RU2810868C1 - Deeply throttled liquid rocket engine - Google Patents

Abstract

FIELD: rocket engineering.

SUBSTANCE: deeply throttled liquid rocket engine, including at least two combustion chambers with regenerative cooling paths and mixing heads, according to the invention, contains separately operating main and additional structural circuits, while the main structural circuit ensures engine operation at the stage of vehicle launch with a thrust throttling coefficient up to 0.4. The supply of fuel components to the combustion chambers during operation of the additional structural circuit is carried out through belts of injectors installed in a ring on the side surfaces of the combustion chambers at an angle to the axes of the chambers. The return of the first stage of the launch vehicle is ensured by the operation of an additional structural circuit, while deep throttling of the engine thrust is ensured at a nominal thrust equal to 10% of the nominal engine thrust created by the main structural circuit, as well as due to the possibility of throttling the thrust with a throttling coefficient of up to 0.2. Separate operation of the main and additional structural circuits is ensured by the mutual operation of their shut-off valves installed in the pipelines at the points of their approach to the chambers.

EFFECT: invention ensures a soft landing of the returning first stages of launch vehicles.

4 cl, 1 dwg

Description

Technical field

The invention relates to the field of rocket technology and can be used in the creation of liquid rocket engines (LPRE) for the return stages of medium and super-heavy class launch vehicles.

Currently, the development of promising rocket engines for medium and super-heavy class launch vehicles, designed for decades of operation, must take into account the trend towards reusability of their first stages. Ignoring this trend may be associated with some non-economic considerations, and therefore should be strongly condemned.

State of the art

A known single-chamber Raptor rocket engine developed by the US private company SpaceX (ru.wikipedia.org/wiki/Raptor) of a closed type with complete gasification of fuel components, taken as an analogue, intended for installation on both stages of a two-stage fully reusable launch vehicle Starship Super Heavy for manned flights to the Moon or Mars and running on liquid oxygen and liquid methane components. The engine thrust in the second version at sea level is 230 tf, in the void 250 tf. Specific impulse at sea level is 330 s, in vacuum 375 s. The pressure in the combustion chamber is 336.5 kg/cm ² , the degree of gas expansion is 40 at sea level and 200 in vacuum. The dry weight of the engine is 1.5 tons, height 3.10 m, diameter 1.3 m.

Control of the engine thrust vector is ensured by its swing in two planes. An undoubted advantage of the engine is the ability to deeply throttle thrust with a throttling coefficient of 0.2. The disadvantage of the engine is its thrust, which is insufficient for the Starship Super Heavy launch vehicle, since it requires equipping the first stage with 33 engines, and the second stage with 6 engines, which is associated with a complication of the control system for these engines.

The four-chamber liquid propellant engine RD-171MV (RD-171MV - Wikipedia) is known, taken as a prototype developed by Russia based on the existing RD-171 engine produced in the USSR. The thrust of the RD-171 engine in vacuum is 806 tf. The specific impulse at sea level is 311.3 s, and in vacuum 337.8 s. The dry weight of the engine is 10.3 tons, height 4.15 m, diameter 3.565 m. Control of the engine thrust vector is ensured by independently swinging each combustion chamber in two planes. The ability to start the engine ten times is provided. The engine is being developed for the first stages of the two-stage medium-class launch vehicle Soyuz-5 (Irtysh) and the three-stage super-heavy class launch vehicle Yenisei, intended for flights to the Moon or Mars, the first stage of which is multi-block. The obvious advantage of the engine is its unrivaled thrust, which is needed to create promising launch vehicles for future space flights. At the same time, a significant drawback of the engine is the insufficient degree of thrust throttling. The minimum engine thrust throttling factor of 0.4 does not allow the first stages of the launch vehicles on which it is installed to be reusable, since it does not ensure their soft landing. Attempts to save the first stages using parachutes look unreliable. Today, it seems unreasonable to create promising launch vehicles for decades of operation without the ability to save their first stages.

Disclosure of the invention

A deeply throttled liquid-propellant engine is proposed, including at least two combustion chambers with regenerative cooling paths, mixing heads and supersonic nozzles, containing in addition to the main structural circuit (OSC) also an additional structural circuit (DSC), with each of the complexes made according to the scheme with afterburning of the generator gas according to patent No. RU 2520771 C1, contains a turbopump power supply system (TNA) of gas generators and engine chambers, a control and regulation system having start-up shut-off valves, a draft regulator and a fuel component ratio throttle, while the turbopump power supply system of the engine contains two turbopump units fed by two autonomous oxidizing gas generators, and the first and second TPU have the same power and include a coaxially installed and sequentially located on the same shaft a fuel pump, an oxidizer pump and a gas turbine, and the fuel pump of the second TPU is made of two stages, in addition, the outputs from the fuel and oxidizer pumps of the first TPU are connected pipelines with the inputs of the fuel and oxidizer pumps of the second heating pump, the oxidizer pump of the second heating pump is connected to the mixing heads of the specified gas generators through pipelines in which start-up shut-off valves are installed, and the output from the second stage of the fuel pump of the second heating pump is connected to the mixing heads of the gas generators through a pipeline and a draft regulator. The supply of fuel components of the additional circuit to the combustion chamber (liquid fuel after passing through the regenerative cooling path and gaseous oxidizer from the oxidation gas generator) is carried out through a belt of injectors installed in a ring on the side surface of the combustion chamber at an angle to the axis of the chamber.

The main structural contour ensures engine operation at the stage of launch vehicle launch with a thrust throttling coefficient of up to 0.4. To ensure deep throttling of the engine at the stage of return of the launch vehicle stage, an additional structural circuit is used when the main structural circuit is inoperative. In this case, deep throttling of the engine thrust is ensured with a nominal thrust of the additional structural circuit equal to 10% of the nominal thrust of the engine when the main structural circuit is operating, and also due to the possibility of throttling this thrust with a throttling coefficient of up to 0.2. The inevitable reduction in the specific impulse of the engine during operation of the additional structural circuit is more preferable than the creation and placement of additional low-thrust chambers on the return stage of the launch vehicle.

The objective of the invention is to develop a deeply throttled liquid-propellant rocket engine that ensures a soft landing of the re-entry first stages of the launch vehicles on which it is installed.

The problem is solved by the fact that a deeply throttled liquid rocket engine, including at least two combustion chambers with regenerative cooling paths and mixing heads, according to the invention contains separately operating main and additional structural circuits, while the main structural circuit ensures the operation of the engine at the stage of launching the rocket - carrier with a thrust throttling coefficient of up to 0.4.

The supply of fuel components to the combustion chambers during operation of the additional structural complex is carried out through belts of injectors installed in a ring on the side surfaces of the combustion chambers at an angle to the axes of the chambers.

The return of the first stage of the launch vehicle is ensured by the operation of an additional structural circuit, while deep throttling of the engine thrust is ensured at a nominal thrust equal to 10% of the nominal engine thrust created by the main structural circuit, as well as due to the possibility of throttling the thrust with a throttling coefficient of up to 0.2.

Separate operation of the main and additional structural circuits is ensured by the mutual operation of their shut-off valves installed in the pipelines at the points of their approach to the chambers.

The essence of the invention is illustrated by the drawing.

The drawing (Fig. 1) shows a simplified block diagram of a deeply throttled two-chamber ultra-high-thrust liquid-propellant rocket engine with afterburning of generator gas with an excess of oxidizer in the engine chambers.

In this drawing:

1 - cameras;

2 - OSK pipeline for supplying fuel for regenerative cooling of the chambers;

3 - DSC fuel supply pipeline for regenerative cooling of the chambers;

4 - nozzle belt;

5 - mixing head;

6 - OSK pipeline for supplying oxidizing gas to the mixing heads;

7 - DSC pipeline for supplying oxidizing gas to the mixing heads;

8 - main structural contour;

9 - additional structural contour;

10 - channel for transmitting control commands;

11 - channel for transmitting feedback information;

12 - engine supply line with liquid oxidizer;

13 - liquid fuel supply line to the engine.

Carrying out the invention

An example of a possible implementation of the proposed technical solution.

The deeply throttled liquid-propellant engine contains (Fig. 1) chambers 1, fuel supply pipeline 2 from OSK for regenerative cooling of the chambers, fuel supply pipeline 3 from DSC for regenerative cooling of the chambers, nozzle belt 4, mixing heads 5, oxidation supply pipelines OSK 6 and DSC 7 gas to the mixing heads, main structural circuit 8, additional structural circuit 9, control command transmission channel 10, feedback information transmission channel 11, engine supply line with liquid oxidizer 12, engine supply line with liquid fuel, start-up shut-off valves ensuring separate operation of the main and additional structural contours (not shown in Fig. 1), installed in pipelines in places where they approach the chambers, as well as regenerative cooling paths for the chambers of the main and additional structural contours (not shown in Fig. 1).

When the engine is installed on a Soyuz-5 launch vehicle with a return first stage dry weight of 30 tons and a fuel reserve of 10 tons, at the stage of stage return it develops a nominal thrust of 80 tf, which, when throttled to a thrust of 16 tf, ensures a soft landing of the stage.

A deeply throttled liquid rocket engine works as follows. During the launch phase of the launch vehicle on which it is installed, the main structural circuit is connected to the cameras. At the stage of stage return, start-up shut-off valves provide connection to the combustion chambers of an additional structural circuit, which ensures the creation of less thrust. In this configuration, the engine is turned on three times. The first switching occurs after the first stage separates and rotates. In this case, a speed pulse is issued to return the stage to the starting point. The second switching is performed before the stage enters the dense layers of the atmosphere in order to reduce its longitudinal velocity. Finally, the third activation ensures a soft landing of the step.

As a result of the application of the present invention, a technical solution aimed at developing a deeply throttled liquid rocket engine, providing the ability to return the first stage of the launch vehicle on which it is installed, is implemented by installing in the combustion chambers a belt of nozzles placed in a ring on the side surface of the chambers at an angle to the axes of the chambers, the introduction of an additional structural circuit into the engine structure, ensuring the engine operates on fuel components supplied to the injector belt, which create less thrust, as well as the introduction of start-up shut-off valves installed in the pipelines in places where they approach the chambers and ensuring separate operation of the main and additional structural complexes.

Claims (4)

1. A deeply throttled liquid rocket engine, including at least two combustion chambers with regenerative cooling paths and mixing heads, characterized in that it contains separately operating main and additional structural circuits, while the main structural circuit ensures operation of the engine at the stage of launch vehicle launch from thrust throttling coefficient up to 0.4. 2. The engine according to claim 1, characterized in that the supply of fuel components to the combustion chambers during operation of the additional structural circuit is carried out through belts of injectors installed in a ring on the side surfaces of the combustion chambers at an angle to the axes of the chambers. 3. The engine according to claim 2, characterized in that the return of the first stage of the launch vehicle is ensured by the operation of an additional structural circuit, while deep throttling of the engine thrust is ensured at a nominal thrust equal to 10% of the nominal engine thrust created by the main structural circuit, and also thanks to the ability to throttle thrust with a throttling coefficient of up to 0.2. 4. The engine according to claim 3, characterized in that the separate operation of the main and additional structural circuits is ensured by the mutual operation of their shut-off valves installed in the pipelines at the points of their approach to the chambers.

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