A heat dissipation device and method for radiation calibration experiments of space optical cameras

Abstract

This invention relates to the field of camera radiometric calibration technology, specifically providing a heat dissipation device and method for radiometric calibration experiments of space optical cameras. The device includes a calibration chamber and a space optical camera, a fan, a temperature and humidity control system, and a cryogenic liquid chiller, all housed within the chamber. The space optical camera comprises an electrical control assembly and a focal plane assembly. A liquid cooling pipeline connects the focal plane assembly and the cryogenic liquid chiller. The fan provides air cooling for the electrical control assembly, and the cryogenic liquid chiller provides a low temperature to the focal plane assembly via the liquid cooling pipeline. The temperature and humidity control system detects the temperature and humidity within the calibration chamber and performs heat dissipation and dehumidification to maintain a constant temperature and humidity within the chamber. This invention integrates the cryogenic liquid chiller and other structures within the calibration chamber, shortening the length of the liquid cooling pipeline, reducing heat leakage from the water cooling system to the environment, improving water cooling efficiency, reducing the difficulty of sealing the calibration chamber, minimizing the risk of leakage from the calibration chamber and the cryogenic medium, and reducing the risk of condensation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of camera radiation calibration, and particularly provides a space optical camera radiation calibration test heat dissipation device and a heat dissipation method. BACKGROUND

[0002] A space optical camera needs to be calibrated in a laboratory before launch, and the radiation performance of the camera is adjusted and optimized through radiation calibration, so as to fully exert the capability of the camera to capture radiation information of a scene and thus obtain an image of the best quality. For a space optical camera in the visible light to near-infrared wave band, the radiation calibration test is generally performed in a normal temperature and normal pressure environment. A focal plane detector (such as a CCD, CMOS or the like) of the camera usually needs to work in a low-temperature environment, and the low-temperature environment is conducive to reducing dark current and noise and improving the imaging quality of the camera. Some detectors are designed to work below 0℃ and have a long-term working mode.

[0003] When the space optical camera is in orbit, low temperature will cause plastic deformation of an optical-mechanical structure of the camera and reduce the precision, and therefore, the temperature of the optical-mechanical structure of the space optical camera needs to be controlled at a normal temperature, while the focal plane detector needs to work in a low-temperature environment, and therefore, there is always a large temperature difference between the two. When the radiation calibration test of the space camera is performed in a normal temperature and normal pressure environment, the heat dissipation of electronic components is generally performed by water cooling or air cooling, that is, the heat dissipation is finally dissipated to the surrounding environment by a liquid cooling machine or a fan through a convection heat exchange mode. However, for the focal plane detector working in a low-temperature environment, especially when the working temperature of the detector is greatly different from the ambient temperature, a low-temperature water cooling system needs to be designed to realize the low-temperature working of the detector. However, in a normal temperature and normal pressure environment, if the temperature of the detector is reduced below the dew point temperature of the environment, the detector will appear low-temperature condensation, and thus, there is a risk of short circuit damage.

[0004] To ensure the safety of the detector in the radiation calibration test, for the detector working in a low-temperature environment, the temperature of the detector is generally not reduced below the dew point temperature of the environment in the test, and the radiation calibration parameters at the actual working temperature are calculated through the measured data at the test temperature and theoretical calculation, and this method inevitably causes errors in the actual use of the calibration parameters.

[0005] To ensure the accuracy of the radiation calibration parameters, a vacuum tank can be used to create a low-temperature and vacuum environment for the calibration test, but additional insulation design is needed for the camera and the radiation calibration test tool, and some test tools (such as an integrating sphere) need to be modified to adapt to the vacuum environment, and these measures will make the test system too complex and cause a substantial increase in the test cost. Therefore, for the radiation calibration test of the space optical camera in a normal temperature and normal pressure environment, it is urgent to solve the heat dissipation problem of the low-temperature focal plane detector. SUMMARY

[0006] The application provides a heat dissipation device and a heat dissipation method for a space optical camera radiation calibration test.

[0007] The heat dissipation device for the space optical camera radiation calibration test comprises:

[0008] The calibration cabin, the space optical camera, the fan, the temperature and humidity control system and the low-temperature liquid cooling machine are arranged in the calibration cabin, the space optical camera comprises an electric box assembly and a focal plane assembly, and a liquid cooling pipeline is connected between the focal plane assembly and the low-temperature liquid cooling machine.

[0009] The calibration cabin forms a closed space inside;

[0010] The fan provides air cooling for the electric box assembly, and the low-temperature liquid cooling machine provides low temperature for the focal plane assembly through the liquid cooling pipeline.

[0011] The temperature and humidity control system is used for detecting the temperature and humidity in the calibration cabin, adjusting the temperature and humidity in the calibration cabin according to target temperature and target humidity, and keeping the temperature and humidity in the calibration cabin constant.

[0012] Preferably, the heat dissipation device further comprises an integrating sphere light source, the calibration cabin is provided with a calibration cabin window, the integrating sphere light source provides light for the space optical camera, and the light enters the calibration cabin through the calibration cabin window.

[0013] Preferably, the heat dissipation device further comprises a support table, and the calibration cabin and the space optical camera are fixed on the support table.

[0014] Preferably, the center of the integrating sphere light source and the center of the calibration cabin window are on the optical axis of the space optical camera.

[0015] Preferably, the target humidity is that the humidity in the calibration cabin is not greater than 5%.

[0016] Preferably, the low-temperature liquid cooling machine outputs low-temperature medium, and the low-temperature medium flows through the focal plane assembly along the liquid cooling pipeline and then returns to the low-temperature liquid cooling machine.

[0017] Preferably, the outer surface of the liquid cooling pipeline is coated with thermal insulation material.

[0018] Preferably, the temperature and humidity control system is used for refrigeration, heating or dehumidification.

[0019] Preferably, the fan can move in parallel along the X-axis, the Y-axis and the Z-axis in the calibration cabin.

[0020] The heat dissipation method for the space optical camera radiation calibration test based on the heat dissipation device for the space optical camera radiation calibration test comprises the following steps of:

[0021] The low-temperature liquid cooler inputs the low-temperature medium to the focal plane assembly along the liquid cooling pipeline, cools the focal plane assembly through heat exchange, and then flows back to the low-temperature liquid cooler through the liquid cooling pipeline;

[0022] The temperature and humidity inside the calibration cabin are measured by the temperature and humidity control system, and the temperature inside the calibration cabin is adjusted to the target temperature by cooling or heating of the temperature and humidity control system.

[0023] The humidity inside the calibration cabin is reduced by dehumidification of the temperature and humidity control system.

[0024] Compared with the prior art, the present application can achieve the following beneficial effects:

[0025] The present application provides a sealed calibration cabin and sets a low-temperature liquid cooler inside the calibration cabin, effectively reduces the length of the liquid cooling pipeline, and further reduces the degree of heat exchange between the liquid cooling pipeline and the environment, improves the refrigeration efficiency, and under the same refrigeration capacity, can realize stable work of the focal plane assembly in a lower temperature range, on the contrary, under the same working temperature range, the low-temperature medium in the low-temperature liquid cooler will not be too low, reducing the risk of dew formation in the water cooling system in the calibration cabin. At the same time, the low-temperature liquid cooler is arranged inside the calibration cabin, avoiding the design of the through-cabin flange specially for the liquid cooling pipeline, reducing the sealing difficulty of the calibration cabin, and reducing the risk of leakage of the calibration cabin and the low-temperature medium.

[0026] The present application synchronously sets a water cooling system and an air cooling system to realize heat dissipation of the components of the space optical camera in different working temperature ranges during radiation calibration, especially for the focal plane assembly, ensuring that the radiation calibration temperature is consistent with the actual on-orbit working temperature, effectively reducing the error of the radiation calibration test, and avoiding the short circuit damage of the focal plane assembly due to dew formation.

[0027] A temperature and humidity control system is further arranged in the calibration cabin, which can realize temperature and humidity detection, refrigeration, heating and dehumidification functions, can discharge the heat generated by the operation of each component to the outside of the calibration cabin, and ensure the constant temperature and humidity inside the calibration cabin. Ensure efficient and stable operation of the device and reduce the risk of dew formation.

[0028] Compared with the existing radiation calibration scheme in the vacuum tank, the present application has lower cost. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structure diagram of a space optical camera radiation calibration test heat dissipation device provided according to an embodiment of the present application.

[0030] The reference signs in the drawings include:

[0031] Split-sphere light source 1, calibration cabin 2, space optical camera 3, focal plane assembly 4, electrical box assembly 5, fan 6, temperature and humidity control system 7, liquid cooling pipeline 8, low-temperature liquid cooler 9, support table 10, calibration cabin window 11. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and do not constitute a limitation on the present application. Similar elements in different embodiments use similar element numbers. In the following embodiments, many details are described in order to make the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different cases, or can be replaced by other elements, materials or methods. In some cases, some operations related to the present application are not shown or described in the specification in order to avoid the core part of the present application being overwhelmed by too much description, and it is not necessary to describe these related operations in detail for those skilled in the art according to the description in the specification and general technical knowledge in the art.

[0033] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other to form various embodiments without conflict. Meanwhile, the steps or actions in the method description can also be sequentially adjusted or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for the purpose of clearly describing a certain embodiment, and do not mean that the sequence is necessary, unless otherwise stated that a certain sequence must be followed.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, 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, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] This invention provides a heat dissipation device and method for a radiometric calibration experiment of a space optical camera, such as... Figure 1 As shown, the heat dissipation device includes an integrating sphere light source 1, a calibration chamber 2, a space optical camera 3, a fan 6, a temperature and humidity control system 7, liquid cooling pipes 8, a cryogenic liquid chiller 9, a support platform 10, and a calibration chamber window 11. The space optical camera 3 includes a focal plane assembly 4 and an electrical box assembly 5. The calibration chamber 2 is mounted on the support platform 10, forming a sealed space. The space optical camera 3, fan 6, temperature and humidity control system 7, liquid cooling pipes 8, and cryogenic liquid chiller 9 are located inside the calibration chamber, and the space optical camera 3 is fixedly connected to the support platform 10.

[0038] The space optical camera 3 comprises a focal plane assembly 4 and an electrical box assembly 5, the electrical box assembly 5 has a wide working temperature range requirement, therefore, for the electrical box assembly 5, the embodiment of the present application adopts a wind cooling mode for heat dissipation. The electrical box assembly 5 needs to work continuously during the radiation calibration test of the space optical camera 3, a fan 6 is connected to the inner wall of the calibration cabin 2 towards the electrical box assembly 5, the center of the fan 6 is arranged opposite to the electrical box assembly 5 and other devices needing wind cooling heat dissipation during use, the wind blown by the fan 6 can be vertically blown to the electrical box assembly 5, the fan 6 provides wind for the electrical box assembly 5, and the electrical box assembly 5 is cooled. In order to ensure that the fan 6 can meet various requirements, the fan 6 of the embodiment of the present application can move in parallel along the X axis, the Y axis and the Z axis, thereby adjusting the relative position and distance between the fan 6 and the electrical box assembly 5, and achieving more sufficient heat dissipation. By using the fan 6 in the calibration cabin 2, the heat dissipation of long-term working heat consumption can be achieved through the convection heat exchange between the fan 6 and the air in the calibration cabin 2. Compared with water cooling, this kind of mode is simple and reliable, the installation position is flexible, and there is no risk of cooling medium leakage and pollution.

[0039] The embodiment of the present application adopts a water cooling mode for the focal plane assembly 4 of the space optical camera 3 to realize low-temperature operation and heat dissipation of long-term operation. The low-temperature liquid cooling machine 9 is fixed on the inner wall of the calibration cabin 2 and connected with the focal plane assembly 4 through the liquid cooling pipeline 8. The low-temperature medium, which can be water or other liquids, flows in the liquid cooling pipeline 8. The low-temperature liquid cooling machine 9 outputs the low-temperature medium, which flows through the focal plane assembly 4 along the liquid cooling pipeline 8 and returns to the low-temperature liquid cooling machine 9 to realize circulation. The liquid cooling pipeline 8 is provided with a mounting interface, which is in heat conduction connection with the adapter interface of the heat dissipation path of the focal plane assembly 4, and provides a low-temperature environment for the focal plane assembly 4 through heat exchange. In order to improve the water cooling efficiency, the liquid cooling pipeline 8 is coated with a heat insulation material on the outer surface, which reduces the heat exchange between the liquid cooling pipeline 8 and the environment. At the same time, the lower limit of the working temperature of the low-temperature medium in the low-temperature liquid cooling machine 9 should be 30℃ lower than the working temperature of the focal plane assembly 4, so as to ensure the temperature stability of the focal plane assembly 4 and the safe operation of the whole water cooling system. The specific temperature of the low-temperature medium is determined according to the focal plane detector temperature, the focal plane detector heat dissipation, and the thermal resistance of the heat dissipation path from the detector to the liquid cooling machine. The low-temperature liquid cooling machine 9 is arranged inside the calibration cabin 2 and as close to the focal plane assembly 4 as possible. Compared with the water cooling system arranged outside the calibration cabin 2 in the prior art, the heat dissipation of the low-temperature liquid cooling machine 9 arranged inside the calibration cabin 2 can reduce the length of the liquid cooling pipeline 8, reduce the heat leakage of the liquid cooling pipeline 8 to the environment, make the temperature difference between the low-temperature medium in the low-temperature liquid cooling machine 9 and the focal plane assembly 4 as small as possible, and improve the heat dissipation efficiency of the water cooling system. Under the same refrigeration capacity of the liquid cooling machine, the focal plane assembly 4 can stably work in a lower temperature range. On the contrary, under the same working temperature range requirement of the focal plane assembly 4, the low-temperature medium flowing out of the low-temperature liquid cooling machine 9 does not need a lower temperature due to the short liquid cooling pipeline 8, thereby reducing the risk of dew formation in the calibration cabin 2. In addition, the water cooling system is integrated with the calibration cabin 2, and there is no need to design a cabin flange for the liquid cooling pipeline 8, thereby reducing the risk of leakage of the calibration cabin 2 and the low-temperature medium.

[0040] The calibration cabin 2 provides a closed environment for the space optical camera 3. In consideration of the anti-pollution requirement of the space optical camera 3, the pressure inside the calibration cabin 2 should be greater than that outside the calibration cabin 2, and the difference should be greater than 10 Pa or more. At the same time, the space optical camera 3 generally performs adjustment and assembly at normal temperature, and the temperature control target of the optical-mechanical structure is generally set to 20 DEG C, so the temperature inside the calibration cabin 2 should also be kept at 20 DEG C. In order to control the overall temperature and humidity inside the calibration cabin 2, the embodiment of the present application is provided with a temperature and humidity control system 7 inside the calibration cabin 2, and the temperature and humidity control system 7 is also arranged on the inner wall of the calibration cabin 2. The temperature and humidity control system 7 can detect the temperature inside the calibration cabin 2, and can also heat or cool, so as to adjust the temperature inside the calibration cabin 2 to be constant and close to the target temperature. The heat dissipation of the electrical box assembly 5 of the space optical camera 3, the heat dissipation of the low-temperature liquid cooler 9, the heat dissipation of the fan 6, and the heat dissipation of the surrounding environment through the cabin wall of the calibration cabin 2 are finally dissipated to the external environment of the calibration cabin 2 by the temperature and humidity control system 7 of the calibration cabin 2, and the refrigeration capacity of the temperature and humidity control system 7 of the calibration cabin 2 should be able to ensure the temperature stability of each device inside the calibration cabin 2. At the same time, in order to stabilize the humidity inside the calibration cabin 2 and control dewing, the temperature and humidity control system 7 of the calibration cabin 2 also has a dehumidification function, which can discharge the water vapor inside the calibration cabin 2 to the outside of the calibration cabin 2 to realize the dehumidification function and control the humidity close to the target humidity. According to the temperature of the low-temperature medium in the low-temperature liquid cooler 9 and the environment temperature inside the calibration cabin 2, the relative humidity inside the calibration cabin 2 is controlled and a dewing prevention margin is left, and the relative humidity inside the calibration cabin 2 should generally be ensured to be not greater than 5%.

[0041] In order to ensure the calibration function, the embodiment of the present application is provided with an integrating sphere light source 1 outside the calibration cabin 2, and a calibration cabin window 11 is formed on one end of the calibration cabin 2 towards the integrating sphere light source 1, and the center of the calibration cabin window 11 and the center of the integrating sphere light source 1 are both on the optical axis of the space optical camera 3. The calibration cabin window 11 is made of a light-transmitting material. In the embodiment of the present application, the calibration cabin window 11 adopts a single-layer plane mirror structure, the lens of the calibration cabin window 11 has high transmittance for incident light in the visible light and near-infrared wave bands, and the uniformity of the whole lens is high. By arranging the calibration cabin window 11, it is ensured that the incident light of the integrating sphere light source 1 can enter the calibration cabin 2 in a closed condition, and the calibration experiment of the space optical camera 3 is completed.

[0042] For the heat dissipation device of the space optical camera radiation calibration test, the embodiment of the present application provides a heat dissipation method of the space optical camera radiation calibration test, the fan 6 is arranged towards the electric box assembly 5, and the electric box assembly 5 is provided with wind power, heat dissipation of the electric box assembly is realized, the low-temperature liquid cooler 9 inputs the low-temperature medium to the focal plane assembly 4 along the liquid cooling pipeline 8, refrigeration is realized for the focal plane assembly 4 through heat exchange, and then the low-temperature medium flows back to the low-temperature liquid cooler 9 through the liquid cooling pipeline 8, circulation refrigeration is completed, the temperature and humidity control system 7 detects the temperature and humidity in the calibration cabin 2, and adjusts the temperature or humidity in the calibration cabin 2 through refrigeration, heating or dehumidification, so that the calibration cabin 2 is kept constant in temperature and humidity.

[0043] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

[0044] The specific embodiments of the present application do not constitute a limitation on the protection scope of the present application. Any various other corresponding changes and modifications made according to the technical concept of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A heat sink for a space optical camera radiometric calibration test, comprising: The calibration cabin and the space optical camera, fan, temperature and humidity control system and low-temperature liquid cooler arranged in the calibration cabin are included. The calibration cabin forms a closed space inside. The fan is connected to the inner wall of the calibration cabin towards the electric box assembly, and the center of the fan is opposite to the electric box assembly during use. The fan provides air cooling for the electric box assembly. The low-temperature liquid cooler is fixed on the inner wall of the calibration cabin.

2. The space optical camera radiometric calibration test heat sink of claim 1, wherein, The temperature and humidity control system is used to detect the temperature and humidity in the calibration cabin and adjust the temperature and humidity in the calibration cabin according to the target temperature and target humidity to maintain constant temperature and humidity in the calibration cabin.

3. The space optical camera radiometric calibration test heat sink of claim 2, wherein, The calibration cabin window is arranged on the calibration cabin, and the integral sphere light source provides light for the space optical camera.

4. The space optical camera radiometric calibration test heat sink of claim 3, wherein, The calibration cabin and the space optical camera are fixed on the support table.

5. The space optical camera radiometric calibration test heat sink of claim 1, wherein, The center of the integral sphere light source and the center of the calibration cabin window are on the optical axis of the space optical camera.

6. The space optical camera radiometric calibration test heat sink of claim 1, wherein, The target humidity is not more than 5% in the calibration cabin.

7. The space optical camera radiometric calibration test heat sink of claim 1, wherein, The low-temperature liquid cooler outputs low-temperature medium, which flows through the focal plane assembly along the liquid cooling pipeline and returns to the low-temperature liquid cooler.

8. The space optical camera radiometric calibration test heat sink of claim 1, wherein, The outer surface of the liquid cooling pipeline is coated with thermal insulation material.

9. The space optical camera radiometric calibration test heat sink of claim 1, wherein, The temperature and humidity control system is used for refrigeration, heating or dehumidification.

10. A method of dissipating heat from a space optical camera radiometric calibration test device based on the space optical camera radiometric calibration test device of any one of claims 1 to 9, wherein, The fan can move in X, Y and Z directions in the calibration cabin. The fan provides wind power towards the electric box assembly to achieve heat dissipation of the electric box assembly. The low-temperature liquid cooler inputs low-temperature medium to the focal plane assembly along the liquid cooling pipeline, and the low-temperature medium flows back to the low-temperature liquid cooler after refrigeration of the focal plane assembly through heat exchange. The temperature and humidity control system measures the temperature and humidity in the calibration cabin and adjusts the temperature in the calibration cabin to the target temperature through refrigeration or heating. The temperature and humidity control system dehumidifies to reduce the humidity in the calibration cabin.

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