A liquid rocket engine multiple start system and method

Abstract

The application provides a multiple starting system and method of a liquid rocket engine, comprising a differential tank, a liquid path stabilizer, a pressure increasing check valve, a first gas generator, a powder starter, a starting control valve, a throttle ring, a starting check valve, a turbine, a second gas generator, a fuel pump and an oxidizer pump; the liquid path stabilizer is connected between a liquid cavity of the differential tank and an inlet of the first gas generator; one end of the pressure increasing check valve is connected with an output pipeline of the first gas generator, and the other end is communicated with a gas cavity of the differential tank; the starting control valve, the throttle ring, the starting check valve and the turbine are sequentially connected on a side of an outlet of the first gas generator; the turbine is coaxially connected with the fuel pump and the oxidizer pump; an inlet of the second gas generator is connected with outlets of the fuel pump and the oxidizer pump, and an outlet is connected with the turbine. The application realizes pre-packaging of starting energy, adapts to the demand of no fixed number of starting, simplifies the complexity of the multiple starting system, reduces the use and maintenance demand, and shortens the rocket launching preparation time.

Description

Technical Field

[0001] This application relates to the field of liquid rocket engine technology, and in particular to a liquid rocket engine multiple-start system and method. Background Technology

[0002] Liquid rocket engines typically use a propellant starter and a high-pressure gas turbine to initially pressurize the propellant, thereby starting the engine. For multiple-start systems, multiple propellant starters or multiple high-pressure gas cylinders are required to achieve the function, which has disadvantages such as system complexity, large weight, complex use and maintenance, poor mission scalability, and long launch preparation time.

[0003] The existing technology has the following drawbacks: (1) For the need to start more than three times, the gunpowder starting or high-pressure gas starting methods have disadvantages such as complex system, large weight, and complicated use and maintenance.

[0004] (2) For tasks with no fixed number of starts, the gunpowder start or high-pressure gas start methods are not adaptable enough.

[0005] (3) Before the rocket launch, it is necessary to fill the high-pressure gas and maintain the pressure of the gas cylinder. The use and maintenance are more complicated, and the launch preparation time is increased, which is not conducive to rapid launch.

[0006] (4) Once the number of times a liquid rocket engine is started is determined in the design phase, it is difficult to adjust according to the needs of subsequent missions, resulting in poor mission scalability.

[0007] Therefore, the urgent technical problem to be solved is: how to provide a liquid rocket engine multiple start-up system and start-up method to achieve pre-packaged start-up energy, adapt to the need for no fixed number of start-ups, simplify the complexity of the multiple start-up system, reduce the engine use and maintenance needs before rocket launch, and shorten the rocket launch preparation time. Summary of the Invention

[0008] The purpose of this application is to provide a liquid rocket engine multiple-start system and method, which realizes pre-packaging of starting energy, adapts to the need for no fixed number of starts, simplifies the complexity of the multiple-start system, reduces the engine use and maintenance needs before rocket launch, and shortens the rocket launch preparation time.

[0009] To achieve the above objectives, as a first aspect of this application, this application provides a liquid rocket engine multiple-start system, comprising: a differential tank, a liquid circuit regulator, a booster check valve, a first gas generator, a propellant starter, a start control valve, a throttle coil, a start check valve, a turbine, a second gas generator, a fuel pump, and an oxidizer pump; the differential tank, the liquid circuit regulator, the booster check valve, the first gas generator, and the propellant starter constitute a positive feedback loop system; the liquid circuit regulator is connected between the liquid chamber of the differential tank and the inlet of the first gas generator; one end of the booster check valve is connected to the output pipeline of the first gas generator via a pipeline, and the other end is connected to the gas chamber of the differential tank; the start control valve, the throttle coil, the start check valve, and the turbine are sequentially connected to the outlet side of the first gas generator; the turbine is coaxially connected to the oxidizer pump and the fuel pump; the inlet of the second gas generator is connected to the outlet of the fuel pump and the oxidizer pump, and the outlet is connected to the turbine.

[0010] The liquid rocket engine multiple start-up system described above, wherein the differential tank includes: a differential tank shell, a vent, a differential piston, a filling and draining valve, and a differential tank outlet liquid circuit diaphragm valve; A differential piston is installed inside the differential tank shell, dividing its internal cavity into a differential tank gas chamber and a differential tank liquid chamber; The vent is connected to the differential storage tank air chamber; The filling and draining valve is connected to the liquid chamber of the differential storage tank; The differential tank outlet liquid circuit diaphragm valve is installed on the differential tank outlet liquid circuit.

[0011] In the liquid rocket engine multiple-start system described above, the differential tank liquid chamber is pre-packaged with fuel, which is one of hydrazine, anhydrous hydrazine, or single-thrust-3.

[0012] In the liquid rocket engine multiple start-up system described above, the inlet and outlet of the first gas generator are respectively equipped with a first gas generator inlet diaphragm valve and a first gas generator outlet diaphragm valve.

[0013] In the liquid rocket engine multiple start-up system described above, the outlet end of the propellant starter is connected to the differential tank shell and communicates with the differential tank gas chamber; The outlet end of the gunpowder starter is equipped with a gunpowder starter outlet diaphragm valve.

[0014] In the liquid rocket engine multiple-start system described above, the liquid circuit regulator has a set shut-off pressure. When the outlet pressure of the liquid circuit regulator reaches the set closing pressure, the liquid circuit regulator closes; when the outlet pressure of the liquid circuit regulator drops below the set closing pressure, the liquid circuit regulator opens.

[0015] The liquid rocket engine multiple-start system described above also includes a second gas generator. The input end of the second gas generator is connected to the fuel pump and the oxidant pump, and the output end is connected to the turbine; The fuel in the fuel pump and the oxidant in the oxidant pump are fed into the second gas generator, where they are combusted to produce high-temperature, high-pressure gas to drive the turbine.

[0016] In the liquid rocket engine multiple-start system described above, both the fuel pump and the oxidizer pump are connected to the thrust chamber, and the fuel in the fuel pump and the oxidizer in the oxidizer pump are delivered to the thrust chamber.

[0017] As a second aspect of this application, this application provides a method for multiple restarts of a liquid rocket engine, applied to the aforementioned liquid rocket engine multiple restart system, the method comprising the following steps: Step S1, pre-packaging and filling the differential propellant tank: Before the liquid rocket engine is installed on the rocket, propellant fuel is added to the differential propellant tank through the filling vent valve. After filling, the propellant fuel is sealed in the differential propellant tank through the diaphragm valve of the differential propellant tank outlet liquid circuit. After the differential propellant tank is filled, it is installed on the rocket along with the liquid rocket engine. Step S2: When the liquid rocket engine receives the start-up preparation command, the gunpowder starter generates high-temperature and high-pressure gas through an electric explosion, which is then injected into the differential storage tank gas chamber. The gas is then compressed by the differential piston in the differential storage tank. When the fuel reaches a certain pressure, it breaks the diaphragm valve of the differential storage tank outlet liquid circuit and enters the first gas generator. Step S3, Start-up and filling process: The first gas generator produces high-temperature and high-pressure gas. The gas in the gas pipeline flows into the differential storage tank gas chamber through the booster check valve for pressurization. When the system pressure rises until the outlet pressure of the liquid circuit regulator reaches its set shut-off pressure, the liquid circuit regulator closes, the first gas generator stops working, the start-up and filling process is completed, and the system enters the working standby state. Step S4: When the liquid rocket engine receives the first to Nth start command, the start control valve opens, and the gas generated by the first gas generator starts the turbine, which drives the oxidizer pump and fuel pump to work. After each startup is completed, return to step S3.

[0018] Where N>1.

[0019] Understandably, returning to step S3 is automatic and requires no additional instructions. After each start-up, the gas pipeline pressure drops due to gas discharge, the hydraulic regulator automatically opens, the system enters a positive feedback loop, and automatically rebuilds its standby state, awaiting the next start-up command.

[0020] The liquid rocket engine multiple start-up method described above further includes, after each start-up is completed: step S5, closing the start-up control valve, the second gas generator starts working, and takes over driving the turbine to work.

[0021] Understandably, the relay-driven turbine operation means that as the second gas generator operates, it produces gas to continue driving the turbine. The second gas generator takes over from the first gas generator to continue providing the working fluid to drive the turbine, maintaining turbine speed and ensuring continuous operation during the engine's main operating phase. Closing the start-up control valve cuts off the gas passage between the first gas generator and the turbine. At this point, the gas produced by the second gas generator continues to drive the turbine, achieving a smooth transition between operating phases.

[0022] The beneficial effects achieved by this application are as follows: (1) This application uses a positive feedback loop system consisting of a gunpowder starter, a differential tank, a hydraulic regulator, a gas generator and a booster check valve to achieve the self-pressurization function of starting energy. The gas generator is used to start the turbine, which can enable the engine to start multiple times.

[0023] (2) The differential tank of this application adopts an integrated design. The gas chamber of the differential tank integrates a propellant starter, a pressure boosting check valve and a vent, and the liquid chamber of the differential tank integrates a filling and draining valve and a diaphragm valve for the liquid circuit of the differential tank outlet, so as to realize the propellant pre-packaging function in the differential tank and improve the usability and maintainability. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 This is a schematic diagram of the structure of a liquid rocket engine multiple-start system according to an embodiment of this application.

[0026] Figure 2 This is a flowchart of a method for multiple starts of a liquid rocket engine according to an embodiment of this application.

[0027] Reference numerals in the attached figures: 1-Differential tank; 2-Liquid circuit regulator; 3-Boosting check valve; 4-First gas generator; 5-Starting control valve; 6-Throttle ring; 7-Starting check valve; 8-Turbine; 9-Fuel pump; 10-Oxidant pump; 11-Differential tank liquid chamber; 12-Differential tank gas chamber; 13-Vent nozzle; 14-Differential piston; 15-Addition and discharge valve; 16-Powder starter; 17-Differential tank outlet liquid circuit diaphragm valve; 18-Powder starter outlet diaphragm valve; 19-Second gas generator; 41-First gas generator inlet diaphragm valve; 42-First gas generator outlet diaphragm valve. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] Example 1 like Figure 1 As shown, this application provides a liquid rocket engine multiple-start system, including: a differential tank 1, a liquid circuit regulator 2, a booster check valve 3, a first gas generator 4, a propellant starter 16, a start control valve 5, a throttle ring 6, a start check valve 7, a turbine 8, a second gas generator 19, a fuel pump 9, and an oxidizer pump 10; the differential tank 1, liquid circuit regulator 2, booster check valve 3, first gas generator 4, and propellant starter 16 constitute a positive feedback loop system; the liquid circuit regulator 2 is connected to the differential tank 1... Between the liquid chamber and the inlet of the first gas generator 4; one end of the booster check valve 3 is connected to the output pipeline of the first gas generator 4 through a pipeline, and the other end is connected to the gas chamber of the differential storage tank 1; the start control valve 5, the throttle ring 6, the start check valve 7, and the turbine 8 are connected in sequence to the outlet side of the first gas generator 4; the turbine 8 is coaxially connected to the oxidant pump 10 and the fuel pump 9; the inlet of the second gas generator 19 is connected to the outlet of the fuel pump 9 and the outlet of the oxidant pump 10, and the outlet of the second gas generator 19 is connected to the turbine 8.

[0030] This application achieves automatic pressurization through differential storage tank 1, liquid circuit regulator 2 and first gas generator 4, eliminating the high-pressure gas filling process.

[0031] like Figure 1As shown, the differential tank 1 includes: a differential tank shell, a vent 13, a differential piston 14, a filling and draining valve 15, and a differential tank outlet liquid circuit diaphragm valve 17. The differential piston 14 is installed inside the differential tank shell, dividing its internal cavity into a differential tank air chamber 12 and a differential tank liquid chamber 11. The differential tank air chamber 12 and the differential tank liquid chamber 11 are separated by the differential piston 14 and are not connected. The vent 13 is connected to the differential tank air chamber 12. The filling and draining valve 15 is connected to the differential tank liquid chamber 11. The differential tank outlet liquid circuit diaphragm valve 17 is installed on the differential tank 1 outlet liquid circuit. The differential tank outlet liquid circuit diaphragm valve 17 seals the fuel within the differential tank liquid chamber 11.

[0032] In a specific embodiment of the present invention, the differential piston 14 can slide axially along the inner wall of the differential tank housing. A sealing ring is provided between the differential piston 14 and the inner wall of the differential tank housing to ensure the airtightness between the gas chamber and the liquid chamber, while allowing the differential piston 14 to move freely under the action of pressure difference. The initial state of the differential tank gas chamber 12 is atmospheric pressure or pre-filled with low-pressure inert gas, and the differential tank liquid chamber 11 is pre-packaged with propellant fuel. Through the area difference on both sides of the differential piston 14, the pressure change of the differential tank gas chamber 12 can be transmitted to the differential tank liquid chamber 11, and a corresponding pressure change is generated in the differential tank liquid chamber 11.

[0033] The vent 13 is used when filling the differential tank 1. Under normal operating conditions, the vent 13 is in a closed state.

[0034] In a specific embodiment of the present invention, the differential propellant tank 11 is pre-packaged with fuel, which is one of hydrazine, anhydrous hydrazine, or DT-3. Before the liquid rocket engine is installed on the rocket, fuel is added to the differential propellant tank 1 through the fueling vent valve 15. After the differential propellant tank 1 is fueled, it is installed on the rocket along with the liquid rocket engine.

[0035] like Figure 1 As shown, the inlet and outlet of the first gas generator 4 are respectively equipped with a first gas generator inlet diaphragm valve 41 and a first gas generator outlet diaphragm valve 42. The gas generator outlet diaphragm valve 42 is connected to a start control valve 5, a throttle coil 6, a start check valve 7, and a turbine 8.

[0036] It should be explained that the first gas generator 4 only receives fuel supplied by the differential storage tank 1, which decomposes to produce gas under the action of a catalyst; the second gas generator 19 receives fuel and oxidant supplied by the fuel pump 9 and the oxidant pump 10, which combust to produce gas.

[0037] It should be explained that the first gas generator 4 includes a housing, injector, catalyst bed, and nozzle. The catalyst bed is filled with an iridium-based or cobalt-based catalyst, used to catalytically decompose hydrazine-based fuels to produce high-temperature, high-pressure gas. The second gas generator 19 includes a housing, injector, and body. The first gas generator 4 generates gas to drive the turbine 8 during the engine start-up phase, while the second gas generator 19 is used during the main operating phase, receiving fuel and oxidizer from the fuel pump 9 and oxidizer pump 10. The gas produced by the combustion of these two fuels continues to drive the turbine 8.

[0038] It should be explained that the throttle ring 6 is located between the start control valve 5 and the start check valve 7 to regulate the gas flow, thereby controlling the starting speed of the turbine 8. The throttle ring 6 has a fixed throttle orifice, the diameter of which is designed according to the starting characteristics of the turbine 8 to ensure that the turbine 8 accelerates smoothly to its operating speed.

[0039] It should be explained that the starting check valve 7 is located between the throttle ring 6 and the turbine 8, allowing gas to flow from the first gas generator 4 towards the turbine 8, and preventing the gas generated by the second gas generator 19 from flowing in the reverse direction during rocket engine operation. The opening pressure of the starting check valve 7 is lower than the opening pressure of the booster check valve 3, ensuring that the gas output from the first gas generator 4 prioritizes driving the turbine 8 during the start-up phase.

[0040] like Figure 1 As shown, the outlet end of the gunpowder starter 16 is connected to the differential storage tank housing and communicates with the differential storage tank air chamber 12; in order to prevent the gunpowder starter 16 from getting damp, a gunpowder starter outlet diaphragm valve 18 is installed at the outlet end of the gunpowder starter 16.

[0041] As a specific embodiment of the present invention, the liquid circuit regulator 2 has a set shut-off pressure. When the outlet pressure of the liquid circuit regulator 2 reaches the set shut-off pressure, the liquid circuit regulator 2 shuts off; when the outlet pressure of the liquid circuit regulator 2 drops below the set shut-off pressure, the liquid circuit regulator 2 opens.

[0042] like Figure 1 As shown, the liquid rocket engine multiple start-up system also includes a second gas generator 19. The input end of the second gas generator 19 is connected to the fuel pump 9 and the oxidizer pump 10, and the output end is connected to the turbine 8. The fuel in the fuel pump 9 and the oxidizer in the oxidizer pump 10 are input into the second gas generator 19, where they are combusted to generate high-temperature and high-pressure gas, which is used to drive the turbine 8.

[0043] In a specific embodiment of the present invention, both the fuel pump 9 and the oxidant pump 10 are connected to the thrust chamber, and the fuel in the fuel pump 9 and the oxidant in the oxidant pump 10 are transported to the thrust chamber.

[0044] In a specific embodiment of the present invention, when the liquid rocket engine receives the start-up preparation command, the system enters the start-up and filling state. High-temperature, high-pressure gas is generated by the electric explosion of the propellant starter 16. This high-temperature, high-pressure gas breaks through the diaphragm valve 18 at the outlet of the propellant starter, fills the differential storage tank gas chamber 12, and compresses the fuel in the differential storage tank liquid chamber 11 through the differential piston 14. When the fuel in the differential storage tank liquid chamber 11 reaches a certain pressure, it breaks through the differential storage tank outlet liquid circuit diaphragm valve 17 and enters the first gas generator 4. In the first gas generator 4, the fuel undergoes catalytic decomposition by the catalyst bed to generate high-temperature, high-pressure gas. Once the high-temperature, high-pressure gas reaches a certain pressure, it breaks through the gas generator outlet diaphragm valve 42.

[0045] As a specific embodiment of the present invention, during the filling process, the pressure in the gas pipeline of the positive feedback loop system gradually increases. When the gas pressure in the gas pipeline is greater than the internal pressure of the differential storage tank gas chamber 12, the booster check valve 3 opens, and the gas in the gas pipeline flows into the differential storage tank gas chamber 12 to boost its pressure. The pressure in the differential storage tank liquid chamber 11 increases synchronously under the amplification effect of the area difference on both sides of the differential piston 14. The fuel in the differential storage tank liquid chamber 11 is continuously supplied downstream to the first gas generator 4, causing the downstream gas pipeline pressure to increase further. The gas in the gas pipeline continues to flow into the differential storage tank gas chamber 12 to boost its pressure, thus increasing the pressure in the differential storage tank liquid chamber 11 again. The gas pipeline pressure increases. Under the action of this positive feedback mechanism, the system pressure accelerates until the outlet pressure of the liquid circuit regulator 2 reaches its set closing pressure. The liquid circuit regulator 2 closes, and the first gas generator 4 stops working. The starting filling process is completed, and the system enters the working standby state.

[0046] The starting and filling process is achieved through a positive feedback loop system consisting of a differential storage tank 1, a liquid circuit regulator 2, a booster check valve 3, a first gas generator 4, and a gunpowder starter 16.

[0047] Understandably, the positive feedback loop works as follows: The high-temperature, high-pressure gas generated by the gunpowder starter 16 enters the differential storage tank gas chamber 12, pushing the differential piston 14 to compress the fuel in the differential storage tank liquid chamber 11. The fuel then enters the first gas generator 4 via the liquid circuit regulator 2 for catalytic decomposition to produce gas. This gas enters the gas circuit, increasing the gas circuit pressure. When the gas circuit pressure is higher than the pressure in the differential storage tank gas chamber 12, the booster check valve 3 opens, allowing the gas in the gas circuit to flow back to the differential storage tank gas chamber 12, further increasing the pressure in the differential storage tank gas chamber 12. Due to the force transmission effect of the differential piston 14, the pressure in the differential storage tank liquid chamber 11 increases synchronously, pushing more fuel into the first gas generator 4, producing more gas, and further increasing the gas circuit pressure. Under this positive feedback mechanism, the system pressure rises rapidly until the pressure at the outlet of the hydraulic regulator 2 reaches its set shut-off pressure. The hydraulic regulator 2 shuts off, cutting off the fuel supply to the differential storage tank 11. The first gas generator 4 stops working, the positive feedback cycle terminates, and the system enters a standby state.

[0048] As a specific embodiment of the present invention, when the liquid rocket engine receives the first start command, the start control valve 5 is opened, and the gas generated by the first gas generator 4 starts the turbine 8, causing the turbine 8 to rotate. The turbine 8 drives the oxidizer pump 10 and the fuel pump 9 to work. The start control valve 5 is then closed, and subsequently the second gas generator 19 works, taking over to drive the turbine 8. After the liquid rocket engine starts for the first time, the gas generated by the first gas generator 4 is discharged, causing the pressure in the gas pipeline to decrease. The pressure decrease is transmitted to the outlet of the upstream liquid pipeline regulator 2, and the liquid pipeline regulator 2 opens. The fuel in the differential storage tank liquid chamber 11 flows from the differential storage tank 1 into the first gas generator 4. The first gas generator 4 generates gas to replenish the downstream pressure. As fuel flows out, the differential storage tank 1's differential storage tank gas chamber 12 increases in volume and decreases in pressure. When the pressure in the differential storage tank gas chamber 12 is less than the upstream gas pipeline pressure of the booster check valve 3, the booster check valve 3 opens, and the system enters a positive feedback working state, realizing the start-up and filling process.

[0049] As a specific embodiment of the present invention, when the liquid rocket engine receives the Nth start command, the start control valve 5 is reopened, the first gas generator 4 generates gas to start the turbine 8, the turbine 8 drives the oxidizer pump 10 and the fuel pump 9 to work, the start control valve 5 is closed, and then the second gas generator 19 works to drive the turbine 8 to work.

[0050] Understandably, the hydraulic pressure regulator 2 uses a diaphragm to sense changes in oral pressure and controls the opening and closing of the valve core through the balance between spring force and hydraulic force, thereby achieving automatic adjustment and cut-off of hydraulic pressure.

[0051] Example 2 like Figure 2As shown, this application provides a method for multiple restarts of a liquid rocket engine, applied to a liquid rocket engine multiple restart system. The method includes the following steps: Step S1: Pre-packaged filling is performed into the differential storage tank liquid chamber.

[0052] The pre-packaging and refueling of the differential propellant tank includes: before the liquid rocket engine is installed on the rocket, propellant fuel is added to the differential propellant tank through a refueling vent valve; after refueling, the propellant fuel is sealed within the differential propellant tank through a diaphragm valve in the differential propellant tank outlet liquid path. After refueling, the differential propellant tank is installed on the rocket along with the liquid rocket engine.

[0053] This application enables the early loading of propellant fuel, reduces the gas cylinder filling process, simplifies launch preparation work, and shortens launch preparation time.

[0054] Step S2: When the liquid rocket engine receives the start-up preparation command, the gunpowder starter generates high-temperature and high-pressure gas through an electric explosion, which is then injected into the differential storage tank gas chamber. The gas is then compressed by the differential piston. When the fuel reaches a certain pressure, it breaks the diaphragm valve of the differential storage tank outlet liquid circuit and enters the first gas generator.

[0055] In step S3, the first gas generator produces high-temperature and high-pressure gas. The gas in the gas pipeline flows into the differential storage tank gas chamber through the booster check valve for pressurization. When the system pressure rises until the outlet pressure of the liquid circuit regulator reaches its set shut-off pressure, the liquid circuit regulator closes, the first gas generator stops working, the start-up and filling process is completed, and the system enters the working standby state.

[0056] Step S4: When the liquid rocket engine receives the first to Nth start command, the start control valve opens, and the gas generated by the first gas generator starts the turbine, which drives the oxidizer pump and fuel pump to work.

[0057] After each startup is completed, return to step S3.

[0058] Where N>1.

[0059] After each startup is completed, it also includes: Step S5: Close the start control valve, the second gas generator starts working, and takes over to drive the turbine.

[0060] This application discloses a method for multiple starts of a liquid rocket engine that is suitable for engines with no fixed number of starts and is applicable to engines using conventional propellants and cryogenic propellants.

[0061] The beneficial effects achieved by this application are as follows: (1) This application uses a positive feedback loop system consisting of a gunpowder starter, a differential tank, a hydraulic regulator, a gas generator and a booster check valve to achieve the self-pressurization function of starting energy. The gas generator is used to start the turbine, which can enable the engine to start multiple times.

[0062] (2) The differential tank of this application adopts an integrated design. The gas chamber of the differential tank integrates a propellant starter, a pressure boosting check valve and a vent, and the liquid chamber of the differential tank integrates a filling and draining valve and a diaphragm valve for the liquid circuit of the differential tank outlet, so as to realize the propellant pre-packaging function in the differential tank and improve the usability and maintainability.

[0063] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0064] In the description of this application, the word "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0065] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A liquid rocket engine multiple-start system, characterized in that, include: Differential storage tank, hydraulic regulator, booster check valve, first gas generator, propellant starter, start control valve, throttle ring, start check valve, turbine, second gas generator, fuel pump and oxidizer pump; The differential storage tank, the liquid circuit regulator, the booster check valve, the first gas generator, and the gunpowder starter constitute a positive feedback loop system. The hydraulic regulator is connected between the liquid chamber of the differential tank and the inlet of the first gas generator; One end of the booster check valve is connected to the output pipeline of the first gas generator via a pipeline, and the other end is connected to the gas chamber of the differential storage tank. The starting control valve, the throttle ring, the starting check valve, and the turbine are sequentially connected to the outlet side of the first gas generator; The turbine is coaxially connected to the oxidant pump and the fuel pump; The inlet of the second gas generator is connected to the outlet of the fuel pump and the oxidant pump, and the outlet is connected to the turbine.

2. The liquid rocket engine multiple-start system according to claim 1, characterized in that, The differential tank includes: a differential tank shell, a vent, a differential piston, a filling and draining valve, and a differential tank outlet diaphragm valve; A differential piston is installed inside the differential tank shell, dividing its internal cavity into a differential tank gas chamber and a differential tank liquid chamber; The vent is connected to the differential storage tank air chamber; The filling and draining valve is connected to the liquid chamber of the differential storage tank; The differential tank outlet liquid circuit diaphragm valve is installed on the differential tank outlet liquid circuit.

3. The liquid rocket engine multiple-start system according to claim 2, characterized in that, The differential tank liquid chamber is pre-packaged with fuel, which is one of hydrazine, anhydrous hydrazine, or single-push-3.

4. The liquid rocket engine multiple-start system according to claim 1, characterized in that, The inlet and outlet of the first gas generator are respectively equipped with a first gas generator inlet diaphragm valve and a first gas generator outlet diaphragm valve.

5. The liquid rocket engine multiple-start system according to claim 2, characterized in that, The outlet end of the gunpowder starter is connected to the differential storage tank shell and communicates with the differential storage tank air chamber; The outlet end of the gunpowder starter is equipped with a gunpowder starter outlet diaphragm valve.

6. The liquid rocket engine multiple-start system according to claim 1, characterized in that, The hydraulic regulator has a set shut-off pressure. When the outlet pressure of the liquid circuit regulator reaches the set closing pressure, the liquid circuit regulator closes; when the outlet pressure of the liquid circuit regulator drops below the set closing pressure, the liquid circuit regulator opens.

7. The liquid rocket engine multiple-start system according to claim 1, characterized in that, It also includes a second gas generator. The input end of the second gas generator is connected to the fuel pump and the oxidant pump, and the output end is connected to the turbine; The fuel in the fuel pump and the oxidant in the oxidant pump are fed into the second gas generator, where they are combusted to produce high-temperature, high-pressure gas to drive the turbine.

8. The liquid rocket engine multiple-start system according to claim 1, characterized in that, Both the fuel pump and the oxidizer pump are connected to the thrust chamber, and the fuel in the fuel pump and the oxidizer in the oxidizer pump are delivered to the thrust chamber.

9. A method for multiple starts of a liquid rocket engine, characterized in that, Applied to the system according to any one of claims 1-8, the method comprises the following steps: Step S1, pre-packaging and filling the differential propellant tank: Before the liquid rocket engine is installed on the rocket, propellant fuel is added to the differential propellant tank through the filling vent valve. After filling, the propellant fuel is sealed in the differential propellant tank through the diaphragm valve of the differential propellant tank outlet liquid circuit. After the differential propellant tank is filled, it is installed on the rocket along with the liquid rocket engine. Step S2: When the liquid rocket engine receives the start-up preparation command, the gunpowder starter generates high-temperature and high-pressure gas through an electric explosion, which is then injected into the differential storage tank gas chamber. The gas is then compressed by the differential piston in the differential storage tank. When the fuel reaches a certain pressure, it breaks the diaphragm valve of the differential storage tank outlet liquid circuit and enters the first gas generator. Step S3, Start-up and filling process: The first gas generator produces high-temperature and high-pressure gas. The gas in the gas pipeline flows into the differential storage tank gas chamber through the booster check valve for pressurization. When the system pressure rises until the outlet pressure of the liquid circuit regulator reaches its set shut-off pressure, the liquid circuit regulator closes, the first gas generator stops working, the start-up and filling process is completed, and the system enters the working standby state. Step S4: When the liquid rocket engine receives the first to Nth start command, the start control valve opens, and the gas generated by the first gas generator starts the turbine, which drives the oxidizer pump and fuel pump to work. After each startup is completed, return to step S3; Where N>1.

10. The method for multiple starts of a liquid rocket engine according to claim 9, characterized in that, After each startup is completed, it also includes: Step S5: Close the start control valve, the second gas generator starts working, and takes over to drive the turbine.

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