Based on the perspective of the observer, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0070] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0071] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid oxygen-methane needle-type rich combustion gas generator, characterized in that: Includes a needle-type injector (7), a generator housing, an igniter (1101), and a methane flow channel; The needle-type injector (7) includes a central cylinder (2), which is a cavity structure with a liquid oxygen radial injection groove (1) to form a liquid oxygen flow channel. A liquid oxygen inlet (6) is provided on the side of the central cylinder (2). The liquid oxygen radial injection groove (1) is designed with a structure in which the main groove and the auxiliary groove are arranged alternately. The generator housing includes a generator housing head (11) and a generator housing body (5). The generator housing head (11) is provided with a needle-type injector (7) and an igniter (1101) mounting interface, and also includes a methane inlet collection chamber (3), a diversion chamber (12) and an injection chamber (4). The generator housing body (5) includes a body atomizing and mixing zone (51), a body cylindrical section (52) and a body converging section (53). A body pressure measuring hole (15) is opened on the outer side of the body cylindrical section (52). A methane inlet (10) is opened on the generator housing head (11) and a pressure measuring pipe nozzle (9) is installed. The igniter (1101) is a gaseous oxygen or gaseous methane igniter (1101). The distance between the outlet of the igniter (1101) and the central cylinder (2) is 25mm to 35mm. The angle between the axis of the igniter (1101) and the axis of the generator is 20° to 45°. The methane flow channel includes a methane inlet collection chamber (3), a methane distribution chamber (12) and a methane injection chamber (4) located at the head (11) of the generator housing, a regeneration cooling channel (26) located in the front half of the body (5) of the generator housing, a first ring collector (13), a second ring collector (14), and a methane injection annular gap (8) located between the head (11) of the generator housing and the central cylinder (2). The liquid oxygen ejected from the radial liquid oxygen injection tank (1) and the methane ejected from the methane injection ring (8) collide with each other to form a spray fan. The angle between the spray fan and the generator axis is 50°~80°. The main tank and the auxiliary tank form spray fans at different angles, while also taking into account the downward leakage of methane.

2. The liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: The methane flow channel also includes a pressure measuring nozzle (9) installed at the head of the generator for measuring the pressure of the methane inlet collection chamber (3).

3. The liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: The first ring-shaped collector (13) includes a ring-shaped spray front cavity. An axial DC hole of the ring-shaped collector is opened on the body (5) of the generator housing. The first ring-shaped spray front cavity is connected to the first ring-shaped spray front hole. The axis of the first ring-shaped spray front hole is parallel to the axis of the body (5) of the generator housing. The second ring-shaped collector (14) includes a second ring-shaped spray front cavity. Two axial DC holes of the ring-shaped collector are opened on the body (5) of the generator housing. The two axial DC holes of the ring-shaped collector are connected to the second ring-shaped spray front cavity. The axis of the two axial DC holes of the ring-shaped collector is parallel to the axis of the body (5) of the generator housing.

4. The liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: The two-ring collector (14) is connected to the one-ring collector (13) through the regeneration cooling channel (26) of the generator housing body (5), and the one-ring collector (13) is connected to the methane diversion chamber (12) of the generator housing head (11) through the regeneration cooling channel (26). According to the above structure, the generator housing body (5) realizes a cooling scheme of regeneration cooling in the first half and liquid film cooling in the second half of the side area.

5. A liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: The gas generator has a characteristic length of 1.5m to 3.0m. As the liquid film in the edge region moves downstream, it continuously evaporates and mixes with the mainstream gas, thereby reducing the temperature of the main gas and improving the uniformity of the gas temperature.

6. A liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: The methane splitting chamber (12) is connected to both the regeneration cooling channel (26) of the generator housing body (5) and the methane injection chamber (4). The flow distribution between the two is achieved by designing the flow resistance of the regeneration cooling channel (26) and the methane injection chamber (4). The flow rate of the first and second ring coolant accounts for 25% to 35% of the total methane flow rate. The number of ring belts is not limited to two ring belts, and can be designed as one ring belt or three or more ring belts, with the ring belts connected by a regeneration cooling channel (26).

7. A liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: The point of impact between the liquid oxygen methane spray fan and the generator housing body (5) is located in front of the DC outlet of the ring belt, and the distance between the two is 10mm to 30mm. The generator housing is integrally formed based on additive manufacturing process.

8. A liquid oxygen-methane needle-type rich combustion gas generator according to claim 1, characterized in that: A circular plate (16) is fixedly connected to the side of the generator housing body (5) away from the generator housing head (11). A sleeve plate (17) is sleeved on the outer side of the circular plate (16). An annular groove (18) is opened on the inner wall of the sleeve plate (17). Several limiting blocks (19) that are adapted to the annular groove (18) are fixedly connected to the outer side of the circular plate (16). An arc-shaped cover (20) is fixedly connected to the side of the socket plate (17). A telescopic block (21) is movably inserted inside the arc-shaped cover (20). An air pump body and a start / stop controller are provided inside the arc-shaped cover (20). A plug-in block (22) is fixedly connected to a pair of sides of the telescopic block (21). A plug-in groove (23) adapted to the plug-in block (22) is provided on a pair of inner sidewalls of the arc-shaped cover (20). A rubber extrusion block (24) is fixedly connected between the plug-in groove (23) and the plug-in block (22). A sealing block (25) is provided between the socket plate (17) and the arc-shaped cover (20) and on a pair of inner sidewalls and inner top wall of the arc-shaped cover (20). The sealing block (25) abuts against the outer side of the telescopic block (21).

9. A start-up control method for a liquid oxygen-methane needle-type rich gas generator, the method being applicable to the liquid oxygen-methane needle-type rich gas generator according to any one of claims 1-8, characterized in that: Includes the following steps: S1: The oxygen and methane igniter (1101) is working, forming a stable torch inside the gas generator; S2: Methane enters from the inlet of the generator shell head (11), and is divided into three paths through the methane inlet collection chamber (3) and the diversion chamber (12): one path is sprayed out through the head methane injection ring (8) and outwards; the other two paths enter the body regeneration cooling channel (26), and are divided into the first ring collector (13) and the second ring collector (14), and are sprayed out through the direct flow hole to form a liquid film, which cools the wall surface and mixes to reduce the temperature of the main combustion gas and improve the temperature uniformity; S3: Liquid oxygen enters from the central cylinder (2) and the liquid oxygen inlet (6), and is injected into the liquid oxygen radial injection tank (1). It collides with the methane sprayed backward from the methane injection annular seam (8) to form a spray fan. The impact point of the spray fan with the generator housing body (5) is located in front of the DC outlet of the ring belt. After the liquid oxygen and methane are atomized and mixed, they are ignited by the torch of the igniter (1101).

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