CN-116046180-B - Vacuum low-temperature surface source blackbody

CN116046180BCN 116046180 BCN116046180 BCN 116046180BCN-116046180-B

Abstract

The invention discloses a vacuum low-temperature surface source blackbody, wherein a pyramid structure of a polygonal pyramid is processed on the surface of a blackbody radiation panel and is matched with a high-emissivity coating, so that the surface source blackbody with a radiation surface containing a microcavity structure is formed, and the effective emissivity of the vacuum low-temperature surface source blackbody is improved. In addition, the invention adopts a reasonable liquid nitrogen pipeline and an I-shaped heat conduction bridge to form a low-temperature module, and the cold quantity is uniformly distributed by connecting the temperature equalization plate, so that the radiation performance of the vacuum low-temperature surface source blackbody is ensured. The vacuum low-temperature surface source black body has the characteristics of high emissivity, uniform temperature field distribution and the like. The liquid nitrogen cooling mode is adopted, so that the requirement on the use environment is reduced, real-time calibration of the full caliber and the full temperature area of the laboratory of the infrared detector can be realized, the calibration precision is effectively improved, and the detection precision of the infrared detector is further improved.

Inventors

HAO XIAOPENG
WANG GANG
ZHOU JINGJING
SONG JIAN

Assignees

中国计量科学研究院

Dates

Publication Date: 20260512
Application Date: 20230228

Claims (8)

1. The vacuum low-temperature surface source blackbody is characterized by comprising a blackbody radiation source, wherein the blackbody radiation source comprises a radiation-proof shell, a fixed base, a blackbody radiation panel, a heating mechanism, a temperature equalizing plate, a heat insulation cushion block, a temperature sensor, a heat conduction bridge, a liquid nitrogen pipeline and a pipeline back fixing mechanism, wherein the blackbody radiation panel is fixed in the radiation-proof shell; one side of the heating mechanism is arranged on the back of the blackbody radiation panel, the other side of the heating mechanism is connected with one side of the heat conduction bridge through a temperature equalizing plate, the other side of the heat conduction bridge is connected with the pipeline back fixing mechanism, and the liquid nitrogen pipeline is arranged between the heat conduction bridge and the pipeline back fixing mechanism and is attached to the heat conduction bridge and the pipeline back fixing mechanism; The back of the blackbody radiation panel is uniformly provided with a plurality of temperature measuring holes with the same depth in an array mode, one temperature measuring hole is positioned at the center of the back of the blackbody radiation panel, the other temperature measuring holes are symmetrical to the center of the back of the blackbody radiation panel, and each temperature measuring sensor is embedded into the corresponding temperature measuring hole through a counter bore and is close to the front of the blackbody radiation panel; the heat-conducting bridge is in an I shape, one end of the pipe is in a cambered surface for wrapping the liquid nitrogen pipeline, the other end is in a plane structure and is used for being connected with the temperature equalizing plate.
2. The vacuum low-temperature surface source blackbody according to claim 1, wherein the blackbody radiation source further comprises a protective housing, the blackbody radiation panel, the heating mechanism and Wen Banjun are all arranged in the protective housing, a heat insulation block is arranged between the outer wall of the blackbody radiation panel and the inner wall of the protective housing, and a heat insulation gasket is arranged between the outer wall of the protective housing and the inner wall of the radiation-proof housing.
3. The vacuum low-temperature surface source black body according to claim 1, wherein the front surface of the black body radiation panel is formed by arranging a plurality of multi-pyramid arrays, and the surface of the black body radiation panel is sprayed with high-emissivity black paint.
4. A vacuum low temperature surface source black body according to claim 3, wherein said high emissivity black paint is Nextel Velvet Black 811-21 black paint.
5. The vacuum low-temperature surface source black body according to claim 1, wherein the heating mechanism comprises a plurality of polyimide heating films, each polyimide heating film is adhered to a heating area corresponding to the back surface of the black body radiation panel through heat conduction grease according to a distribution mode of a temperature sensor, one polyimide heating film is located in the central area of the back surface of the black body radiation panel, and the distribution of each polyimide heating film is in central symmetry with the back surface of the black body radiation panel.
6. The vacuum low-temperature surface source blackbody according to claim 5, wherein a high-purity indium sheet is adhered between the polyimide heating film and the temperature equalization plate through heat conduction grease, so that good contact and heat conduction are ensured.
7. The vacuum cryogenic surface source blackbody according to claim 1, wherein the liquid nitrogen pipeline comprises a liquid nitrogen inlet pipe, a liquid nitrogen outlet pipe and a plurality of liquid nitrogen flow pipes, wherein the top ends of the liquid nitrogen flow pipes are communicated with the liquid nitrogen inlet pipe, and the bottom ends of the liquid nitrogen flow pipes are communicated with the liquid nitrogen outlet pipe.
8. The vacuum low-temperature surface source blackbody according to claim 1, further comprising a control cabinet, a power supply system, a temperature control system and a self-pressurization liquid nitrogen tank, wherein the temperature control system is connected with the control cabinet, the blackbody radiation source is arranged in the vacuum cabin, the control cabinet, the temperature control system and the power supply system are all arranged outside the vacuum cabin, the control cabinet and the temperature control system are powered by the power supply system, a lead of a temperature sensor is welded on a multi-core aviation plug, the multi-core aviation plug is connected with the temperature control system outside the vacuum cabin through an electric flange, the liquid nitrogen pipeline is communicated with the self-pressurization liquid nitrogen tank through a control valve, and the control valve, the heating mechanism and the temperature control system are all connected with the control cabinet.

Description

Vacuum low-temperature surface source blackbody Technical Field The invention relates to the technical field of infrared measurement, in particular to a vacuum low-temperature surface source blackbody. Background With the rapid development of infrared technology, the application range of the infrared technology is spread over various fields. In the 21 st century, the world has great investment in the aerospace field, and in-orbit satellites are launched in batches to realize large-scale real-time earth monitoring, the infrared remote sensing technology is an important observation means of a space-based earth observation system, and the infrared detection instrument is used as key equipment in the observation means, so that the accuracy of information acquisition is directly influenced. The infrared detection instrument is required to achieve the purpose of detecting different infrared targets by accurately measuring the radiation characteristic differences of the different targets. With the continuous increase of the caliber of an optical system, the imaging area of the aerospace infrared remote sensing is larger and larger, and the measured position resolution is continuously improved. As an infrared imaging instrument, it uses a focal plane array infrared detector as a signal receiver. Therefore, accurate calibration of parameters such as detection sensitivity, linearity, response on spectrum and time variation, and the like of each unit detector of the focal plane array is required to ensure the detection precision of the detection instrument. This is accomplished by full field-of-view internal calibration of the instrument by a large caliber infrared calibration source (vacuum cryogenic blackbody radiation source). However, the level of the large-caliber calibration source in China is not high at present, and the calibration level of infrared detection is directly limited. Therefore, the ultra-large-caliber uniform blackbody radiation source is necessary to be developed as a laboratory calibration blackbody of aerospace infrared remote sensing load, so that the calibration level of infrared target detection in China is improved. In order to take account of factors such as radiation surface size, temperature uniformity, blackbody volume and the like, the current large-caliber blackbody radiation source mainly comprises a surface blackbody source. This also results in a disadvantage of its limited emissivity compared to cavity blackbody sources. Meanwhile, the calibration of the full caliber of the laboratory requires that the infrared detection equipment and the surface source black body are placed in a vacuum bin simulating the space environment at low temperature and high vacuum. The laboratory calibration of the infrared detector needs to be calibrated from a low-temperature section to a high-temperature Duan Shixian full-temperature area according to the requirement, so that the vacuum low-temperature surface source blackbody is required to provide uniform, stable and high-precision infrared radiation energy from the low-temperature section to the high-temperature section so as to ensure that the field of view of the infrared camera is fully covered. At present, the vacuum bin simulating the space environment in China is usually cooled by adopting liquid nitrogen so as to reach a low-temperature state, and the reserved flange window is smaller and is difficult to realize the requirement of installing a refrigerator, so that the blackbody is required to realize the calibration of a low-temperature section by adopting a liquid nitrogen cooling mode, and the universality of vacuum low-temperature surface source blackbody calibration is enhanced by adopting a liquid nitrogen cooling refrigeration mode. The flow rate of liquid nitrogen and the existence of gas-liquid two phases lead to great influence on the temperature uniformity and stability of the black body. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a vacuum low-temperature surface source black body. In order to achieve the above purpose, the present invention adopts the following technical scheme: The vacuum low-temperature surface source blackbody comprises a blackbody radiation source, wherein the blackbody radiation source comprises a radiation-proof shell, a blackbody radiation panel, a heating mechanism, a temperature equalizing plate, a fixing base, a heat insulation cushion block, a temperature measuring sensor, a heat conduction bridge, a liquid nitrogen pipeline and a pipeline back fixing mechanism, the blackbody radiation panel is fixed in the radiation-proof shell, one surface of the heating mechanism is arranged on the back of the blackbody radiation panel, the other surface of the heating mechanism is connected to one surface of the heat conduction bridge through the temperature equalizing plate, the other surface of the heat conduction bridge is connected to the pipeline back fixing m