RU2556091C1 - Liquid-propellant engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to liquid-propellant engines (LPE) and can be used at their bench fire development for improvement of operating reliability of a combustion chamber. LPE containing a frame, components, consumption manifolds, a chamber that includes fuel manifolds on a nozzle and a cylindrical part, a pipeline for fuel transfer between manifolds with a fuel drain valve installed in it, in which, according to the invention, in the pipeline for fuel transfer between manifolds in front of the fuel drain valve there installed is a T-piece, to the threaded nozzle of which there connected is a fuel drain line consisting of a transition piece, a pipeline and a reusable start and cutoff valve fixed on the frame tie member, between the transition piece and the pipeline of the fuel drain line there installed is an eccentric compensator, in a detachable connection between the pipeline and the reusable start and cutoff valve of the fuel drain line there installed is a turning flange, and attachment clamps of the reusable start and cutoff valve to the frame tie member are adjustable. The pipeline of the fuel drain line has a compensation bend.

EFFECT: improving reliability and duration of operation of the chamber due to excluding the occurrence of a coke-shaped film on the inner cover of the chamber on the side of the cooling circuit during several cutoffs of the engine at shutdown.

4 cl, 12 dwg

Description

The invention relates to liquid-propellant rocket engines (LRE) and can be used with their fire bench testing to improve the reliability of the combustion chamber.

Known liquid rocket engine (LRE) F-1, developed by the company "Rocketdain" for the first stage of the rocket "Saturn-5", in which the fuel-kerosene separately through two pipelines is sent to the chamber. On each of them the main start-shut-off valves are installed.

External cooling of the chamber is carried out by fuel (70% of the total flow rate), which enters the cooling path near the mixing head. Fuel flows through the outer tubes toward the nozzle, and through the inner tubes it returns to the head (Design and Design of Liquid Rocket Engines, Moscow, Mechanical Engineering, 1989, edited by Professor G.G. Gakhun, p. 86 -88).

In the known rocket engine, if it is repeatedly turned on and off on the walls of the inner tubes of the nozzle, the formation of a coke-like film from various fractions of superheated kerosene, which can lead to disruption of heat transfer in the cooling tract of the chamber and an emergency outcome of the fire test. That is, the disadvantage of the analogue is the insecurity of the camera from overheating of the nozzle inner tubes when the engine is turned off repeatedly at a stop.

Known liquid rocket engine RD-107 of the first stage of the Vostok space rocket operating on fuel components: oxygen + kerosene in an open circuit. Internal and external cooling of the engine chamber was carried out using kerosene supplied to the head of the chamber and the collectors on its nozzle (Liquid Rocket Engines, Moscow, Mechanical Engineering, 1968, edited by MV Dobrovolsky, p. 257 )

The well-known liquid-propellant rocket engine was developed during the heyday of the development of domestic space exploration and rocket engine building, when a relatively large number of development bench engines were envisaged for the development of R&D for its creation, and the question was not acute about saving material parts, as well as about combining various types of tests and tasks for limited number of engines. In this engine, there is no device for draining fuel from the cooling channel of the chamber, ensuring its reliable operation at a stop in case of multiple starts at the stand, and the engine was not designed to work for several thousand seconds.

Thus, the disadvantage of this analogue is its limited time.

Known liquid rocket engine with afterburning of the generator gas, in the chamber of which the products of gas generation and liquid fuel (kerosene) are converted into high-temperature products and create reactive thrust when they expire from the nozzle ("14D23.00-00.000 Engine. Technical description, developed by JSC KBHA, Voronezh, pp. 27, 30 "- prototype).

The chamber of this rocket engine (see Fig. 1) is an integral solder-welded construction and consists of a mixing head 2 with a gas duct 1, a combustion chamber 3, an upper nozzle 5, a lower nozzle 6, a bandage with trunnions 4.

Fuel in the cooling path 7 of the chamber is supplied through the collector 8 (see Fig. 2). Having turned around at the nozzle exit, it enters the manifold 9 on the nozzle and then through the pipe 11, valve 12 passes to the manifold 10 on the mixing head.

During the experimental development of the well-known liquid propellant rocket engine due to the high cost of the material part and the limited number of engines, it became necessary to increase the number of engine starts and the tasks to be solved during fire bench tests: testing start and stop, ensuring reliability under the influence of various environmental factors, vibration etc.

However, after two or three engine starts, the walls of some of its chambers burned out and lost their integrity. The reason for this phenomenon was the following: a sharp decrease in fuel consumption in the cooling path of the heated chamber during shutdown led to kerosene overheating, as a result of which a thinnest film of sintered oily fractions of kerosene was formed on the wall of the inner shell of the chamber, i.e. the so-called "coke", which caused a sharp decrease in the coefficient of thermal conductivity, deterioration in cooling and an increase in the temperature of the material of construction above the permissible.

Thus, the disadvantage of the LRE - prototype is the limited number of accident-free launches (≈ 2 ÷ 3) and the operating time (≈ 300 ÷ 600 s) due to unreliable cooling of its chamber.

The objectives of the proposed LRE with a device for draining fuel from the cooling path of the LRE chamber are the following:

- improving the reliability and duration of the camera by eliminating the appearance of a coke-like film on the inner shell of the camera from the cooling path during several engine shutdowns at a stop;

- an increase in the number of rocket launcher launches during firing bench tests due to the organization of the discharge of fuel from the transfer pipe into the bench container;

- the increase in the frequency of use of the DSE of the fuel drain and start-shut-off valves on several rocket engines due to their re-installation;

- ensuring the constant coordinates of the connecting flange of the start-shut-off valve at the junction with the bench line;

- improving the reliability of the threaded fitting on the tee of the transfer pipe on the camera.

The tasks are achieved by the fact that in the proposed LRE containing a frame, assemblies, supply lines, a chamber that includes fuel manifolds on a nozzle and a cylindrical part, a fuel transfer pipe between collectors with a fuel drain valve installed in it, in which, according to the invention, in a transfer pipe between the manifolds, a tee is installed in front of the fuel drain valve, to the threaded fitting of which a fuel drain line is connected, consisting of an adapter, a pipeline and a start-up an eccentric compensator is installed between the adapter and the pipeline of the fuel drain line, a rotary flange is installed in the detachable connection between the pipeline and the start-shut-off reusable valve of the fuel drain line, and the clamps for attaching the start-shut-off reusable valve to the frame extension are made adjustable, while the pipeline fuel drain is made with a compensation bend.

The invention is illustrated by sketches.

In FIG. 1 presents an image of the design of the chamber of the rocket engine - prototype, where:

1 - gas duct;

2 - mixing head;

3 - combustion chamber;

4 - axle;

5 - upper nozzle;

6 - lower nozzle.

In FIG. 2 shows a diagram of the cooling path of the LRE chamber of the prototype, where:

3a - the cylindrical part of the combustion chamber;

7 - channel cooling chamber;

8, 9, 10 - fuel collectors;

11 - fuel transfer pipe;

12 - fuel drain valve.

In FIG. 3 shows the main view of the proposed LRE with afterburning of the generator gas, where:

13 - frame;

14 - units;

15 - supply lines;

16 - camera;

16a - turbopump unit (TNA);

17 - liquid rocket engine;

A - a remote element with a fuel drain line from the chamber cooling path to the stand.

In FIG. 4 shows a wiring diagram of a device for draining fuel from the cooling path of the chamber of the proposed LRE, where:

18 - tee;

19 - threaded fitting;

20 - fuel drain line;

21 - adapter;

22 - eccentric compensator;

23 - pipeline;

24 - start-shut-off reusable valve.

In FIG. 5 shows a highway for draining fuel from the cooling path of the rocket engine chamber, where:

25, 26 - adjustable clamps,

27 - the core of the frame;

28 - compensation bending of the pipeline.

In FIG. 6 shows a cross-section of the detachable connection of the drain line adapter with the fitting of the tee of the transfer pipe of the combustible chamber, where:

29 - flat copper sealing gasket;

30 - flare nut.

In FIG. 7 shows the connection of the compensator with the adapter and the pipeline of the drain line, where:

31 - backing rings;

L is the length of the compensator;

E is the eccentricity of the compensator;

- сварные швы.

- welds.

In FIG. 8 shows a section of a detachable connection of a pipeline of a fuel drain line with a start-shut-off reusable valve, where:

32 - the nipple of the pipeline 20 at the junction of it with the start-shut-off reusable valve 24;

33 - connecting flange of the start-shut-off reusable valve 24;

34 - rotary flange;

35 - flat copper sealing gasket;

36 - a bolt;

37 - a nut;

38 - washer.

In FIG. 9 shows the mounting of the start-shut-off reusable valve on the frame rod using adjustable clamps, where:

Y - coordinate of the connecting flange of the start-shut-off reusable valve;

39, 40, 41, 42 - rack clamps.

In FIG. 10 shows a section DD on mating struts of the clamp (see Fig. 9).

In FIG. 11 shows a wiring diagram of an LCI engine chamber with a plug on a threaded fitting 19 of a fuel transfer pipe tee, where:

Ε - remote element connecting the plug with a threaded fitting.

In FIG. 12 shows a cross-section through the extension element Ε of the connection of the fitting 19 with the plug (see Fig. 11), where:

43 - a stub;

44 - union nut;

45 - flat copper sealing gasket;

46 - a lock ring;

47 - safety wire;

48 - seal.

A liquid-propellant rocket engine 17 (see FIG. 3) comprises a frame 13, aggregates 14, consumable lines 15, a chamber 16, which includes collectors 8, 9 on the nozzle and 10 on the cylindrical part 3a (see FIG. 2).

The manifolds 9 and 10 of the chamber are interconnected by a fuel transfer pipe 11 containing a fuel drain valve 12, as well as a tee 18 (see Fig. 4) with a threaded fitting 19. A fuel drain 20, which contains an adapter 21, is connected to the threaded fitting 19 of the tee. , an eccentric compensator 22, a pipe 23 and a reusable shut-off valve 24 (see Fig. 4, 5), fixed with adjustable clamps 25, 26 on the shaft 27 of the frame 13 of the engine 17.

The adapter 21 is connected to the threaded fitting 19 through a flat copper sealing gasket 29 using a union nut 30 (Fig. 6).

по стыкам с установкой подкладных колец 31, предотвращающих проплавы и уменьшение проходного сечения магистрали горючего.The connection of the adapter 21 with the pipe 23 is made through an eccentric compensator 22 (Fig. 7) using welds

at the joints with the installation of washer rings 31, preventing penetration and reducing the flow area of the fuel line.

The connection of the pipeline 23 with the start-and-shut-off reusable valve 24 (Fig. 8) is made detachable through a flat copper gasket 35 using a rotary flange 34 and fasteners: bolts 36, nuts 37 and washers 38 (see Fig. 8).

(фиг. 10).Racks 41 and 42 of the clamp 26 have a channel profile in the DD section and are interconnected by a weld $$\sqrt{}$$

(Fig. 10).

The design of the clamps allows you to compensate for errors in the manufacture of the frame 13, the location of the DSE of the fuel drain line and provide the specified coordinates of the docking flange at the outlet of the start-shut-off reusable valve 24.

LRE with a device for draining fuel from the cooling channel of the chamber operates as follows.

When you turn off at the engine stop at the stand after the fire test, the fuel pressure behind the pump of the turbopump unit 16a (see Fig. 3) and in the cooling path of the chamber 7 gradually decreases. This leads to the closure of the fuel drain valve 12 in the fuel transfer pipe 11. At the same time, the start-shut-off reusable valve 24 opens in the fuel drain line 20. Fuel under residual pressure from the transfer pipe 11 enters through the DSE of the fuel drain line 20 and the start-shut-off reusable valve 24 into the bench line and stand capacity (not shown). Under the influence of the current fuel consumption in the cooling path of the chamber 7, the latter is cooled. At the same time, overheating of the fuel does not occur, which means that the film is also formed from coke-like deposits, too, the integrity of the chamber 16 is ensured, and no burnouts are observed.

The number of engine starts at the stand increases from 2 ÷ 3 to 6 ÷ 7 or more, and the operating time - from 300-500 s to 3000-4000 s, i.e. almost 10 times. It is known that the operating time of the engine is one of the most important indicators of its reliability.

In developing the design of a device for draining fuel from the cooling channel of the LRE chamber, other problems were also solved.

One of them is the reusable use of the DSE of the fuel drain line 20 and the start-shut-off reusable valve 24 on several engines by reinstalling them. For this purpose, in addition to the detachable connection of the adapter 21 with the threaded fitting 19 of the tee 18 of the transfer pipe 11, an eccentric compensator 22 is installed between the adapter 21 and the pipe 23, the clamps 25 and 26 are adjustable. The eccentric compensator 22 is cut when re-installing the material from one engine to another. In this case, the docking places on the adapter 21 and the pipeline 23 are restored or their tips are replaced.

When reinstalling the DSE of the fuel drain line 17 and the start-shut-off reusable valve 24 on the frame 13 of the engine 17, replace the flat copper gaskets 26, 32 in its detachable connections B, C, D (see Fig. 4).

Another problem solved by this technical device is to ensure that the coordinates of the docking flange 33 at the exit of the start-shut-off reusable valve 24 (see Fig. 5 and Fig. 9) at the junction with a bench tube (not shown) are constant. When reinstalling the DSE and the start-and-shut-off reusable valve 24 of the fuel drain line 20 to another engine due to deviations in the location of the threaded fitting 19 on the tee 18 of the transfer pipe 11 and the shaft 27 of the frame 13, withstand the coordinates of the connecting flange 33 at the exit of the start-and-shut refillable valve 24 is not possible. Therefore, to compensate for these deviations, the clamps 25 and 26 of the fastening of the reusable shut-off valve 24 are made adjustable in height and width of their racks 39, 40, 41, 42, in the pipe 23, the flange 34 is rotatable around the nipple 32, and between the adapter 21 and the pipe 23 an eccentric compensator 22 is installed, which is adjusted along the length "L" and the eccentricity "E", taking into account the actual location of the DSE. To ensure the constancy of the aforementioned X and Y coordinates of the outlet connecting flange 33 of the start-shut-off reusable valve 24, it was also necessary to manufacture slipway equipment to provide the coordinates of the threaded fitting 19 in the tee 18 of the transfer pipe 11, as well as the slipway equipment to ensure the coordinates of the outlet docking flange 33 of the reusable start-up - shut-off valve 24.

In the initial version of the design of the liquid fuel rocket engine with a fuel drain device, the base of the threaded fitting 19 in the tee 18 of the fuel transfer pipe 11 was destroyed due to the stiffness of the pipe 23 of the fuel drain pipe 20, the effects of vibrations from the start-shut-off reusable valve 24 and the fuel transfer pipe 11, located and fixed in different systems: on the engine and stand. To eliminate this defect, the diameter of the pipeline 23 and its wall thickness were reduced to optimal from the point of view of hydraulic resistance and flexibility, the pipeline 23 itself is made with a compensation bend 28, and the entire fuel drain line is fixed to the engine, i.e. in one system. The material of the tee 18 and adapter 21 was replaced from steel 12X1 VN10T to steel 07X16H6, which has a double safety margin. Thus, the third task was solved: the integrity of the threaded fitting 19 of the tee 18 was ensured.

After the control and technical fire test (CTI) of each engine at the stand, the fuel drain line 20 with the start-shut-off reusable valve 24 is dismantled from the engine. To do this, unscrew the union nut 30 at the point of its connection with the threaded fitting 19 of the tee 18 of the fuel transfer pipe 11, dismantle the clamps 25 and 26 from the rod 27 of the frame 13 and remove the DSE and the start-shut-off reusable valve 24 of the fuel drain line 20.

A flat copper sealing gasket 29 (see Fig. 6) is removed from the threaded fitting 19 without damaging the sealing places of the fitting 19, a new sealing gasket 29 and a plug 43 (see Fig. 12) with a union nut 44, locked by a wire 47 and fixed, are installed seal 48. In this design, the engine is sent for space flight tests (LCI) as part of the product.

The positive effects of the implementation of the proposed LRE with a device for draining fuel from the cooling path of its chamber are:

- improving the reliability of its 4 cameras, by eliminating coke formation on the inner wall of the nozzle by organizing the discharge of kerosene;

- an increase of ≈ 10 times the operating time of the engine, which allows us to solve and work out several different tasks on one material part (for example, throttling issues, accuracy of tuning, starting and stopping, vibration testing of power fittings and fasteners, testing in warranty ranges, etc. .), which reduces the material and financial costs of experimental development;

- re-installation of the components of the same fuel drain line on several engines significantly saves labor and material costs for manufacturing the material part of the engine, reduces the time it takes to prepare it for bench fire tests;

- ensuring the constancy of the coordinates of the outlet connecting flange of the start-shut-off reusable valve in the fuel drain line improves the conditions of connection with the bench pipe and also reduces the time for preparing the bench for fire tests;

- the manufacture of a pipe 23 of a fuel drain line 20 with a compensation bend 28, and a tee 18 of a fuel transfer pipe 11 and an adapter 21 made of steel with higher strength characteristics increase the reliability of the device when exposed to vibration loads during bench fire tests;

- installation of a fuel drain line as part of the engine, rather than a stand, is more preferable and expedient for a number of reasons: the need to place the start-shut-off valve closer to the place of fuel selection for drain, to fix it and the drain pipe in one system - on the engine, which increases the reliability of the threaded fitting on the tee of the transfer pipe and excludes the possibility of its breakage from loads from the side of the bench line.

Components, components, assemblies of the device are quite simple to manufacture, reliable in operation and quite solve the tasks.

Claims (4)

1. A liquid rocket engine containing a frame, assemblies, consumables, a chamber that includes fuel manifolds on a nozzle and a cylindrical part, a fuel transfer pipe between collectors with a fuel drain valve installed therein, characterized in that there is a fuel transfer pipe between collectors in front of the fuel drain valve have a tee installed, to the threaded fitting of which a fuel drain line is connected, consisting of an adapter, a pipeline and a start-and-shut valve fixed a stretching frame. 2. The liquid propellant rocket engine according to claim 1, characterized in that an eccentric compensator is installed between the adapter and the pipeline for the fuel drain line. 3. The liquid-propellant rocket engine according to claim 1, characterized in that a rotary flange is installed in it in a detachable connection between the pipeline and the start-shut-off reusable valve of the fuel drain line, and the clamps of the start-shut-off valve to the frame extension are adjustable. 4. LRE according to claim 1, characterized in that in it the pipeline of the fuel drain line is made with a compensation bend.

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