Liquid rocket engine thrust adjusting system and method

Abstract

The invention discloses a liquid rocket engine thrust adjusting system and method, and belongs to the technical field of liquid rocket engines. Comprising a thrust chamber, a gas turbine, an oxidant pump used for pumping an oxidant into the thrust chamber, a fuel pump used for pumping fuel into the thrust chamber and an auxiliary system used for generating fuel gas needed for driving the gas turbine. The gas turbine is coaxially connected with the oxidant pump and the fuel pump; the auxiliary system comprises a fuel gas generator and an adjustable cavitation pipe used for controlling the flow of a propellant entering the fuel gas generator. According to the invention, synchronous regulation of oxidant and fuel flow in the auxiliary system can be realized by utilizing a mechanical structure, the working reliability of the engine is improved, and the complexity of the system is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid rocket engines, and particularly relates to a thrust adjustment system and adjustment method for a liquid rocket engine. Background Art

[0002] A variable-thrust liquid rocket engine is a liquid rocket engine that can adjust the thrust magnitude under different operating conditions. Compared with a fixed-thrust engine, a variable-thrust engine can achieve a soft landing on the ground during the first-stage recovery process of a launch vehicle. In addition, a variable-thrust engine can also control the overload during the rocket flight to meet the maximum allowable overload requirements of the payload.

[0003] At present, the thrust adjustment schemes for pump-fed liquid rocket engines at home and abroad mainly include auxiliary system gas path adjustment, auxiliary system single-path adjustment, and auxiliary system dual-path adjustment. Among them, for the auxiliary system gas path adjustment, a bypass gas release path is set at the generator outlet, and this part of the gas directly enters the turbine exhaust pipe without doing work on the turbine. By adjusting the opening degree of the gas regulating valve in the bypass gas release path, the gas discharge amount is adjusted, thereby changing the gas flow rate entering the turbine and the turbine output power to achieve thrust adjustment. For the auxiliary system single-path adjustment, an adjustable cavitation tube is set on the oxidizer path of the auxiliary system. By adjusting the oxidizer flow rate of the auxiliary system, the generator mixture ratio is changed, and then the gas temperature and flow rate of the generator are changed, thereby changing the turbine output power to achieve thrust adjustment. For the auxiliary system dual-path adjustment, adjustable cavitation tubes are set on both the oxidizer and fuel paths of the auxiliary system, and the oxidizer and fuel flow rates entering the generator are adjusted simultaneously, and then the gas flow rate driving the turbine is changed to achieve thrust adjustment.

[0004] At present, the existing thrust adjustment systems for pump-fed liquid rocket engines have the following deficiencies:

[0005] The auxiliary system gas path adjustment will cause a large loss of engine performance, thereby reducing the carrying capacity of the rocket.

[0006] The auxiliary system single-path adjustment will greatly change the generator mixture ratio during the thrust adjustment process. If the mixture ratio is too high, the gas temperature at the generator outlet will be too high, resulting in turbine ablation. If the mixture ratio is too low, ignition will be difficult and combustion will be difficult to maintain. Therefore, the thrust adjustment ability of this scheme is severely limited.

[0007] The auxiliary system dual-path adjustment requires separately controlling the movement of two adjustable cavitation tubes, and has a very high requirement for the synchronization of the movement. Once the synchronization is not good, the generator mixture ratio will change violently, and the risk of ablation or flameout is relatively high.

[0008] In view of this, it is necessary to provide a new technical solution to solve the above problems. Summary of the Invention

[0009] To solve the above technical problems, the present application provides a thrust adjustment system and method for a liquid rocket engine, which can realize synchronous adjustment of the oxidizer and fuel flow rates in the subsystem by using a mechanical structure, improve the reliability of the engine operation, and simplify the system complexity at the same time.

[0010] A thrust adjustment system for a liquid rocket engine, characterized in that it includes: a gas turbine, an oxidizer pump for pumping oxidizer into the thrust chamber, a fuel pump for pumping fuel into the thrust chamber, and a subsystem for generating the gas required to drive the gas turbine; the gas turbine is coaxially connected to the oxidizer pump and the fuel pump; the subsystem includes a gas generator and an adjustable cavitation tube for controlling the flow rate of the propellant entering the gas generator.

[0011] Preferably, the adjustable cavitation tube includes an oxidizer path adjustable cavitation tube and a fuel path adjustable cavitation tube;

[0012] The inlet end of the oxidizer path adjustable cavitation tube is communicated with the outlet of the oxidizer pump; the outlet end of the oxidizer path adjustable cavitation tube is communicated with the inlet of the gas generator;

[0013] The inlet end of the fuel path adjustable cavitation tube is communicated with the outlet of the fuel pump; the outlet end of the fuel path adjustable cavitation tube is communicated with the inlet of the gas generator.

[0014] Preferably, the subsystem further includes a linear drive mechanism for driving the valve core in the adjustable cavitation tube to move to adjust the flow rate of the propellant entering the gas generator; the linear drive mechanism is fixedly connected to the valve cores in the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube.

[0015] Preferably, the linear drive mechanism is a linear motor.

[0016] Preferably, the linear drive mechanism is fixedly connected to the valve cores in the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube through a force transmission rod.

[0017] According to another aspect of the present application, there is also provided a thrust adjustment method for a liquid rocket engine, which is adjusted by using the thrust adjustment system of the liquid rocket engine described in the claims, including:

[0018] Input a control command to the DC motor to control the moving shaft of the DC motor to drive the force transmission rod to move axially along it;

[0019] The force transmission rod drives the valve cores of the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube to move axially synchronously in two paths, synchronously changing the throat areas inside the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube, and changing the flow rate of the propellant entering the gas generator;

[0020] The output power of the gas turbine is changed by altering the propellant flow rate into the gas generator;

[0021] The output powers of the oxidizer pump and the fuel pump are synchronously changed according to the output power of the gas turbine to achieve the change of the propellant flow rate, thereby changing the engine thrust.

[0022] Compared with the prior art, the present application has at least the following beneficial effects:

[0023] 1. The present invention can use a mechanical structure to achieve synchronous adjustment of the oxidizer and fuel flow rates in the subsystem, keeping the mixture ratio in the gas generator constant during thrust adjustment, improving the reliability of the engine operation, and simplifying the system complexity at the same time.

[0024] 2. The present invention uses a linear drive mechanism to simultaneously adjust the flow rates of the two propellants in the subsystem, simplifying the control complexity of the engine thrust adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Some specific embodiments of the present invention will be described in detail hereinafter with reference to the drawings in an exemplary but not restrictive manner. The same reference numerals in the drawings denote the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale.

[0026] In the drawings:

[0027] Figure 1 is the schematic diagram of the thrust adjustment system of the liquid rocket engine of the present invention.

[0028] Among them, the above-mentioned drawings include the following reference numerals:

[0029] 1. Oxidizer pump; 2. Fuel pump; 3. Gas turbine; 4. Linear drive mechanism; 5. Force transmission rod; 6. Adjustable cavitation tube for oxidizer line; 7. Adjustable cavitation tube for fuel line; 8. Gas generator; 9. Thrust chamber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0031] As Figure 1As shown in the figure, a thrust regulation system for a liquid rocket engine includes: a gas turbine 3, an oxidizer pump 1 for pumping oxidizer into a thrust chamber 9, a fuel pump 2 for pumping fuel into the thrust chamber 9, and a subsystem for generating the gas required to drive the gas turbine 3; the gas turbine 3 is coaxially connected to the oxidizer pump 1 and the fuel pump 2; the subsystem includes a gas generator 8 and an adjustable cavitation tube for controlling the flow rate of the propellant entering the gas generator 8.

[0032] Specifically, the adjustable cavitation tube includes an oxidizer path adjustable cavitation tube 6 and a fuel path adjustable cavitation tube 7. The inlet end of the oxidizer path adjustable cavitation tube 6 is communicated with the outlet of the oxidizer pump 1, and the outlet end of the oxidizer path adjustable cavitation tube 6 is communicated with the inlet of the gas generator 8. The inlet end of the fuel path adjustable cavitation tube 7 is communicated with the outlet of the fuel pump 2, and the outlet end of the fuel path adjustable cavitation tube 7 is communicated with the inlet of the gas generator 8.

[0033] In addition, the subsystem further includes a linear drive mechanism 4 for driving the valve core in the adjustable cavitation tube to move to adjust the flow rate of the propellant entering the gas generator 8; the linear drive mechanism 4 is fixedly connected to the valve cores in the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7.

[0034] Preferably, the linear drive mechanism 4 is a linear motor.

[0035] In addition, the linear drive mechanism 4 can also be a driving mechanism such as an electric push rod that can perform linear drive.

[0036] The linear drive mechanism 4 is fixedly connected to the valve cores in the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7 through a force transmission rod 5.

[0037] A thrust regulation method for a liquid rocket engine, which is adjusted by using the thrust regulation system of the liquid rocket engine, includes:

[0038] Input a control instruction to a DC motor to control the moving shaft of the DC motor to drive the force transmission rod 5 to move along its axial direction.

[0039] The force transmission rod 5 drives the valve cores of the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7 to move synchronously along the axial direction in two paths, synchronously changing the throat areas inside the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7, and changing the flow rate of the propellant entering the gas generator 8. Among them, the throats inside the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7 are the cross-sectional areas with the smallest flow areas in the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7. Since the position of the throat is fixed, by controlling the distance between the valve cores in the oxidizer path adjustable cavitation tube 6 and the fuel path adjustable cavitation tube 7 and the throat, the effective control of the propellant flow rate can be achieved.

[0040] It should be noted that the input end of the force transmission rod 5 is fixedly connected to the linear drive mechanism 4, and its output end is divided into two paths, which are respectively fixedly connected to the valve cores of the adjustable cavitation tube 6 of the oxidizer path and the adjustable cavitation tube 7 of the fuel path. Under the driving action of the linear drive mechanism 4 and relying on the transmission action of the force transmission rod 5, the synchronous movement of the valve cores in the adjustable cavitation tube 6 of the oxidizer path and the adjustable cavitation tube 7 of the fuel path can be realized, so as to realize the flow rate adjustment of the two paths of propellants in the subsystem by one linear drive mechanism. At the same time, due to the synchronous movement of the valve cores in the adjustable cavitation tube 6 of the oxidizer path and the adjustable cavitation tube 7 of the fuel path, the ratio of the mass flow rate of the oxidizer to the mass flow rate of the fuel entering the combustion device can be guaranteed to be constant, ensuring the stability of the thrust of the liquid rocket engine.

[0041] The output power of the gas turbine 3 is changed by changing the flow rate of the propellant entering the gas generator 8.

[0042] The output powers of the oxidizer pump 1 and the fuel pump 2 are synchronously changed by the output power of the gas turbine 3 to realize the change of the propellant flow rate, and thereby change the engine thrust.

[0043] For the sake of convenience in description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the attached drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations are made for the spatial relative descriptions used here.

[0044] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0045] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0046] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A thrust regulation system for a liquid rocket engine, characterized in that, Comprising: A gas turbine, an oxidizer pump for pumping oxidizer into a thrust chamber, a fuel pump for pumping fuel into the thrust chamber, and a subsystem for generating the gas required to drive the gas turbine; the gas turbine is coaxially connected to the oxidizer pump and the fuel pump; the subsystem includes a gas generator and an adjustable cavitation tube for controlling the flow rate of the propellant entering the gas generator.

2. The thrust adjustment system of the liquid rocket engine according to claim 1, characterized in that The adjustable cavitation tube includes an oxidizer path adjustable cavitation tube and a fuel path adjustable cavitation tube; The inlet end of the oxidizer path adjustable cavitation tube is communicated with the outlet of the oxidizer pump; the outlet end of the oxidizer path adjustable cavitation tube is communicated with the inlet of the gas generator; The inlet end of the fuel path adjustable cavitation tube is communicated with the outlet of the fuel pump; the outlet end of the fuel path adjustable cavitation tube is communicated with the inlet of the gas generator.

3. The thrust adjustment system of a liquid rocket engine according to claim 2, wherein The subsystem further includes a linear drive mechanism for driving the valve core in the adjustable cavitation tube to move to adjust the flow rate of the propellant entering the gas generator; the linear drive mechanism is fixedly connected to the valve cores in the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube.

4. The thrust adjustment system of the liquid rocket engine according to claim 3, characterized in that, The linear drive mechanism is a linear motor.

5. The thrust regulation system of a liquid rocket engine according to claim 4, characterized in that, The linear drive mechanism is fixedly connected to the valve cores in the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube through a force transmission rod.

6. A thrust regulation method for a liquid rocket engine, characterized in that, Performing progressive adjustment by using the liquid rocket engine thrust adjustment system according to any one of claims 5, including: Inputting a control instruction to a DC motor to control the moving shaft of the DC motor to drive the force transmission rod to move axially along it; The force transmission rod drives the valve cores of the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube to move axially synchronously in two paths, synchronously changing the throat areas inside the oxidizer path adjustable cavitation tube and the fuel path adjustable cavitation tube, and changing the flow rate of the propellant entering the gas generator; Changing the output power of the gas turbine by changing the flow rate of the propellant entering the gas generator; Synchronously changing the output powers of the oxidizer pump and the fuel pump through the output power of the gas turbine, realizing the change of the propellant flow rate, and thereby changing the engine thrust.

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