Extrusion liquid rocket with film cooling system

Abstract

This invention discloses a compression-type liquid rocket with a film cooling system, comprising a fuel tank, a liquid oxygen tank, a liquid nitrogen tank, a liquid nitrogen pump, a thrust chamber, and a flow-guiding flange ring. In this invention, the conical surface of the blocking component precisely aligns with the outlet of the film cooling hole. After the cryogenic nitrogen gas impacts the conical surface of the blocking component, it forms a ring-shaped jet. The diffused nitrogen gas absorbs the high temperature of the thrust chamber wall, forming a fully covered, wall-adhering nitrogen film. Because nitrogen has a boiling point as low as -196°C and is an inert gas that does not participate in combustion, this nitrogen film forms a ring-shaped diffusion, achieving a fully covered, pure cooling film. This not only enhances the cooling and heat insulation effect but also reduces the number of openings. Furthermore, the inert nature of nitrogen does not corrode the wall surface, extending the service life of the thrust chamber. This invention uses four arc-shaped flanges spliced ​​together and surrounding the outer wall of the thrust chamber to form a flange ring that secures the thrust chamber wall, enhancing the high-pressure resistance of the thrust chamber wall. Simultaneously, the liquid nitrogen tanks on the inner walls of the arc-shaped flanges are interconnected to form a vaporization channel.

Description

Technical Field

[0001] The present invention specifically relates to a squeeze-type liquid rocket with a film cooling system. Background Technology

[0002] Currently, launch vehicles are divided into two main types: solid fuel and liquid fuel. Solid fuel rockets have the disadvantages of high cost and low payload capacity.

[0003] While squeeze-type liquid rockets offer advantages such as low cost and simple, reliable structure, they also require overall pressurization of the liquid fuel tank. This necessitates the tank structure to withstand extremely high internal pressures. The upper limit of the tank's internal pressure reduces propellant flow, resulting in significantly lower combustion chamber pressures compared to turbopump-based systems. Consequently, the engine's specific impulse is drastically reduced, hindering the achievement of high thrust. Furthermore, the demand for high-pressure gas for pressurization is far greater than that of pump-fed engines, leading to increased thickness and weight of the high-pressure gas cylinder structure, thus increasing flight exhaust weight. Consequently, existing squeeze-type liquid rockets are primarily used as final stages.

[0004] Therefore, most liquid rockets need to use pump-pressurized liquid rockets as the mainstream high-thrust first stage rockets, which have the disadvantages of complex structure, low reliability and high cost. For example, the invention patent with patent number CN2021112515598 discloses an open-stage combustion exhaust cycle first stage rocket engine, whose turbine is driven by fuel-rich gas drawn from the upper chamber of the thrust chamber. The thrust chamber adopts a staged combustion mode with fuel-rich upper chamber and supplementary combustion in lower chamber. The peripheral wall of the thrust chamber is also provided with fuel cooling channels. The design still has many shortcomings: the turbopump is used to pump fuel and oxidizer, and the pump chambers are isolated only by dynamic seals. Under high-speed rotation, the seals are prone to wear and failure, which leads to leakage and premixing of fuel and oxidizer in the pump chamber, causing catastrophic safety accidents such as spontaneous combustion, deflagration, and pump body explosion. Furthermore, the turbopump is directly used to pressurize the liquid propellant, which can easily lead to poor impeller pump operation, and the oxygen pump is more easily oxidized, which can lead to turbopump damage. The thrust chamber of this engine uses a fuel cooling channel as a cooling system, which makes the engine too heavy. At the same time, this engine can only be manufactured by 3D printing and cannot be mass-produced, which leads to excessively high manufacturing costs.

[0005] Meanwhile, existing technologies also employ heat insulation and cooling methods such as sweating or film cooling on the combustion chamber walls. However, fuel is commonly used as a coolant, which means that the fuel will participate in combustion after cooling. This not only limits the cooling effect but also affects propulsion efficiency due to coolant consumption. Furthermore, since the film coverage area generated by a single film vent is small, it is easy to cause local overheating of the combustion chamber walls. Therefore, a large number of film vents need to be opened to increase the heat insulation effect, resulting in a complex structure and complicated manufacturing and installation processes, which in turn leads to high engine manufacturing costs.

[0006] In addition, the use of fuel film combustion, which involves gasification and combustion against the wall, can easily corrode the combustion chamber wall, reduce engine life, and is not conducive to the development of frequent test runs and multiple rocket body recovery. Summary of the Invention

[0007] To overcome the shortcomings mentioned above, the present invention aims to provide a technical solution that can solve the above problems.

[0008] A squeeze-type liquid rocket with a film cooling system includes: a fuel tank, a liquid oxygen tank, a liquid nitrogen tank, a liquid nitrogen pump, a thrust chamber, and a flow guide flange ring; The flow guide flange ring is composed of four arc-shaped flanges spliced ​​together. The inner wall of each arc-shaped flange is in contact with the outer wall of the thrust chamber, and a liquid nitrogen tank is opened on the inner wall of each arc-shaped flange. The thrust chamber wall has corresponding air film holes along its radial X-axis and Y-axis directions, and the air film holes connect the liquid nitrogen tank to the interior of the thrust chamber. Each of the arc-shaped flanges has a bolt post in its liquid nitrogen tank that corresponds one-to-one with the gas film hole. The bolt post extends into the interior of the thrust chamber through the corresponding gas film hole, and a circular blocking member is installed at the end of the bolt post located inside the thrust chamber. The outer diameter of the blocking member is larger than the inner diameter of the gas film hole. The inlet of the flow guide flange ring is connected to the outlet of the liquid nitrogen pump via a cryogenic pipeline, and the inlet of the liquid nitrogen pump is connected to the outlet of the liquid nitrogen storage tank. The outlet of the flow guide flange ring is connected to the air cushion space of the fuel tank, the air cushion space of the liquid oxygen tank, and the air cushion space of the liquid nitrogen tank via high-pressure pipelines. Preferably, the side of the blocking member closest to the inner wall of the thrust chamber is conical, and its conical surface forms a 45° angle with the axis of the bolt column; Preferably, the bolt column has an external thread section at one end inside the thrust chamber, and the blocking member has an internal thread hole at its center that matches the external thread section. The blocking member is screwed onto the external thread section of the bolt column through its internal thread hole. Preferably, the joint between the blocking member and the bolt column is welded circumferentially by argon arc welding to form a continuous annular weld. Preferably, each arc flange has integrally formed folded lugs at both ends, and any two adjacent arc flanges are connected by fastening bolts that pass through the corresponding folded lugs; Preferably, the joint of any two adjacent arc-shaped flanges is sealed by argon arc welding. The inner wall of each arc-shaped flange is provided with an annular welding bevel along the circumference. Full penetration welding is performed by argon arc welding along the annular welding bevel to connect the liquid nitrogen tanks and form a vaporization channel.

[0009] Compared with the prior art, the advantages of the present invention are: In this invention, the conical surface of the blocking component is precisely aligned with the outlet of the film gas hole. After the low-temperature nitrogen gas impacts the conical surface of the blocking component, it forms an annular jet. The diffused nitrogen gas absorbs the high temperature of the thrust chamber wall, forming a fully covered nitrogen gas film. Since nitrogen has a boiling point as low as -196°C and is an inert gas that does not participate in combustion, this nitrogen gas film forms an annular diffusion, achieving a fully covered pure cooling gas film. This not only enhances the cooling and heat insulation effect but also reduces the number of openings. At the same time, the inertness of nitrogen gas does not corrode the wall surface, extending the service life of the thrust chamber.

[0010] This invention employs four arc-shaped flanges spliced ​​together and surrounding the outer wall of the thrust chamber to form a flange ring that secures the thrust chamber wall, thereby enhancing the high-pressure resistance of the thrust chamber wall. At the same time, the liquid nitrogen tanks on the inner walls of the arc-shaped flanges are connected to form a vaporization channel. This vaporization flange ring not only enhances the rigidity of the thrust chamber wall but also achieves the effect of liquid nitrogen vaporization.

[0011] The vaporization flange ring of the present invention adopts a four-arc flange splicing structure, which is set on the outer wall of the thrust chamber, making the entire vaporization flange ring assembly process simple, avoiding complex installation procedures, reducing labor costs, and improving the overall assembly efficiency of the vaporization flange ring.

[0012] This invention pressurizes liquid nitrogen using a liquid nitrogen pump. After heat exchange within the vaporization channel, the liquid nitrogen expands into high-pressure nitrogen gas. This high-pressure nitrogen gas simultaneously pressurizes the gas pillow spaces of the fuel tank, liquid oxygen tank, and liquid nitrogen tank, eliminating the need for high-pressure gas cylinders. This reduces flight exhaust weight and breaks through the upper limit of the tank internal pressure of traditional squeeze rockets, significantly increasing propellant flow rate. The combustion chamber pressure can approach that of a pump-fed rocket combustion chamber, achieving high thrust output and making it suitable for use as a mainstream first-stage rocket.

[0013] This invention does not directly pump propellant, but only pressurizes liquid nitrogen through a liquid nitrogen pump, and then indirectly pressurizes the propellant tank through the liquid nitrogen. There are no high-speed rotating sealing components, which completely avoids the risk of propellant leakage.

[0014] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the overall structure of the thrust chamber of the present invention.

[0018] Figure 3 This is a cross-sectional view of the overall structure of the thrust chamber of the present invention.

[0019] Figure 4 This is a schematic diagram illustrating the working principle of the air film vent and the blocking component. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Please see Figures 1-4 In this embodiment of the invention, a squeeze-type liquid rocket with a film cooling system includes: a fuel tank 1, a liquid oxygen tank 2, a liquid nitrogen tank 3, a liquid nitrogen pump 4, a thrust chamber 5, and a vaporization flange ring. The liquid nitrogen pump 4 is a cryogenic centrifugal pump, which can be driven by an electric motor or a turbine.

[0025] In this embodiment, the vaporization flange ring is composed of four arc-shaped flanges 6 spliced ​​together. The inner wall of each arc-shaped flange 6 is in contact with the outer wall of the thrust chamber 5, and each arc-shaped flange 6 has a liquid nitrogen tank 61 on its inner wall. The wall surface of the thrust chamber 5 has corresponding gas film holes 51 along its radial X-axis and Y-axis directions. The gas film holes 51 connect the liquid nitrogen tank 61 to the interior of the thrust chamber 5. Each arc-shaped flange 6 has a bolt post 62 in its liquid nitrogen tank 61 that corresponds one-to-one with the gas film hole 51. One end of the bolt post 62 located in the liquid nitrogen tank 61 is fixed to the arc-shaped flange 6 by argon arc welding. The blocking member 7 is screwed into the external thread section of the bolt post 62 through its internal thread hole. The joint between the blocking member 7 and the bolt post 62 is argon arc welded along the circumferential direction to form a continuous annular weld.

[0026] Each bolt post 62 has an annular blocking element 7 installed at one end inside the thrust chamber 5. The outer diameter of the blocking element 7 is larger than the inner diameter of the air film hole 51. The side of the blocking element 7 near the inner wall of the thrust chamber 5 is conical, and its conical surface is inclined at a 45° angle to the axis of the bolt post 62. The bolt post 62 has an external thread section at one end inside the thrust chamber 5. The center of the blocking element 7 has an internal thread hole that matches the external thread section. The blocking element 7 is screwed onto the external thread section of the bolt post 62 through its internal thread hole. The joint between the blocking element 7 and the bolt post 62 is circumferentially welded by argon arc welding to form a continuous annular weld.

[0027] In this embodiment, each arc-shaped flange 6 has integrally formed flanged ear plates 63 at both ends. Any two adjacent arc-shaped flanges 6 are connected by fastening bolts that pass through the corresponding flanged ear plates 63. The splice seam of any two adjacent arc-shaped flanges 6 is sealed by argon arc welding. An annular welding bevel is opened along the circumferential direction on the inner wall of each arc-shaped flange 6, and full penetration welding is performed along the annular welding bevel by argon arc welding, so that the liquid nitrogen tank 61 forms a sealed flow channel. The present invention uses four arc-shaped flanges 6 spliced ​​together and surrounding the outer wall of the thrust chamber 5 to form a flange ring that fastens the wall of the thrust chamber 5, which enhances the high pressure resistance of the wall of the thrust chamber 5. At the same time, the liquid nitrogen tanks 61 on the inner wall of the arc-shaped flanges 6 are connected to form a vaporization flow channel. This vaporization flange ring not only enhances the rigidity of the wall of the thrust chamber 5, but also achieves the effect of liquid nitrogen vaporization.

[0028] During assembly, the bolts 62 on each arc-shaped flange 6 are passed through the air film hole 51, so that the external thread section of the bolt 62 extends into the thrust chamber 5. The splicing end faces of adjacent arc-shaped flanges 6 fit together. They are positioned by the integrated flange ear plates 63 at both ends of the arc-shaped flanges 6. Through holes are opened on the flange ear plates 63, and high-strength stainless steel bolts are passed through the through holes. The bolts and nuts are tightened by the pre-tightening torque to achieve the initial fixation of the four arc-shaped flanges 6. The blocking part 7 is screwed into the external thread section of the bolt 62 through the internal thread hole. After screwing, the end face of the blocking part 7 fits tightly with the shoulder of the bolt 62. Circumferential argon arc welding is performed along the joint between the blocking part 7 and the bolt 62 to form a continuous annular weld. The weld surface smoothly transitions with the conical surface of the blocking part 7 without any protruding edges. Argon arc welding is performed to seal the splicing joint of adjacent arc-shaped flanges 6 to form a continuous annular sealing weld. After welding, the weld is ground.

[0029] The vaporization flange ring of the present invention adopts a splicing structure of four arc-shaped flanges 6, which are arranged on the outer wall of the thrust chamber 5, simplifying the assembly process of the entire vaporization flange ring, avoiding complex installation procedures, reducing labor costs, and improving the overall assembly efficiency of the vaporization flange ring.

[0030] In a specific embodiment of the present invention, the inlet of the vaporization flange ring is connected to the outlet of the liquid nitrogen pump 4 via a cryogenic pipeline, and the inlet of the liquid nitrogen pump 4 is connected to the outlet of the liquid nitrogen storage tank 3. The outlet of the vaporization flange ring is connected to the air cushion space of the fuel storage tank 1, the air cushion space of the liquid oxygen storage tank 2, and the air cushion space of the liquid nitrogen storage tank 3 via high-pressure pipelines. In addition, the outlets of the liquid oxygen storage tank 2 and the fuel storage tank 1 are connected to the dual-component injector of the thrust chamber 5.

[0031] Start the liquid nitrogen pump 4. Under the action of pump pressure, liquid nitrogen enters the vaporization channel of the vaporization flange ring through the cryogenic pipeline. The liquid nitrogen absorbs the residual heat of the thrust chamber 5 wall (preheated at room temperature) in the vaporization channel and vaporizes into high-expansion high-pressure nitrogen gas (or high-pressure liquid-gas mixture nitrogen).

[0032] Most of the high-pressure nitrogen enters the gas cushion space of each propellant tank through high-pressure pipelines, increasing the pressure in the gas cushion space and pressurizing the liquid nitrogen, liquid oxygen, and fuel. The liquid nitrogen undergoes pressurized circulation, while the liquid oxygen and fuel are injected into the thrust chamber 5 through a dual-component injector to mix and burn, generating thrust. The pressurization pressure of the high-pressure nitrogen originates from the pressurization of the liquid nitrogen pump 4 combined with the vaporization expansion force of the liquid nitrogen. Therefore, when high-pressure nitrogen is used to compress the two propellants, the liquid oxygen and fuel have sufficient pressurization pressure to enter the combustion chamber at a high flow rate, thereby achieving ultra-high temperature and pressure in the combustion chamber, and ultimately enabling the rocket to output high thrust.

[0033] A very small portion of the high-pressure nitrogen gas 8 is injected into the thrust chamber 5 through the annular gap between the gas film hole 51 and the bolt column 62. Because the conical surface of the baffle 7 located inside the thrust chamber forms a 45-degree angle with the axis of the bolt column 62 (i.e., the conical surface forms a 45-degree angle with the axis of the gas film hole 51), the very small portion of the high-pressure nitrogen gas 8, after impacting the conical surface of the baffle 7, diffuses in an annular pattern, forming a nitrogen gas film adhering to the inner wall of the thrust chamber 5. This nitrogen gas film is an inert gas, does not participate in combustion, and has an extremely low temperature, forming a "low-temperature isolation layer" only on the inner wall of the thrust chamber 5. Simultaneously, the annular diffusion of the nitrogen gas film results in a very high coverage area, achieving highly efficient cooling and heat insulation. Therefore, the nitrogen gas film of this invention not only enhances the cooling and heat insulation effect but also reduces the number of openings. Furthermore, the inert nature of nitrogen does not corrode the wall surface, extending the service life of the thrust chamber 5.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A squeeze-type liquid rocket with a film cooling system, characterized in that, Includes: fuel tank, liquid oxygen tank, liquid nitrogen tank, liquid nitrogen pump, thrust chamber, and flow guide flange ring; The flow guide flange ring is composed of four arc-shaped flanges spliced ​​together. The inner wall of each arc-shaped flange is in contact with the outer wall of the thrust chamber, and a liquid nitrogen tank is opened on the inner wall of each arc-shaped flange. The thrust chamber wall has corresponding film gas holes along its radial X-axis and Y-axis directions, which connect the liquid nitrogen tank to the interior of the thrust chamber. Each arc-shaped flange has a bolt post in its liquid nitrogen tank that corresponds to one of the film gas holes. The bolt post extends into the interior of the thrust chamber through the corresponding film gas hole, and a circular blocking member is installed at the end of the bolt post located inside the thrust chamber. The outer diameter of the blocking member is larger than the inner diameter of the film gas hole. The side of the blocking member closest to the inner wall of the thrust chamber is conical, and its conical surface is inclined at a 45° angle to the axis of the bolt column; The inlet of the flow guide flange ring is connected to the outlet of the liquid nitrogen pump via a cryogenic pipeline, and the inlet of the liquid nitrogen pump is connected to the outlet of the liquid nitrogen storage tank; The outlet of the flow guide flange ring is connected to the air cushion space of the fuel tank, the air cushion space of the liquid oxygen tank, and the air cushion space of the liquid nitrogen tank via high-pressure pipelines.

2. The extrusion liquid rocket with a film cooling system according to claim 1, characterized in that, The bolt column has an external thread section at one end inside the thrust chamber, and the blocking member has an internal thread hole at its center that matches the external thread section. The blocking member is screwed onto the external thread section of the bolt column through its internal thread hole.

3. The extrusion liquid rocket with a film cooling system according to claim 2, characterized in that, The joint between the blocking component and the bolt column is welded circumferentially by argon arc welding to form a continuous annular weld.

4. The extrusion liquid rocket with a film cooling system according to claim 1, characterized in that, Each arc flange has integrally formed folded lugs at both ends, and any two adjacent arc flanges are connected by fastening bolts that pass through the corresponding folded lugs.

5. The extrusion liquid rocket with a film cooling system according to claim 4, characterized in that, The joint between any two adjacent arc-shaped flanges is sealed by argon arc welding. An annular welding bevel is opened on the inner wall of each arc-shaped flange in the circumferential direction. Full penetration welding is performed by argon arc welding along the annular welding bevel to connect the liquid nitrogen tanks and form a vaporization channel.

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