Thermal radiation cover for laser terminal and manufacturing method of thermal radiation cover

Abstract

The invention discloses a thermal radiation cover for a laser terminal and a manufacturing method thereof, and belongs to the technical field of thermal control of high-orbit spacecrafts. The heat radiation cover comprises a heat radiation cover body, a heat radiation surface coating and silicone rubber; the outer envelope of the thermal radiation cover adopts a cuboid or polygonal prism, is made of an aluminum alloy material, is mounted on the outer surface of a telescope tube of an optical component of the laser terminal, and is tightly attached to the telescope tube; the interface between the thermal radiation cover and the telescope tube is filled with silicone rubber; a plurality of plane areas are arranged on the outer surface of the heat radiation cover and used for pasting a heat radiation surface coating. According to the invention, the problems of small available heat dissipation surface, low heat dissipation surface efficiency, poor adaptability to multiple application scenes, poor heat dissipation efficiency of a heat dissipation surface coating and large design difficulty of a heater caused by small heat capacity of the assembly of the optical assembly are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to a heat radiation cover for a laser terminal and a manufacturing method thereof, and belongs to the technical field of thermal control of high-orbit spacecraft. BACKGROUND

[0002] Compared with microwave space communication technology, laser space communication technology has many advantages such as large communication capacity, light weight, small size, low power consumption, strong anti-interference and anti-eavesdropping ability, and is an important development direction of space communication technology at home and abroad. At present, on-orbit tests and launches of laser space communication technology are carried out at home and abroad, and laser space communication is initially realized.

[0003] The laser terminal is one of the important components of laser space communication technology, which is generally composed of an optical antenna assembly, a servo mechanism, a rear optical path assembly and an electronic assembly, wherein the optical antenna assembly is composed of multiple optical assemblies. For space communication (satellite-ground communication, inter-satellite communication), the transmission distance is long and the relative speed is fast, and laser has the characteristics of energy concentration and small divergence angle, so there is a high requirement for the direction stability of laser signal to realize stable reception of space laser signal. The most important factor affecting the stability of the optical path is the thermal deformation of the optical assembly, so in order to effectively reduce the thermal deformation of the optical assembly, the temperature of the optical assembly and the telescope barrel needs to be controlled within a very narrow temperature range (generally 20±4℃ or even 20±1℃), and the temperature gradient is also required to be high (generally ≤0.5℃).

[0004] At present, the thermal control design of the optical assembly of the laser terminal generally adopts the method of using the surface of the optical assembly itself as the heat dissipation surface, using thermal control white paint as the heat dissipation surface coating, and pasting an electric heater on the surface, and achieving high-precision temperature control of the optical assembly by designing the control strategy of the electric heater. This method has the following disadvantages:

[0005] (1) The surface area of the optical assembly itself is limited, and the available heat dissipation surface is small.

[0006] (2) The surface structure of the optical assembly is complex, and there is mutual infrared influence between the heat dissipation surfaces and between the heat dissipation surfaces and other structural parts, resulting in low efficiency of the heat dissipation surface.

[0007] (3) The same laser terminal product is equipped on multiple models, and is installed outside the star. The different application scenarios result in great differences in the characteristics of external heat flow. For example, the GEO satellite laser terminal has a 360-degree change of solar external heat flow in a certain plane within 24 hours; the IGSO satellite laser terminal has a continuous irradiation of sunlight within a certain angle range under the condition of star attitude control. The productized optical assembly is difficult to design the corresponding heat dissipation surface according to the characteristics of external heat flow in different application scenarios.

[0008] (4) Limited by the compact structure and uneven surface of the optical assembly, only heat control white paint can be sprayed on the surface of the assembly for assembly heat dissipation, and the glass type secondary surface mirror (OSR) cannot be pasted. Compared with the OSR, the heat control white paint has many shortcomings: it is easy to be contaminated and difficult to be cleaned when stored on the ground; the optical property stability under space environment conditions is poor, the solar absorptance degradation is fast, and the heat dissipation capacity is poor; in addition, during long life use, the solar absorptance degradation may have a certain deviation compared with the ground test results due to the influence of the contamination of volatilization on the satellite and the deviation between the actual space environment conditions and the ground test conditions, further increasing the uncertainty of thermal design and thermal analysis and the risk of thermal design.

[0009] (5) The optical assembly itself has small heat capacity, and the space external heat flow changes sharply, so the fluctuation amplitude of the temperature of the optical assembly itself with the external heat flow is large, thus leading to great difficulty in the design of the heater and the temperature control strategy. SUMMARY

[0010] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art, solve the problems of small available heat dissipation surface of the optical assembly, low heat dissipation surface efficiency, poor adaptability to multiple application scenarios, poor heat dissipation efficiency of the heat dissipation surface coating, and great difficulty in the design of the heater due to small heat capacity of the assembly.

[0011] The object of the present application is achieved by the following technical solutions:

[0012] In a first aspect, the present application provides a heat radiation cover for a laser terminal, comprising a heat radiation cover, a heat dissipation surface coating, and a silicone rubber.

[0013] The outer envelope of the heat radiation cover is a cuboid or a polygonal prism made of aluminum alloy material, and is installed on the outer surface of the telescope cylinder of the optical assembly of the laser terminal and tightly adheres to the telescope cylinder.

[0014] The interface between the heat radiation cover and the telescope cylinder is filled with silicone rubber.

[0015] The outer surface of the heat radiation cover is provided with a plurality of planar regions for pasting the heat dissipation surface coating.

[0016] In an embodiment based on the first aspect, the heat radiation cover is structurally designed according to the telescope cylinder reinforcing rib surface to ensure that it tightly adheres to the reinforcing rib of the telescope cylinder and has sufficient adhesion area to reduce thermal resistance.

[0017] In an embodiment based on the first aspect, the heat radiation cover further comprises an extension portion for shielding sunlight from irradiating the heat dissipation surface.

[0018] In an embodiment based on the first aspect, the heat dissipation surface coating adopts a glass type secondary surface mirror.

[0019] In a second aspect, the present application provides a method for manufacturing a heat radiation cover for a laser terminal, comprising:

[0020] According to the layout of the laser terminal on the satellite, the orbit and attitude of the satellite, the variation of the external heat flow of the laser terminal is analyzed, and the high-temperature working condition and the low-temperature working condition of the laser terminal are determined in combination with the working mode of the laser terminal, and the shape and size requirements of the heat radiation cover are determined through thermal analysis;

[0021] According to the analysis results and the size of the telescope barrel, the size, position and orientation of the heat dissipation surface of the heat radiation cover are determined, and whether an extended part is needed; when the high-temperature working condition appears in the sunlight irradiating the inside of the telescope barrel, the heat radiation cover structure is designed to have an extended part;

[0022] The heat radiation cover is processed, and the mounting surface of the heat radiation cover needs to be closely attached to the telescope barrel; the heat radiation cover is adjusted according to radiation protection, structural strength and heat capacity;

[0023] After the heat radiation cover is processed, a heat dissipation surface coating is pasted on the outer surface of the heat radiation cover;

[0024] The heat radiation cover is fixedly installed with the telescope barrel; during installation, the mounting surfaces of the heat radiation cover and the telescope barrel are filled with silicone rubber on both sides.

[0025] Based on the second aspect, in an embodiment of the present application, when the external heat flow of the south-north heat dissipation surface is stable and small in the high-temperature working condition, the heat radiation cover structure adopts the form of the south-north heat dissipation surface.

[0026] Based on the second aspect, in an embodiment of the present application, the heat radiation cover is made of aluminum alloy.

[0027] Based on the second aspect, in an embodiment of the present application, a small area where the heat dissipation surface coating cannot be pasted is supplemented with F46 film.

[0028] Based on the second aspect, in an embodiment of the present application, the area where the heat dissipation surface coating is not pasted is finally coated with a multi-layer thermal insulation assembly.

[0029] Based on the second aspect, in an embodiment of the present application, the heat dissipation surface coating adopts a glass-type secondary surface mirror.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] (1) The heat radiation cover of the present application can effectively increase the heat dissipation area of the optical assembly and improve the heat dissipation capacity;

[0032] (2) The surface of the heat radiation cover of the present application is flat, and compared with the structure of the optical assembly itself, the heat dissipation surface is greatly reduced in the influence of the surrounding structure, and the heat dissipation efficiency is improved;

[0033] (3) The heat radiation cover of the present application can be designed according to the external heat flow characteristics of the laser terminal in specific application scenarios, including the size, position and orientation of the main heat dissipation surface, to improve the heat dissipation efficiency of the heat dissipation surface; for a certain IGSO satellite laser terminal, the sunlight is continuously irradiated within a small angle range in the XZ plane under the condition of satellite attitude control, and the heat radiation cover is designed to have the heat dissipation surface facing +Y and -Y (south and north), which can greatly improve the heat dissipation efficiency of the heat radiation cover;

[0034] (4) The extreme high temperature working condition of a certain GEO satellite laser terminal occurs inside the lens barrel irradiated by sunlight, which will cause the temperature of the lens barrel to rise. According to the external heat flow characteristics, the structure of the heat radiation cover is expanded, the heat dissipation surface is expanded, and the main heat dissipation surface is shielded from sunlight, thereby improving the heat dissipation capacity of the main heat dissipation surface;

[0035] (5) The outer surface of the heat radiation cover of the present application is a plane, and OSR can be pasted as a heat dissipation surface coating. Compared with the currently available heat control white paint, OSR has higher heat dissipation efficiency and more stable optical properties during long-term use, which is beneficial to thermal design and thermal analysis;

[0036] (6) The heat radiation cover of the present application increases the heat capacity of the optical assembly, improves the temperature stability of the optical assembly itself under the condition of severe external heat flow change, and reduces the design difficulty of the heater and temperature control strategy. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 FIG. 1 is a schematic diagram of a heat radiation cover designed for a certain IGSO satellite laser terminal with +Y and -Y (south and north) orientation;

[0038] Figure 2 FIG. 4 is a schematic diagram of a heat radiation cover expansion part shielding sunlight for a certain GEO satellite laser terminal in an extreme high temperature working condition.

[0039] REFERENCE NUMERALS:

[0040] 1-south heat dissipation surface, 2-north heat dissipation surface, 3-main heat dissipation surface, 4-expansion part, 5-sunlight, 6-lens barrel interior. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0042] A heat radiation cover for a laser terminal, comprising a heat radiation cover, a heat dissipation surface coating and GD414C silicone rubber. The outer envelope of the heat radiation cover adopts a cuboid (as shown in Figure 1 ) or a polygonal prism (as shown in Figure 2 ).

[0043] (1) The heat radiation cover is made of aluminum alloy with good thermal conductivity, is installed on the outer surface of the telescope barrel of the optical assembly of the laser terminal, is tightly attached to the telescope barrel, increases the heat capacity of the optical assembly, increases the heat dissipation area of the optical assembly and provides good implementation conditions for the heat dissipation surface coating. The heat radiation cover is used to reduce the temperature fluctuation of the optical assembly when the external heat flow changes. The heat radiation cover is structurally designed according to the rib surface of the telescope barrel, so as to ensure that the heat radiation cover is tightly attached to the ribs of the telescope barrel and has sufficient attachment area to reduce thermal resistance. According to the specific application scene of the laser terminal, the size, position and orientation of the heat dissipation surface are designed. At the same time, under the condition of extremely high temperature, the extension part 4 blocks the sunlight 5 from irradiating the main heat dissipation surface 3, thereby improving the overall heat dissipation capacity. The outer surface of the heat radiation cover is provided with a plurality of planar regions for pasting the heat dissipation surface coating (such as glass type secondary surface mirror (OSR)). According to the structural design needs, screw holes are opened.

[0044] (2) The heat dissipation surface coating uses OSR, which is pasted on the planar region on the outer surface of the heat radiation cover.

[0045] (3) GD414C silicone rubber is used as the interface filler between the heat radiation cover and the telescope barrel, which is used to strengthen the heat conduction between the two, and also takes advantage of the less volatile feature to avoid pollution to the optical assembly.

[0046] A design method of a heat radiation cover for a laser terminal, comprising:

[0047] (1) According to the layout of the laser terminal on the satellite, the orbit and attitude of the satellite, the change of the external heat flow of the laser terminal is analyzed, and the high temperature working condition and the low temperature working condition of the laser terminal are determined considering the working mode of the laser terminal. The shape and size requirements of the heat radiation cover are determined by thermal analysis means;

[0048] (2) According to the analysis results and the size of the telescope barrel, the size, position, orientation and extension part of the heat dissipation surface of the heat radiation cover are designed. For example, when the high temperature working condition occurs when the sunlight 5 irradiates the inside 6 of the telescope barrel, the heat radiation cover is designed to have an extension part 4, which is designed to avoid the sunlight 5 from irradiating the main heat dissipation surface 3 in the high temperature working condition, as shown in Figure 2 For example, when the external heat flow of the south and north heat dissipation surfaces is very small (the external heat flow of the south and north heat dissipation surfaces of the GEO satellite heat radiation cover is stable and small in the cycle), according to the position and orientation of the laser terminal, the heat radiation cover is designed to have the heat dissipation surfaces facing south and north, as shown in Figure 1 , so as to improve the heat dissipation efficiency; the heat radiation cover Figure 1 may also have an extension part 4 as needed;

[0049] (3) Heat radiation cover processing. The heat radiation cover is made of aluminum alloy with good heat conduction performance; the thickness is generally 1-2 mm, and can be adjusted according to the specific needs of radiation protection, structural strength, heat capacity size, etc.; the mounting surface of the heat radiation cover needs to be closely combined with the telescope cylinder, and the flatness of the rest of the outer surface should be less than 0.1 mm / 100 mm*100 mm, so as to facilitate the pasting of the OSR;

[0050] (4) After the heat radiation cover is processed, the outer surface is pasted with OSR according to the thermal design, and F46 film is pasted in the small area where the OSR cannot be pasted, so as to enhance the radiation heat exchange with the cold space, and the area which is not pasted with OSR is finally coated with a multilayer thermal insulation assembly;

[0051] (5) The heat radiation cover and the telescope cylinder are fixed by screws, and the heat radiation cover and the telescope cylinder need to be pre-designed and installed with an interface;

[0052] (6) When the heat radiation cover is installed, the mounting surface of the heat radiation cover and the telescope cylinder is filled with GD414C silicone rubber on both sides, which is used to strengthen the heat conduction and heat exchange between the two.

[0053] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

[0054] Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made on the above embodiments according to the technical essence of the present application, which does not deviate from the technical solutions of the present application, belongs to the protection scope of the technical solutions of the present application.

Claims

1. A heat radiation cover for a laser terminal, characterized by, The heat radiation cover, the heat dissipation surface coating, and the silicone rubber; The outer envelope of the heat radiation cover is a cuboid or a polygonal prism made of aluminum alloy, which is installed on the outer surface of the telescope barrel of the optical assembly of the laser terminal and tightly adheres to the telescope barrel. The interface between the heat radiation cover and the telescope barrel is filled with silicone rubber. The outer surface of the heat radiation cover is provided with multiple planar regions for pasting the heat dissipation surface coating.

2. The heat radiation cover according to claim 1, wherein The heat radiation cover is designed according to the cylindrical surface of the reinforcing ribs of the telescope barrel to ensure that it tightly adheres to the reinforcing ribs and has sufficient adhesion area to reduce thermal resistance.

3. The heat radiation cover according to claim 1, wherein The heat radiation cover also includes an extension part for shielding sunlight from the heat dissipation surface.

4. The heat radiation cover according to claim 1, wherein The heat dissipation surface coating is a glass-type secondary surface mirror.

5. A method for manufacturing a heat radiation cover for a laser terminal, characterized by, The method comprises the following steps: According to the layout of the laser terminal on the satellite, the orbit and attitude of the satellite, the variation of the external heat flow of the laser terminal is analyzed, and the high-temperature working condition and the low-temperature working condition of the laser terminal are determined by combining the working mode of the laser terminal, and the shape and size requirements of the heat radiation cover are determined through thermal analysis; According to the analysis results and the size of the telescope barrel, the size, position and orientation of the heat dissipation surface of the heat radiation cover are determined, and whether an extension part is needed; when the high-temperature working condition appears in the sunlight irradiation inside the telescope barrel, the heat radiation cover is designed with an extension part; The heat radiation cover is processed, and the mounting surface of the heat radiation cover needs to be tightly adhered to the telescope barrel; the heat radiation cover is adjusted according to radiation protection, structural strength, and heat capacity; After the heat radiation cover is processed, the heat dissipation surface coating is pasted on the outer surface of the heat radiation cover; The heat radiation cover is fixedly installed on the telescope barrel; during installation, the mounting surface of the heat radiation cover and the telescope barrel is filled with silicone rubber on both sides.

6. The heat-radiation case manufacturing method according to claim 5, wherein When the external heat flow of the south and north heat dissipation surfaces is stable and small under the high-temperature working condition, the heat radiation cover adopts the form of the south and north heat dissipation surfaces.

7. The heat-radiation case manufacturing method according to claim 5, wherein The heat radiation cover is made of aluminum alloy.

8. The heat-radiation case manufacturing method according to claim 5, wherein The small areas where the heat dissipation surface coating cannot be pasted are supplemented with F46 film.

9. The heat-radiation case manufacturing method according to claim 5, wherein The areas where the heat dissipation surface coating is not pasted are finally coated with multiple thermal insulation components.

10. The heat-radiation case manufacturing method according to claim 5, wherein The heat dissipation surface coating is a glass-type secondary surface mirror.

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