Conical homogenizing device for a microwave radiometer calibration source operating in vacuum

Abstract

The application discloses a conical temperature equalizing device for a microwave radiometer calibration source, which comprises a liquid distribution cold plate, a liquid distributor, a conical temperature equalizing structure, a heating rod, an electromagnetic valve, a single-cone mounting plate, a temperature sensor, a temperature controller, a Dewar tube and a Dewar bottle. The application transmits the temperature field generated by the liquid distribution cold plate and smoothed by the conical temperature equalizing structure to the single-cone mounting plate; meanwhile, the conical temperature equalizing structure with controllable temperature is used to optimize and adjust the physical temperature field of the radiator, so that the single fixed and heavy temperature control structure of the current microwave radiometer calibration source is solved, the weight of the microwave radiometer calibration source is reduced under the premise that the physical temperature of the microwave radiometer calibration source is continuously adjustable from liquid nitrogen to a high-temperature zone, the temperature control structure is suitable for multiple temperature control structures, and the conical temperature equalizing device can provide temperature equalization for a large-diameter microwave radiometer calibration source.

Description

Technical Field

[0001] This invention relates to the field of radiometer technology, and in particular to a conical temperature equalization device for a variable temperature calibration source used in a microwave radiometer operating in a vacuum environment. Background Technology

[0002] A microwave radiometer is a highly sensitive receiver that receives the natural radiation of an object. Years of research have shown that while different objects have different radiation characteristics (or brightness temperatures), the differences between them are not significant. The brightness temperature of the same object under different conditions may vary to some extent, but it is usually very small. Microwave radiometers must undergo standardized, precise, and reliable calibration. This means using the radiometer to receive the radiation signal from a precisely known calibration source with precisely known microwave radiation characteristics. Only then can a quantitative relationship be accurately constructed between the radiometer's electrical signal output and the received radiation value, ensuring the accuracy and application value of passive remote sensing information. The radiometer calibration source, by precisely controlling the physical temperature of the radiating body, can make the radiating body output a precisely known signal. The working principle of the radiometer calibration source is as follows: Figure 1 As shown, the temperature controller controls cooling and heating based on the input temperature information. Cooling is achieved by controlling the opening and closing of the liquid nitrogen valve, and heating is achieved by controlling the current of the heating rod.

[0003] Microwave radiometer calibration sources generally need to operate between -190℃ and 60℃. With the continuous advancement of radiometer technology, the requirements for the uniformity of temperature across the entire aperture of the radiometer calibration source are becoming increasingly stringent, and the required aperture size of the calibration source is increasing. Existing temperature equalization devices for radiometer calibration sources can no longer meet the current requirements.

[0004] The problem with the original temperature equalization structure lies in its temperature equalization principle. Specifically, the original radiometer calibration source was fed into a liquid distribution pipe via a liquid nitrogen pipeline. The liquid nitrogen then entered the temperature control body and, through the temperature equalization body, transferred its cooling capacity to the radiator. However, neither the existing distributor nor the temperature control body can eliminate the influence of gravity and liquid nitrogen pressure. Gravity causes uneven distribution, or changes in local atmospheric pressure cause pressure changes in the Dewar flask, resulting in uneven flow of liquid nitrogen into the temperature control body and causing excessive overall temperature differences. Furthermore, the original temperature equalization body was simply aluminum with low heat capacity. To meet the requirement of temperature uniformity transmitted to the radiator, the existing temperature homogenizer needs to strictly control the contact area and surface finish between itself and the temperature control body and the single-cone mounting plate; it also needs to be infinitely thickened, resulting in a bulky and heavy radiometer calibration source. The larger the aperture of the radiometer calibration source, the greater the cooling capacity required, the larger the temperature control body volume, and the larger and heavier the temperature homogenizer volume, making it impossible to further optimize the uniformity of the existing calibration source, reduce the weight of the entire radiometer calibration source, and make it impossible to make a large-aperture variable temperature calibration source for radiometers. Summary of the Invention

[0005] The purpose of this invention is to provide a conical temperature control device for a microwave radiometer calibration source operating in a vacuum environment. This device achieves continuous adjustment of the physical temperature of the microwave radiometer calibration source from liquid nitrogen to the high-temperature region, while reducing weight and being applicable to various temperature control structures. It can also provide uniform temperature for large-aperture microwave radiometer calibration sources, solving the technical problem of the current microwave radiometer calibration source temperature control structure being single, fixed, and bulky.

[0006] This invention provides a conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment, comprising a liquid-dispensing cooling plate, a liquid dispenser, a conical temperature equalization structure, a single-cone mounting plate, a temperature sensor, a Dewar tube, and a Dewar flask, wherein:

[0007] The Dewar bottle is connected to the dispenser via the Dewar tube;

[0008] The liquid dispenser is connected to the liquid dispensing cooling plate;

[0009] One end of the conical temperature equalization structure is connected to the liquid distribution cooling plate, and the other end is connected to the single cone mounting plate;

[0010] The temperature sensor is installed in a calibration source located on the front side of the single-cone mounting plate.

[0011] In some embodiments, the liquid-distributing cooling plate has a plurality of liquid nitrogen channels inside, one end of each liquid nitrogen channel is connected to a distributing pipe of the liquid distributor; the other ends of all the liquid nitrogen channels are concentrated at the center of the liquid-distributing cooling plate and are connected to the outside through an outlet pipe.

[0012] In some embodiments, the liquid nitrogen channel has a rectangular cross-section, and there are six channels arranged in three rows on the entire surface of the liquid cooling plate; each liquid nitrogen channel is arranged in an S-shape.

[0013] In some embodiments, the conical temperature equalization structure is a square pyramid structure with rectangular ends; the conical temperature equalization structure has a conical cavity inside.

[0014] In some embodiments, a solid rectangular thin plate is provided at one end of the conical temperature equalization structure that is connected to the liquid distribution cooling plate, and a connecting plate with a central circle is provided on the side that is connected to the single cone mounting plate.

[0015] In some embodiments, a heating rod and a temperature controller are also included, the heating rod being mounted within the solid rectangular thin plate, and the temperature controller being electrically connected to both the heating rod and the temperature sensor.

[0016] In some embodiments, the number of heating rods is 10, arranged in two rows; and the two rows of heating rods are staggered.

[0017] In some embodiments, the liquid dispensing plate, the liquid dispenser, the Dewar tube, and the Dewar bottle are all made of copper.

[0018] In some embodiments, the conical temperature equalization structure and the single-cone mounting plate are both made of magnesium-aluminum material.

[0019] In some embodiments, a solenoid valve disposed on the Dewar tube is also included.

[0020] In some embodiments, the surface finish of the solid rectangular thin plate connected to the liquid distribution cooling plate is 1.6 μm, and thermal grease is coated between the solid rectangular thin plate and the liquid distribution cooling plate.

[0021] In some embodiments, the number of conical temperature equalization devices is one or more. When the number of conical temperature equalization devices is two or more, all the conical temperature equalization devices are arranged in an array and spliced ​​to form a large-diameter temperature equalization device, which is connected to a large-diameter calibration source.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention provides a conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment. By setting the temperature equalization structure in a conical shape and incorporating conical holes within the conical structure, the temperature generated by the liquid cooling plate is smoothly transferred to the single-conical mounting plate through the conical temperature equalization structure. Simultaneously, the temperature-controllable conical temperature equalization structure optimizes and adjusts the physical temperature field of the radiator, thus solving the problem of the single, fixed, and bulky temperature control structure of current microwave radiometer calibration sources. This invention achieves weight reduction while ensuring continuous adjustment of the physical temperature of the microwave radiometer calibration source from liquid nitrogen to high-temperature regions. Furthermore, because the temperature equalization structure of the present invention has rectangular ends, it is suitable for various temperature control structures. By arranging and splicing the temperature equalization devices in an array to form a large-diameter temperature equalization device, it can provide temperature equalization for large-diameter microwave radiometer calibration sources, solving the problem of excessive weight and difficulty in installation and transportation of existing temperature equalization devices for microwave radiometer calibration sources. It also solves the problem that existing radiometer calibration sources cannot control large-diameter (1m and above) sources and the problem that existing microwave radiometer calibration sources can only be matched with a single temperature control structure. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the temperature equalization device for the calibration source of a microwave radiometer in the prior art.

[0025] Figure 2 This is a side view of the conical temperature equalization device for the microwave radiometer calibration source used in a vacuum environment according to the present invention.

[0026] Figure 3 This is a front view of the conical temperature equalization device for the calibration source of a microwave radiometer operating in a vacuum environment according to the present invention.

[0027] Figure 4 This is a schematic diagram of the liquid separator in the conical temperature equalization device of the microwave radiometer calibration source for operation in a vacuum environment according to the present invention.

[0028] Figure 5 This is a schematic diagram of the internal structure of the liquid-cooling plate in the conical temperature equalization device of the microwave radiometer calibration source for operation in a vacuum environment according to the present invention.

[0029] Figure 6 This is a schematic diagram of the conical temperature equalization structure in the conical temperature equalization device of the microwave radiometer calibration source for operation in a vacuum environment according to the present invention.

[0030] Figure 7 This is a cross-sectional view of the microwave radiometer calibration source used in this invention for operation in a vacuum environment.

[0031] In the diagram: 1. Liquid separator; 2. Liquid dispenser; 3. Conical temperature equalization structure; 4. Heating rod; 5. Solenoid valve; 6. Single cone mounting plate; 7. Temperature sensor; 9. Dewar flask; 10. Dewar tube; 11. Gas outlet pipe; 12. Liquid nitrogen tank path; 13. Solid rectangular thin plate; 14. Connecting plate. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0034] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0035] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions has been enlarged, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0036] like Figure 2 As shown, this invention provides a conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment, comprising a liquid-dispensing cooling plate 1, a liquid dispenser 2, a conical temperature equalization structure 3, a single-cone mounting plate 6, a temperature sensor 7, a Dewar tube 10, and a Dewar flask 9, wherein:

[0037] The Dewar flask 9 contains liquid nitrogen and is connected to the distributor 2 via the Dewar tube 10 for delivering liquid nitrogen into the distributor 2.

[0038] The liquid separator 2 is connected to the liquid separator cooling plate 1 and is used to divide the delivered liquid nitrogen into multiple streams and deliver them into the liquid separator cooling plate 1.

[0039] One end of the conical temperature equalization structure 3 is connected to the liquid distribution cooling plate 1, and the other end is connected to the single cone mounting plate 6;

[0040] Temperature sensor 7 is installed in the calibration source located on the front side of the single cone mounting plate 6. The temperature sensor is a precise physical temperature response of the radiator, used to measure the physical temperature of the radiator and feed it back to the temperature controller.

[0041] Furthermore, temperature sensors 7 are installed at different positions on the single-cone mounting plate 6 to measure the uniformity of the physical temperature transmitted by the single-cone mounting plate 6. At the same time, the temperature sensors feed back the measured physical temperature to the temperature controller, which then adjusts the control parameters.

[0042] The conical temperature equalization device of the present invention uses a Dewar flask 9 to deliver liquid nitrogen via a distributor 2 to a liquid-distributing cold plate 1 composed of copper cold plates to provide cooling capacity. Figure 2 As shown. Liquid nitrogen enters through Dewar tube 10 and exits through gas outlet tube 11; the separator 2 is made of copper tube, and the liquid separator cooling plate 1 is made of welded copper plate.

[0043] The present invention provides a conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment. By setting the temperature equalization structure into a cone shape and setting a conical hole inside the conical temperature equalization structure, the temperature generated by the liquid cooling plate is transferred to the single cone mounting plate through the conical temperature equalization structure to form a smooth temperature field, thereby achieving temperature uniformity of the radiator.

[0044] like Figure 5 As shown, in some embodiments, the liquid-distributing cooling plate 1 has several liquid nitrogen channels 12 inside, one end of each liquid nitrogen channel 12 is connected to a distributing pipe of the liquid distributor 2; the other ends of all the liquid nitrogen channels 12 are concentrated in the center of the liquid-distributing cooling plate 1 and are connected to the outside through the gas outlet pipe 11.

[0045] It should be noted that the beginning of all liquid nitrogen tank paths 12 is located on the outer periphery of the liquid distribution cooling plate 1, while the end of the liquid nitrogen tank path 12, which is the gas outlet, is located at the center of the liquid distribution cooling plate 1. This allows multiple liquid nitrogen tank paths 12 to be concentrated at one point, making it convenient for all liquid nitrogen to circulate within the liquid distribution cooling plate 1 and then be discharged at one point.

[0046] like Figure 5 As shown, specifically in this embodiment, the liquid nitrogen channel 12 has a rectangular cross-section, and there are six channels arranged in three rows on the entire surface of the liquid distribution cooling plate 1. Each liquid nitrogen channel 12 is arranged in an S-shape. This structure is also used to ensure that the liquid nitrogen flows evenly through the entire liquid distribution cooling plate 1 to form a uniform temperature field.

[0047] like Figure 6 As shown, in this embodiment, the conical temperature equalization structure 3 is a four-sided pyramid structure with rectangular ends. The conical temperature equalization structure 3 has a conical cavity inside, which is used to evenly distribute the physical cooling capacity with a large temperature difference from the liquid cooling plate 1 through the conical hollow structure. This ensures that the temperature equalization result is not affected by gravity and presents a very uniform temperature physical quantity to the single cone mounting plate 6. Through the conical shape and the conical cavity, a temperature equalization structure is formed to facilitate the uniform transfer of the temperature field and form a uniform temperature field.

[0048] As an optional embodiment of the present invention, a solid rectangular thin plate 13 is provided at one end of the conical temperature equalization structure 3 that is connected to the liquid distribution cooling plate 1, and a connecting plate 14 with a central circle is provided on the side that is connected to the single cone mounting plate 6.

[0049] like Figure 2 As shown, specifically, it also includes a heating rod 4 and a temperature controller. The heating rod 4 is installed inside the solid rectangular thin plate 13. The temperature controller is electrically connected to both the heating rod 4 and the temperature sensor 7. Through the above structural setup, the temperature of the conical heat equalization structure 3 can be controlled. Furthermore, five heating rod mounting holes are respectively opened on the opposite two sides of the solid rectangular thin plate 13. The surface of the heating rod 4 is coated with thermal grease and then inserted into the mounting holes. Its function is to regulate the physical temperature transmitted from the conical heat equalization structure to the single-cone mounting plate.

[0050] The temperature controller is used to control the physical temperature of the conical temperature equalization structure 3, including heating and cooling functions; the heating power and the on / off time of the solenoid valve are automatically adjusted based on the temperature measured by the temperature sensor 7.

[0051] This invention utilizes a temperature-controlled conical isothermal structure to optimize and regulate the physical temperature field of the radiator, thereby solving the problem of the current single, fixed, and bulky temperature control structure of microwave radiometer calibration sources. It achieves weight reduction while ensuring continuous adjustment of the physical temperature of the microwave radiometer calibration source from liquid nitrogen to the high-temperature region. The temperature controller adjusts the heating rod 4 based on the measurement results of the temperature sensor 7, ensuring long-term temperature stability of the radiator.

[0052] In this embodiment, there are 10 heating rods 4 arranged in two rows; and the two rows of heating rods 4 are staggered to increase the physical temperature of the conical uniform temperature structure. The heating power can be controlled by a temperature controller.

[0053] like Figure 3 and Figure 4 As shown, specifically in this embodiment, the liquid-dispensing cooling plate 1, the liquid dispenser 2, the Dewar tube 10, and the Dewar flask 9 are all made of copper, and more specifically, of pure copper. The liquid-dispensing cooling plate is a rectangular metal plate, preferably made of pure copper. That is, the liquid-dispensing cooling plate 1 is machined from a pure copper plate, the liquid dispenser 2 and the Dewar tube 10 are made from pure copper tubes, and the Dewar flask 9 is machined from a pure copper plate. Inside the cooling plate is a machined rectangular liquid nitrogen channel; the liquid-dispensing cooling plate has six liquid nitrogen inlets and one liquid nitrogen outlet. The six liquid nitrogen inlets are respectively connected to the six dispensing tubes of the liquid dispenser 2, and the one liquid nitrogen outlet is connected to the gas outlet pipe.

[0054] Furthermore, such as Figure 7 As shown, both the conical temperature equalization structure 3 and the single-cone mounting plate 6 are made of magnesium-aluminum alloy. Specifically, the conical temperature equalization structure is made of magnesium-aluminum alloy plate, with two rectangles of different lengths and widths at both ends. The overall structure appears as a near-quadrangular prism, and the interior of the conical temperature equalization structure has a central conical structure. The single-cone mounting plate 6 is made of magnesium-aluminum alloy. One side is coated with thermal grease and connected to the conical temperature equalization structure with screws, while the other side is fitted with a radiator. Its function is to allow one side of the single-cone mounting plate 6 to be matched with radiators of different frequency bands and connected to the temperature equalization structure to form microwave radiometer calibration sources of different frequency bands.

[0055] like Figure 3 As shown, it also includes a solenoid valve 5 mounted on the Dewar tube 10. The solenoid valve is connected to the Dewar flask and is used to supply liquid nitrogen cooling to the liquid cooling plate 1. The supply of liquid nitrogen can be adjusted by a temperature controller.

[0056] It should be noted that in this invention, the liquid separator 2 is made of 7 copper tubes welded together and welded to the liquid separator cooling plate 1. It has one liquid nitrogen inlet and six liquid nitrogen outlets. The Dewar tube connected to the liquid separator 2 is equipped with a solenoid valve 5. The solenoid valve 5 is connected to a temperature controller. The temperature controller can control the opening and closing of the solenoid valve 5 to control the flow rate of liquid nitrogen entering the liquid separator cooling plate 1.

[0057] In this embodiment, the surface finish of the solid rectangular thin plate 13 connected to the liquid-distributing cooling plate 1 is 1.6 μm. During installation, thermal grease is applied between the solid rectangular thin plate 13 and the liquid-distributing cooling plate 1, and then they are connected together with screws.

[0058] When the calibration source is a large-diameter calibration source, the number of conical temperature equalization devices is one or more. When the number of conical temperature equalization devices is two or more, all conical temperature equalization devices are arranged in an array and spliced ​​together to form a large-diameter temperature equalization device, which is connected to the large-diameter calibration source.

[0059] The temperature equalization structure of this invention, with its rectangular ends, is suitable for various temperature control structures. By arranging and splicing the temperature equalization devices in an array to form a large-diameter temperature equalization device, it can provide temperature equalization for large-diameter microwave radiometer calibration sources, solving the problem that the temperature equalization devices of existing microwave radiometer calibration sources are too heavy and difficult to install and transport; it also solves the problem that existing radiometer calibration sources cannot control the temperature of large-diameter (1m and above) sources; and it solves the problem that existing microwave radiometer calibration sources can only be matched with a single temperature control structure.

[0060] The conical temperature uniformity structure of this invention solves the problems of excessively low center temperature and poor temperature uniformity to a great extent, significantly improving the temperature difference caused by the liquid distribution cooling plate, and is adaptable to liquid distribution cooling plates of various sizes. Furthermore, it can be assembled into a modular structure suitable for large-aperture microwave radiation calibration sources of 1m or more, solving the problems of excessive weight of radiometers and the inability to calibrate large-aperture radiometers.

Claims

1. A conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment, characterized in that, Includes a liquid dispensing cooling plate, a liquid dispenser, a conical temperature equalization structure, a single-cone mounting plate, a temperature sensor, a Dewar tube, and a Dewar flask, among which: The Dewar bottle is connected to the dispenser via the Dewar tube; The liquid dispenser is connected to the liquid dispensing cooling plate; One end of the conical temperature equalization structure is connected to the liquid distribution cooling plate, and the other end is connected to the single-cone mounting plate. The liquid distribution cooling plate has several liquid nitrogen channels inside, one end of each channel connected to a dispensing pipe of the liquid distributor. The other ends of all the liquid nitrogen channels are concentrated at the center of the liquid distribution cooling plate and connected to the outside via an outlet pipe. The liquid nitrogen channels have a rectangular cross-section, number six, and are arranged in three rows across the entire surface of the liquid distribution cooling plate. Each liquid nitrogen channel extends in an S-shape. The conical temperature equalization structure is a square pyramid structure with rectangular ends. A conical cavity is provided inside the conical temperature equalization structure. A solid rectangular thin plate is provided at the end of the conical temperature equalization structure connected to the liquid distribution cooling plate, and a connecting plate with a central circle is provided on the side connected to the single-cone mounting plate. The temperature sensor is installed in a calibration source located on the front side of the single-cone mounting plate.

2. The conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment according to claim 1, characterized in that, It also includes a heating rod and a temperature controller. The heating rod is installed inside the solid rectangular thin plate, and the temperature controller is electrically connected to both the heating rod and the temperature sensor.

3. The conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment according to claim 2, characterized in that, The number of heating rods is 10, arranged in two rows; and the two rows of heating rods are staggered.

4. The conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment according to claim 1, characterized in that, It also includes a solenoid valve mounted on the Dewar tube.

5. The conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment according to claim 1, characterized in that, The surface finish of the solid rectangular thin plate connected to the liquid-distributing cooling plate is 1.6 μm, and thermal grease is coated between the solid rectangular thin plate and the liquid-distributing cooling plate.

6. The conical temperature equalization device for a microwave radiometer calibration source operating in a vacuum environment according to claim 1, characterized in that, The number of the conical temperature equalization devices is one or more. When the number of the conical temperature equalization devices is two or more, all the conical temperature equalization devices are arranged in an array and spliced ​​to form a large-diameter temperature equalization device, which is connected to a large-diameter calibration source.

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