RU2451199C1 - Liquid-propellant rocket engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed engine comprises, at least, one extra fuel high-pressure tank, gas generator to produce working medium for turbine by combusting fuel components therein. Note here that gas blanket of said extra fuel high-pressure tank is communicated via pipeline with compressed gas cylinder. Fluid section of said tank is communicated with gas generators nozzles. Gas generator outlet is communicated with turbine inlet while turbine outlet is communicated with said gas blanket and/or ambient medium.

EFFECT: decreased weight, better performances.

1 dwg

Description

The invention relates to rocket technology, and in particular to the creation of launch vehicles (LV) and booster rocket blocks (RB) with liquid rocket engines (LRE). It is known that the main components of a liquid rocket or booster block are fuel tanks (oxidizer and fuel), liquid propellant rocket engines, power elements and a control system. Based on the task of minimizing the mass of fuel tanks, when using a pumping fuel supply system, the pressure in them is prescribed as minimal - usually at the level of 0.15-0.35 MPa. This pressure level is not enough for cavitation-free operation of high-speed liquid-propellant LRE pumps, which forces engine designers to use special low-speed auxiliary pumps installed between the tank and the main engine pump. The pressure created by such an upstream pump is a small amount necessary only to ensure normal (cavitation-free) operation of the main pump (usually 0.3-1.5 MPa). The design of such a pre-pump can be different, up to supplying it with an individual turbo drive and designing it together with a turbine (gas or hydraulic) in an autonomous structurally isolated unit called a booster turbopump unit (BTNA). BTNA can be placed directly on the engine frame, and can be placed on any part of the fuel pipeline from the tank to the engine. Many LREs operate according to this scheme, for example, the American Erodzhet engine with a thrust of 182 tons (Foreign Aircraft and Rocket Engines, 1971, TsIAM, p. 473). The same technical solution is embedded in the design of the SSME engine (see Design and engineering of liquid rocket engines. M: Mashinostroenie, 1989, p. 225).

The limiting case is the placement of BTNA directly on the outlet of the tank. In this case, the following benefits are realized to the maximum:

- the diameter of the fuel pipeline is reduced by 1.5-2 times over the entire section from the tank to the engine. This makes it possible to reduce the weight of the fuel system and facilitate the laying of the pipeline along the rocket and in the engine compartment;

- there is an additional opportunity to reduce the pressure in the fuel tank by the amount of hydraulic resistance of the fuel pipeline;

- for the cryogenic fuel component, the cooling process of the engine structure is facilitated (the structural elements of the BTNA are cooled automatically when the tank is filled with the fuel component).

- the dynamics of the fuel pipeline is improved due to the impact of a large pressure drop between the inlet and the outlet, which is important for the stage of starting the engine and other transients.

BTNA turbine power is traditionally supplied from engine systems either by generating gas taken from engine systems (in the case of using a gas turbine in BTNA), or by a high-pressure liquid fuel component taken from the engine drift line (in case of using a hydraulic turbine in BTNA). The removal of the working fluid after the turbine is carried out, as a rule, into the environment through nozzles (if the working fluid is gas), or to the low-pressure line (mainly when the working fluid is a liquid). An example of a well-known implementation of the propulsion system adopted as a prototype is the propulsion system of the DM boost block with an 11D58M engine, in which fuel and oxidizer BTNAs are located directly in the bottoms of the tanks of the same name, and the gas turbines of these BTNAs are sequentially fed with high-temperature high-pressure gas selected after the gas generator (in front of the turbine of the main TNA) of the engine. The exhaust gas emission on BTNA turbines in this unit is carried out into the environment through roll nozzles (see S.P. Umansky. Booster rockets, cosmodromes. M: Restart +, 2001, p. 46, 88).

The disadvantages of the prototype used in the design solution are:

- the presence of extended communications of the supply of the working fluid of the turbine from the engine to the BTNA, which increase the mass of the propulsion system;

- structural detachment of the BTNA from the engine makes it difficult to experimentally test the BTNA-engine system due to the need to simulate the bench conditions of the BTNA placement with bench means while providing gas-dynamic communication between the gas generator of the engine and the BTNA turbine;

- the complete impossibility of joint experimental testing of BTNA and a separate engine if several autonomous engines are used as part of a propulsion system;

- it is difficult to realize the synchronous start of the BTNA and the engine due to the large length of the pipeline for supplying the working fluid to the turbine from the engine;

- the gas after the BTNA turbine emitted into the environment is used for useful purposes only partially (only to create traction in the nozzles of the roll), while its energy reserve may be sufficient to boost the fuel tank.

The aim of the invention is the development of such a design of the missile unit, which would be devoid of the above disadvantages and would have advantages due to:

- exclusion of an extended pipeline for supplying a working fluid to the BTNA turbine from the engine;

- providing the possibility of independent independent testing of both BTNA and engine;

- nullifying the significance of the issue of ensuring synchronous start of BTNA and the engine, since BTNA can be started ahead of engine start;

- ensuring the use of gas exhausted in the BTNA turbine for boosting the fuel tank;

This goal is achieved in that the liquid rocket propulsion system includes a fuel tank, a liquid rocket engine, a turbo pump booster unit with a turbine, a compressed gas cylinder, pipelines with shut-off and control valves, while the installation is equipped with (at least one structural element) additional a high-pressure tank for the fuel component, a gas generator to generate the working fluid of the BTNA turbine by burning fuel components in it, and the gas "cushion" of the additional tank and the high-pressure pipe is connected with a cylinder of compressed gas, liquid portion of the vessel is connected with the nozzles of the gas generator, the gas generator output is connected to the input of the turbine BTNA and exhaust tube connected to the gas turbine "cushion" the fuel tank and / or the environment.

The essence of the invention is illustrated by the circuit shown in figure 1, where:

1 - oxidizer tank;

2 - fuel tank;

3 - liquid rocket engine;

4 - BTNA turbines;

5 - additional capacity of the oxidizer of high pressure;

6 - additional fuel high pressure tank;

7 - cylinders with compressed gas;

8, 9 - fuel pipelines;

10 - gas generator operating with an excess of oxidizing agent;

11 - a gas generator operating with excess fuel;

12 - pipelines for boosting fuel tanks;

13 - emissions of exhaust gases from turbines into the environment;

14 - high pressure gas supply valves for pressurization of tanks 5, 6;

15 - valves for supplying fuel components to gas generators 10 and 11;

16 - BTNA pumps;

17 - starting valves.

The proposed propulsion system operates as follows. Before starting the launch vehicle, the oxidizer and fuel tanks 1 and 2 and additional tanks 5 and 6 are filled with fuel components to valves 15 and 17, which are closed in the initial state. BTNA pumps 16 are filled with fuel components. Cylinders 7 are filled with compressed gas (usually helium or nitrogen) to valves 14. Valves 14 are closed. By the “start” command, the valves 14 are opened and pressure is created in the additional tanks 5 and 6. Then, the valves 15 are opened, which ensures the flow of fuel components into the gas generators 10 and 11, in which the combustion process begins, and they are started. Simultaneously with the start of gas generators, BTNA is unwound and the fuel tanks are pressurized with exhaust gases of the turbine. During or after entering the operating mode of the BTNA, the starting valves 17 open and the fuel components enter the engine under the pressure created by the operating BTNA.

The engine is switched off by turning off the engine and closing the valves 15 and 14.

The alleged invention, due to the installation of additional high-pressure tanks and gas generators for generating the working fluids of BTNA turbines directly in the area where the latter are located, allows implementing the layout of the propulsion system with reduced diameters of the fuel pipelines with a minimum length of the pipelines for supplying the working fluid to the BTNA turbines, negating the problem of starting synchronization BTNA and engine (due to the possibility of independent advanced start of the gas generator and BTNA), about to conduct experimental testing of BTNA on an autonomous stand regardless of engine testing.

Claims (1)

A liquid rocket propulsion system, including a fuel tank, a liquid propellant rocket engine, a turbo pump booster unit with a turbine, a compressed gas cylinder, and pipelines with shut-off and control valves, characterized in that it is equipped with an additional high-pressure tank for the fuel component, a gas generator for the development of the working fluid of the turbine of the booster turbopump unit by burning fuel components in it, and the gas “pillow” of the additional capacity is connected by a pipeline to llonom compressed gas, liquid portion of the vessel is connected with the nozzles of the gas generator, the gas generator output is connected to the input of the booster turbine of the turbopump unit, and the exhaust tube connected to the gas turbine "cushion" the fuel tank and / or the environment.