Low temperature soak visual camera monitoring device and liquid rocket

Abstract

The utility model provides a kind of low-temperature soaking visual camera monitoring device and liquid rocket, camera monitoring device includes: fixed pipe, inner cylinder cover plate, inner cylinder, vacuum isolation valve, outer cylinder, transparent observation window subassembly and camera device;Camera device is installed on fixed pipe, fixed pipe passes through inner cylinder cover plate and extends into the inside of inner cylinder, and with inner cylinder cover plate fixed connection, the outside of inner cylinder cover plate is connected with the bottom end of the inner cylinder;The top of outer cylinder is connected with the outside of transparent observation window subassembly, and the bottom end of outer cylinder is connected with the lateral wall of inner cylinder;The outside of the top of inner cylinder is connected with the inside of transparent observation window subassembly;The connecting interface of vacuum isolation valve is connected with the lateral wall of outer cylinder.This application provides suitable temperature field for normal work by setting vacuum interlayer structure and camera low-temperature blowing replacement mode for ordinary camera, greatly reduces low-temperature shooting cost.

Description

Technical Field

[0001] This utility model relates to the field of liquid rocket launch technology, specifically to a cryogenic immersion visualization camera monitoring device, its usage method, and a liquid rocket. Background Technology

[0002] In today's booming modern aerospace industry, liquid rockets, with their advantages such as high specific impulse and wide thrust adjustment range, have become key launch vehicles for missions such as space exploration and satellite launches. Liquid rocket engines often use cryogenic propellants such as liquid hydrogen and liquid oxygen, which operate in extremely low-temperature environments (liquid oxygen from -183°C to -218.8°C, and liquid hydrogen from -252.8°C to -259.1°C). Therefore, cryogenic imaging technology plays an irreplaceable and crucial role in the field of liquid rockets, demonstrating its clear applications and necessity.

[0003] In the manufacturing process of liquid rockets, the quality of components is crucial to the success or failure of the rocket's flight. Many rocket components need to operate stably in cryogenic environments, making the cryogenic performance of materials and the cryogenic compatibility of components critical. Cryogenic imaging technology can be used to detect deformation and crack initiation in components under cryogenic conditions. Traditional inspection methods are mostly static or rely on experience, making it difficult to detect subtle defects caused by cryogenic stress. Using cryogenic imaging technology, under simulated cryogenic conditions, the changes in the state of components can be observed directly and dynamically, allowing for the timely screening of substandard products and ensuring the overall quality and reliability of the rocket.

[0004] Rocket launch is a high-risk, highly complex mission where even the smallest malfunction can have serious consequences. During the pre-launch preparation phase, cryogenic imaging is used to monitor the cryogenic propellant loading process. Traditional monitoring methods are slow to detect potential leaks and other anomalies. Cryogenic imaging technology allows for real-time monitoring of fuel loading rates, liquid level changes, and the presence of leaks. When an anomaly is detected, immediate measures can be taken to prevent fuel leaks from causing safety accidents and ensure the successful completion of the launch mission.

[0005] Fault analysis is crucial after liquid rocket flight tests and actual launches. Cryogenic imaging provides key clues for troubleshooting. By analyzing cryogenic images of the engine during operation, it's possible to determine if seal failure or pipe brittleness is caused by the low-temperature environment, thus providing strong evidence for subsequent design improvements and process optimization, preventing similar failures from recurring. Therefore, cryogenic imaging technology plays an irreplaceable role in the entire process of liquid rocket development, production, launch, and subsequent fault analysis. However, current technology still has shortcomings in image clarity and the cryogenic adaptability of imaging equipment. Seal leakage is also a serious problem when immersed in cryogenic media, and the high cost of cryogenic imaging equipment increases rocket development costs, hindering large-scale deployment. Further innovation and improvement are urgently needed to meet the evolving needs of liquid rocket technology. Utility Model Content

[0006] In view of this, the purpose of this utility model embodiment is to provide a low-temperature immersion visual camera monitoring device, a method of use, and a liquid rocket to solve at least one of the above-mentioned technical problems.

[0007] To achieve the above objectives, in a first aspect, this utility model provides a cryogenic immersion visualization camera monitoring device, installed inside a rocket propellant tank, comprising: a fixed tube, an inner cylinder, an outer cylinder, a transparent observation window assembly, and a camera device;

[0008] The camera device is mounted on the fixed tube, which extends through the inner cylinder cover plate into the interior of the inner cylinder and is fixedly connected to the inner cylinder cover plate.

[0009] The transparent observation window assembly is disposed between the inner cylinder and the outer cylinder, and is connected to both the inner cylinder and the outer cylinder respectively;

[0010] A vacuum isolation valve is installed on the outer cylinder.

[0011] In some possible implementations, the inner cylinder cover includes: a main board, a gas purging inlet, and a gas purging outlet;

[0012] The fixing tube extends into the inner cylinder through the inner hole on the main board and is connected to the main board.

[0013] The outer sides of the nozzles of the gas purging inlet and the gas purging outlet are provided with threads, and the gas delivery pipeline is connected to the nozzles of the gas purging inlet and the gas purging outlet respectively through nuts.

[0014] In some possible implementations, the fixed tube includes an outer wall and an inner wall, the outer wall being fixedly connected to the inner hole of the inner cylinder cover plate;

[0015] The inner wall is a threaded section, and the camera device is connected to the fixed pipe through the threaded section.

[0016] In some possible implementations, the transparent viewing window assembly includes: an inner flange, an outer flange, and a transparent structure;

[0017] The transparent structure is disposed between the first sealing groove of the inner flange and the second sealing groove of the outer flange;

[0018] The inner flange, the transparent structure, and the outer flange are fastened together using flange fixing studs and flange fixing nuts.

[0019] In some possible implementations, the inner cylinder includes: a first cylinder body and a first top inner weld ring;

[0020] The first cylinder body is connected to the inner cylinder cover plate;

[0021] The inner flange is fixedly connected to the first cylinder body via the first top inner welding ring.

[0022] In some possible implementations, the outer cylinder includes: a second cylinder body, an outer wall welding ring, a second top inner welding ring, and a bottom inner welding ring;

[0023] The interface of the vacuum isolation valve is connected to the cylinder body hole provided on the second cylinder body, and the outer wall welding ring of the cylinder is connected to the target device to be used;

[0024] The outer flange is connected to the second cylinder body via the second top inner welding ring;

[0025] The inner cylinder is fixedly connected to the second cylinder body via the inner welding ring at the bottom end.

[0026] In some possible implementations, the inner flange is provided with a plurality of bolt through holes evenly distributed around its circumference, and the outer flange is provided with a plurality of threaded blind holes evenly distributed around its circumference. The flange fixing stud passes through the bolt through holes of the inner flange and is disposed in the threaded blind holes of the outer flange.

[0027] In some possible implementations, a first sealing gasket is disposed in the first sealing groove, and a second sealing gasket is disposed in the second sealing groove; the transparent structure is disposed between the first sealing gasket and the second sealing gasket.

[0028] In some possible implementations, both the first sealing gasket and the second sealing gasket are L-shaped sealing gaskets.

[0029] Secondly, this utility model embodiment provides a liquid rocket, wherein the liquid rocket employs any one of the cryogenic immersion visualization camera monitoring devices of the first aspect.

[0030] The present invention has the following beneficial effects:

[0031] This utility model provides a low-temperature immersion visualization camera monitoring device that can be directly immersed in a low-temperature medium such as liquid oxygen or liquid nitrogen to photograph targets, or placed above a low-temperature medium to photograph the interface and liquid level changes of the low-temperature medium in a low-temperature environment. It solves the problem of medium leakage when immersed in a low-temperature medium and greatly reduces the requirements for cameras at low temperatures. Ordinary cameras can be used for shooting or recording, which greatly reduces the cost of low-temperature photography. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the overall structure of a low-temperature immersion visual camera monitoring device according to an embodiment of this utility model;

[0034] Figure 2A This is a front view of an inner cylinder cover plate according to an embodiment of the present utility model;

[0035] Figure 2B This is a side view of an inner cylinder cover plate according to an embodiment of the present utility model;

[0036] Figure 3 This is a schematic diagram of the structure of a fixing tube according to an embodiment of the present utility model;

[0037] Figure 4 This is a schematic diagram of the structure of a transparent observation window assembly according to an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the structure of an inner cylinder according to an embodiment of the present utility model;

[0039] Figure 6 This is a schematic diagram of the structure of an outer cylinder according to an embodiment of the present utility model.

[0040] Explanation of icon numbers:

[0041] 1. Fixed tube; 11. Outer wall; 12. Inner wall;

[0042] 2. Inner cylinder cover plate; 21. Main plate; 22. Inner hole; 24. First fixing hole; 23. First lug; 26. Second fixing hole; 25. Second lug; 27. Gas purging inlet; 28. Gas purging outlet;

[0043] 3. Inner cylinder; 32. First cylinder body; 33. First top inner welding ring; 31. Third lug; 34. Fourth lug;

[0044] 4. Vacuum isolation valve;

[0045] 5. Outer cylinder; 51. Cylinder body hole; 52. Outer wall weld ring; 53. Second cylinder body; 54. Second top inner weld ring; 55. Bottom inner weld ring;

[0046] 6. Transparent observation window assembly; 61. Inner flange; 62. Outer flange; 63. Transparent structure; 64. First sealing gasket; 65. Second sealing gasket; 66. Flange fixing stud; 67. Flange fixing nut; 61-1. Bolt through hole; 61-2. First sealing groove; 62-1. Threaded blind hole; 62-2. Second sealing groove;

[0047] 7. Camera device. Detailed Implementation

[0048] The features and exemplary embodiments of various aspects of this utility model will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this utility model. However, it will be apparent to those skilled in the art that this utility model can be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this utility model by illustrating examples of it. In the accompanying drawings and the following description, at least some well-known structures and techniques have not been shown to avoid unnecessarily obscuring the utility model; and, for clarity, the dimensions of some structures may be exaggerated. Furthermore, the features, structures, or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0049] Example 1

[0050] like Figure 1 As shown, the low-temperature immersion visualization camera monitoring device includes: a fixed tube 1, an inner cylinder 3, an outer cylinder 5, a transparent observation window assembly 6, and a camera device 7; the camera device 7 is installed on the fixed tube 1, the fixed tube 1 passes through the inner cylinder cover plate 2 and extends into the interior of the inner cylinder 3, and is fixedly connected to the inner cylinder cover plate 2; the transparent observation window assembly 6 is disposed between the inner cylinder 3 and the outer cylinder 5, and is connected to the inner cylinder 3 and the outer cylinder 5 respectively; a vacuum isolation valve 4 is installed on the outer cylinder 5.

[0051] Specifically, the outer side of the inner cylinder cover plate 2 is connected to the bottom end of the inner cylinder 3; the top end of the outer cylinder 5 is connected to the outer side of the transparent observation window assembly 6, and the bottom end of the outer cylinder 5 is connected to the inner cylinder 3; the outer side of the top end of the inner cylinder 3 is connected to the inner side of the transparent observation window assembly 6; and the connection interface of the vacuum isolation valve 4 is connected to the outer cylinder 5.

[0052] In this embodiment, the camera device 7 is a camera. The camera is fixed by screwing the external thread at the tail end to the inner wall 12 of the fixing tube 1. The camera cable passes through the camera fixing tube 1 to transmit video signals to the outside. The camera fixing tube 1 passes through the center hole of the inner cylinder cover plate 2 and extends into the inner cylinder 3. It is fixed by welding the outer wall of the camera fixing tube 1 to the center hole of the inner cylinder cover plate 2. The fixing holes on both sides of the inner cylinder cover plate 2 are connected to the fixing holes on both sides of the bottom end of the inner cylinder 3 by bolts to fix the inner cylinder cover plate 2. The top end of the outer cylinder 5 is welded to the outer flange 62 of the transparent observation window assembly 6, and the bottom end is welded to the outer wall of the inner cylinder 3. The top end of the inner cylinder 3 is welded to the inner flange 61 of the transparent observation window assembly 6. The connection interface of the vacuum isolation valve 4 passes through the reserved hole of the outer cylinder 5 and is fixed to the outer wall of the outer cylinder 5 by welding. The camera takes pictures of the inside of the target container or storage tank through the transparent observation window assembly 6.

[0053] In this embodiment, a vacuum is created in the space between the inner cylinder 3 and the outer cylinder 5 using a vacuum isolation valve 4. The gas in the inner cylinder 3 is then purged and replaced, expelling the air. A protective gas is installed in the inner cylinder 3 to prevent water vapor from pre-condensing on the inner side of the low-temperature transparent observation window assembly 6 when the outer side of the assembly comes into direct contact with a low-temperature medium such as liquid oxygen or liquid nitrogen, thus affecting the imaging effect. The protective gas in this embodiment can be nitrogen, or other inert gases such as helium or argon, as long as the liquefaction point (triple point) of the inert gas is lower than the temperature of the external low-temperature liquid.

[0054] This utility model embodiment provides a suitable temperature field for ordinary cameras to work normally by setting up a vacuum sandwich structure and using a camera low-temperature blow-out replacement method, which greatly reduces the cost of low-temperature shooting; the design of an inner and outer cylinder isolation structure ensures that no medium leakage problem occurs inside the low-temperature medium.

[0055] The visual camera monitoring device provided by this utility model can be immersed inside a cryogenic medium to continuously capture changes in a target object, or it can be placed on top of the cryogenic medium to capture changes in the liquid level and interface. The visual camera monitoring device provided in this embodiment can be used horizontally or vertically, offering high adaptability, low cost, and strong scalability. Furthermore, the interlayer between the inner cylinder 3 and the outer cylinder 5 can also be filled with carbon dioxide protective gas, as carbon dioxide solidifies at low temperatures to form a vacuum interlayer.

[0056] like Figure 2A and Figure 2B As shown, in some embodiments, the inner cylinder cover plate 2 includes: a main plate 21, a gas purging inlet 27, and a gas purging outlet 28; the fixing tube 1 extends into the inner cylinder 3 through the inner hole 22 on the main plate 21 and is connected to the main plate 21; the outer sides of the nozzles of the gas purging inlet 27 and the gas purging outlet 28 are provided with threads, and the gas delivery pipeline is connected to the nozzles of the gas purging inlet 27 and the gas purging outlet 28 respectively through nuts.

[0057] Specifically, the main board 21 is provided with a first lug 23 with a first fixing hole 24 and a second lug 25 with a second fixing hole 26. The inner cylinder cover plate 2 is connected to the inner cylinder 3 through the first fixing hole 24 on the first lug 23 and the second fixing hole 26 on the second lug 25.

[0058] In this embodiment, the inner hole 22 is located at the center of the inner cylinder cover plate 2. The inner cylinder cover plate 2 is fastened to the inner cylinder 3 by bolts through the first fixing hole 24 and the second fixing hole 26. The outer sides of the nozzles of the gas purging inlet 27 and the gas purging outlet 28 are both threaded. The gas delivery pipeline can be connected and fixed to the nozzles of the gas purging inlet 27 and the gas purging outlet 28 by a corresponding specification outer nut. The gas purging outlet 28 discharges the gas that enters from the purging inlet and mixes with the inner cylinder 3. Throughout the entire usage process, nitrogen continuously enters from the purging gas purging inlet 27 and exits from the gas purging outlet 28, maintaining a flowing state.

[0059] like Figure 3 As shown, in some embodiments, the fixed tube 1 includes: an outer wall 11 and an inner wall 12, the outer wall 11 being fixedly connected to the inner hole 22 of the inner cylinder cover plate 2; the inner wall 12 is a threaded section, and the camera device 7 is connected to the fixed tube 1 through the threaded section.

[0060] In this embodiment, the outer wall 11 is a smooth outer wall, which is fixed to the inner hole 22 of the inner cylinder cover plate 2 by welding; the inner wall 12 is a threaded section, which is used to tighten and fix the camera. When the smooth outer wall 11 contacts the inner hole 22 of the inner cylinder cover plate 2, the surface has no protrusions, grooves, or other structures, allowing for a tighter fit. During welding, the weld is uniform and continuous, reducing welding defects such as porosity and slag inclusions, thereby enhancing the connection strength and stability between the fixing pipe 1 and the inner cylinder cover plate 2. Furthermore, the smooth surface requires no additional treatment before welding, reducing processing complexity. Simultaneously, the welded surface is flat, facilitating subsequent inspection of the weld quality (e.g., non-destructive testing).

[0061] like Figure 4As shown, in some embodiments, the transparent observation window assembly 6 includes: an inner flange 61, an outer flange 62, and a transparent structure 63; the transparent structure 63 is disposed between the first sealing groove 61-2 of the inner flange 61 and the second sealing groove 62-2 of the outer flange 62; the inner flange 61 is uniformly provided with a plurality of bolt through holes 61-1 in the circumferential direction, and the outer flange 62 is uniformly provided with a plurality of threaded blind holes 62-1 in the circumferential direction; the inner flange 61, the transparent structure 63, and the outer flange 62 are fastened together by flange fixing studs 66 and flange fixing nuts 67.

[0062] In this embodiment, the transparent structure 63 is also a low-temperature transparent structure 63, such as low-temperature transparent glass. The low-temperature transparent glass is clamped and fixed by the inner flange 61 and the outer flange 62. After the low-temperature transparent structure 63 is clamped by the inner flange 61 and the outer flange 62, several flange fixing studs 66 are evenly distributed around the inner flange 61, allowing the flange fixing studs 66 to completely pass through the bolt through holes 61-1. Several flange fixing studs 66 are evenly distributed around the outer flange 62, with threaded blind holes 62-1 matching the threads of the flange fixing studs 66. The flange fixing studs 66 are tightened and fixed by bolt through holes 61-1, threaded blind holes 62-1 and flange fixing nuts 67 according to torque to ensure the sealing of the low-temperature transparent glass. The low-temperature transparent glass allows the camera to take pictures of the outside through the body.

[0063] like Figure 5 As shown, in some embodiments, the inner cylinder 3 includes: a first cylinder body 32 and a first top inner welding ring 33; the first cylinder body 32 is connected to the inner cylinder cover plate 2; the inner flange 61 is fixedly connected to the first cylinder body 32 through the first top inner welding ring 33.

[0064] In this embodiment, the inner cylinder 3 is fastened to the first fixing hole 24 of the first fixing hole 23 and the second fixing hole 26 of the second fixing hole 25 of the inner cylinder cover plate 2 by bolts through the third supporting ear 31 and the fourth supporting ear 34 respectively; the inner wall of the first top inner welding ring 33 is welded and fixed to the outer wall of the inner flange 61.

[0065] like Figure 6 In some embodiments, the outer cylinder 5 includes: a second cylinder body 53, an outer wall welding ring 52, a second top inner welding ring 54, and a bottom inner welding ring 55; the interface of the vacuum isolation valve 4 is connected to the cylinder body hole 51 provided on the second cylinder body 53, and the outer wall welding ring 52 is connected to the target device to be used; the outer flange 62 is connected to the second cylinder body 53 through the second top inner welding ring 54; the inner cylinder 3 is fixedly connected to the second cylinder body 53 through the bottom inner welding ring 55.

[0066] In this embodiment, the interface of the vacuum isolation valve 4 is welded to the cylinder hole 51 on the second cylinder 53, so that the interlayer between the inner cylinder 3 and the outer cylinder 5 is connected to the valve core; the outer wall welding ring 52 of the barrel is welded to the outer wall of the target of this device, such as a container or storage tank, and penetrates into the container or storage tank to fix the entire visual camera monitoring device and monitor and photograph the situation inside the container or storage tank. The part below the outer wall welding ring 52 (in the direction of 52 to 54) can be immersed in the low temperature medium.

[0067] In some embodiments, the number of bolt through holes 61-1 and threaded blind holes 62-1 are both eight. Specifically, in flange connections, eight bolts can evenly distribute axial forces, bending moments, and other loads across the entire connection surface, reducing the risk of deformation or fatigue damage caused by uneven stress, and also meeting the sealing reliability requirements under medium and low pressure conditions.

[0068] This embodiment uses a symmetrical installation method to ensure uniform contact of the connecting surfaces, avoiding misalignment caused by improper installation sequence. Furthermore, the moderate spacing of the eight holes facilitates operation with wrenches, power tools, etc., improving assembly efficiency. If the spacing is smaller, the number of bolt through holes 61-1 and threaded blind holes 62-1 can also both be six.

[0069] In some embodiments, a first sealing gasket 64 is disposed in the first sealing groove 61-2, and a second sealing gasket 65 is disposed in the second sealing groove 62-2; a transparent structure 63 is disposed between the first sealing gasket 64 and the second sealing gasket 65.

[0070] Specifically, the first sealing groove 61-2 of the inner flange 61 is fitted with the second sealing gasket 65, the second sealing groove 62-2 of the outer flange 62 is fitted with the first sealing gasket 64, and the transparent structure 63 is disposed between the first sealing gasket 64 and the second sealing gasket 65, so that the inner flange 61, the outer flange 62 and the low-temperature transparent structure 63 constitute a sealing structure; in this embodiment, the first sealing gasket 64 and the second sealing gasket 65 are both low-temperature sealing gaskets.

[0071] In some embodiments, both the first sealing gasket 64 and the second sealing gasket 65 are L-shaped sealing gaskets.

[0072] In this embodiment, both the first sealing gasket 64 and the second sealing gasket 65 are L-shaped gaskets. The right-angled structure of the L-shape can tightly fit two vertical surfaces (such as flange corners or equipment edges), filling gaps at 90° angles without additional auxiliary components. This is especially suitable for rectangular or L-shaped pipe interfaces or box corners. Compared to traditional flat gaskets, the L-shape can be directly embedded in corners, avoiding installation difficulties caused by limited space. This is particularly advantageous in compact mechanical components or multi-layered assembly structures.

[0073] The two vertical surfaces of the L-shape can simultaneously abut against the surfaces of two adjacent components, forming a two-dimensional sealing surface. Compared to a single-plane seal, this can simultaneously block fluid penetration in two directions (e.g., lateral and longitudinal leakage). When components experience slight displacement due to vibration or thermal expansion and contraction, the elastic deformation of the L-shaped structure can adaptively fill the gaps, maintain sealing surface pressure, and reduce the risk of leakage due to deformation. Furthermore, the right-angled sides of the L-shape can serve as an installation reference, facilitating quick alignment of component interfaces and reducing the probability of misalignment during installation.

[0074] The method of using a low-temperature immersion visual camera monitoring device provided in this embodiment of the utility model is as follows: Connect the vacuum isolation valve 4 to the outlet of the vacuum pumping equipment, open the vacuum isolation valve 4, start the vacuum pumping equipment to reduce the vacuum degree of the interlayer between the inner cylinder 3 and the outer cylinder 5 to below the first preset pressure value, and close the vacuum isolation valve 4; blow the protective gas with a pressure above the second preset pressure value into the inner cylinder 3 through the gas blowing port on the inner cylinder cover plate 2, and blow and replace for a preset replacement time; start the camera device 7, and the camera device 7 starts shooting through the transparent observation window component 6, add the low-temperature medium to the target container to be used until the visual camera monitoring device is immersed; reduce the pressure of the protective gas to the third preset pressure value, and continue to blow it during the shooting process.

[0075] Specifically, during use, first connect the vacuum isolation valve 4 outlet to the vacuum pumping equipment, open the vacuum isolation valve 4, start the vacuum pumping equipment to reduce the vacuum level of the inner cylinder 3 and outer cylinder 5 interlayer to below the first preset pressure value (e.g., 2 kPa), and close the vacuum isolation valve 4; then, purge the inner cylinder 3 with nitrogen protective gas at a pressure above the second preset pressure value (e.g., 1 MPa) through the gas purging port on the inner cylinder cover plate 2, purging and replacing for about 15 minutes; start the camera to begin filming, add cryogenic media such as liquid nitrogen / liquid oxygen to the container until the entire device is submerged; finally, reduce the nitrogen purging gas pressure to 0.5 MPa and continue purging during the filming process.

[0076] Nitrogen gas is blown into the inner cylinder 3 through the gas purging inlet 27. After mixing with the original air in the inner cylinder 3, it is discharged together from the gas purging outlet 28, replacing the air in the inner cylinder 3 and creating a high nitrogen environment in the inner cylinder 3. This prevents water vapor from pre-cooling and condensing on the inner side of the transparent observation window assembly 6 when the outside of the transparent observation window assembly 6 comes into direct contact with a low-temperature medium such as liquid oxygen or liquid nitrogen, which would affect the shooting effect.

[0077] The purging and replacement process of about 15 minutes refers to the process of continuously blowing high-pressure nitrogen (above 1 MPa) into the inner cylinder 3 of the device to completely replace the original air in the inner cylinder 3 with nitrogen. The duration of about 15 minutes can minimize the proportion of the original air. When the high-pressure nitrogen is blown in, the protective gas and the original air in the inner cylinder 3 are replaced through convection mixing and diffusion.

[0078] The purging gas supply is provided by the supply pipeline upstream of the purging interface, and its pressure is controlled by the upstream valve. The reason for reducing the purging pressure is for economic considerations. After purging and replacing at 1MPa pressure for 15 minutes, the inner cylinder 3 is already a high nitrogen environment. At this time, it is only necessary to supply low-pressure nitrogen gas for continuous purging to ensure that nitrogen gas is continuously discharged, so as to continuously prevent water vapor from entering the inner cylinder 3.

[0079] This utility model embodiment provides a suitable temperature field for ordinary cameras to work normally by designing a vacuum sandwich structure and a camera low-temperature blowing method, which greatly reduces the cost of low-temperature shooting; the design of an inner and outer cylinder 5 isolation structure ensures that no medium leakage occurs inside the low-temperature medium.

[0080] The visualization monitoring device provided in this embodiment can be immersed inside a cryogenic medium to continuously capture changes in the target object, or it can be placed on top of a cryogenic medium to capture changes in the liquid level and interface of the cryogenic medium. It has high adaptability, low cost, and strong scalability.

[0081] Example 2

[0082] This utility model embodiment also provides a liquid rocket, which adopts a cryogenic immersion visualization camera monitoring device from Embodiment 1.

[0083] In the description of the embodiments of this utility model, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the utility model and for 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 the utility model. Furthermore, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0084] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this utility model embodiment should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0085] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cryogenic immersion visual video monitoring device, installed inside a rocket propellant tank, characterized in that, include: Fixed tube (1), inner cylinder (3), outer cylinder (5), transparent observation window assembly (6) and camera device (7); The camera device (7) is installed on the fixed tube (1), the fixed tube (1) passes through the inner cylinder cover plate (2) and extends into the interior of the inner cylinder (3), and is fixedly connected to the inner cylinder cover plate (2); The transparent observation window assembly (6) is disposed between the inner cylinder (3) and the outer cylinder (5), and is connected to the inner cylinder (3) and the outer cylinder (5) respectively; A vacuum isolation valve (4) is installed on the outer cylinder (5).

2. The low-temperature immersion visual video monitoring device according to claim 1, characterized in that, The inner cylinder cover plate (2) includes: a main plate (21), a gas purging inlet (27), and a gas purging outlet (28); The fixing tube (1) extends into the inner cylinder (3) through the inner hole (22) on the main board (21) and is connected to the main board (21); The outer sides of the nozzles of the gas purging inlet (27) and the gas purging outlet (28) are provided with threads, and the gas delivery pipeline is connected to the nozzles of the gas purging inlet (27) and the gas purging outlet (28) respectively through nuts.

3. The low-temperature immersion visual video monitoring device according to claim 1, characterized in that, The fixed tube (1) includes an outer wall (11) and an inner wall (12), wherein the outer wall (11) is fixedly connected to the inner hole (22) of the inner cylinder cover plate (2); The inner wall (12) is a threaded section, and the camera device (7) is connected to the fixed tube (1) through the threaded section.

4. The low-temperature immersion visual video monitoring device according to claim 1, characterized in that, The transparent observation window assembly (6) includes: an inner flange (61), an outer flange (62), and a transparent structure (63); The transparent structure (63) is disposed between the first sealing groove (61-2) of the inner flange (61) and the second sealing groove (62-2) of the outer flange (62); The inner flange (61), the transparent structure (63), and the outer flange (62) are fastened together by flange fixing studs (66) and flange fixing nuts (67).

5. The low-temperature immersion visual video monitoring device according to claim 4, characterized in that, The inner cylinder (3) includes: a first cylinder body (32) and a first top inner welding ring (33); The first cylinder body (32) is connected to the inner cylinder cover plate (2); The inner flange (61) is fixedly connected to the first cylinder body (32) through the first top inner welding ring (33).

6. The low-temperature immersion visual video monitoring device according to claim 4, characterized in that, The outer cylinder (5) includes: a second cylinder body (53), an outer wall welding ring (52), a second top inner welding ring (54), and a bottom inner welding ring (55); The interface of the vacuum isolation valve (4) is connected to the cylinder hole (51) provided on the second cylinder (53), and the outer wall welding ring (52) of the cylinder is connected to the target device to be used; The outer flange (62) is connected to the second cylinder body (53) via the second top inner welding ring (54); The inner cylinder (3) is fixedly connected to the second cylinder body (53) through the bottom inner welding ring (55).

7. The low-temperature immersion visual video monitoring device according to claim 4, characterized in that, The inner flange (61) is provided with a plurality of bolt through holes (61-1) evenly arranged in the circumference, and the outer flange (62) is provided with a plurality of threaded blind holes (62-1) evenly arranged in the circumference. The flange fixing stud (66) passes through the bolt through holes (61-1) of the inner flange (61) and is provided in the threaded blind holes (62-1) of the outer flange (62).

8. The low-temperature immersion visual video monitoring device according to claim 4, characterized in that, A first sealing gasket (64) is provided in the first sealing groove (61-2), and a second sealing gasket (65) is provided in the second sealing groove (62-2); the transparent structure (63) is provided between the first sealing gasket (64) and the second sealing gasket (65).

9. A low-temperature immersion visual video monitoring device according to claim 8, characterized in that, Both the first sealing gasket (64) and the second sealing gasket (65) are L-shaped sealing gaskets.

10. A liquid rocket, characterized in that, The liquid rocket employs a cryogenic immersion visualization camera monitoring device as described in any one of claims 1-9.

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