RU2200866C2 - Controlled liquid-propellant rocket engine - Google Patents

Abstract

FIELD: rocketry. SUBSTANCE: controlled liquid-propellant rocket engine contains chamber, gas generator and turbopump set with centrifugal pumps and turbine. Automatic control system contains valves, liquid flow controllers and liquid flow stabilizer. High-and low-pressure propellant main lines include at least two high- pressure liquid propellant main lines with liquid flow controllers operated by drives when electric commands are sent. Engine is furnished with control electric valves and command shaping unit to form commands for operation of control electric valves. At least two high-pressure liquid propellant main lines are branched into two parallel lines provided with common inlet and common outlet for each main line. Each liquid flow controller is made in form of hydraulic valves installed in corresponding lines of main lines and operated by control electric valves. Said hydraulic valves have two fixed positions, namely open and closed. EFFECT: improved response of liquid propellant engine control system with provision of quickly changing thrust value. 4 cl, 6 dwg

Description

Technical field
The invention relates to rocket propulsion and can be used in aircraft engine construction.

State of the art
Liquid rocket engines (LRE) with thrust regulation by controlling the flow of fuel components supplied to the chamber and the LRE gas generator are widely used in technology.

 So, there is a known scheme for regulating the thrust of a liquid propellant rocket engine by regulating the flow of fuel components to a gas generator based on pressure regulators and changing the ratio of fuel components in the chamber according to the signal from the tank emptying system using a regulator. This LRE has at least two liquid high-pressure fuel lines with fluid flow controllers (see Design and Design of Liquid Rocket Engines. / Under the General Edition of Prof. GG Gakhun. M: Mechanical Engineering, 1989, pp. 51, 52 paragraph "Regulation of engine thrust"). This technical decision is taken as an analogue of the invention. The disadvantage of the analogue is that it is difficult to provide a high-speed regulation system in the actual dimensions of the LRE.

 In addition, the throttle actuator shown on page 51 of this monograph as a fluid flow regulator in many cases requires a powerful electric drive, which not only leads to large dimensions and weight, but also requires special electrical production for its manufacture. It can be difficult to organize in rocket engine plants. Another drawback of the analogue is the complexity of the control scheme based on the use of three regulators in a liquid propellant rocket engine operating on two fuel components.

 Known rocket engine RD-253 (see encyclopedia: Cosmonautics. / Edited by V.P. Glushko. M., 1985, p. 331) on two-component fuel. This LRE is taken as a prototype of the invention. The prototype has a chamber, a gas generator, a turbopump unit with a turbine and centrifugal pumps, an automation system with valves, fluid flow controllers and a device for stabilizing the fluid flow; it has high and low pressure fuel lines, and at least two lines are high pressure fuel liquid lines, in which fluid flow controllers are installed. The disadvantage of the prototype is that it has a small speed control system with the actual dimensions of the rocket engine. In addition, the fluid flow regulators (throttle and flow regulator) are equipped with electric drives, the development and manufacture of which requires special production, which complicates and increases the cost of manufacturing the rocket engine.

Disclosure of Invention
The basis of the present invention, the LRE is the task of increasing the speed of the control system of the LRE in order to more quickly change the magnitude of the thrust vector. The need to create such a rocket engine is dictated by the feasibility of greater maneuverability of the rocket aircraft and its more accurate launch into orbit.

 The essence of the invention of an adjustable LRE is that the LRE includes a chamber, a gas generator, a turbopump with centrifugal pumps and a turbine. There is also an automation system that contains valves, fluid flow controllers and a device for stabilizing fluid flow, as well as high and low pressure fuel lines. In this case, the engine contains at least two high-pressure liquid fuel lines, on which the specified fluid flow controllers and a device for stabilizing the fluid flow are installed. Moreover, fluid flow controllers are controlled by drives by submitting the appropriate electrical commands. A distinctive feature of the claimed LRE is that it is equipped with electro-control valves, the issuance of commands for which makes it possible to change the operating mode of the LRE, that is, regulation both in terms of missile speed and in emptying the fuel tanks of a rocket propulsion system.

 The control electro-valves receive commands from the command-forming unit on the engine. This unit does not have to be mounted on the engine. It can also be mounted elsewhere in the rocket.

 In the inventive rocket engine, at least two high-pressure liquid fuel lines are branched into parallel branches having a common input and a common output for each of the lines. Each control unit is made in the form of hydraulic valves installed in the corresponding branches of the main lines. These hydraulic valves are controlled by electro-control valves (i.e., electro-control valves can connect control cavities of hydraulic valves to low or high pressure lines, ensuring their opening or closing, changing the hydraulic resistance of the corresponding line).

 This leads to a corresponding change in the magnitude of the thrust vector of the engine and the given coordination in the emptying of the tanks of the rocket propulsion system. Both electrovalves and hydrovalves have two fixed positions "open" and "closed". The electrovalves are controlled by applying electric current to their electromagnets. Solenoid valves receive commands from the command generation unit, which amplifies low-current commands coming, for example, from a system for controlling the apparent speed of a rocket and a tank emptying system. In principle, the most effective scheme with electro-hydraulic valves as electro-valves, although it is possible to build circuits with a gas cylinder and electro-pneumatic valves.

 In the particular case, the number of control electro-valves for each control unit corresponds to the number of independent branches of its hydraulic line with the hydraulic valves installed in them. It should be noted that the number of solenoid valves does not have to be equal to the number of hydraulic valves of the corresponding fuel line. It is possible when the control solenoid valve can control more than one hydraulic valve, for example two hydraulic valves. It is also possible when more than one control solenoid valve, for example two solenoid valves, will control one hydraulic valve. This may be due to engine layout conditions as well as technological considerations.

 It should be noted that for us in the present case, important are independent branches with hydraulic valves of the corresponding fluid flow regulator. By such branches, we mean branches that are opened by one single command that controls the fluid flow regulator and comes from the unit for generating commands to the corresponding electrovalve (or electrovalves).

где индекс i обозначает соответствующую ветвь магистрали и ее гидроклапан;
F_i - площадь проходного сечения открытого соответствующего i-го гидроклапана;
ζ_i - суммарный коэфициент гидравлического сопротивления i-й ветви магистрали с ее гидроклапаном.Hydraulically in the open position of the corresponding hydraulic valve (s), such a branch is characterized by the ratio

where the index i denotes the corresponding branch of the highway and its hydraulic valve;
F _i is the flow area of the corresponding corresponding i-th hydraulic valve;
ζ _i is the total hydraulic resistance coefficient of the i-th branch of the pipeline with its hydraulic valve.

образуют геометрическую прогрессию со знаменателем 2, то есть отношение

для каждой ветви магистрали определяется выражением

где индекс 1 относится к 1-й ветви магистрали со своим гидроклапаном.For different branches of a relationship

form a geometric progression with denominator 2, that is, the ratio

for each branch of the highway is determined by the expression

where index 1 refers to the 1st branch of the highway with its hydraulic valve.

 As a device for stabilizing the fluid flow, a differential pressure stabilizer can be used on at least one of the fluid flow regulators. To stabilize the flows in the highways of the claimed LRE, special nozzles can also be used.

 In yet another particular case, the branched high-pressure liquid fuel line can be bypassed with respect to the main line for supplying this fuel. It should be noted that the schematic diagram of the inventive adjustable rocket engine is not of particular importance. LRE can be performed both according to the scheme with afterburning of the gas-generating gas, and according to the open scheme. It is important in it that the implementation of a branched liquid fuel line, as well as the installation of hydraulic valves in the branches of this highway and the presence of control electrovalves.

 It must be said that the claimed adjustable LRE for a three-component engine will not essentially differ from the fundamental solution we considered for a two-component LRE. In this case, it is advisable to carry out branched three high-pressure liquid fuel lines, and each control unit to be installed in the corresponding line in the form of hydraulic valves in its corresponding parallel branches. This allows for reliable regulation of the engine at the apparent speed of the rocket and the corresponding simultaneous emptying of the fuel tanks of the rocket.

 It is not difficult to use the proposed technical solution in a single-component rocket engine with a balloon fuel supply system. In this case, it may be appropriate to use in such a liquid-propellant rocket engine only one fluid flow regulator or in general any fluid medium, made similar to the technical solution proposed in this application.

 The technical result of the present invention lies in the fact that, first of all, the speed of the control units is increased, especially when the controller is shifted from one extreme position to another (by two orders of magnitude). The accuracy of regulation in comparison with the regulators controlled by analog drives doubles. Due to the lack of an electric drive in the declared rocket engine, mass reduction is provided. This also provides simplification of the design. It should be noted that the claimed invention has advantages compared to a digital electrohydraulic actuator, which requires a special complex hydraulic system. The claimed device is both simpler and easier.

 The inventive adjustable LRE is conveniently manufactured at a rocket and engine plant, while a LRE with a well-known regulatory system requires special production, where an electric drive could be designed and manufactured. It should be noted that the proposed liquid propellant rocket engine can provide almost any change in the program of its start and stop without making any changes to the design of the engine. This is all an additional technical result.

Brief Description of the Drawings
Figure 1 shows a schematic diagram of an adjustable rocket engine;
in FIG. 2 - a unit for generating commands with electrohydro valves connected to it;
figure 3 - electrohydrovalve;
figure 4 - fluid flow regulator in a branched line;
in FIG. 5 - fluid flow regulator in a branched line with differential pressure stabilizer;
in FIG. 6 - fluid flow regulator in a branched line, connected bypass.

An example implementation of the invention
The schematic diagram of the proposed two-component adjustable LPRE is presented in figure 1, where 1 is the chamber, and 2 is the gas generator, which is in communication with the chamber 1 through the gas ducts 3 and 4 and the turbine 5 of the turbopump assembly, which also includes a centrifugal oxidizer pump 6 and a centrifugal fuel pump of the first stage 7 and the second stage 8. At the inlet of the gas generator 2, a fuel valve 9 and an oxidizer valve 10 are installed. With the cooling jacket (not indicated) of the chamber 1, the main valve of the fuel 11 is connected. The LPRE has a high pressure pipeline oxidized Itel 12 installed at the outlet of the centrifugal pump of the oxidizing agent 6 in front of the gas generator 2. There is also a high-pressure fuel line 13 located at the outlet of the second stage of the centrifugal fuel pump. At the outlet of the first stage 7 of the centrifugal fuel pump, there is a high-pressure fuel line 14, which is hydraulically connected to the entrance to the second stage 8 of the fuel pump by a pipe 15, and a high pressure pipe 16 is also installed between the exit of the fuel pump of the first stage 7 and the chamber 1. low pressure pipelines are located at the inlet of the LRE - oxidizer 17 and fuel 18 pipelines entering the LRE, which are hydraulically connected to the entrances to the oxidizer pump 6 and the first stage of the fuel pump 7, respectively of course.

 In the high-pressure highway of the fuel of the first stage 8 of the pump between the pipelines 14 and 16, a fluid flow regulator 19 is installed (see also Fig. 4), and in the high-pressure pipeline of the fuel 13 a fluid flow regulator 20 is installed with a differential pressure stabilizer on it 21, combined in block 22 (see also figure 5). The fluid flow controllers 19 and 20 are structurally similar in principle. In our case, they contain eight hydraulic valves. In principle, this number may be another integer.

 A structural diagram of a fluid flow regulator 19 is shown in FIG. 4, where the high-pressure fuel line 14 is branched into parallel branches 23, 24, 25, 26, 27, 28, 29, 30, which also have a common outlet 16 (hereinafter, the positions of the eight branches of this hydraulic line and the elements of its branches are located in the procedure for reducing their hydraulic resistances, except for the last three branches of the eight indicated, which for structural reasons in our particular case have equal hydraulic resistances). In these branches, hydraulic washers 31, 32, 33, 34, 35, 36, 37, 38 are installed (in principle, a design without hydraulic washers is also possible) and hydraulic valves 39, 40, 41, 42, 43, 44, 45, 46 To these hydraulic valves, to their control cavities (positions are not indicated), the corresponding supply lines 47, 48, 49, 50, 51, 52, 53, 54 of the supply of control pressure are connected (see also FIGS. 2, 3).

где F₁- площадь проходного сечения открытого гидроклапана;
а ζ₁ - суммарный коэфициент гидравлического сопротивления этой первой ветви, включая eе гидравлическую шайбу и гидроклапан.In the design of the fluid flow regulator 19 under consideration (as well as the fluid flow regulator 20), it is important that their respective branches between the exit from the highway 14 and the entrance to the highway 16 also include hydraulic washers (if any) included in each corresponding branch and hydraulic valves. So, for example, the first branch 23 (see figure 4) with the greatest hydraulic resistance with a washer 31 and a hydraulic valve 39 is determined by a certain ratio

where F ₁ - the area of the bore of the open hydraulic valve;
and ζ ₁ is the total hydraulic resistance coefficient of this first branch, including its hydraulic washer and hydraulic valve.

где индекс i обозначает соответствующую ветвь с гидроклапаном и шайбой (если таковая имеется);
F - площадь проходного сечения открытого гидроклапана;
ζ - суммарный коэфициент гидравлического сопротивления ветви с гидроклапаном и гидравлической шайбой (если такая имеется).The ratio of other branches is defined as

where the index i denotes the corresponding branch with a hydraulic valve and a washer (if any);
F is the flow area of an open hydraulic valve;
ζ is the total coefficient of hydraulic resistance of the branch with a hydraulic valve and a hydraulic washer (if any).

Ветви 29 и 30 в принципе могут иметь такое же значение этого соотношения, как и ветвь 28, что справедливо для фиг.4

Впрочем работоспособность устройства может быть обеспечена и при замене этого выражения выражением

так как в нашем случае на гидроклапаны 45 и 46 подается одна общая команда. Они могут функционировать от общего электрогидроклапана регулирования, например 61. Магистрали 47, 48, 49, 50, 51, 52, 53, 54 соответственно сообщены с злектрогидроклапанами регулирования 55, 56, 57, 58, 59, 60, 61, 62. Принципиальное конструктивное исполнение одного из этих клапанов (а именно электрогидроклапана 55) представлено на фиг.3, где 63 - корпус, 64 - электромагнит, 65 - золотник, 66 - пружина, 67 - штуцер высокого давления, 68 - штуцер низкого давления, например, в дренаж или в трубопровод 18.This means that, for example, for branch 28

The branches 29 and 30, in principle, can have the same value of this ratio as the branch 28, which is true for figure 4

However, the operability of the device can be ensured by replacing this expression with the expression

since in our case, one common command is given to hydraulic valves 45 and 46. They can function from a common control electro-hydraulic valve, for example 61. Highways 47, 48, 49, 50, 51, 52, 53, 54, respectively, are connected to control electro-hydraulic valves 55, 56, 57, 58, 59, 60, 61, 62. The principle constructive the design of one of these valves (namely, the electrohydro valve 55) is shown in Fig. 3, where 63 is the body, 64 is the electromagnet, 65 is the spool, 66 is the spring, 67 is the high pressure fitting, 68 is the low pressure fitting, for example, in the drain or in the pipeline 18.

 The hydraulic valves 39, 40, 41, 42, 43, 44, 45, 46 of the fluid flow regulators 19 and 20 have gates, in the closed position of the hydraulic valve are indicated by 69a, and in the open position by 69c (see figure 4). The arrows indicate the direction of fluid flow with the corresponding valves open.

 It should be noted that setting the branches 23, 24, 25, etc. can be made either by changing the hydraulic resistance of the corresponding hydraulic valves 39, 40, 41, etc., or by using the corresponding hydraulic washers 31, 32, 33, etc., or by using the channels of the main branches by conducting appropriate spills, either by theoretical calculations.

 Figure 5 is a structural diagram of a block 22 containing a fluid flow regulator 20 and a differential pressure stabilizer 21 on this regulator (see also figure 1). Although in FIGS. 4 and 5, the hydraulic valves 39, 40, 41, 42, 43, 44, 45, 46 are identical, they can differ in both dimensions and design to ensure optimal mass characteristics, as they are designed for different hydraulic resistances and working pressures for various hydraulic washers 31, 32, 33, 34, 35, 36, 37, 38 both in fluid flow controllers 19 and in fluid flow controllers 20.

 The liquid propellant rocket engine has a command generation unit 70 (see FIGS. 1, 2) for electrovalves, to which signals 71, 72 are supplied for controlling valves and controllers from a rocket aircraft, respectively (not shown in the drawings). These signals are converted and amplified in the command generation unit 70. This unit is also electrically connected to the electrohydro valves 73, which control the hydraulic valves of the fluid flow regulators 19 and 20, and to the electro valves 74, which control the fuel valves 9, 10, 11. The command generation unit 70 is also connected power supply 75.

 In the LRE scheme, a number of elements and systems are omitted from consideration that are not of fundamental importance in this case (such as the ignition system, emergency start of the LRE and others). In this case, the command generating unit 69 will also be electrically connected with other corresponding elements and automation units, which are absent in the liquid-propellant rocket engine circuit in Fig. 1, and, for example, the electrohydro valves of group 74 can be supplemented with additional electro-control valves.

 As an embodiment of the installation of the installation of the fluid flow regulator on the LRE in Fig.6 shows the bypass location of this regulator in the high-pressure line. The branches of the high-pressure line are basically similar to the fluid flow controllers 19 and 20 shown in Fig. 1, however, the fluid flow control (see Fig. 6) is installed bypass of the main line 76 and may contain a hydraulic washer 77.

 The present invention can be used both in a single component and in a three-component liquid-propellant rocket engine with the required adjustment of the number of corresponding controllers.

 The claimed adjustable rocket engine works as follows. In the initial position, the fuel and oxidizer lines are filled through the reduced pressure pipelines of the fuel 18 and oxidizer 17 up to valves 9, 10, 11, which are closed in the initial position. The fluid flow controllers 19 and 20 are set to the start position. This means that power is supplied only to those solenoid valves 55, 56, 57, 58, 59, 60, 61, 62 (73) that provide the closed position of the corresponding hydraulic valves 39, 40, 41, 42, 43, 44, 45, 46 (for both the regulators 19 and the regulators 20) and, therefore, the corresponding hydraulic resistance of the fluid flow regulators 19 and 20 of their branches 23, 24, 25, 26, 27, 28, 29, 30 together with washers 31, 32, 33 , 34, 35, 36, 37, 38.

 At the start of the liquid propellant rocket engine, the corresponding commands are issued to the valve of group 74, which control valves 9, 10, 11. This ensures the opening of these valves.

 In the LRE, the ignition of the fuel components and the initiation of processes in the gas generator 2 and chamber 1, as well as the acceleration of the turbopump assembly from the turbine 5, which drives the centrifugal pumps 6, 7, 8 and the launch of the LRE, are ensured.

 During the startup process, it is possible to change the hydraulic resistances of the mains in which the fluid flow regulators 19 and 20 are installed by submitting the appropriate commands through the command generation unit 70 to the electrohydro valves 55, 56, 57, 58, 59, 60, 61, 62 (73), which control corresponding hydraulic valves of regulators 19 and 20.

 LRE goes into mode. If it is necessary to change the operating mode of the liquid propellant rocket engine, the yes-no system commands are sent via the electro-hydraulic valves 55, 56, 57, 58, 59, 60, 61, 62 (73) to the hydraulic valves 39, 40, 41, 42 43, 44, 45, 46 fluid flow controllers 19 and 20. Of these hydraulic valves, open and closed are only those that provide the specified hydraulic resistance of the fuel lines in which the regulators 19 and 20 are installed. Electrohydro valves 55, 56, 57, 58, 59 , 60, 61, 62 (73) all at the same time or a given part of them can be in open or closed m position, which provides different modes of operation of the liquid propellant rocket engine due to various combinations of hydraulic resistances of fluid flow regulators 19 and 20 due to the corresponding open or closed hydraulic valves 39, 40, 41, 42, 43, 44, 45, 46 One of such modes may be the mode of the final stage of the rocket engine.

 The differential pressure stabilizer 21 provides a predetermined differential pressure value on the fluid flow regulator 20. Thus, essentially the digital regulators 19 and 20 are used in the inventive LRE. This makes it possible, first of all, to ensure the speed of the transfer of the LRE from one mode to another.

 In principle, such a rocket engine may not have a turbopump supply system, but a balloon supply system. In addition, it is possible to use in the inventive LRE driven by liquid or gas booster pump units and side valves at the engine inlet. In some cases, booster pump units are necessary to provide an increased input pressure to centrifugal pumps to ensure their cavitation-free operation.

Industrial applicability
The invention is intended for use in liquid propellant rocket engines of various thrusts and operating on various fuel components. The invention is ready for industrial use.

Claims (4)

 1. An adjustable liquid propellant rocket engine, including a chamber, a gas generator, a turbopump unit with centrifugal pumps and a turbine, comprising valves, fluid flow regulators and a device for stabilizing fluid flow, an automation system, as well as high and low pressure fuel lines, including at least two liquid high-pressure fuel lines with the indicated fluid flow controllers, controlled by drives by applying the appropriate electrical commands, characterized in that the liquid the rocket engine is equipped with control electro-valves and a command generation unit, including control electro-valves, and at least two high-pressure liquid fuel lines are branched into parallel branches having a common input and a common output for each line, and each liquid flow regulator is made in the form installed in the corresponding branches of these lines of hydraulic valves controlled by control electrovalves, moreover, the hydraulic valves have two fixed positions - open closed. 2. A liquid-propellant rocket engine according to claim 1, characterized in that the number of solenoid valves for each fluid flow regulator corresponds to the number of independent branches of its hydraulic line with installed hydraulic valves, and hydraulically characterizing these branches and their hydraulic valves in the open position

where the index i denotes the corresponding branch and hydraulic valve, F _i is the flow area of the corresponding open hydraulic valve, and ζ _i is the total hydraulic resistance coefficient of the branch with its hydraulic valve, they form a geometric progression with denominator 2 for different branches, i.e., the ratio

for each branch of the highway is determined by the expression

where index 1 - refers to the 1st branch of the highway with its hydraulic valve.  3. A liquid rocket engine according to claim 2, characterized in that therein, as a device for stabilizing the fluid flow, a differential pressure stabilizer is made on at least one of the fluid flow regulators.  4. A liquid rocket engine according to claim 1, characterized in that the branched line for supplying liquid fuel is bypassed relative to the main line for supplying this fuel.

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