Electric pump pre-boosted liquid rocket engine and method of operation

Abstract

The application discloses an electric pump pre-pressurization liquid rocket engine, which comprises a pre-pressurization unit, a turbine pump and a gas generator which are sequentially connected; and a thrust chamber connected with the turbine pump; the pre-pressurization unit comprises a power supply, and an oxidant pre-pressurization assembly and a fuel pre-pressurization assembly are connected to the power supply; the oxidant pre-pressurization assembly and the fuel pre-pressurization assembly are connected with the turbine pump. The electric pump pre-pressurization liquid rocket engine overcomes the deficiency that the pre-pressurization pump cannot provide positive lift and has low efficiency at the initial stage of starting of a traditional engine, is beneficial to improving the adaptability of the engine to low inlet pressure in the whole working process, avoids cavitation of the main pump, has a simple structure and improves working reliability. The application further discloses a working method of the electric pump pre-pressurization liquid rocket engine.

Description

Technical Field

[0001] This invention belongs to the field of liquid rocket engine technology, specifically relating to an electric pump pre-pressurized liquid rocket engine, and also to a method for operating an electric pump pre-pressurized liquid rocket engine. Background Technology

[0002] Liquid rocket engines are an important part of liquid-fueled launch vehicles, providing the power required for flight.

[0003] As launch vehicles place increasing demands on engine thrust, specific impulse, and thrust-to-weight ratio, pump-fed liquid rocket engines have a greater advantage over squeeze-type liquid rocket engines in the selection of the primary power source for the basic stage of launch vehicles.

[0004] Pump-fed liquid rocket engines reduce the pressure requirements of the rocket propellant tanks. By pressurizing the propellant with a turbopump, higher thrust chamber pressures can be achieved, contributing to greater thrust. Liquid rocket engines with thrust exceeding 70 tons, both domestically and internationally, such as my country's YF-100 series liquid oxygen-kerosene high-pressure staged combustion engine, Russia's RD-253 ambient temperature propellant high-pressure staged combustion engine, and the US's Raptor liquid oxygen-methane full-flow staged combustion engine, all employ turbopumps for propellant supply.

[0005] For pump-driven liquid rocket engines, preventing the pump from operating in a cavitation state is crucial. Pump cavitation in liquid rocket engines refers to the phenomenon where, when the local pressure in a certain area of ​​the pump is lower than the saturated vapor pressure of the liquid at the current temperature, the liquid will rapidly vaporize, forming a large number of tiny bubbles.

[0006] During the critical liftoff and high-altitude ignition phases of a rocket launch, the high flow resistance of the propellant delivery system during the start-up of the liquid rocket engine can lead to situations where the engine inlet pressure is lower than the saturated vapor pressure at propellant temperature. This can cause cavitation, which may result in sudden pump failure, preventing the engine from starting or causing an explosion. This is especially true for reusable rockets, where the recovery stage engine requires multiple ignitions during the main deceleration and landing phases. The already low tank pressure during these phases further reduces the engine inlet pressure, significantly increasing the risk of pump cavitation during the start-up process.

[0007] During the steady-state operation of a pump-fed liquid rocket engine, when operating under cavitation conditions, the actual pump head is lower than the design value, and as cavitation intensifies, the head may drop precipitously. Efficiency losses can reach 10% to 30% or even higher than under normal operating conditions, leading to unstable engine thrust output. In some cases, flow fluctuations caused by cavitation can directly affect the propellant mixture ratio in the combustion chamber, potentially causing combustion instability, pressure oscillations, and thrust output fluctuations, thus affecting rocket flight trajectory control. Prolonged operation of the pump under cavitation conditions can damage internal flow components due to the impact pressure generated by cavitation collapse, significantly reducing pump lifespan and even causing pump blade breakage, resulting in serious consequences.

[0008] With the increasingly widespread application of cryogenic propellants such as liquid oxygen, methane, and hydrogen, the need to suppress pump cavitation has become more urgent. Current solutions for suppressing pump cavitation involve installing a pre-pressurization system before the main pump. After the propellant enters the engine, it is first pressurized by the pre-pressurization pump before entering the main pump. There are currently two types of pre-pressurization pumps: turbine pre-pressurization pumps and jet pre-pressurization pumps. Liquid rocket engines employing turbine pre-pressurization pumps, such as my country's YF-100 and YF-115 liquid oxygen-kerosene high-pressure staged combustion engines, have their pre-pressurization pump and pre-pressurization turbine coaxial. The pre-pressurization turbine is either a gas turbine or a liquid turbine, driven by high-temperature, high-pressure gas or high-pressure propellant, which in turn rotates the coaxial pre-pressurization pump to achieve pre-pressurization. Liquid rocket engines employing jet preload pumps, such as Russia's RD-253 ambient propellant high-pressure staged combustion engine, utilize jet preload pumps that have no rotating parts and require no seals. These pumps offer advantages such as simple structure and light weight. The jet preload pump utilizes the working principle of exchanging flow between the jet and the main flow, converting dynamic pressure into static pressure, to increase the propellant pressure. In contrast, liquid rocket engines using turbine preload pumps experience low speeds during the initial startup phase before the combustion components ignite and build up pressure. The engine itself cannot provide the energy needed to drive the preload turbine, and the preload pump remains in a flow resistance state, unable to achieve positive head and thus failing to suppress cavitation in the main pump during the initial startup phase.

[0009] To address the issue of turbine preload pumps, Chinese patent CN109736953B provides a gas-driven preload turbine method, which is beneficial for improving cavitation suppression during engine start-up. However, this method requires additional gas cylinders and valves, making the engine system more complex. The problem with jet preload pumps is that, due to limitations in their working principle, they suffer from significant power loss and low efficiency, typically around 10%, resulting in substantial engine power loss. Summary of the Invention

[0010] The purpose of this invention is to provide an electric pump pre-pressurized liquid rocket engine that overcomes the shortcomings of traditional engine pre-pressurization pumps that cannot provide positive head during the initial start-up phase, have complex systems, and are inefficient. This invention is beneficial for improving the engine's adaptability to low inlet pressure throughout its operation, avoiding cavitation in the main pump, simplifying the engine structure, and improving operational reliability.

[0011] The first technical solution adopted in this invention is an electric pump pre-pressurized liquid rocket engine, which includes a pre-pressurization unit, a turbopump, and a gas generator connected in sequence; it also includes a thrust chamber connected to the turbopump.

[0012] The pre-pressurization unit includes a power supply, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0013] The invention is further characterized in that: The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller, an oxidant pre-pressurization pump motor, and an oxidant pre-pressurization pump connected in sequence; an oxidant isolation valve is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump; the outlet of the oxidant pre-pressurization pump is connected to the turbo pump through an oxidant pre-pressurization pipeline; The fuel pre-boosting assembly includes a fuel pre-boosting pump motor controller, a fuel pre-boosting pump motor, and a fuel pre-boosting pump connected in sequence; a fuel isolation valve is installed on the pipe connected to the inlet of the fuel pre-boosting pump; the outlet of the fuel pre-boosting pump is connected to the turbo pump through a fuel pre-boosting pipe.

[0014] Turbop pumps include a gas turbine, an oxidizer pump, a primary fuel pump, and a secondary fuel pump arranged coaxially. The gas turbine inlet is connected to the gas generator outlet via the gas generator exhaust pipe, and the gas turbine outlet is connected to the oxygen-enriched gas inlet of the thrust chamber via the oxygen-enriched gas supply pipeline. The inlet of the oxidant pump is connected to the outlet of the oxidant pre-pressurization pump via an oxidant pre-pressurization pipeline, and the outlet of the oxidant pump is connected to the oxidant inlet of the gas generator via an oxidant supply pipeline. The inlet of the primary fuel pump is connected to the outlet of the primary fuel pump via a fuel pre-pressurization pipeline, and the outlet of the primary fuel pump is connected to the fuel inlet of the thrust chamber via a first fuel supply pipeline. The inlet of the secondary fuel pump is connected to the first fuel supply line through the third fuel supply line, and the outlet of the secondary fuel pump is connected to the fuel inlet of the gas generator through the second fuel supply line.

[0015] A main fuel valve is installed on the first fuel supply pipeline.

[0016] The second fuel supply line is equipped with a flow regulator and a fuel auxiliary valve.

[0017] An oxidant main valve is installed on the oxidant supply pipeline.

[0018] The second technical solution adopted in this invention is a working method for an electric pump pre-pressurized liquid rocket engine, which specifically includes the following steps: Step S1: Preparations before starting the engine; Step S2: Start the engine; Step S3: Adaptive pressurization during steady-state operation.

[0019] The invention is further characterized in that: Step S1 is as follows: Before the engine is started, the fuel isolation valve and oxidizer isolation valve are closed, and the corresponding fuel propellant and oxidizer propellant are filled to the front of the fuel isolation valve and oxidizer isolation valve; The fuel isolation valve and oxidizer isolation valve are opened in sequence, and the fuel propellant and oxidizer propellant begin to fill the corresponding fuel pre-pressurization pump and oxidizer pre-pressurization pump, respectively.

[0020] Step S2 specifically involves the following steps: When the engine starts, the oxidant pre-boost pump motor controller and the fuel pre-boost pump motor controller provide three-phase alternating current to the oxidant pre-boost pump motor and the fuel pre-boost pump motor, respectively. The oxidant pre-pressurization pump is started by the motor of the oxidant pre-pressurization pump to pre-pressurize the oxidant before it enters the oxidant pump; the fuel pre-pressurization pump is started by the motor of the fuel pre-pressurization pump to pre-pressurize the fuel before it enters the fuel primary pump. After the fuel propellant and oxidizer propellant are filled into the gas generator, they are ignited and burned. The oxygen-rich gas produced drives the gas turbine to start rotating. The speed of the engine oxidizer pump, fuel primary pump, and fuel secondary pump gradually increases, and the outlet pressure of the oxidizer pump, fuel primary pump, and fuel secondary pump increases accordingly. At this time, the fuel has been freely filled into the fuel main valve. As the engine's turbopump speed increases, the fuel flow rate into the gas generator rises rapidly, the gas turbine output power increases rapidly, the engine operating condition climb rate accelerates, and the forced filling process of fuel into the thrust chamber cooling channel also accelerates. After the fuel is forced into the fuel nozzle of the thrust chamber, the thrust chamber is ignited and pressurized, and then the operating conditions are gradually improved, and the engine enters a steady-state operating condition.

[0021] Step S3 is as follows: During the engine's steady-state operation, when the inlet pressure of the oxidizer pump and the first-stage fuel pump is lower than the corresponding minimum operating pressure Pio min Pif minAt the same time, the motor speed is controlled by the oxidizer pre-boost pump motor controller, and the motor speed is controlled by the fuel pre-boost pump motor controller, which in turn controls the head of the oxidizer pre-boost pump and the fuel pre-boost pump, respectively, so that the inlet pressure of the engine oxidizer pump and the inlet pressure of the first-stage fuel pump are higher than the corresponding minimum operating pressure Pio. min Pif min This ensures that cavitation does not occur in the oxidizer pump and the first-stage fuel pump during steady-state operation.

[0022] The beneficial effects of this invention are: (1) Compared with traditional turbine pre-pressure pump engines, the engine of the present invention eliminates the pre-pressure turbine and the driving medium delivery pipeline, which overcomes the shortcomings of traditional engines that the pre-pressure pump cannot provide positive head, the system is complex and the efficiency is low at the beginning of start-up. It is beneficial to improve the adaptability of the engine to low inlet pressure throughout the working process, avoid cavitation of the main pump, simplify the engine structure, improve the working reliability, and reduce the engine processing and manufacturing cost.

[0023] (2) The engine in this invention has no pre-pressure turbine, which eliminates the flow resistance of the pre-pressure turbine and correspondingly increases the main pump inlet pressure during the initial start-up of the engine.

[0024] (3) Compared with traditional pre-pressurized pump engines, the pre-pressurized pump in this invention is powered by an electric motor, which decouples the operation of the pre-pressurized pump from the operation of the engine. This can overcome the shortcomings of traditional engines, such as the inability of the pre-pressurized pump to provide positive head and low efficiency in the initial stage of starting, and is conducive to improving the reliability of engine starting.

[0025] (4) The engine pre-boost pump in this invention does not require the engine to provide driving energy, nor does it require the main turbine pump to provide the power required for the pre-boost pump to work, thus reducing the engine's own power consumption. Compared with traditional pre-boost pump engines, under the same target thrust, this invention can reduce the turbine pump speed and the gas temperature in the oxygen-rich gas supply pipeline, which is beneficial to improving the engine's working reliability. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the electric pump pre-pressurized liquid rocket engine provided in an embodiment of the present invention.

[0027] In the diagram, 1. Power supply, 2. Oxidant pre-boost pump motor controller, 3. Fuel pre-boost pump motor controller, 4. Oxidant pre-boost pump motor, 5. Fuel pre-boost pump motor, 6. Oxidant pre-boost pump, 7. Fuel pre-boost pump, 8. Oxidant pump, 9. Primary fuel pump, 10. Secondary fuel pump, 11. Gas generator, 12. Gas turbine, 13. Thrust chamber, 14. Flow regulator, 15. Oxidant main valve, 16. Fuel auxiliary valve, 17. Fuel main valve, 18. Oxidant isolation valve, 19. Fuel isolation valve, 20. Oxygen-enriched gas supply line, 21. First fuel supply line, 22. Second fuel supply line, 23. Fuel pre-boost line, 24. Oxidant supply line, 25. Gas generator exhaust pipe, 26. Oxidant pre-boost line, 27. Third fuel supply line. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] This invention provides an electric pump-pre-pressurized liquid rocket engine, such as... Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0030] The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller 2, an oxidant pre-pressurization pump motor 4, and an oxidant pre-pressurization pump 6 connected in sequence; an oxidant isolation valve 18 is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump 6; the outlet of the oxidant pre-pressurization pump 6 is connected to the turbo pump through the oxidant pre-pressurization pipeline 26. The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller 3, a fuel pre-pressurization pump motor 5, and a fuel pre-pressurization pump 7 connected in sequence; a fuel isolation valve 19 is installed on the pipe connected to the inlet of the fuel pre-pressurization pump 7; the outlet of the fuel pre-pressurization pump 7 is connected to the turbo pump through the fuel pre-pressurization pipe 23.

[0031] Oxidant pre-boost pump 6 is coaxially connected to oxidant pre-boost pump motor 4; fuel pre-boost pump 7 is coaxially connected to fuel pre-boost pump motor 5; oxidant pre-boost pump motor 4 is connected to oxidant pre-boost pump motor controller 2 via a three-phase cable, and fuel pre-boost pump motor 5 is connected to fuel pre-boost pump motor controller 3 via a three-phase cable; power supply 1 is connected to both oxidant pre-boost pump motor controller 2 and fuel pre-boost pump motor controller 3 via cables. The operating voltage of power supply 1 is no greater than DC 700V. Oxidant pre-boost pump motor 4 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of oxidant pre-boost pump 6 according to the instructions of oxidant pre-boost pump motor controller 2. Fuel pre-boost pump motor 5 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of fuel pre-boost pump 7 according to the instructions of fuel pre-boost pump motor controller 3.

[0032] The turbopump is a coaxial turbopump, which includes a coaxially arranged gas turbine 12, an oxidizer pump 8, a primary fuel pump 9, and a secondary fuel pump 10. The inlet of the gas turbine 12 is connected to the gas outlet of the gas generator 11 through the gas generator exhaust pipe 25, and the outlet of the gas turbine 12 is connected to the oxygen-enriched gas inlet of the thrust chamber 13 through the oxygen-enriched gas supply pipeline 20. The inlet of the oxidant pump 8 is connected to the outlet of the oxidant pre-pressurization pump 6 through the oxidant pre-pressurization pipeline 26, and the outlet of the oxidant pump 8 is connected to the oxidant inlet of the gas generator 11 through the oxidant supply pipeline 24. The inlet of the primary fuel pump 9 is connected to the outlet of the primary fuel pump 7 via the fuel pre-pressurization pipeline 23, and the outlet of the primary fuel pump 9 is connected to the fuel inlet of the thrust chamber 13 via the first fuel supply pipeline 21. The inlet of the secondary fuel pump 10 is connected to the first fuel supply line 21 via the third fuel supply line 27, and the outlet of the secondary fuel pump 10 is connected to the fuel inlet of the gas generator 11 via the second fuel supply line 22.

[0033] A fuel main valve 17 is installed on the first fuel supply pipeline 21.

[0034] The second fuel supply line 22 is equipped with a flow regulator 14 and a fuel auxiliary valve 16.

[0035] An oxidant main valve 15 is installed on the oxidant supply pipeline 24.

[0036] This invention also provides a method for operating an electric pump-pre-pressurized liquid rocket engine, specifically: Step S1, preparations before starting the engine, specifically: Before the engine is started, the fuel isolation valve 19 and the oxidizer isolation valve 18 are in the closed state, and the fuel propellant and oxidizer propellant are filled to the front of the fuel isolation valve 19 and the oxidizer isolation valve 18 respectively. The fuel isolation valve 19 and the oxidizer isolation valve 18 are opened in sequence, and the fuel propellant and oxidizer propellant begin to fill the corresponding fuel pre-pressurization pump 7 and oxidizer pre-pressurization pump 6, respectively. Step S2, starting the engine, specifically: When the engine starts, the oxidant pre-boost pump motor controller 2 and the fuel pre-boost pump motor controller 3 provide three-phase alternating current to the oxidant pre-boost pump motor 4 and the fuel pre-boost pump motor 5, respectively. The oxidant pre-pressurization pump 6 is started to rotate by the oxidant pre-pressurization pump motor 4, and pre-pressurization is performed before the oxidant enters the oxidant pump 8; the fuel pre-pressurization pump 7 is started to rotate by the fuel pre-pressurization pump motor 5, and pre-pressurization is performed before the fuel enters the fuel primary pump 9. After the fuel propellant and oxidizer propellant are filled into the gas generator 11, they are ignited and burned. The oxygen-rich gas produced drives the gas turbine 12 to start rotating. The speed of the engine oxidizer pump 8, fuel primary pump 9, and fuel secondary pump 10 gradually increases, and the outlet pressure of oxidizer pump 8, fuel primary pump 9, and fuel secondary pump 10 increases accordingly. At this time, the fuel has been freely filled into the fuel main valve 17. As the engine's turbopump speed increases, the fuel flow rate entering the gas generator 11 rises rapidly, the output power of the gas turbine 12 increases rapidly, the engine's operating condition climb rate accelerates, and the forced filling process of fuel into the cooling channel cavity of the thrust chamber 13 also accelerates. When fuel is forced into the fuel nozzle of the thrust chamber 13, the thrust chamber 13 is ignited and pressurized, the gas turbine pressure ratio decreases, and the engine operating condition climb rate slows down accordingly. Step S3, Steady-state operating section, adaptive pressurization steady-state condition, the specific working process is as follows: During rocket flight, the inlet pressure of oxidizer pump 8 and first-stage fuel pump 9 decreases due to the pressure drop in the rocket's propellant tanks. During the engine's steady-state operation, when the inlet pressure of oxidizer pump 8 and first-stage fuel pump 9 falls below the corresponding minimum operating pressure (Pio)... min Pif min At the same time, the motor speed is controlled by the oxidizer pre-boost pump motor controller 2, and the motor speed is controlled by the fuel pre-boost pump motor controller 3, which in turn controls the head of the oxidizer pre-boost pump 6 and the fuel pre-boost pump 7, so that the inlet pressure of the engine oxidizer pump 8 and the inlet pressure of the first-stage fuel pump 9 are higher than the corresponding minimum operating pressure Pio. min Pif min This ensures that cavitation does not occur in the oxidizer pump 8 and the first-stage fuel pump 9 during the steady-state operation phase.

[0037] Example 1 Electric pump pre-pressurized liquid rocket engines, such as Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0038] Example 2 Electric pump pre-pressurized liquid rocket engines, such as Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0039] The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller 2, an oxidant pre-pressurization pump motor 4, and an oxidant pre-pressurization pump 6 connected in sequence; an oxidant isolation valve 18 is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump 6; the outlet of the oxidant pre-pressurization pump 6 is connected to the turbo pump through the oxidant pre-pressurization pipeline 26. The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller 3, a fuel pre-pressurization pump motor 5, and a fuel pre-pressurization pump 7 connected in sequence; a fuel isolation valve 19 is installed on the pipe connected to the inlet of the fuel pre-pressurization pump 7; the outlet of the fuel pre-pressurization pump 7 is connected to the turbo pump through the fuel pre-pressurization pipe 23.

[0040] Example 3 Electric pump pre-pressurized liquid rocket engines, such as Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0041] The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller 2, an oxidant pre-pressurization pump motor 4, and an oxidant pre-pressurization pump 6 connected in sequence; an oxidant isolation valve 18 is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump 6; the outlet of the oxidant pre-pressurization pump 6 is connected to the turbo pump through the oxidant pre-pressurization pipeline 26. The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller 3, a fuel pre-pressurization pump motor 5, and a fuel pre-pressurization pump 7 connected in sequence; a fuel isolation valve 19 is installed on the pipe connected to the inlet of the fuel pre-pressurization pump 7; the outlet of the fuel pre-pressurization pump 7 is connected to the turbo pump through the fuel pre-pressurization pipe 23.

[0042] Oxidant pre-boost pump 6 is coaxially connected to oxidant pre-boost pump motor 4; fuel pre-boost pump 7 is coaxially connected to fuel pre-boost pump motor 5; oxidant pre-boost pump motor 4 is connected to oxidant pre-boost pump motor controller 2 via a three-phase cable, and fuel pre-boost pump motor 5 is connected to fuel pre-boost pump motor controller 3 via a three-phase cable; power supply 1 is connected to both oxidant pre-boost pump motor controller 2 and fuel pre-boost pump motor controller 3 via cables. The operating voltage of power supply 1 is no greater than DC 700V. Oxidant pre-boost pump motor 4 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of oxidant pre-boost pump 6 according to the instructions of oxidant pre-boost pump motor controller 2. Fuel pre-boost pump motor 5 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of fuel pre-boost pump 7 according to the instructions of fuel pre-boost pump motor controller 3.

[0043] Example 4 Electric pump pre-pressurized liquid rocket engines, such as Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0044] The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller 2, an oxidant pre-pressurization pump motor 4, and an oxidant pre-pressurization pump 6 connected in sequence; an oxidant isolation valve 18 is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump 6; the outlet of the oxidant pre-pressurization pump 6 is connected to the turbo pump through the oxidant pre-pressurization pipeline 26. The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller 3, a fuel pre-pressurization pump motor 5, and a fuel pre-pressurization pump 7 connected in sequence; a fuel isolation valve 19 is installed on the pipe connected to the inlet of the fuel pre-pressurization pump 7; the outlet of the fuel pre-pressurization pump 7 is connected to the turbo pump through the fuel pre-pressurization pipe 23.

[0045] Oxidant pre-boost pump 6 is coaxially connected to oxidant pre-boost pump motor 4; fuel pre-boost pump 7 is coaxially connected to fuel pre-boost pump motor 5; oxidant pre-boost pump motor 4 is connected to oxidant pre-boost pump motor controller 2 via a three-phase cable, and fuel pre-boost pump motor 5 is connected to fuel pre-boost pump motor controller 3 via a three-phase cable; power supply 1 is connected to both oxidant pre-boost pump motor controller 2 and fuel pre-boost pump motor controller 3 via cables. The operating voltage of power supply 1 is no greater than DC 700V. Oxidant pre-boost pump motor 4 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of oxidant pre-boost pump 6 according to the instructions of oxidant pre-boost pump motor controller 2. Fuel pre-boost pump motor 5 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of fuel pre-boost pump 7 according to the instructions of fuel pre-boost pump motor controller 3.

[0046] The turbopump is a coaxial turbopump, which includes a coaxially arranged gas turbine 12, an oxidizer pump 8, a primary fuel pump 9, and a secondary fuel pump 10. The inlet of the gas turbine 12 is connected to the gas outlet of the gas generator 11 through the gas generator exhaust pipe 25, and the outlet of the gas turbine 12 is connected to the oxygen-enriched gas inlet of the thrust chamber 13 through the oxygen-enriched gas supply pipeline 20. The inlet of the oxidant pump 8 is connected to the outlet of the oxidant pre-pressurization pump 6 through the oxidant pre-pressurization pipeline 26, and the outlet of the oxidant pump 8 is connected to the oxidant inlet of the gas generator 11 through the oxidant supply pipeline 24. The inlet of the primary fuel pump 9 is connected to the outlet of the primary fuel pump 7 via the fuel pre-pressurization pipeline 23, and the outlet of the primary fuel pump 9 is connected to the fuel inlet of the thrust chamber 13 via the first fuel supply pipeline 21. The inlet of the secondary fuel pump 10 is connected to the first fuel supply line 21 via the third fuel supply line 27, and the outlet of the secondary fuel pump 10 is connected to the fuel inlet of the gas generator 11 via the second fuel supply line 22.

[0047] Example 5 Electric pump pre-pressurized liquid rocket engines, such as Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0048] The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller 2, an oxidant pre-pressurization pump motor 4, and an oxidant pre-pressurization pump 6 connected in sequence; an oxidant isolation valve 18 is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump 6; the outlet of the oxidant pre-pressurization pump 6 is connected to the turbo pump through the oxidant pre-pressurization pipeline 26. The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller 3, a fuel pre-pressurization pump motor 5, and a fuel pre-pressurization pump 7 connected in sequence; a fuel isolation valve 19 is installed on the pipe connected to the inlet of the fuel pre-pressurization pump 7; the outlet of the fuel pre-pressurization pump 7 is connected to the turbo pump through the fuel pre-pressurization pipe 23.

[0049] Oxidant pre-boost pump 6 is coaxially connected to oxidant pre-boost pump motor 4; fuel pre-boost pump 7 is coaxially connected to fuel pre-boost pump motor 5; oxidant pre-boost pump motor 4 is connected to oxidant pre-boost pump motor controller 2 via a three-phase cable, and fuel pre-boost pump motor 5 is connected to fuel pre-boost pump motor controller 3 via a three-phase cable; power supply 1 is connected to both oxidant pre-boost pump motor controller 2 and fuel pre-boost pump motor controller 3 via cables. The operating voltage of power supply 1 is no greater than DC 700V. Oxidant pre-boost pump motor 4 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of oxidant pre-boost pump 6 according to the instructions of oxidant pre-boost pump motor controller 2. Fuel pre-boost pump motor 5 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of fuel pre-boost pump 7 according to the instructions of fuel pre-boost pump motor controller 3.

[0050] The turbopump is a coaxial turbopump, which includes a coaxially arranged gas turbine 12, an oxidizer pump 8, a primary fuel pump 9, and a secondary fuel pump 10. The inlet of the gas turbine 12 is connected to the gas outlet of the gas generator 11 through the gas generator exhaust pipe 25, and the outlet of the gas turbine 12 is connected to the oxygen-enriched gas inlet of the thrust chamber 13 through the oxygen-enriched gas supply pipeline 20. The inlet of the oxidant pump 8 is connected to the outlet of the oxidant pre-pressurization pump 6 through the oxidant pre-pressurization pipeline 26, and the outlet of the oxidant pump 8 is connected to the oxidant inlet of the gas generator 11 through the oxidant supply pipeline 24. The inlet of the primary fuel pump 9 is connected to the outlet of the primary fuel pump 7 via the fuel pre-pressurization pipeline 23, and the outlet of the primary fuel pump 9 is connected to the fuel inlet of the thrust chamber 13 via the first fuel supply pipeline 21. The inlet of the secondary fuel pump 10 is connected to the first fuel supply line 21 via the third fuel supply line 27, and the outlet of the secondary fuel pump 10 is connected to the fuel inlet of the gas generator 11 via the second fuel supply line 22.

[0051] A fuel main valve 17 is installed on the first fuel supply pipeline 21.

[0052] Example 6 Electric pump pre-pressurized liquid rocket engines, such as Figure 1 As shown, it includes a pre-pressurization unit, a turbopump, and a gas generator 11 connected in sequence; it also includes a thrust chamber 13 connected to the turbopump; The pre-pressurization unit includes a power source 1, to which an oxidizer pre-pressurization component and a fuel pre-pressurization component are connected; both the oxidizer pre-pressurization component and the fuel pre-pressurization component are connected to a turbopump.

[0053] The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller 2, an oxidant pre-pressurization pump motor 4, and an oxidant pre-pressurization pump 6 connected in sequence; an oxidant isolation valve 18 is installed on the pipeline connected to the inlet of the oxidant pre-pressurization pump 6; the outlet of the oxidant pre-pressurization pump 6 is connected to the turbo pump through the oxidant pre-pressurization pipeline 26. The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller 3, a fuel pre-pressurization pump motor 5, and a fuel pre-pressurization pump 7 connected in sequence; a fuel isolation valve 19 is installed on the pipe connected to the inlet of the fuel pre-pressurization pump 7; the outlet of the fuel pre-pressurization pump 7 is connected to the turbo pump through the fuel pre-pressurization pipe 23.

[0054] Oxidant pre-boost pump 6 is coaxially connected to oxidant pre-boost pump motor 4; fuel pre-boost pump 7 is coaxially connected to fuel pre-boost pump motor 5; oxidant pre-boost pump motor 4 is connected to oxidant pre-boost pump motor controller 2 via a three-phase cable, and fuel pre-boost pump motor 5 is connected to fuel pre-boost pump motor controller 3 via a three-phase cable; power supply 1 is connected to both oxidant pre-boost pump motor controller 2 and fuel pre-boost pump motor controller 3 via cables. The operating voltage of power supply 1 is no greater than DC 700V. Oxidant pre-boost pump motor 4 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of oxidant pre-boost pump 6 according to the instructions of oxidant pre-boost pump motor controller 2. Fuel pre-boost pump motor 5 is a permanent magnet synchronous or brushless DC motor, and its speed can be continuously adjusted to change the head of fuel pre-boost pump 7 according to the instructions of fuel pre-boost pump motor controller 3.

[0055] The turbopump is a coaxial turbopump, which includes a coaxially arranged gas turbine 12, an oxidizer pump 8, a primary fuel pump 9, and a secondary fuel pump 10. The inlet of the gas turbine 12 is connected to the gas outlet of the gas generator 11 through the gas generator exhaust pipe 25, and the outlet of the gas turbine 12 is connected to the oxygen-enriched gas inlet of the thrust chamber 13 through the oxygen-enriched gas supply pipeline 20. The inlet of the oxidant pump 8 is connected to the outlet of the oxidant pre-pressurization pump 6 through the oxidant pre-pressurization pipeline 26, and the outlet of the oxidant pump 8 is connected to the oxidant inlet of the gas generator 11 through the oxidant supply pipeline 24. The inlet of the primary fuel pump 9 is connected to the outlet of the primary fuel pump 7 via the fuel pre-pressurization pipeline 23, and the outlet of the primary fuel pump 9 is connected to the fuel inlet of the thrust chamber 13 via the first fuel supply pipeline 21. The inlet of the secondary fuel pump 10 is connected to the first fuel supply line 21 via the third fuel supply line 27, and the outlet of the secondary fuel pump 10 is connected to the fuel inlet of the gas generator 11 via the second fuel supply line 22.

[0056] A fuel main valve 17 is installed on the first fuel supply pipeline 21.

[0057] The second fuel supply line 22 is equipped with a flow regulator 14 and a fuel auxiliary valve 16.

Claims

1. An electric pump-pre-pressurized liquid rocket engine, characterized in that, It includes a pre-pressurization unit, a turbo pump and a gas generator (11) connected in sequence; it also includes a thrust chamber (13) connected to the turbo pump. The pre-pressurization unit includes a power supply (1), and an oxidant pre-pressurization component and a fuel pre-pressurization component are connected to the power supply (1); both the oxidant pre-pressurization component and the fuel pre-pressurization component are connected to a turbo pump.

2. The electric pump pre-pressurized liquid rocket engine according to claim 1, characterized in that, The oxidant pre-pressurization assembly includes an oxidant pre-pressurization pump motor controller (2), an oxidant pre-pressurization pump motor (4), and an oxidant pre-pressurization pump (6) connected in sequence; an oxidant isolation valve (18) is installed on the pipe connected to the inlet of the oxidant pre-pressurization pump (6); the outlet of the oxidant pre-pressurization pump (6) is connected to the turbine pump through the oxidant pre-pressurization pipeline (26); The fuel pre-pressurization assembly includes a fuel pre-pressurization pump motor controller (3), a fuel pre-pressurization pump motor (5), and a fuel pre-pressurization pump (7) connected in sequence; a fuel isolation valve (19) is installed on the pipe connected to the inlet of the fuel pre-pressurization pump (7); the outlet of the fuel pre-pressurization pump (7) is connected to the turbo pump through the fuel pre-pressurization pipe (23).

3. The electric pump pre-pressurized liquid rocket engine according to claim 1, characterized in that, The turbopump includes a gas turbine (12) coaxially arranged, an oxidizer pump (8), a primary fuel pump (9) and a secondary fuel pump (10). The inlet of the gas turbine (12) is connected to the gas outlet of the gas generator (11) through the gas generator exhaust pipe (25), and the outlet of the gas turbine (12) is connected to the oxygen-enriched gas inlet of the thrust chamber (13) through the oxygen-enriched gas supply pipeline (20). The inlet of the oxidant pump (8) is connected to the outlet of the oxidant pre-pressurization pump (6) through the oxidant pre-pressurization pipeline (26), and the outlet of the oxidant pump (8) is connected to the oxidant inlet of the gas generator (11) through the oxidant supply pipeline (24). The inlet of the primary fuel pump (9) is connected to the outlet of the pre-pressurization pump (7) through the fuel pre-pressurization pipeline (23), and the outlet of the primary fuel pump (9) is connected to the fuel inlet of the thrust chamber (13) through the first fuel supply pipeline (21). The inlet of the secondary fuel pump (10) is connected to the first fuel supply line (21) through the third fuel supply line (27), and the outlet of the secondary fuel pump (10) is connected to the fuel inlet of the gas generator (11) through the second fuel supply line (22).

4. The electric pump pre-pressurized liquid rocket engine according to claim 3, characterized in that, A fuel main valve (17) is provided on the first fuel supply pipeline (21).

5. The electric pump pre-pressurized liquid rocket engine according to claim 3, characterized in that, The second fuel supply line (22) is equipped with a flow regulator (14) and a fuel auxiliary valve (16).

6. The electric pump pre-pressurized liquid rocket engine according to claim 3, characterized in that, An oxidant main valve (15) is provided on the oxidant supply pipeline (24).

7. The operating method of the electric pump pre-pressurized liquid rocket engine according to any one of claims 1-6, characterized in that, Specifically, the steps include the following: Step S1: Preparations before starting the engine; Step S2: Start the engine; Step S3: Adaptive pressurization during steady-state operation.

8. The operating method of the electric pump pre-pressurized liquid rocket engine according to claim 7, characterized in that, Step S1 is as follows: Before the engine is started, the fuel isolation valve (19) and the oxidizer isolation valve (18) are closed, and the fuel propellant and oxidizer propellant are filled to the front of the fuel isolation valve (19) and the oxidizer isolation valve (18) respectively. The fuel isolation valve (19) and the oxidizer isolation valve (18) are opened in sequence, and the fuel propellant and oxidizer propellant begin to fill the corresponding fuel pre-pressurization pump (7) and oxidizer pre-pressurization pump (6) respectively.

9. The operating method of the electric pump pre-pressurized liquid rocket engine according to claim 7, characterized in that, Step S2 is as follows: When the engine starts, the oxidant pre-boost pump motor controller (2) and the fuel pre-boost pump motor controller (3) provide three-phase alternating current to the oxidant pre-boost pump motor (4) and the fuel pre-boost pump motor (5), respectively. The oxidant pre-pressurization pump (6) is started to rotate by the oxidant pre-pressurization pump motor (4) to pre-pressurize the oxidant before it enters the oxidant pump (8); the fuel pre-pressurization pump (7) is started to rotate by the fuel pre-pressurization pump motor (5) to pre-pressurize the fuel before it enters the fuel primary pump (9); When both fuel propellant and oxidizer propellant are filled into the gas generator (11), they are ignited and burned. The oxygen-rich gas produced drives the gas turbine (12) to start rotating. The speed of the engine oxidizer pump (8), fuel primary pump (9), and fuel secondary pump (10) gradually increases, and the outlet pressure of the oxidizer pump (8), fuel primary pump (9), and fuel secondary pump (10) increases accordingly. At this time, the fuel has been freely filled into the fuel main valve (17). As the engine's turbopump speed increases, the fuel flow rate into the gas generator (11) rises rapidly, the output power of the gas turbine (12) increases rapidly, the engine operating condition rises faster, and the forced filling process of fuel into the cooling channel of the thrust chamber (13) also accelerates. When the fuel is forced to fill the fuel nozzle of the thrust chamber (13), the thrust chamber (13) is ignited and pressurized, and then the operating conditions are gradually improved, and the engine enters a steady state.

10. The operating method of the electric pump pre-pressurized liquid rocket engine according to claim 7, characterized in that, Step S3 is as follows: When the inlet pressure of the oxidizer pump (8) and the first-stage fuel pump (9) is lower than the corresponding minimum operating pressure Pio min Pif min At the same time, the motor speed is controlled by the oxidant pre-boost pump motor controller (2) and the motor speed is controlled by the fuel pre-boost pump motor controller (3), respectively controlling the head of the oxidant pre-boost pump (6) and the fuel pre-boost pump (7), so that the inlet pressure of the engine oxidant pump (8) and the inlet pressure of the fuel primary pump (9) are higher than the corresponding minimum operating pressure Pio. min Pif min To ensure that cavitation does not occur in the oxidizer pump (8) and the first-stage fuel pump (9) during the steady-state operation phase.

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