RU2406857C1 - Liquid-propellant rocket engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed liquid-propellant rocket engine comprises combustion chamber, gas generator, turbine, fuel pump, oxidiser pump, fuel and oxidiser pipelines communicating pumps outlets with gas generator and combustion chamber, starting tank for fuel component to be displaced therefrom on starting the engine. In compliance with this invention, working space of said starting tank is tightly divided by piston or flexible membrane into two parts, one being communicated with fuel pipeline and another communicates with oxidiszer pipeline.

EFFECT: simplified design, higher reliability and stability of engine starting.

1 dwg

Description

The invention relates to the field of liquid rocket engines. One of the challenges facing the creators of the rocket engine is the development of design solutions that provide reliable and stable engine start.

Difficulties arise, as a rule, due to the inconsistency of the pressures (and, as a consequence of this, the costs) of the oxidizer and fuel at the initial moment of start-up with idle or insufficiently untwisted pumps. Most often, a situation arises when the pressure along the line of one of the fuel components significantly exceeds the pressure along the line of the other fuel component (mainly due to the difference in the height of the column and the density of the components in the rocket tank). At the same time, changes in these pressures during the startup process occur in different ways. This affects the costs of the gas generator during ignition and can lead to “throws” or “dips” in temperature in the gas generator due to a mismatch in the ratio of the flow rates of the fuel components and, as a consequence, to the instability of the engine starting.

A well-known solution for starting the engine by supplying fuel components to the gas generator is the use of starting tanks with oxidizer and fuel, working on the principle of displacing the component with neutral gas (helium, nitrogen).

Known liquid rocket engine LR-89-NA, LR-79-NA (see the encyclopedia "Cosmonautics", 1985, p.216, 217), where the start of the gas generator is made by igniting the fuel components supplied from the launch tanks.

The RD-219 engine is also known - a prototype (see the "Cosmonautics" encyclopedia, 1985, p. 300), where the generator is also launched by supplying fuel components from the launch tanks.

The disadvantage of the prototype is the relative complexity, which consists in the presence of 2 tanks (for oxidizer and fuel)

The aim of the invention is to simplify the design, providing the same tasks with fewer units.

This goal is achieved by the fact that in the known liquid propellant rocket engine containing a combustion chamber, a gas generator, a turbine, a fuel pump, an oxidizer pump, fuel and oxidizer pipelines, communicating exits from pumps with a gas generator and a combustion chamber, a launch tank for displacing the fuel component from it when the engine is started , according to the invention, the working cavity of the launch tank is hermetically divided by a piston or a flexible membrane into two parts, one of which is connected to the fuel pipeline, and the other to the oxidizer pipeline.

The essence of the invention is illustrated by the diagram shown in the drawing, where the following notation:

1 - TNA oxidizer pump;

2 - fuel pump TNA;

3 - turbine TNA;

4 - gas generator;

5 - camera;

6 - a starting tank;

7 - cavity oxidizer launch tank;

8 - cavity of the fuel starting basque;

9 - a separating piston with a seal;

11 - filling valve starting tank;

12, 13 - check valve;

14, 15, 21, 22 - start-off valve;

16, 17 - tuning washer;

18 - fuel pipeline;

19 - oxidizer pipe;

10, 20 - starting valve.

The proposed engine design, therefore, consists of start-up valves 10 and 20, chamber 5, a turbopump assembly (including an oxidizer pump 1, a fuel pump 2 and a turbine 3), a gas generator 4, fuel pipelines 18 and an oxidizer 19, communicating exits from the gas generator pumps and a chamber, one starting tank 6, separated by a piston 9 (with a tight seal) into a fuel cavity 8 and an oxidizer cavity 7, each of which is connected to the supply line of the gas generator. The fuel cavity is equipped with a filling line with a valve 11. In the supply lines of the gas generator there are check valves 12 and 13 and start-off valves 14 and 15. In the supply lines of the chamber there are start-off valves 21 and 22.

The engine operates as follows. Before starting, the starting tank through the valve 11 is filled with the fuel component whose pressure at the engine inlet is insufficient (in this circuit it is fuel). After refueling, valve 11 closes. Valves 14, 15, 10, 20, 21 and 22 are also in the closed position. Starting the engine begins with the opening of valves 10 and 20. The lines are filled with fuel components that fill the pumps 1 and 2, and, opening the check valves 12 and 13, enter the pipelines 18 and 19, connecting to the cavities 7 and 8 of the launch tank.

In the cavities of the tank, a pressure equal to the highest of the pressures in the drift lines (oxidizer) is established. After the valves 14 and 15 are opened, the fuel components under this pressure enter the gas generator, providing after the ignition it develops a working process with a constant (or close to constant) gas temperature due to the constant ratio of the oxidizer to fuel consumption.

Thus, a smooth start-up of gas generator without temperature rises.

The gas produced in the gas generator spins the turbine, the pressure behind the pumps rises, the gas generator begins to be fed from the pump lines, the valves 21 and 22 of the chamber open, and the engine enters the design mode. The presence of one starter tank instead of two for the prototype favorably affects the increase in reliability.

Claims (1)

A liquid rocket engine containing a combustion chamber, a gas generator, a turbine, a fuel pump, an oxidizer pump, fuel and oxidizer pipelines, communicating exits from pumps with a gas generator and a combustion chamber, a launch tank for displacing fuel components from it when the engine starts, characterized in that the working the cavity of the launch tank is hermetically divided by a piston or a flexible membrane into two parts, one of which is connected to the fuel pipeline, and the other to the oxidizer pipeline.

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