Variable thrust engine

Abstract

The invention provides a variable thrust engine. The variable thrust engine comprises a thruster, a torch igniter, a flow regulator and a pipeline system, the torch igniter is arranged at the head of the thruster, and the flow regulator is connected with the thruster and the torch igniter through the pipeline system. A flow regulator of an adjustable cavitation venturi scheme is adopted to synchronously control the flow of liquid oxygen, liquid methane and cooling methane of an engine, the safety of a thermal structure of a spray pipe is ensured through independent cooling methane supply, and meanwhile propellants of a torch igniter and a thruster are uniformly supplied and pre-cooled; the variable thrust engine provided by the integral structure is suitable for medium and small thrust liquid oxygen and methane engines, is also suitable for medium and small thrust rocket engines combining liquid oxygen with liquid hydrogen, alcohol, kerosene and the like, and is wide in application range.

Description

Technical Field

[0001] The present invention belongs to the field of rocket engine technology, and specifically relates to a variable thrust engine, especially a variable thrust liquid oxygen-methane engine, and also a small and medium thrust rocket engine that is suitable for a combination of liquid oxygen and liquid hydrogen, alcohol, kerosene, etc. Background Art

[0002] High-performance, low-cost, and easy-to-maintain liquid oxygen-methane engines and space propulsion systems have become the mainstream development direction of commercial aerospace, with SpaceX's Super Heavy / Starship fully reused space transportation system, Intuitive Machines' Nova-C lunar lander, Blue Arrow Aerospace's Suzaku-2 launch vehicle, and Kyushu Cloud Arrow's Longyun engine as typical representatives, all of which are carrying out engineering practice and flight applications. Among them, engine variable thrust technology is the key to achieving vertical recovery of launch vehicles and lunar landing of spacecraft.

[0003] Patent document CN109595097B discloses a liquid oxygen and methane engine and control method using an insert valve, including a head body, an injector, a thrust chamber, a liquid oxygen solenoid valve, a methane solenoid valve and a spark plug. The injector is installed on the lower end surface of the head body by diffusion welding, the thrust chamber is installed on the lower end surface of the injector by screws, the liquid oxygen solenoid valve and the methane solenoid valve are respectively installed on the left and right sides of the head body by screw insertion, and the spark plug is installed on the upper part of the head body by threads.

[0004] However, for small and medium-thrust engines of spacecraft that fly in orbit for a long time, special requirements such as thousands of ignitions and high reliability still put forward higher requirements for variable thrust engines to simplify the structural design, ensure variable thrust performance and thermal structure safety. Summary of the invention

[0005] In view of the defects in the prior art, an object of the present invention is to provide a variable thrust engine.

[0006] A variable thrust engine provided according to the present invention comprises: a thruster 1, a torch igniter 2, a flow regulator 3, and a pipeline system 4.

[0007] The torch igniter 2 is arranged at the head of the thruster 1, and the flow regulator 3 is connected to the thruster 1 and the torch igniter 2 respectively through the pipeline system 4; the flow regulator 3 is arranged on the same side of the head of the thruster 1.

[0008] Preferably, the thruster 1 comprises an injector oxygen chamber 11, an injector combustion chamber 12, an injection unit 13, a flare ignition pipe 14, a nozzle 15, an oxygen main valve 16, a combustion main valve 17, and a cooling valve 18;

[0009] The injector oxygen chamber 11 and the injector combustion chamber 12 are of an integral structure but their respective cavities are not connected. The injector oxygen chamber 11 is used for collecting and distributing liquid oxygen in the thruster 1.

[0010] The injector combustion chamber 12 is used for collecting and distributing liquid methane in the thruster 1;

[0011] One or more of the injection units 13 are embedded in the injector oxygen chamber 11 and the injector combustion chamber 12;

[0012] The injector oxygen chamber 11 is provided with a torch igniter 2 on one side and an injector combustion chamber 12 on the other side;

[0013] The torch ignition tube 14 runs through the structural center of the injector oxygen chamber 11 and the injector combustion chamber 12, and its inlet is connected to the outlet of the torch igniter 2;

[0014] The nozzle 15 is arranged on the side of the injector combustion chamber 12 that is not connected to the injector oxygen chamber 11, and is used for the combustion of liquid oxygen and liquid methane and converting the heat energy into the injection kinetic energy of the combustion products to generate thrust;

[0015] The oxygen main valve 16 is installed on the injector oxygen chamber 11 and is used to control the supply and cut-off of liquid oxygen to the thruster 1;

[0016] The main combustion valve 17 is installed on the injector combustion chamber 12 and is used to control the supply and cutoff of liquid methane to the thruster 1;

[0017] The cooling valve 18 is installed on the nozzle 15 and is used to control the supply and cutoff of cooling methane for the thruster 1 .

[0018] Preferably, the injection unit 13 includes an oxygen nozzle 131 and a fuel nozzle 132.

[0019] The oxygen nozzle 131 is connected to the injector oxygen chamber 11 through the oxygen injection hole 133;

[0020] The fuel nozzle 132 is connected to the injector combustion chamber 12 through the fuel injection hole 133;

[0021] The fuel nozzle 132 is connected to the injector combustion chamber 12 through the fuel injection hole 133.

[0022] Preferably, the nozzle 15 adopts a composite cooling form of channel cooling and air film vortex cooling, and the cooling methane is independently supplied through the cooling valve 18;

[0023] The nozzle groove 151 arranged on the outer periphery of the nozzle 15 is in the form of a straight groove or a spiral groove, and the inner wall surface of the nozzle 15 is provided with tangential injection holes 151 at intervals. The cooling methane enters the nozzle 15 through the tangential injection holes 151 and then vaporizes and forms a cooling air film close to the inner wall surface in the form of a vortex.

[0024] Preferably, the torch igniter 2 comprises: a torch body 21, a spark plug 22, a torch oxygen valve 23, and a torch combustion valve 24;

[0025] Two independent spark plugs 22 are installed on the top of the torch body 21, and the top direction of the torch body 21 is consistent with the head direction of the thruster 1;

[0026] The torch oxygen valve 23 and the torch combustion valve 24 are installed on both sides of the torch body 21 to control the supply and cutoff of liquid oxygen and liquid methane independently delivered to the torch igniter 2 respectively.

[0027] Preferably, the flow regulator 3 comprises: a permanent magnet synchronous motor 31, a ball screw 32, and a combined venturi 33;

[0028] The motor rotor shaft 311 of the permanent magnet synchronous motor 31 and the screw shaft 321 of the ball screw 32 are integrated structures to shorten the length of the transmission shaft; a customized ball nut 322 is arranged on the screw shaft 321; a flexible dust cover 323 is arranged between the housing of the permanent magnet synchronous motor 31 and the housing of the ball nut 322, and the flexible dust cover 323 can move back and forth and retract as the ball nut 322 moves.

[0029] Preferably, the combined venturi 33 comprises: a liquid oxygen venturi channel 331, a liquid methane venturi channel 332, a cooling methane venturi channel 333, and is provided with a liquid oxygen plug cone 334, a liquid methane plug cone 335 and a cooling methane plug cone 336 respectively;

[0030] The liquid oxygen plug cone 334, the liquid methane plug cone 335 and the cooling methane plug cone 336 are all directly fixedly mounted on the ball nut 322;

[0031] A low-temperature-resistant flexible shielding sleeve 337 is disposed on the outer side of each of the liquid oxygen plug cone 335, the liquid methane plug cone 3360 and the cooling methane plug cone 334;

[0032] One end of the low-temperature-resistant flexible shielding sleeve 337 is connected and sealed to the housing of the ball nut 322 , and the other end is connected and sealed to the housing of the combined venturi 33 .

[0033] Preferably, the inner and outer surfaces of the liquid oxygen venturi channel 331 and the liquid oxygen plug cone 335, the liquid methane venturi channel 332 and the liquid methane plug cone 335, and the cooling methane venturi channel 333 and the cooling methane plug cone 336 are respectively matched with each other and are customized to match the variable thrust working characteristics of the thruster 1;

[0034] The liquid oxygen plug cone 335, the liquid methane plug cone 336 and the cooling methane plug cone 337 move synchronously with the forward and backward movement of the ball nut 322, respectively controlling the liquid oxygen flow rate, the liquid methane flow rate and the cooling methane flow rate supplied to the thruster 1, so that they correspond one by one to the thrust operating conditions of the thruster 1.

[0035] Preferably, the pipeline system 4 includes: an oxygen delivery pipe 41, a methane delivery pipe 42, a cooling methane delivery pipe 43, a flare oxygen delivery pipe 44, a flare methane delivery pipe 45, an oxygen precooling discharge pipe 46, a methane precooling discharge pipe 47, an oxygen precooling discharge valve 48, and a methane precooling discharge valve 49;

[0036] One end of the oxygen delivery pipe 41 is connected to the outlet of the liquid oxygen venturi channel 331, and the other end is connected to the inlet of the oxygen main valve 16;

[0037] One end of the methane delivery pipe 42 is connected to the outlet of the liquid methane venturi channel 333, and the other end is connected to the inlet of the main combustion valve 17;

[0038] One end of the cooling methane delivery pipe 43 is connected to the outlet of the cooling methane venturi channel 333, and the other end is connected to the inlet of the cooling valve 18;

[0039] One end of the torch oxygen delivery pipe 44 is connected to the inlet manifold of the oxygen main valve 16, and the other end is connected to the inlet of the torch oxygen valve 23;

[0040] One end of the flare methane delivery pipe 45 is connected to the inlet manifold of the main combustion valve 17, and the other end is connected to the inlet of the flare combustion valve 24;

[0041] One end of the oxygen precooling discharge pipe 46 is connected to the inlet manifold of the torch oxygen valve 23, and the other end is connected to the oxygen precooling discharge valve 48;

[0042] One end of the methane precooling discharge pipe 47 is connected to the inlet manifold of the flare combustion valve 24 , and the other end is connected to the methane precooling discharge valve 49 .

[0043] Preferably, the pipeline system 4 transports liquid oxygen and liquid methane to the thruster 1 first, and then to the torch igniter 2, and finally controls the propellant temperature in the pipeline system 4 within the engine operating range through the oxygen precooling discharge valve 48 and the methane precooling discharge valve 49 respectively; the injector oxygen chamber 11, the injector combustion chamber 12, the injection unit 13 and the nozzle 15 are integrated by 3D printing.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention adopts a flow regulator of an adjustable cavitation venturi solution to synchronously control the flow rates of liquid oxygen, liquid methane and cooling methane in the engine, adapts to a wide range of flow conditions through a fixed structure injector, ensures the thermal structure safety of the nozzle through an independent cooling methane supply, and uniformly supplies and precools the propellants of the torch igniter and thruster; the engine system solution and component structure are simple, and the variable thrust operation reliability is high.

[0046] 2. The flow regulator used in the present invention simultaneously controls the high-precision regulation of three media, and integrates the motor shaft and the screw shaft into an integrated design, and directly installs the three plug cones on the ball nut, which minimizes the axial length and overall structural dimensions of the flow regulator, and improves the structure's adaptability to harsh spatial mechanical environments.

[0047] 3. The injector oxygen chamber, injector combustion chamber, injection unit and nozzle of the thruster of the present invention have no moving parts and can be formed by integrated 3D printing, which can greatly reduce the number of parts and the number of active connections or welding, improve structural reliability and reduce product manufacturing costs.

[0048] 4. The torch igniter of the present invention controls the ignition work by an independent oxygen / fuel valve and is equipped with two independent spark plugs, which improves the working reliability of the torch igniter and the thermal structure safety during the thrust change process of the thruster.

[0049] 5. The present invention is not only applicable to small and medium thrust liquid oxygen and methane engines, but also to small and medium thrust rocket engines composed of liquid oxygen and liquid hydrogen, alcohol, kerosene, etc., and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0051] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0052] Figure 2 Schematic diagram of the structure of the injection unit according to an embodiment of the present invention.

[0053] The figure shows:

[0054] DETAILED DESCRIPTION

[0055] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0056] like Figure 1 to Figure 2 As shown, an embodiment of the present invention provides a variable thrust engine, comprising: a thruster 1, a torch igniter 2, a flow regulator 3 and a pipeline system 4, wherein the torch igniter 2 is arranged at the head of the thruster 1, and the flow regulator 3 is respectively connected to the thruster 1 and the torch igniter 2 through the pipeline system 4; the flow regulator 3 is arranged on the same side of the head of the thruster 1.

[0057] Furthermore, the thruster 1 comprises an injector oxygen chamber 11, an injector combustion chamber 12, an injection unit 13, a torch ignition pipe 14, a nozzle 15, an oxygen main valve 16, a combustion main valve 17 and a cooling valve 18; the injector oxygen chamber 11 and the injector combustion chamber 12 are structurally integrated but the chambers are not connected, the injector oxygen chamber 11 is used for the collection and distribution of liquid oxygen in the thruster 1, and the injector combustion chamber 12 is used for the collection and distribution of liquid methane in the thruster 1; one or more of the injectors The injection units 13 are embedded in the injector oxygen chamber 11 and the injector combustion chamber 12, and the number and distribution pattern of the injection units 13 can be set according to the shape, size, thrust, etc. of the thruster 1; a torch igniter 2 is arranged on one side of the injector oxygen chamber 11, and an injector combustion chamber 12 is arranged on the other side; the torch ignition pipe 14 runs through the structural center of the injector oxygen chamber 11 and the injector combustion chamber 12, and its inlet is connected to the outlet of the torch igniter 2, and a high-temperature resistant alloy material is selected.

[0058] The nozzle 15 is arranged on the side of the injector combustion chamber 12 that is not connected to the injector oxygen chamber 11, and is used for the combustion of liquid oxygen and liquid methane and converting heat energy into the injection kinetic energy of the combustion products to generate thrust; the oxygen main valve 16 is installed on the injector oxygen chamber 11, and is used to control the supply and cut-off of liquid oxygen of the thruster 1; the combustion main valve 17 is installed on the injector combustion chamber 12, and is used to control the supply and cut-off of liquid methane of the thruster 1; the cooling valve 18 is installed on the nozzle 15, and is used to control the supply and cut-off of cooling methane of the thruster 1.

[0059] Furthermore, if Figure 2As shown, the injection unit 13 includes an oxygen nozzle 131 and a fuel nozzle 132, the oxygen nozzle 131 is connected to the injector oxygen chamber 11 through the oxygen injection hole 133, the fuel nozzle 132 is connected to the injector combustion chamber 12 through the fuel injection hole 133, and the fuel nozzle 132 is connected to the injector combustion chamber 12 through the fuel injection hole 133, and through the flow path and structural design of the oxygen nozzle 131 and the oxygen injection hole 133, the fuel nozzle 132 and the fuel injection hole 134, at the outlet of the injection unit 13, liquid oxygen and liquid methane are mixed and atomized by shearing or mutual impact, etc., and the fixed structure injection unit 13 can adapt to the injection flow rate of not less than 5:1, and ensure the mixing effect of liquid oxygen and methane under low flow conditions, and ensure that the injection pressure drop and injection speed are within the empirical design range under high flow conditions.

[0060] The injector oxygen chamber 11, the injector combustion chamber 12, the injection unit 13 and the nozzle 15 can be formed by integrated 3D printing, which can greatly reduce the number of parts and the number of live connections or welds, improve structural reliability and reduce product manufacturing costs.

[0061] Furthermore, the nozzle 15 adopts a composite cooling form of channel cooling and air film vortex cooling, including a cooling channel 151; cooling methane is independently supplied through the cooling valve 18, which can meet the thermal protection requirements of the nozzle 15 when the engine is working with variable thrust with a minimum cooling flow. The nozzle channel 151 arranged on the outer periphery of the nozzle can be in the form of a straight groove or a spiral groove. A circle of tangential injection holes 151 are opened at a certain distance on the inner wall surface of the nozzle 15. After the cooling methane enters the interior of the nozzle through the tangential injection holes 151, it is vaporized and forms a cooling air film close to the inner wall surface in the form of a vortex. The size, number, circumferential and axial spacing of the tangential injection holes 151 can be set according to the structural size of the nozzle 15, the cooling methane flow rate and other parameters.

[0062] Furthermore, the torch igniter 2 includes a torch body 21, a spark plug 22, a torch oxygen valve 23 and a torch combustion valve 24; two independent spark plugs 22 are installed on the top of the torch body 21 to control the ignition work of the torch igniter 2, and the two spark plugs 22 can ignite independently or synchronously, thereby improving the working reliability of the torch igniter 2; the top direction of the torch body 21 is consistent with the head direction of the thruster 1.

[0063] The flare oxygen valve 23 and the flare combustion valve 24 are installed on the flare body 21, and respectively control the supply and cutoff of liquid oxygen and liquid methane independently delivered to the flare igniter 2, so that the flare igniter 2 can work independently and can be closed after igniting the thruster 1, ensuring the thermal structure safety of the flare igniter 2 during the thrust change process of the thruster 1.

[0064] Furthermore, the flow regulator 3 includes a permanent magnet synchronous motor 31, a ball screw 32 and a combined venturi 33; the motor rotor shaft 311 of the permanent magnet synchronous motor 31 and the screw shaft 321 of the ball screw 32 are an integrated structure to minimize the length of the transmission shaft; a customized ball nut 322 is arranged on the screw shaft 321 to convert the forward rotation of the screw shaft 321 into the forward movement of the ball nut 322, and convert the reverse rotation of the screw shaft 321 into the backward movement of the ball nut 322; a flexible dust cover 323 is arranged between the housing of the permanent magnet synchronous motor 31 and the housing of the ball nut 322 to protect the screw shaft 321 from being affected by redundant objects and affecting its working reliability, and the flexible dust cover 323 can freely extend and retract as the ball nut 322 moves forward and backward.

[0065] The combined venturi 33 includes a liquid oxygen venturi channel 331, a liquid methane venturi channel 332 and a cooling methane venturi channel 333, and a liquid oxygen plug cone 334, a liquid methane plug cone 335 and a cooling methane plug cone 336 are arranged one by one, and the liquid oxygen plug cone 334, the liquid methane plug cone 335 and the cooling methane plug cone 336 are all directly fixedly mounted on the ball nut 322, further shortening the axial length and structural dimensions of the flow regulator 3, and improving the adaptability of the flow regulator 3 to the harsh space mechanical environment;

[0066] A low-temperature resistant flexible shielding sleeve 337 is respectively arranged on the outside of the liquid oxygen plug cone 335, the liquid methane plug cone 336 and the cooling methane plug cone 334. One end of the low-temperature resistant flexible shielding sleeve 337 is connected and sealed to the shell of the ball nut 322, and the other end is connected and sealed to the shell of the combined venturi tube 33, which can prevent excess matter from affecting the sealing reliability of the liquid oxygen plug cone 334, the liquid methane plug cone 335 and the cooling methane plug cone 336 during actuation, and can also prevent the local unrestrained diffusion of gas caused by dynamic seal leakage.

[0067] Furthermore, the inner and outer surfaces of the liquid oxygen venturi channel 331 and the liquid oxygen plug cone 335, the liquid methane venturi channel 332 and the liquid methane plug cone 335, and the cooling methane venturi channel 333 and the cooling methane plug cone 336 are respectively matched and formed to match the variable thrust working characteristics of the thruster 1. The liquid oxygen plug cone 335, the liquid methane plug cone 336 and the cooling methane plug cone 337 move synchronously with the forward and backward movement of the ball nut 322, respectively controlling the liquid oxygen flow rate, the liquid methane flow rate and the cooling methane flow rate supplied to the thruster 1, so that they correspond one to one with the thrust working conditions of the thruster 1, ensuring that the combustion performance and the cooling performance of the thruster 1 meet the use requirements, and improving the variable thrust working reliability of the thruster 1.

[0068] Furthermore, the pipeline system 4 includes an oxygen delivery pipe 41, a methane delivery pipe 42, a cooling methane delivery pipe 43, a flare oxygen delivery pipe 44, a flare methane delivery pipe 45, an oxygen precooling discharge pipe 46, a methane precooling discharge pipe 47, an oxygen precooling discharge valve 48 and a methane precooling discharge valve 49; one end of the oxygen delivery pipe 41 is connected to the outlet of the liquid oxygen venturi channel 331, and the other end is connected to the inlet of the oxygen main valve 16, which is used to deliver liquid oxygen to the thruster 1 according to the flow rate set by the flow regulator 3 corresponding to the thrust condition; one end of the methane delivery pipe 42 is connected to the outlet of the liquid methane venturi channel 333, and the other end is connected to the inlet of the combustion main valve 17, which is used to deliver liquid methane according to the flow rate set by the flow regulator 3 corresponding to the thrust condition. The cooling methane delivery pipe 43 is connected to the outlet of the cooling methane venturi channel 333 at one end, and is connected to the inlet of the cooling valve 18 at the other end, so as to deliver the cooling methane to the thruster 1 according to the flow rate set by the flow regulator 3 for the corresponding thrust condition; the flare oxygen delivery pipe 44 is connected to the inlet manifold of the oxygen main valve 16 at one end, and is connected to the inlet of the flare oxygen valve 23 at the other end; the flare methane delivery pipe 45 is connected to the inlet manifold of the combustion main valve 17 at one end, and is connected to the inlet of the flare combustion valve 24 at the other end; the oxygen precooling discharge pipe 46 is connected to the inlet manifold of the flare oxygen valve 23 at one end, and is connected to the oxygen precooling discharge valve 48 at the other end; the methane precooling discharge pipe 47 is connected to the inlet manifold of the flare combustion valve 24 at one end, and is connected to the methane precooling discharge valve 49 at the other end.

[0069] The pipeline system 4 first transports liquid oxygen and liquid methane to the thruster 1, then to the torch igniter 2, and finally discharges precooling in a small flow rate through the oxygen precooling discharge valve 48 and the methane precooling discharge valve 49 respectively to control the propellant temperature in the pipeline system 4 within the engine operating range.

[0070] In summary, the embodiment of the present invention provides a variable thrust engine, which mainly includes: a thruster 1, a torch igniter 2, a flow regulator 3 and a pipeline system 4; the flow regulator adopts an adjustable cavitation venturi solution to synchronously control the flow rates of liquid oxygen, liquid methane and cooling methane in the engine, adapts to a wide range of flow conditions through a fixed structure injector, ensures the thermal structure safety of the nozzle through an independent cooling methane supply, and uniformly supplies and pre-cools the propellants of the torch igniter and the thruster; at the same time, the flow regulator uses a set of permanent magnet synchronous motors and ball screw devices to simultaneously control the high-precision regulation of three media, and the motor shaft and the screw shaft are designed as an integrated whole, and the three plug cones are directly installed on the ball nut, so as to minimize the axial length of the flow regulator and The overall structural dimensions improve the adaptability to the harsh space mechanical environment; the thruster's injector oxygen chamber, injector combustion chamber, injection unit and nozzle have no moving parts and can be formed by integrated 3D printing, which can greatly reduce the number of parts and the number of active connections or welding, improve structural reliability and reduce product manufacturing costs; the torch igniter is controlled by an independent oxygen / fuel valve to control the ignition work, and is equipped with two independent spark plugs for ignition, which can improve the working reliability of the torch igniter and the thermal structure safety during the thruster thrust change process; the variable thrust engine provided by the overall structure of the present invention is suitable for small and medium thrust liquid oxygen and methane engines, and is also suitable for small and medium thrust rocket engines composed of liquid oxygen and liquid hydrogen, alcohol, kerosene, etc., and has a wide range of applications.

[0071] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0072] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A variable thrust engine, characterized in that: include: thruster (1), flare igniter (2), flow regulator (3), piping system (4), The torch igniter (2) is arranged at the head of the thruster (1), and the flow regulator (3) is respectively connected to the thruster (1) and the torch igniter (2) through a pipeline system (4); the flow regulator (3) is arranged on the same side of the head of the thruster (1).

2. The variable thrust engine according to claim 1, characterized in that: The thruster (1) comprises an injector oxygen chamber (11), an injector combustion chamber (12), an injection unit (13), a flare ignition pipe (14), a nozzle (15), an oxygen main valve (16), a combustion main valve (17), and a cooling valve (18); The injector oxygen chamber (11) and the injector combustion chamber (12) are of an integral structure but their respective cavities are not connected. The injector oxygen chamber (11) is used for collecting and distributing liquid oxygen in the thruster (1). The injector combustion chamber (12) is used for collecting and distributing liquid methane in the thruster (1); One or more of the injection units (13) are embedded in the injector oxygen chamber (11) and the injector combustion chamber (12); A torch igniter (2) is provided on one side of the injector oxygen chamber (11), and an injector combustion chamber (12) is provided on the other side; The torch ignition tube (14) passes through the structural center of the injector oxygen chamber (11) and the injector combustion chamber (12), and its inlet is connected to the outlet of the torch igniter (2); The nozzle (15) is arranged on a side of the injector combustion chamber (12) that is not connected to the injector oxygen chamber (11), and is used for combustion of liquid oxygen and liquid methane and converting heat energy into injection kinetic energy of combustion products to generate thrust; The oxygen main valve (16) is installed on the injector oxygen chamber (11) and is used to control the supply and cut-off of liquid oxygen to the thruster (1); The main combustion valve (17) is installed on the injector combustion chamber (12) and is used to control the supply and cut-off of liquid methane to the thruster (1); The cooling valve (18) is installed on the nozzle (15) and is used to control the supply and cutoff of cooling methane for the thruster (1).

3. The variable thrust engine according to claim 2, characterized in that: The injection unit (13) comprises an oxygen nozzle (131) and a fuel nozzle (132). The oxygen nozzle (131) is connected to the injector oxygen chamber (11) through the oxygen injection hole (133); The fuel nozzle (132) is connected to the injector combustion chamber (12) through the fuel injection hole (133); The fuel nozzle (132) is connected to the injector combustion chamber (12) through the fuel injection hole (133).

4. The variable thrust engine according to claim 2, characterized in that: The nozzle (15) adopts a composite cooling form of channel cooling and air film vortex cooling, and cooling methane is independently supplied through the cooling valve (18); The nozzle groove (151) arranged on the outer periphery of the nozzle (15) is in the form of a straight groove or a spiral groove. The inner wall surface of the nozzle (15) is provided with tangential injection holes (151) at intervals. The cooling methane enters the interior of the nozzle (15) through the tangential injection holes (151) and then vaporizes and forms a cooling gas film close to the inner wall surface in the form of a vortex.

5. The variable thrust engine according to claim 1, characterized in that: The torch igniter (2) comprises: a torch body (21), a spark plug (22), a torch oxygen valve (23), and a torch combustion valve (24); Two independent spark plugs (22) are installed on the top of the torch body (21), and the top direction of the torch body (21) is consistent with the head direction of the thruster (1); The torch oxygen valve (23) and the torch combustion valve (24) are installed on both sides of the torch body (21) to respectively control the supply and cutoff of liquid oxygen and liquid methane independently delivered to the torch igniter (2).

6. The variable thrust engine according to claim 1, characterized in that: The flow regulator (3) comprises: a permanent magnet synchronous motor (31), a ball screw (32), and a combined venturi tube (33); The motor rotor shaft (311) of the permanent magnet synchronous motor (31) and the screw shaft (321) of the ball screw (32) are integrated into a structure to shorten the length of the transmission shaft; a customized ball nut (322) is arranged on the screw shaft (321); a flexible dust cover (323) is arranged between the housing of the permanent magnet synchronous motor (31) and the housing of the ball nut (322), and the flexible dust cover (323) can move forward and backward and retract along with the ball nut (322).

7. The variable thrust engine according to claim 6, characterized in that: The combined venturi (33) comprises: a liquid oxygen venturi channel (331), a liquid methane venturi channel (332), and a cooling methane venturi channel (333), and is provided with a liquid oxygen plug cone (334), a liquid methane plug cone (335), and a cooling methane plug cone (336) in correspondence with each other; The liquid oxygen plug cone (334), the liquid methane plug cone (335) and the cooling methane plug cone (336) are all directly fixedly mounted on the ball nut (322); A low-temperature-resistant flexible shielding sleeve (337) is respectively disposed on the outer side of the liquid oxygen plug cone (335), the liquid methane plug cone (3360) and the cooling methane plug cone (334); One end of the low-temperature-resistant flexible shielding sleeve (337) is connected to and sealed with the housing of the ball nut (322), and the other end is connected to and sealed with the housing of the combined venturi tube (33).

8. The variable thrust engine according to claim 7, characterized in that: The inner and outer surfaces of the liquid oxygen venturi channel (331) and the liquid oxygen plug cone (335), the liquid methane venturi channel (332) and the liquid methane plug cone (335), and the cooling methane venturi channel (333) and the cooling methane plug cone (336) are respectively arranged in pairs and are custom-molded to match the variable thrust working characteristics of the thruster (1); The liquid oxygen plug cone (335), the liquid methane plug cone (336) and the cooling methane plug cone (337) move synchronously with the forward and backward movement of the ball nut (322), respectively controlling the liquid oxygen flow rate, the liquid methane flow rate and the cooling methane flow rate supplied to the thruster (1), so that they correspond one-to-one to the thrust operating conditions of the thruster (1).

9. The variable thrust engine according to claim 7, characterized in that: The pipeline system (4) comprises: an oxygen delivery pipe (41), a methane delivery pipe (42), a cooling methane delivery pipe (43), a flare oxygen delivery pipe (44), a flare methane delivery pipe (45), an oxygen precooling discharge pipe (46), a methane precooling discharge pipe (47), an oxygen precooling discharge valve (48), and a methane precooling discharge valve (49); One end of the oxygen delivery pipe (41) is connected to the outlet of the liquid oxygen venturi channel (331), and the other end is connected to the inlet of the oxygen main valve (16); One end of the methane delivery pipe (42) is connected to the outlet of the liquid methane venturi channel (333), and the other end is connected to the inlet of the main combustion valve (17); One end of the cooling methane delivery pipe (43) is connected to the outlet of the cooling methane venturi channel (333), and the other end is connected to the inlet of the cooling valve (18); One end of the torch oxygen delivery pipe (44) is connected to the inlet manifold of the oxygen main valve (16), and the other end is connected to the inlet of the torch oxygen valve (23); One end of the flare methane delivery pipe (45) is connected to the inlet manifold of the main combustion valve (17), and the other end is connected to the inlet of the flare combustion valve (24); One end of the oxygen precooling discharge pipe (46) is connected to the inlet manifold of the torch oxygen valve (23), and the other end is connected to the oxygen precooling discharge valve (48); One end of the methane precooling discharge pipe (47) is connected to the inlet manifold of the flare combustion valve (24), and the other end is connected to the methane precooling discharge valve (49).

10. The variable thrust engine according to any one of claims 1 to 9, characterized in that: The pipeline system (4) first transports liquid oxygen and liquid methane to the thruster (1), then transports them to the torch igniter (2), and finally controls the propellant temperature in the pipeline system (4) to be within the engine operating range through the oxygen precooling discharge valve (48) and the methane precooling discharge valve (49) respectively; the injector oxygen chamber (11), the injector combustion chamber (12), the injection unit (13) and the nozzle (15) are integrated into a 3D printing shape.

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