Internal connection structure of cryogenic radiometer

Abstract

The present invention provides an internal connection structure for a cryogenic radiometer, comprising a base, a support column, an upper support ring, a lower support ring, an outer temperature zone housing, and an inner temperature zone housing; wherein the outer temperature zone housing is sleeved on the outside of the inner temperature zone housing, and the bottom end of the outer temperature zone housing is fixedly connected to the base, the upper support ring and the lower support ring are respectively fixed at the upper and lower ends of the inner temperature zone housing in a three-point manner, and the upper support ring is also fixedly connected to the outer temperature zone housing in a three-point manner; the lower support ring is fixed to the base via a support column. The present invention can reduce the surface area through a compact design, thereby reducing radiation heat leakage between different temperature zones; the support structure between different temperature zones is designed to effectively reduce heat leakage caused by the support, so as to adapt to the relatively small cooling capacity of the space cryogenic refrigerator and achieve the purpose of precise measurement of space radiation.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation measurement, and in particular to an internal connection structure of a low-temperature radiometer. Background Art

[0002] With the exception of nuclear energy, all other energy sources on Earth come directly or indirectly from solar radiation. Even small changes in solar radiation can lead to dramatic changes in Earth's environment and climate. Therefore, accurate measurement of solar radiation is crucial. Using vacuum, refrigeration, and superconducting technologies can improve and maintain the accuracy of total solar irradiance measurements over the long term. Research on low-temperature radiation measurement in space is currently underway both domestically and internationally.

[0003] Cryogenic radiometers utilize the excellent properties of materials at low temperatures (generally less than 20K) to achieve high-precision radiation power measurement, so a stable low-temperature environment below 20K is required.

[0004] In 2018, the Changchun Institute of Optics, Fine Mechanics and Physics of the Chinese Academy of Sciences developed China's first cryogenic radiometer capable of precision radiation measurement. The cryogenic radiometer used a Sumitomo GM cryocooler imported from Japan, which has a relatively high cooling capacity but also high mass, volume, and power consumption, making it unsuitable for space applications. Currently, 20K cryogenic refrigerators used in space have relatively low cooling capacity, with the first stage (70K) cooling capacity being approximately 3W and the second stage cooling capacity being approximately 350mW. The connection structure between the different operating temperature zones within the cryogenic radiometer suffers from severe heat leakage, making it unsuitable for space refrigerators and, therefore, unsuitable for on-orbit radiation measurement applications.

[0005] The low-temperature radiometer developed by the UK National Physical Laboratory has an operating temperature of 45K. Due to the slightly higher operating temperature, it uses a first-stage Stirling refrigeration. The internal connection structure also has serious heat leakage and is not suitable for 20K refrigeration. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the existing technology and propose an internal connection structure of a cryogenic radiometer. Under the premise of meeting the mechanical properties, it reduces the heat leakage problem, achieves lightweight and miniaturization, perfectly matches the cooling capacity of the space refrigerator, and meets the use requirements of the space 20K cryogenic radiometer.

[0007] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0008] The internal connection structure of the low-temperature radiometer provided by the present invention includes a base, a support column, an upper support ring, a lower support ring, an outer temperature zone shell and an inner temperature zone shell; wherein, the outer temperature zone shell is mounted on the outside of the inner temperature zone shell, and the bottom end of the outer temperature zone shell is fixedly connected to the base, the upper support ring and the lower support ring are respectively fixed at the upper and lower ends of the inner temperature zone shell in a three-point manner, and the upper support ring is also fixedly connected to the outer temperature zone shell in a three-point manner; the lower support ring is fixed to the base through the support column.

[0009] Preferably, the upper support ring and the lower support ring respectively include a support ring body and a three-pointed star support frame, the three free ends of the three-pointed star support frame are respectively fixedly connected to the support ring body, the three-pointed star bracket divides the support ring body into three sector-shaped areas, and three inner temperature layer fixing blocks are respectively protruded at the midpoints of the arcs corresponding to the three sector-shaped areas on the support ring body, and the three inner temperature layer fixing blocks are respectively fixedly connected to the inner temperature zone outer shell.

[0010] Preferably, arc-shaped through grooves located on both sides of the inner temperature layer fixing block are respectively opened on the support ring body corresponding to the arc of each sector-shaped area.

[0011] Preferably, the arc-shaped through groove starts from the inner temperature layer fixing block and ends at the connection point between the support ring body and the three-pronged star support frame.

[0012] Preferably, the three-pointed star support frame includes a support ring and three support rods, the three support rods are distributed at 120°, one end of the three support rods is fixedly connected to the support ring, and the other end of the three support rods is fixedly connected to the support ring body.

[0013] Preferably, the outer circumference of the upper support ring corresponding to the connection between the support ring body and the three-pointed star support frame is fixedly connected to the outer temperature zone shell through the outer temperature layer heat conduction block.

[0014] Preferably, the upper support ring and the lower support ring are respectively made of polyimide material.

[0015] Preferably, there are three support columns, which are respectively supported at the connection points between the support ring body of the lower support ring and the three-pronged star support frame.

[0016] Preferably, the support column is made of titanium alloy material.

[0017] Preferably, the support column is a hollow structure.

[0018] Compared with the internal connection structure of existing cryogenic radiometers, the present invention can reduce the surface area through a compact design, thereby reducing radiation heat leakage between different temperature zones; the design of the support structure between different temperature zones can effectively reduce the heat leakage caused by the support, so as to adapt to the relatively small cooling capacity of the space cryogenic refrigerator and achieve the purpose of precise measurement of space radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 2 is a schematic structural diagram of the internal connection structure of a cryogenic radiometer according to an embodiment of the present invention;

[0020] Figure 2 This is a front view of the internal connection structure of the cryogenic radiometer provided according to an embodiment of the present invention;

[0021] Figure 3 is a top view of the internal connection structure of a cryogenic radiometer provided according to an embodiment of the present invention;

[0022] Figure 4 1 is a diagram showing the results of heat leakage analysis of the internal connection structure of a cryogenic radiometer provided according to an embodiment of the present invention.

[0023] The reference numerals include: base 1, support column 2, upper support ring 3, support ring body 31, arc-shaped through groove 311, three-pointed star support frame 32, support ring 321, support rod 322, inner temperature layer fixing block 33, outer temperature layer heat conduction block 34, screw hole 35, lower support ring 4, outer temperature zone outer shell 5, inner temperature zone outer shell 6. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0026] Figure 1 The structure of the internal connection structure of the cryogenic radiometer provided according to an embodiment of the present invention is shown.

[0027] like Figure 1 As shown, the internal connection structure of the cryogenic radiometer provided by the embodiment of the present invention includes a base 1, a support column 2, an upper support ring 3, a lower support ring 4, an outer temperature zone housing 5 and an inner temperature zone housing 6; wherein the outer temperature zone housing 5 is sleeved on the outside of the inner temperature zone housing ( Figure 1Part of the structure of the outer temperature zone housing 5 is hidden to expose the other structures within the outer temperature zone housing 6. The bottom end of the outer temperature zone housing 5 is fixedly connected to the base 1. The upper support ring 3, lower support ring 4, and inner temperature zone housing 6 are respectively located inside the outer temperature zone housing 6. The upper support ring 3 and lower support ring 4 are respectively fixed to the upper and lower ends of the inner temperature zone housing 6 in a three-point manner. The upper support ring 3 is also fixedly connected to the outer temperature zone housing 5 in a three-point manner. The lower support ring 4 is fixed to the base 1 via the support column 2. The outer temperature zone (i.e., the 70K temperature zone) is formed between the outer temperature zone housing 5 and the inner temperature zone housing 6. The interior of the inner temperature zone housing 6 is the inner temperature zone (i.e., the 20K temperature zone).

[0028] Figure 2 and Figure 3 The main view structure and the top view structure of the internal connection structure of the cryogenic radiometer provided according to an embodiment of the present invention are respectively shown.

[0029] like Figure 2 and Figure 3 As shown together, the upper support ring 3 includes a support ring body 31 and a three-pointed star support frame 32. The three free ends of the three-pointed star support frame 32 are respectively fixedly connected to the support ring body 31. The three-pointed star support frame 32 divides the support ring body 31 into three sector-shaped areas. Three inner temperature layer fixing blocks 33 are formed on the support ring body 31 at the midpoints of the arcs corresponding to the three sector-shaped areas. The three inner temperature layer fixing blocks 33 are respectively fixedly connected to the inner temperature zone outer shell 6. The three inner temperature layer fixing blocks 33 also play a role in contacting the inner temperature zone outer shell 6. Since the upper support ring 3 only contacts the inner temperature zone outer shell 6 through the three inner temperature layer fixing blocks 33, and the other parts do not contact the inner temperature zone outer shell 6, the contact area between the upper support ring 3 and the inner temperature zone outer shell 6 is very small, which can reduce heat leakage.

[0030] The three-pointed star support frame 32 includes a support ring 321 and three support rods 322. The angle between two adjacent support rods 322 is 120°, that is, the three support rods 322 are distributed at 120°. One end of the three support rods 322 is fixedly connected to the support ring 321, and the other end of the three support rods 322 is fixedly connected to the support ring body 31.

[0031] The support ring 321 and the three support rods 322 can be an integrally formed structure or a separate structure, and the support ring body 31 and the three-pointed star support frame 32 can be an integrally formed structure or a separate structure.

[0032] The connection points between the three support rods 322 and the support ring body 31 form three support points, and three hollow fan-shaped areas are formed on the upper support ring 3, so that the upper support ring 3 can reduce the overall weight while meeting the mechanical properties.

[0033] In order to further reduce weight, arc-shaped through grooves 311 are respectively opened on both sides of the inner temperature layer fixing block 33 corresponding to the arc of each sector-shaped area on the support ring body 31, that is, two arc-shaped through grooves 311 are opened in each sector-shaped area on the support ring body 31, and a total of six arc-shaped through grooves 311 are opened.

[0034] In one example of the present invention, the arcuate through groove 311 starts from the inner temperature layer fixing block 33 and ends at the connection between the support ring body 31 and the support rod 322, thereby reducing the weight of the upper support ring 3 to the greatest extent to achieve lightweighting.

[0035] On the outer circumference of the support ring body 31, corresponding to the three support points (where the three support rods 322 are connected to the support ring body 31), outer temperature layer heat conductive blocks 34 are integrally formed or fixedly connected. The three outer temperature layer heat conductive blocks 34 are distributed at 120°, and the outer sides of the three outer temperature layer heat conductive blocks 34 are respectively fixedly connected to the outer temperature zone shell 5.

[0036] The three outer temperature zone heat conducting blocks 34 provide a three-point fixed connection between the upper support ring 3 and the outer temperature zone housing 5. Since the upper support ring 3 contacts the outer temperature zone housing 5 only through the three outer temperature zone heat conducting blocks 34, and the rest of the upper support ring 3 does not, the contact area between the upper support ring 3 and the outer temperature zone housing 5 is very small, thus reducing heat leakage.

[0037] A longer heat conduction path is formed between the inner temperature layer fixing block 33 and the outer temperature layer heat conduction block 34, which can improve thermal resistance and reduce heat leakage.

[0038] On the outer circumference of the support ring body 31, corresponding to the positions of the three support points (i.e., the places where the three support rods 322 are connected to the support ring body 31), screw holes 35 that pass through the thickness of the support ring body 31 and the inner temperature layer fixing block 33 are respectively opened, and threaded blind holes corresponding to the screw holes 35 are opened in the inner temperature zone shell 6, and the upper support ring 3 and the inner temperature zone shell 6 are fixedly connected by screws.

[0039] The upper support ring 3 is preferably made of a material with a low thermal conductivity, such as polyimide.

[0040] The lower support ring 4 is also made of a material with a low thermal conductivity coefficient. The structure of the lower support ring 4 is substantially the same as that of the upper support ring 3 , except that the lower support ring 4 does not have an external temperature layer heat conduction block 34 formed on the outer circumference.

[0041] Through holes are respectively provided in the base 1 and the inner temperature zone housing 6 at positions corresponding to the support rings of the lower support ring 4 , so that the cold head of the space refrigerator can be inserted into the inner temperature zone housing 6 .

[0042] There are three support columns 2 , the top ends of the three support columns 2 are respectively supported on the connection points between the support ring body of the lower support ring 4 and the three-pronged star support frame, and the bottom ends of the three support columns 2 are respectively fixedly connected to the base 1 .

[0043] On the premise of meeting the rigidity requirement, the support column 2 is preferably made of a material with a low thermal conductivity, such as titanium alloy.

[0044] The support column 2 has two functions: one is to increase the heat conduction path, and the other is to adapt to the cold head structure of the space refrigerator.

[0045] The support column 2 is hollow, and the thinner the tube wall is, the better, provided that mechanical conditions permit.

[0046] from Figure 3 It can be seen that the gap between the 20K temperature zone and the 70K temperature zone is very small, which can make the overall structure compact, thereby minimizing the surface area between different temperature zones as much as possible, effectively reducing radiation heat leakage; at the same time, it can meet the lightweight and miniaturization requirements of aerospace applications.

[0047] The above content describes in detail the internal connection structure of the cryogenic radiometer provided by the embodiment of the present invention. The following is a heat leakage analysis of the internal connection structure of the cryogenic radiometer.

[0048] Based on the performance of the space-based refrigerator, finite element analysis software was used to conduct mechanical and thermal analysis of the cryogenic radiometer's internal connection structure. Modal and vibration analyses were performed to determine whether the structure's mechanical properties could withstand the vibration conditions encountered during satellite launch, thereby meeting the requirements. Thermal analysis was also performed to determine whether the structural heat leakage could match the performance of the space-based refrigerator, primarily ensuring that the refrigerator's cooling capacity exceeded the combined cooling capacity of the structure, radiation heat leakage, and the detector's measurement requirements.

[0049] Finite element analysis was used to analyze the thermal structure of the two temperature zones separately. This model was relatively simple and sufficient for verifying heat leakage. The 20K temperature zone was set to a constant temperature, and a certain power of heat was applied externally. The thermal resistance value was calculated from the output temperature difference, and the heat leakage value between the different temperature zones was then calculated.

[0050] Figure 4 The heat leakage analysis results of the internal connection structure of the cryogenic radiometer provided by an embodiment of the present invention are shown.

[0051] like Figure 4As shown in the figure, the input conditions are to define the 20K temperature zone as 20K and apply 1W of heat to the outer wall of the 70K temperature zone, resulting in a final temperature difference of 1003K. This means that the thermal resistance between the two temperature zones is 1003K / W. When the temperature difference is 60K, the heat leakage is 60mW. This structural heat leakage is relatively small compared to the cooling capacity of the refrigerator, accounting for 17% of the cooling capacity of 350mW (the cooling capacity of the secondary cold head of a space cryogenic refrigerator), which meets the cooling capacity specifications of the space cryogenic refrigerator.

[0052] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0053] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0054] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A cryogenic radiometer internal connection structure, characterized in that: It includes a base, a support column, an upper support ring, a lower support ring, an outer temperature zone shell and an inner temperature zone shell; wherein, the outer temperature zone shell is sleeved on the outside of the inner temperature zone shell, and the bottom end of the outer temperature zone shell is fixedly connected to the base, a 70K temperature zone is formed between the outer temperature zone shell and the inner temperature zone shell, and the interior of the inner temperature zone shell is a 20K temperature zone; the upper support ring and the lower support ring are respectively fixed at the upper and lower ends of the inner temperature zone shell in a three-point manner, and the upper support ring is also fixedly connected to the outer temperature zone shell in a three-point manner; the lower support ring is fixed to the base through the support column; The upper support ring and the lower support ring respectively include a support ring body and a three-pointed star support frame, the three free ends of the three-pointed star support frame are respectively fixedly connected to the support ring body, the three-pointed star bracket divides the support ring body into three sector-shaped areas, and three inner temperature layer fixing blocks are respectively protruded at the midpoints of the arcs of the three sector-shaped areas on the support ring body, and the three inner temperature layer fixing blocks are respectively fixedly connected to the inner temperature zone outer shell; outer temperature layer heat conduction blocks are respectively formed on the outer circumference of the upper support ring corresponding to the connection between the support ring body and the three-pointed star support frame, and are fixedly connected to the outer temperature zone outer shell through the outer temperature layer heat conduction blocks.

2. The internal connection structure of the cryogenic radiometer according to claim 1, wherein: Arc-shaped through grooves located on both sides of the inner temperature layer fixing block are respectively opened on the supporting ring body corresponding to the arc of each sector-shaped area.

3. The internal connection structure of the cryogenic radiometer according to claim 2, wherein: The arc-shaped through groove starts from the inner temperature layer fixing block and ends at the connection point between the support ring body and the three-pronged star support frame.

4. The internal connection structure of a cryogenic radiometer according to any one of claims 1 to 3, wherein: The three-pointed star support frame includes a support ring and three support rods, which are distributed at 120°. One end of the three support rods is fixedly connected to the support ring, and the other end of the three support rods is fixedly connected to the support ring body.

5. The internal connection structure of the cryogenic radiometer according to claim 1, wherein: The upper support ring and the lower support ring are respectively made of polyimide material.

6. The internal connection structure of the cryogenic radiometer according to claim 1, wherein: There are three support columns, which respectively support the connection between the support ring body of the lower support ring and the three-pronged star support frame.

7. The internal connection structure of the cryogenic radiometer according to claim 6, wherein: The support column is made of titanium alloy material.

8. The internal connection structure of the cryogenic radiometer according to claim 7, wherein: The support column is a hollow structure.

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