A monopropellant liquid rocket engine and chamber pressure roughness and temperature control method thereof

Abstract

The present invention discloses a monopropellant liquid rocket engine and a method for controlling chamber pressure roughness and temperature thereof. The rocket engine comprises a sleeve, a plug body, a front catalytic bed and a rear catalytic bed, wherein the plug body is coaxially installed inside the sleeve, the front catalytic bed and the rear catalytic bed are nested in sequence on the outside of the plug body, and the plug body is provided with a propellant supply flow channel, a propellant sub-flow channel, a resonance cavity and a resonance cavity balance flow channel. The liquid propellant first reacts in the front catalytic bed to generate gas-liquid phase propellant, and then reacts in the rear catalytic bed to generate high-temperature and high-pressure combustion gas, and the high-temperature and high-pressure combustion gas is divided into two parts, wherein most of the combustion gas is directly discharged when passing through the thrust to generate thrust, and a small part of the combustion gas enters the resonance cavity and then slowly flows out of the resonance cavity. The rocket engine of the present invention has few parts and low assembly difficulty, and also has the functions of low chamber pressure roughness and self-insulation.

Description

Technical Field

[0001] The invention relates to a single-component liquid rocket engine for satellites and detectors, in particular to a single-component liquid rocket engine with self-insulation and low chamber pressure roughness. Background Art

[0002] Monopropellant liquid rocket engines have been maturely used in providing impulse and attitude control in aircraft, satellites, probes, spacecraft, missile warheads, and launch vehicle upper stages due to their simple structure, low cost, and high reliability.

[0003] Since the power energy of a monopropellant liquid rocket engine comes from the catalytic reaction of the propellant, and the catalytic reaction is greatly affected by the temperature of the catalyst bed, it has two starting working modes: cold start and hot start. Among them, cold start causes great damage to the catalyst, and the number of cold starts limits the working life of the monopropellant engine. In addition, the monopropellant engine is in the deep cold environment of space for a long time, and the heat loss is serious. Therefore, the existing technology often uses heating equipment to keep the catalyst bed warm, so that the monopropellant engine can be in a hot start state for a long time and extend the working life. Summary of the invention

[0004] In order to solve the above problems, the present invention aims to provide a monopropellant liquid rocket engine and a method for controlling chamber pressure roughness and temperature thereof, thereby reducing the components of the monopropellant liquid rocket engine, reducing the assembly difficulty and external dimensions of the rocket engine, while reducing the chamber pressure roughness of the rocket engine, and further enabling the rocket engine to obtain the function of self-insulation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A monopropellant liquid rocket engine comprising:

[0007] A sleeve, wherein the interior of the sleeve and along the sleeve axis direction at least include a first cavity, a second cavity and a third cavity which are sequentially divided;

[0008] A front catalytic bed, wherein the front catalytic bed is located in the first cavity;

[0009] a rear catalytic bed, wherein the rear catalytic bed is located in the second cavity;

[0010] A plug body, wherein the plug body is coaxial with the sleeve and simultaneously passes through the front catalytic bed, the rear catalytic bed and the third cavity; a propellant supply channel and a propellant sub-channel are also provided in the plug body; wherein the propellant supply channel is a blind hole opened on the end face of the first end of the plug body; the propellant supply channel extends from the first end of the plug body to the first cavity; one end of the propellant sub-channel is connected with the propellant supply channel, and the other end passes through the surface of the plug body and is connected with the front catalytic bed; the portion of the plug body located in the third cavity is a variable cross-section structure and a resonant cavity and a resonant cavity balancing channel are provided inside; the cross-sectional area of ​​this portion of the plug body gradually increases from small to large in the direction from the second cavity to the third cavity, and then gradually decreases; a thrust chamber with a cross-section that changes from large to small and then from small to large is formed between the surface of this portion of the plug body and the inner wall of the third cavity; the thrust chamber is connected with the resonant cavity through the resonant cavity balancing channel.

[0011] Furthermore, the sleeve is a cylindrical structure with one end open and the other end closed, and a through hole for installing the plug body is opened on the end surface of the closed end of the sleeve, and a fixing seat is also arranged on the circumference of the outer surface of the sleeve corresponding to the closed end of the sleeve.

[0012] Furthermore, the first end of the plug body extends to the outside of the sleeve through the through hole, and the surface of the plug body located outside the sleeve is provided with an external thread, and the plug body is coaxially installed in the sleeve through a fixing nut sleeved on the external thread.

[0013] Furthermore, a sealing structure is provided at a contact position between the plug body and the through hole of the closed end surface of the sleeve.

[0014] Furthermore, a first positioning boss is provided on the surface of the plug body, and the front catalyst bed is sleeved on the outer surface of the plug body and is limited and positioned by the first positioning boss.

[0015] Furthermore, a second positioning boss is provided on the surface of the plug body, and the rear catalytic bed is sleeved on the outer surface of the plug body and is limited and positioned by the second positioning boss.

[0016] Furthermore, the front catalytic bed and the rear catalytic bed are filled with catalyst particles, and the particle size of the catalyst particles in the front catalytic bed is smaller than that of the catalyst particles in the rear catalytic bed.

[0017] Furthermore, the propellant sub-channels are a plurality of holes which are perpendicular to the axial direction of the plug body and arranged in an array.

[0018] Furthermore, the propellant supply channel includes an interface with a conical surface.

[0019] A method for controlling chamber pressure roughness and temperature of a monopropellant liquid rocket engine, comprising:

[0020] The liquid propellant is controlled to react first to generate gas-liquid phase propellant, and then react to generate high-temperature and high-pressure combustion gas, and the high-temperature and high-pressure combustion gas is divided into two parts, most of which is directly discharged through the thrust to generate thrust, and a small part of the combustion gas enters the resonance cavity and then slowly flows out of the resonance cavity.

[0021] further,

[0022] The process of first reacting the liquid propellant to generate the gas-liquid phase propellant is carried out in a first catalytic bed filled with a catalyst;

[0023] The process of generating high-temperature and high-pressure combustion gas by the reaction of the gas-liquid phase propellant is carried out in a second catalytic bed filled with a catalyst, and the catalyst in the first catalytic bed is different from the catalyst in the second catalytic bed;

[0024] The resonant cavity is located at a position in the thrust chamber where the cross section of the fuel gas flow channel is the smallest.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) The monopropellant liquid rocket engine of the present invention has few parts and is easy to assemble;

[0027] (2) The chamber pressure roughness of the monopropellant liquid rocket engine of the present invention is low. The resonant cavity in the plug body is connected to the thrust chamber, and the pressures of the two constitute a resonant relationship. When the chamber pressure is high, a small amount of gas enters the resonant cavity, and the increase in chamber pressure is reduced; when the pressure is low, the gas in the resonant cavity enters the thrust chamber, and the decrease in chamber pressure is reduced;

[0028] (3) The monopropellant liquid rocket engine of the present invention has self-insulation capability and does not require additional heat source insulation. After the engine is shut down, the gas in the resonant cavity cannot be completely discharged instantly, but flows out of the resonant cavity slowly. Therefore, the high-temperature gas remaining in the resonant cavity transfers its own heat to the plug body, so that the engine has a certain insulation capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The three views of the monopropellant liquid rocket engine of the present invention;

[0030] Figure 2 A cross-sectional view of a monopropellant liquid rocket engine according to the present invention;

[0031] Figure 3 It is a schematic diagram of the flow direction of the propellant in the propellant supply flow channel, the propellant sub-flow channel, the front catalytic bed, and the rear catalytic bed, and the flow direction of the combustion gas in the resonant cavity, the resonant cavity balance flow channel, and the thrust chamber in the monopropellant liquid rocket engine of the present invention;

[0032] In the figure, 1-plug body; 2-sleeve; 3-front catalyst bed; 4-rear catalyst bed; 5-fixing nut; 6-resonance cavity. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various modifications, substitutions and changes made according to the common technical knowledge and customary means in the field are included in the scope of the present invention.

[0034] like Figure 1 to Figure 3 As shown, the self-insulating, low-chamber-pressure roughness monopropellant liquid rocket engine of the present invention specifically comprises a plug body 1, a sleeve 2, a front catalytic bed 3, a rear catalytic bed 4 and a fixing nut 5. The cavity inside the sleeve 2 is divided into a first cavity, a second cavity and a third cavity, and correspondingly, the plug body 1 is divided into three regions of a front section, a middle section and a rear section corresponding to the first cavity, the second cavity and the third cavity.

[0035] The plug body 1 is located on the axis of the engine, and the plug body 1 is coaxially fixed with the front catalyst bed 3, the rear catalyst bed 4, and the sleeve 2 through the fixing nut 5. The liquid propellant passes through the front end of the plug body 1 ( Figure 1 and Figure 2 The left end of the plug body 1 flows into the engine, flows into the front catalytic bed 3 along the propellant supply flow channel in the plug body 1 (the flow channel extends along the axial direction of the plug body 1) and the radially distributed propellant sub-flow channel (the sub-flow channel is perpendicular to the axial direction of the plug body 1) and undergoes catalytic reaction to become high-temperature gas-liquid phase propellant (a propellant mixed with gas and liquid phases). The gas-liquid phase propellant then flows through the rear catalytic bed 4 to cause the remaining liquid phase propellant to undergo catalytic reaction to produce high-temperature and high-pressure combustion gas. Most of the combustion gas then flows through the variable-section scaling flow channel formed by the combination of the plug body 1 and the sleeve 2 to become a supersonic fluid and generate thrust. A small amount of combustion gas enters the resonance cavity 6 in the plug body 1 through the resonance cavity balance flow channel to reduce the pressure roughness in the thrust chamber.

[0036] like Figure 2 The sleeve 2 is a closed end with a tapered through hole ( Figure 2 The left end of the middle), the other end of the open cylinder structure ( Figure 2 The conical surface at the conical through hole and the spherical surface structure on the outer wall of the front end of the plug body 1 are combined to form a sealing structure; the end surface of the sleeve 2 ( Figure 2 There are multiple fixing seats with mounting holes arranged circumferentially around the periphery (center left end) for fixing the engine on the probe or satellite system structure.

[0037] like Figure 2 The plug body 1 is roughly cylindrical, or a rotating body. Figure 2The outer wall of the plug body 1 at the front end has an external thread structure, which is used to fix the connection to the propellant supply pipeline; the outer wall of the plug body 1 behind the external thread has a spherical structure, which is used to seal the thrust chamber to prevent the gaseous propellant from escaping from the front section of the sleeve 2 (corresponding to the front catalytic bed 3). Correspondingly, the inner wall of the end face through hole at the closed end of the sleeve 2 is a conical surface, and the conical surface matches the spherical surface to form a conical surface seal; the front end of the plug body 1 ( Figure 2 A propellant supply channel is machined in the middle left end of the plug body 1. The propellant supply channel inside the front section of the plug body 1 is a blind hole machined on the axis of the plug body 1, and at the end of the blind hole, a circumferentially distributed and arrayed through holes (through the surface of the plug body 1) are machined in the radial direction (perpendicular to the axis of the plug body 1) as a propellant sub-channel. A positioning boss is provided on the outer wall of the middle section of the plug body 1 for fixing the rear catalytic bed 4. The raised outer wall profile of the rear section of the plug body 1 is combined with the sleeve 2 to form a space whose cross section gradually decreases and then gradually increases along the airflow direction, that is, the thrust chamber zoom nozzle structure, which converts high-temperature, high-pressure, and low-speed combustion gas into low-temperature, low-pressure, and supersonic combustion gas, and then generates thrust; a resonance cavity 6 for balancing the chamber pressure is machined in the rear section of the plug body 1, and a resonance cavity balancing channel connecting the thrust chamber and the resonance cavity 6 is machined on the plug body 1. The resonant cavity 6 is a Helmholtz resonant cavity. The present invention combines the resonant cavity 6 with the plug nozzle, which not only reduces the radial package size of the engine, but also has the functions of self-insulation and reducing the chamber pressure roughness. The resonant cavity 6 in the present invention has three functions: first, reducing the weight of the engine; second, reducing the chamber pressure roughness; third, retaining a small amount of propellant gas to achieve the heat preservation function of the engine.

[0038] like Figure 2The front catalytic bed 3 and the rear catalytic bed 4 are both annular column structures, coaxially nested and installed on the plug body 1, and assembled and stuck on the positioning boss of the outer wall of the middle section of the plug body 1. The front catalytic bed 3 is filled with fine-particle catalysts to catalyze the reaction of most of the propellants and stabilize the chamber pressure; the rear catalytic bed 4 is filled with coarse-particle catalysts to catalyze the reaction of the remaining uncatalyzed propellants. The catalytic bed is similar to a sponge structure, with an outer size, but there are many gaps inside it. The propellant flows in from one end of the catalytic bed and flows to the other end along the internal gaps. In the present invention, the catalytic bed refers to a structure that allows airflow to flow out, and a large number of dense catalyst particles are filled in the structure. The front catalytic bed 3 and the rear catalytic bed 4, as well as the rear catalytic 4 and the thrust chamber are separated by partitions and partitions. The mesh between the front catalytic bed 3 and the rear catalytic bed 4 is made of a high mesh, in order to prevent the very fine catalyst particles in the front catalytic bed 3 from being washed by the hydraulic force of the propellant and flowing into the rear catalytic bed 4, causing the engine to deviate from the expected design and then affect the performance; the mesh between the rear catalytic bed 4 and the thrust chamber is made of a lower mesh, also for the purpose of preventing the leakage of coarse catalyst particles. The partition is intended to fix the partition, because the partition material is soft and does not bear force, so a partition that can bear force is required for support.

[0039] like Figure 3 The liquid propellant enters the propellant supply channel in the plug body 1 from the propellant supply pipeline (one-way arrow), then flows into the front catalytic bed 3 from the propellant sub-channel (one-way arrow), and then flows into the rear catalytic bed 4 (one-way arrow). Most of the generated high-temperature and high-pressure combustion gas flows through the thrust chamber to generate thrust (one-way arrow), and a small part flows into the resonance cavity 6 through the resonance cavity balance channel and then flows out of the resonance cavity 6 (two-way arrow).

[0040] The monopropellant liquid rocket engine of the present invention controls the liquid propellant to react first to generate gas-liquid phase propellant, and then react to generate high-temperature and high-pressure combustion gas, and the high-temperature and high-pressure combustion gas is divided into two parts, most of which is directly discharged through the thrust to generate thrust, and a small part of the combustion gas enters the resonance cavity 6 and then slowly flows out of the resonance cavity 6. This control process enables the monopropellant liquid rocket engine to have a self-insulating function, and the addition of the resonance cavity 6 reduces the chamber pressure roughness of the thrust chamber.

Claims

1. A monopropellant liquid rocket engine, characterized in that: include, A sleeve (2), wherein the interior of the sleeve (2) and along the axial direction of the sleeve (2) at least comprises a first cavity, a second cavity and a third cavity which are divided in sequence; A front catalytic bed (3), wherein the front catalytic bed (3) is located in the first cavity; A rear catalytic bed (4), wherein the rear catalytic bed (4) is located in the second cavity; A plug body (1), wherein the plug body (1) is coaxial with the sleeve (2) and simultaneously penetrates the front catalytic bed (3), the rear catalytic bed (4) and the third cavity; a propellant supply flow channel and a propellant sub-flow channel are also provided in the plug body (1); wherein the propellant supply flow channel is a blind hole provided on the first end surface of the plug body (1); the propellant supply flow channel extends from the first end of the plug body (1) to the first cavity; one end of the propellant sub-flow channel is connected to the propellant supply flow channel; and the other end penetrates the surface of the plug body (1) and is connected to the front catalytic bed (3); the portion of the plug body (1) located in the third cavity is a variable cross-section structure and is internally provided with a resonant cavity (6) and a resonant cavity balancing flow channel; the cross-sectional area of ​​the portion of the plug body (1) gradually increases from small to large in the direction from the second cavity to the third cavity, and then gradually decreases; a thrust chamber whose cross-section changes from large to small and then from small to large is formed between the surface of the portion of the plug body (1) and the inner wall of the third cavity; the thrust chamber is connected to the resonant cavity (6) through the resonant cavity balancing flow channel.

2. A monopropellant liquid rocket engine according to claim 1, characterized in that: The sleeve (2) is a cylindrical structure with one end open and the other end closed, and a through hole for mounting the plug body (1) is provided on the end surface of the closed end of the sleeve (2), and a fixing seat is also provided in the circumferential direction of the outer surface of the sleeve (2) corresponding to the closed end of the sleeve (2).

3. A monopropellant liquid rocket engine according to claim 2, characterized in that: The first end of the plug body (1) extends to the outside of the sleeve (2) through the through hole, and the surface of the plug body (1) located outside the sleeve (2) is provided with an external thread, and the plug body (1) is coaxially mounted in the sleeve (2) via a fixing nut (5) sleeved on the external thread.

4. A monopropellant liquid rocket engine according to claim 2, characterized in that: A sealing structure is provided at a contact position between the plug body (1) and the through hole of the closed end surface of the sleeve (2).

5. A monopropellant liquid rocket engine according to claim 1, characterized in that: The surface of the plug body (1) is provided with a first positioning boss, and the front catalytic bed (3) is sleeved on the outer surface of the plug body (1) and is limited and positioned by the first positioning boss.

6. A monopropellant liquid rocket engine according to claim 1, characterized in that: The plug body (1) is provided with a second positioning boss on its surface, and the rear catalytic bed (4) is sleeved on the outer surface of the plug body (1) and is limited and positioned by the second positioning boss.

7. A monopropellant liquid rocket engine according to claim 1, characterized in that: The front catalytic bed (3) and the rear catalytic bed (4) are filled with catalyst particles, and the particle size of the catalyst particles in the front catalytic bed (3) is smaller than the particle size of the catalyst particles in the rear catalytic bed (4).

8. A monopropellant liquid rocket engine according to claim 1, characterized in that: The propellant sub-flow channel is a plurality of holes which are perpendicular to the axial direction of the plug body (1) and arranged in an array.

9. A method for controlling chamber pressure roughness and temperature of a monopropellant liquid rocket engine, characterized in that: A monopropellant liquid rocket engine according to claim 1, comprising: The liquid propellant is controlled to react first to generate a gas-liquid phase propellant, and then react to generate a high-temperature and high-pressure combustion gas, and the high-temperature and high-pressure combustion gas is divided into two parts, most of which is directly discharged through the thrust chamber to generate thrust, and a small part of the combustion gas enters the resonance cavity (6) and then slowly flows out of the resonance cavity (6).

10. A method for controlling chamber pressure roughness and temperature of a monopropellant liquid rocket engine according to claim 9, characterized in that: The process of first reacting the liquid propellant to generate the gas-liquid phase propellant is carried out in a first catalytic bed filled with a catalyst; The process of generating high-temperature and high-pressure combustion gas by the reaction of the gas-liquid phase propellant is carried out in a second catalytic bed filled with a catalyst, and the catalyst in the first catalytic bed is different from the catalyst in the second catalytic bed; The resonant cavity (6) is located at a position in the thrust chamber where the cross section of the gas flow channel is the smallest.

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