Double-heat-pipe surface temperature source and calibration method thereof

Abstract

The invention provides a double-heat-pipe surface temperature source calibration device and a calibration method thereof. The calibration device comprises a thermodetector, a platinum resistance thermometer, a heat pipe surface temperature source, a heating device, a heat pipe temperature damper, a temperature equalizing block, a heat insulating layer, a temperature control system, a power meter and a computer. Wherein the heat pipe surface temperature source and the heat pipe temperature damper adopt high-purity cesium as a heat pipe working medium, the shell adopts Inconel 600 high-temperature alloy, and a high-temperature alloy wire mesh made of the same material is welded in an inner cavity of the heat pipe to serve as a liquid absorption core, so that calibration of the surface thermometer can be realized in a temperature region of 300-660 DEG C, and the temperature of the surface thermometer can be measured in a temperature region of 300-660 DEG C; and a high-temperature-resistant high-emissivity coating is sprayed on the surface to serve as a black body radiation surface source to calibrate various radiation thermometers, so that the high-precision temperature calibration capability and level of the surface temperature and the radiation brightness temperature are remarkably improved.

Description

Technical Field

[0001] The present invention relates to a dual-heat-pipe surface temperature source for precisely calibrating surface thermometers and radiation thermometers, and a calibration method thereof, with an applicable temperature range of 300°C to 660°C. Background Art

[0002] A surface temperature source is a metrological standard device for calibrating surface thermometers. It usually uses a pure metal isothermal block to generate a relatively uniform and stable surface temperature, and calibrates the surface thermometer by comparing it with the internal temperature. The temperature stability and uniformity of the metal isothermal block surface source are closely related to the thermal physical properties of the metal material. If the thermal conductivity of the metal material is large, the surface uniformity is relatively good; if the thermal conductivity of the metal material is small, the surface temperature uniformity is relatively poor. In addition, during high-temperature operation, the change in physical properties caused by the oxidation of the material surface also affects the temperature stability and uniformity technical indicators. Usually, the temperature of the metal isothermal block is used as the surface temperature of the surface source, while ignoring the influence of heat exchange. Therefore, this surface temperature calibration method will introduce greater uncertainty and affect the accuracy of surface temperature calibration. Especially in the temperature range above 300°C, the error of the calibration method is greater, resulting in greater uncertainty in the calibration of surface thermometers. Therefore, there is an urgent need for more effective technologies to develop new types of surface temperature sources to improve the accuracy of surface temperature calibration and achieve accurate measurement of surface temperature.

[0003] The blackbody radiation surface source is a reference temperature source for calibrating infrared radiation thermometers by using the Stefan-Boltzmann law to generate a stable and uniform temperature field on a high-emissivity heating surface. The surface temperature source is a temperature reference source for calibrating a surface thermometer that is close to its surface. At present, these two temperature reference sources are independent of each other, and no reference source can be used for the calibration of both infrared radiation thermometers and surface thermometers. The heat pipe is an efficient heat transfer element that uses the phase change of the working fluid to transfer heat. It is known as a thermal superconductor or superconductor. Its working principle is to remove the gas dissolved in the high-purity working fluid, and then use the working fluid gravity to fill the working fluid into the closed heat pipe cavity under high vacuum. The phase change heat transfer of the working fluid under a small temperature difference is used to transfer heat from the high temperature section to the low temperature section. At the same time, under the action of gravity and capillary attraction, the condensed working fluid returns to the high temperature section. Therefore, the heat pipe uses the circulation of the working fluid to achieve efficient heat transfer and can provide a relatively uniform temperature field for temperature calibration. At present, there are reports of using low-temperature ammonia heat pipes in the low temperature section of -50℃ to 50℃. However, in the temperature range of 300℃~660℃, due to the increasing difficulty of manufacturing alkali metal heat pipes, there is no report on alkali metal heat pipe blackbody radiation surface source. The heat transfer coefficient λ of the heat pipe is determined by many factors such as its appearance design, working medium, internal structure, shell material, working temperature, etc. Its calculation model is very complicated. If it is simply used as a temperature-averaging device, it is difficult to use the internal temperature to infer the surface temperature by establishing a heat transfer model, and it is not easy to calibrate the radiation thermometer and the surface thermometer at the same time.

[0004] At the same time, the uniformity and stability of the temperature of the blackbody radiation surface source are the key factors affecting its calibration accuracy. The reference source itself also needs to be placed in a highly uniform temperature field. The current temperature reference sources all use a single temperature-averaging block to provide a uniform temperature field for the reference source. The temperature-averaging effect is not ideal, which hinders the further improvement of temperature measurement accuracy.

[0005] In summary, there is no blackbody radiation surface temperature source that can calibrate both surface thermometers and radiation thermometers in the temperature range of 300℃~660℃. Summary of the invention

[0006] In order to overcome the problem in the background art that there is a lack of a heat pipe surface source for calibrating a surface thermometer and a blackbody radiation surface source for calibrating a radiation thermometer in the temperature range of 300 °C to 660 °C, and to improve the calibration ability and level of surface temperature and radiation temperature, the present invention designs a dual heat pipe surface temperature source applicable to two temperature measurement requirements. The temperature source includes a thermometer, a platinum resistance thermometer, a heat pipe surface temperature source, a heating device, a heat pipe temperature damper, a temperature equalizing block, a heat insulating layer, a temperature control system, a power meter, and a computer. Inside the heating device, a heat insulating layer, a heat pipe temperature damper, a temperature equalizing block, and a heat pipe surface temperature source are coaxially arranged from outside to inside in sequence. The middle part of the heat pipe temperature damper has a generally cylindrical accommodating space for placing the heat pipe surface temperature source and the temperature equalizing block. The heat pipe surface temperature source and the metal temperature equalizing block are coaxially placed in the accommodating space, and the heat pipe surface temperature source is above the metal temperature equalizing block; the temperature control system is used to control the heating power of the heating device, and the power meter measures the heating power of the heating device and sends it to the computer; a high emissivity coating is sprayed on the upper surface of the heat pipe surface temperature source; a surface thermometer to be calibrated is arranged at the center position of the upper surface of the heat pipe surface temperature source or a radiation thermometer to be calibrated is arranged above the upper surface of the heat pipe surface temperature source. The thermometer is used to collect the upper surface temperature of the heat pipe surface temperature source obtained by the surface thermometer or the radiation thermometer as the temperature measurement value to be calibrated; first, second, and third measuring wells are sequentially opened along the vertical direction from top to bottom on the side wall of the heat pipe surface temperature source. The first temperature sensor, the second temperature sensor, and the third temperature sensor are respectively inserted into the three horizontal measuring wells of the heat pipe surface temperature source to respectively obtain the first temperature T1, the second temperature T2, and the third temperature T3 inside the heat pipe surface temperature source and store them in the thermometer. The first temperature T1, the second temperature T2, and the third temperature T3 are located on the same vertical axis.

[0007] The computer establishes a heat conduction model based on the first temperature T1, the second temperature T2, the third temperature T3, and the heating power measured by the power meter, calculates the outer wall temperature of the upper surface of the housing of the heat pipe surface temperature source, and calibrates the temperature measurement value to be calibrated of the surface thermometer or the radiation thermometer with the outer wall temperature of the upper surface of the housing of the heat pipe surface temperature source. Specifically, the computer establishes a first heat conduction model based on the first temperature T1, the second temperature T2, and the third temperature T3, calculates the inner wall temperature of the upper surface of the housing of the heat pipe surface temperature source, then establishes a second heat conduction model based on the inner wall temperature of the upper surface of the housing and the heating power measured by the power meter to calculate the outer wall temperature of the upper surface of the housing of the heat pipe surface temperature source, and finally calibrates the temperature measurement value to be calibrated of the surface thermometer or the radiation thermometer with the outer wall temperature of the upper surface of the housing of the heat pipe surface temperature source.

[0008] The heating device is a two-stage high-precision heating furnace, which includes a bottom heating element and a sidewall heating element, and the heating powers of the bottom heating element and the sidewall heating element are independently controlled by a temperature control system respectively.

[0009] For the heat pipe surface temperature source and the heat pipe temperature damper of the present application, high-purity cesium is used as the heat pipe working medium, the housings of the heat pipe surface temperature source and the heat pipe temperature damper are made of Inconel600 superalloy, and a high-temperature alloy wire mesh of the same material is welded in the internal cavity of the heat pipe as the wick.

[0010] The three horizontal gauge wells on the sidewall of the heat pipe surface temperature source housing are located in the upper half of the heat pipe surface temperature source. The thickness of the upper surface of the heat pipe surface temperature source housing is H1, the vertical distance between the horizontal axis of the first gauge well and the inner wall of the upper surface of the heat pipe surface temperature source housing is H2, the vertical distance between the horizontal axis of the first gauge well and the horizontal axis of the second gauge well is H3, and the vertical distance between the horizontal axis of the second gauge well and the horizontal axis of the third gauge well is H4, where H1 < H2 < H3 = H4.

[0011] The present application also proposes a calibration method for a dual heat pipe surface temperature source, and the calibration method includes:

[0012] Step 1: Establish a one-dimensional heat conduction equations (2), (3) and (4) including the deduced temperature value T of the inner wall of the upper surface of the heat pipe surface temperature source housing, the first temperature T1, the second temperature T2, and the third temperature T3, that is, the first heat conduction model, specifically as follows: interface,n where n is the number for calculating the deduced temperature value of the inner wall of the upper surface of the heat pipe surface temperature source by a linear method in different one-dimensional heat conduction equations, and the thermal conductivity of the heat pipe surface temperature source is λ;

[0013]

[0014]

[0015] Step 2: Calculate the first deduced temperature value T of the inner wall of the upper surface of the heat pipe surface temperature source housing, the second deduced temperature value T, and the third deduced temperature value T respectively according to the above equations; interface,1 interface,2 interface,3 ;

[0016] Step 3: Calculate the average value of the three deduced temperature values as the temperature value T of the inner wall of the upper surface of the heat pipe surface temperature source housing through the following formula (5); interface ;

[0017]

[0018] Step 4: Establish a... including the temperature value T of the inner wall of the upper surface of the heat pipe surface temperature source housing interface ​​​, the outer wall temperature value T of the upper surface of the heat pipe surface temperature source housing surface The one-dimensional heat conduction equation set (6), that is, the second heat conduction model, is specifically as follows:

[0019]

[0020] In Equation (6), q is the power converted into heat measured by the power meter; λsteel is the thermal conductivity of the material of the heat pipe surface temperature source 9 housing;

[0021] Step Five: Calculate the outer wall temperature value T of the upper surface of the heat pipe surface temperature source housing through the above Equation (6) surface As the calibrated temperature value, compare it with the temperature measurement value to be calibrated to complete the calibration of the surface temperature sensor or the radiation thermometer.

[0022] This application improves the temperature stability of the heat pipe surface source by using the heat pipe temperature damping technology. Specifically, it uses the high-efficiency heat transfer of the annular heat pipe to provide a uniform temperature environment. Since the heat pipe absorbs heat by phase change, weakening the rise of the external temperature; and uses the internal vacuum degree of the heat pipe to weaken the decrease of the external temperature. When the external environment is fluctuating at high and low temperatures, the external annular heat pipe temperature damper plays a temperature damping role, weakening the amplitude of the external environmental temperature fluctuation, thereby improving the temperature stability inside the external annular heat pipe cavity. Therefore, this technology is called the "heat pipe temperature damper" and can be used to improve the temperature stability of the heat pipe surface source. Therefore, the use of the double heat pipe technology can significantly improve the stability and uniformity of the surface source temperature and improve the calibration ability of the surface temperature and the radiation temperature.

[0023] This application designs and develops a double heat pipe surface temperature source based on cesium heat pipes, providing a uniform and stable surface temperature, which can calibrate the surface thermometer and can also be used as a blackbody radiation surface source to calibrate the radiation thermometer. Brief Description of the Drawings

[0024] Figure 1 It is the overall schematic diagram of the double heat pipe surface temperature source;

[0025] Figure 2 It is the cross-sectional schematic diagram of the heat pipe temperature damper;

[0026] Figure 3 It is the cross-sectional schematic diagram of the heat pipe surface source;

[0027] Figure 4 It is the schematic diagram of the heat pipe surface temperature determination method;

[0028] Reference numerals: thermometer 1, high emissivity coating 2, platinum resistance thermometer 3 (the first, second, and third temperature sensors are 3A, 3B, and 3C respectively), heat pipe surface source 4, side wall heating element 5, heat pipe temperature damper 6, temperature equalizing block 7, bottom heating element 8, thermal insulation layer 9, temperature control system 10, power meter 11, computer 12. Detailed implementation manners

[0029] The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0030] Figure 1 It is an overall schematic diagram of the dual heat pipe surface temperature source of the present invention. The device includes a thermometer 1, a high emissivity coating 2, the first, second, and third temperature sensors are 3A, 3B, and 3C respectively, a heat pipe surface source 4, a heating device, a heat pipe temperature damper 6, a temperature equalizing block 7, a temperature control system 9, a power meter 10, and a computer 11. Specifically, the temperature sensor is a platinum resistance thermometer.

[0031] Specifically, the heating device is a two-stage high-precision heating furnace. Inside the furnace of the two-stage high-precision heating furnace, a thermal insulation layer 9, a heat pipe temperature damper 6, a metal temperature equalizing block 7, and a heat pipe surface source 4 are coaxially arranged from outside to inside in sequence. The middle part of the heat pipe temperature damper 6 has a generally cylindrical accommodating space for placing the heat pipe surface temperature source 4 and the metal temperature equalizing block 7. The heat pipe surface temperature source 4 and the metal temperature equalizing block 7 are coaxially placed in the accommodating space, and the heat pipe surface temperature source 4 is above the metal temperature equalizing block 7.

[0032] The electric power consumed by the heating device is supplied by the temperature control system 10. The temperature control system 10 uses a Eurotherm 3504 temperature controller to accurately control the furnace temperature through PID. The power it consumes is monitored by a power meter 11 and transmitted to the computer 12 in real time. The power meter uses a PW-3335 power measuring instrument. The heating device includes a side wall heating unit 5 and a bottom heating unit 8. The heating current of the heating device is independently controlled by the temperature control system 10 respectively, and three heating modes of side wall heating, bottom heating, and side wall / bottom heating can be realized. The thermal insulation layer 9 in the furnace uses a non-flammable thermal insulation material to ensure that a large amount of heat cannot be dissipated from the bottom and side surfaces under the calibration conditions, and only the top is in contact with the air during the working state.

[0033] A surface thermometer to be calibrated is arranged at the center position of the upper surface of the heat pipe surface temperature source 4, or a radiation thermometer to be calibrated is arranged above the upper surface of the heat pipe surface temperature source 4. The thermometer 1 is used to collect the upper surface temperature of the heat pipe surface temperature source 4 obtained by the surface thermometer or the radiation thermometer as the temperature measurement value to be calibrated and send it to the computer.

[0034] Figure 2 This is a schematic diagram of the heat pipe temperature damper 6. The heat pipe temperature damper 6 is of a double-layer barrel shape, including a bottom and a side wall portion. The housing of the heat pipe temperature damper 6 is a sealed cavity made of Inconel600 high-temperature alloy steel. The middle part of the heat pipe temperature damper 6 has a containing space. Inside the sealed cavity of the heat pipe, a high-temperature-resistant Inconel600 wire mesh is laid by spot welding as a wick to increase the capillary attraction of the heat pipe. After the heat pipe cavity is welded, it is subjected to vacuum leak detection and cleaned. After high-temperature vacuum degassing in a vacuum degassing furnace, high-purity cesium is filled by the negative pressure method. Since cesium is very chemically active and undergoes a violent chemical reaction when encountering oxygen or water vapor, it is necessary to ensure a high vacuum degree inside the heat pipe cavity during filling. After the heat pipe is filled, the hydraulic cold sealing method is used to ensure the vacuum degree of the heat pipe. After the heat pipe is completed, it should be heated in a vacuum degassing furnace to allow high-purity cesium to be evenly adsorbed on the inner wall of the annular heat pipe cavity. When the heat pipe temperature damper 6 is operating under heating, a temperature field with extremely high temperature uniformity can be formed in the containing space, and its technical effect far exceeds that of an ordinary heat sink, which is beneficial to improving the temperature accuracy of the heat pipe surface source 4.

[0035] Figure 3 This is a schematic diagram of the heat pipe surface source 4 of the present invention. In order to achieve a surface temperature of 300°C to 660°C, the heat pipe surface source 4 also uses high-purity cesium as the heat pipe working medium. The housing of the heat pipe surface source 4 in this application is made of Inconel600 high-temperature alloy steel. The heating vacuum degassing method is used to remove the gas adsorbed inside the housing of the heat pipe surface source to the greatest extent. A wire mesh of the same material is welded at the top of the inner cavity as a wick to increase the capillary attraction, ensuring that the liquid film can be evenly developed under the working state of the heat pipe and making the surface temperature more uniform. Before filling with the high-purity working medium, the heat pipe housing needs to be heated in vacuum for a long time for degassing. Subsequently, high-purity liquid cesium is injected into the heat pipe interior under the action of gravity through a filling tube. Finally, the hydraulic cold sealing technology is used to complete the sealing of the filling tube, completing the production of the heat pipe surface source 4.

[0036] It should be particularly noted that both the heat pipe temperature damper 6 and the heat pipe surface source 4 in this application adopt the cesium heat pipe process. Since both the heat pipe temperature damper 6 and the heat pipe surface source 4 can generate a temperature field with extremely high uniformity inside during high-temperature operation, by arranging the heat pipe surface source 4 in the containing space in the middle of the heat pipe temperature damper 6, due to this double-nested cesium heat pipe structure, the temperature stability of the heat pipe surface source 4 can be significantly improved. Specifically, compared with a single cesium heat pipe surface source, the technical index of the temperature stability of the heat pipe surface source 4 using the heat pipe temperature damper 6 in this application is at least improved by one order of magnitude at a temperature of 300°C to 660°C. Therefore, the double heat pipe surface temperature source proposed in this application has significant technical advantages.

[0037] The upper surface of the heat pipe surface source 4 is sprayed with a black high-temperature coating. In this way, the heat pipe surface source 4 can not only be used for the calibration of surface temperature sensors, but also be used to calibrate radiation thermometers. When the upper surface of the heat pipe surface source 4 is sprayed with a black high-temperature coating, its emissivity is close to 1, and it can be used as an ideal blackbody radiation surface source to calibrate radiation thermometers. During temperature calibration, the surface thermometer to be calibrated is placed on the upper surface of the heat pipe surface source 4, or the surface temperature of the upper surface of the heat pipe surface source 4 is measured by the radiation thermometer to be calibrated. The surface temperature of the upper surface of the heat pipe surface source 4 obtained by the surface thermometer or the radiation thermometer is used as the temperature value to be calibrated. Then, the temperature of the first, second, and third temperature sensors (3A, 3B, 3C) is measured by the thermometer 1, and the linear extrapolation method is used to determine the surface temperature of the heat pipe surface source, and this temperature is used as the calibration temperature to be compared with the temperature value to be calibrated, so as to determine the temperature correction values of the surface thermometer and the radiation thermometer, and realize the calibration of the surface thermometer and the radiation thermometer.

[0038] Specifically, the side wall heating 5 and the bottom heating 8 are two-stage heating devices, and the temperature control is realized by the temperature control system 10. A heat pipe temperature damper 6 is placed in the furnace of the two-stage heating device, and a temperature equalizing block 7 is placed inside the heat pipe temperature damper to fixedly support the heat pipe surface source 4. The electric power consumed by the side wall heating 5 and the bottom heating 8 can be measured by a power meter 11 and stored in a computer 12. The two-stage heating device uses a Eurotherm 3504 temperature controller to accurately control the furnace temperature through PID.

[0039] Three horizontal wells, namely the first well, the second well, and the third well, are successively opened along the vertical direction from top to bottom on the side wall of the heat pipe surface source 4. The first temperature sensor 3A, the second temperature sensor 3B, and the third temperature sensor 3C are respectively inserted into the first well, the second well, and the third well. The inner diameter of the well is 5 mm and the depth is 80 mm. They are three platinum resistance thermometers. The first temperature sensor 3A obtains the first temperature T1 inside the heat pipe surface source 4, the second temperature sensor 3B obtains the second temperature T2 inside the heat pipe surface source 4, and the third temperature sensor 3C obtains the third temperature T3 inside the heat pipe surface source 4. Therefore, the first temperature T1, the second temperature T2, and the third temperature T3 are located on the same vertical axis.

[0040] Figure 4Schematic diagram of the method for determining the surface temperature of the heat pipe surface source. Preferably, the three horizontal wells on the side wall of the housing of the heat pipe surface source 4 are located in the upper half of the heat pipe surface source 4. The thickness of the upper surface of the housing of the heat pipe surface source 4 is H1, that is, the vertical distance from the inner wall to the outer wall of the upper surface of the housing of the heat pipe surface source 4 is H1. The vertical distance from the horizontal axis of the first well to the inner wall of the upper surface of the housing of the heat pipe surface source 4 is H2. The vertical distance between the horizontal axes of the first well and the second well is H3. The vertical distance between the horizontal axes of the second well and the third well is H4. Among them, H1 < H2 < H3 = H4. The purpose of such a setting is to ensure the uniformity of the first temperature T1, the second temperature T2, and the third temperature T3, and at the same time make the first well as close as possible to the inner wall of the upper surface of the housing of the heat pipe surface source 4. In a preferred embodiment, H1 = 5 mm, H2 = 9 mm, H3 = H4 = 10 mm. According to one-dimensional Fourier heat conduction, based on the measured first temperature, second temperature, third temperature and their relative positions, the surface temperature of the surface source can be calculated.

[0041] Figure 4 Schematic diagram of the extrapolation method for the upper surface of the heat pipe surface source 4. According to the one-dimensional heat conduction equation (1):

[0042]

[0043] It can be seen from the above one-dimensional heat conduction equation that the heat flux density is equal in the axial direction of the heat pipe surface source 4. Therefore, for the heat pipe surface source 4, its axial temperature distribution is linearly related to the axial position. The temperature of the inner wall of the upper surface of the housing of the heat pipe surface source is calculated by a linear method; then, according to the power measured by the power meter, the temperature of the outer wall of the surface is calculated according to the one-dimensional heat conduction equation. Specifically as follows:

[0044] Step 1: Establish a one-dimensional heat conduction equation set (2), (3) and (4) including the estimated temperature value T of the inner wall of the upper surface of the housing of the heat pipe surface source 4, the first temperature T1, the second temperature T2, and the third temperature T3, that is, the first heat conduction model, specifically as follows: interface,n That is, the first heat conduction model, specifically as follows:

[0045]

[0046] Where n is the number of the estimated temperature value of the inner wall of the upper surface of the heat pipe surface source 4 calculated by the linear method in different one-dimensional heat conduction equations, and the thermal conductivity of the heat pipe surface source 4 is λ. Since both sides of the equation are multiplied by the thermal conductivity λ in the above equation, it can be canceled out during the calculation process, thus avoiding the modeling and complex calculation of the thermal conductivity of the heat pipe surface source 4.

[0047] Step 2: According to the above equation set, calculate the first estimated value T of the temperature of the inner wall of the upper surface of the housing of the heat pipe surface source, interface,1 the second estimated value T, interface,2and the third estimated value T interface,3 .

[0048] Step 3: Calculate the average value of the three estimated values as the temperature value T of the inner wall of the upper surface of the heat pipe surface source housing through the following formula (5): interface .

[0049]

[0050] Step 4: Establish a one-dimensional heat conduction equation set (6), that is, the second heat conduction model, including the temperature value T of the inner wall of the upper surface of the heat pipe surface source 4 housing interface and the temperature value T of the outer wall of the upper surface of the heat pipe surface source 4 housing surface as follows:

[0051]

[0052] In formula (6), q is the power converted into heat measured by the power meter 11; λsteel is the thermal conductivity of the material of the heat pipe surface source 4 housing, which is the thermal conductivity of Inconel600 stainless steel in this embodiment.

[0053] Step 5: Calculate the temperature value T of the outer wall of the upper surface of the heat pipe surface source 4 housing through the above formula (6) surface as the calibration temperature value, and compare it with the temperature measurement value to be calibrated on the upper surface of the heat pipe surface source 4 collected by the surface temperature sensor or the radiation thermometer to complete the calibration of the surface temperature sensor or the radiation thermometer.

[0054] Those skilled in the art can understand that the above is only the preferred specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be thought of by those skilled in the art within the technical scope disclosed by this application should be covered by the protection scope of this application.

Claims

1. A calibration device for the surface temperature source of a double heat pipe, characterized in that, The calibration device includes a thermometer, a platinum resistance thermometer, a heat pipe surface temperature source, a heating device, a heat pipe temperature damper, an isothermal block, a heat insulation layer, a temperature control system, a power meter, and a computer; Inside the heating device, a heat insulation layer, a heat pipe temperature damper, an isothermal block, and a heat pipe surface temperature source are coaxially arranged from outside to inside in sequence. The middle part of the heat pipe temperature damper has a generally cylindrical accommodating space for placing the heat pipe surface temperature source and the isothermal block. The heat pipe surface temperature source and the metal isothermal block are coaxially placed in the accommodating space, and the heat pipe surface temperature source is above the metal isothermal block; The temperature control system is used to control the heating power of the heating device, and the power meter measures the heating power of the heating device and sends it to the computer; A high emissivity coating is sprayed on the upper surface of the heat pipe surface temperature source; A surface thermometer to be calibrated is arranged at the center position of the upper surface of the heat pipe surface temperature source, or a radiation thermometer to be calibrated is arranged above the upper surface of the heat pipe surface temperature source. The thermometer is used to collect the upper surface temperature of the heat pipe surface temperature source obtained by the surface thermometer or the radiation thermometer as the temperature measurement value to be calibrated; First, second, and third measuring wells are sequentially opened along the vertical direction from top to bottom on the side wall of the heat pipe surface temperature source. The first temperature sensor, the second temperature sensor, and the third temperature sensor are respectively inserted into the three horizontal measuring wells of the heat pipe surface temperature source to respectively obtain the first temperature T1, the second temperature T2, and the third temperature T3 inside the heat pipe surface temperature source and store them in the thermometer. The first temperature T1, the second temperature T2, and the third temperature T3 are located on the same vertical axis; The computer establishes a heat conduction model based on the first temperature T1, the second temperature T2, the third temperature T3, and the heating power measured by the power meter, calculates the outer wall temperature of the upper surface of the shell of the heat pipe surface temperature source, and calibrates the temperature measurement value to be calibrated of the surface temperature sensor or the radiation thermometer with the outer wall temperature of the upper surface of the shell of the heat pipe surface temperature source.

2. The dual heat pipe surface temperature source calibration device according to claim 1, wherein, The computer establishes a first heat conduction model based on the first temperature T1, the second temperature T2, the third temperature T3, calculates the inner wall temperature of the upper surface of the shell of the heat pipe surface temperature source, then establishes a second heat conduction model based on the inner wall temperature of the upper surface of the shell and the heating power measured by the power meter to calculate the outer wall temperature of the upper surface of the shell of the heat pipe surface temperature source, and finally calibrates the temperature measurement value to be calibrated of the surface thermometer or the radiation thermometer with the outer wall temperature of the upper surface of the shell of the heat pipe surface temperature source.

3. The dual heat pipe surface temperature source calibration device according to claim 1, characterized in that, The heating device is a two-stage high-precision heating furnace, and the two-stage high-precision heating furnace includes a bottom heating element and a side wall heating element. The heating powers of the bottom heating element and the side wall heating element are independently controlled by the temperature control system respectively.

4. The dual heat pipe surface temperature source calibration device according to any one of claims 1-3, characterized in that, The heat pipe surface temperature source and the heat pipe temperature damper use high-purity cesium as the heat pipe working medium. The shells of the heat pipe surface temperature source and the heat pipe temperature damper are made of Inconel600 high-temperature alloy, and a high-temperature alloy wire mesh of the same material is welded in the internal cavity of the heat pipe as the wick.

5. The dual heat pipe surface temperature source calibration device according to any one of claims 1-4, characterized in that The three horizontal gauge wells on the side wall of the heat pipe surface temperature source housing are located in the upper half of the heat pipe surface temperature source.

6. The dual heat pipe surface temperature source calibration device according to any one of claims 1-5, characterized in that The thickness of the upper surface of the heat pipe surface temperature source housing is H1. The vertical distance between the horizontal axis of the first gauge well and the inner wall of the upper surface of the heat pipe surface temperature source housing is H2. The vertical distance between the horizontal axis of the first gauge well and the horizontal axis of the second gauge well is H3. The vertical distance between the horizontal axis of the second gauge well and the horizontal axis of the third gauge well is H4, where H1 < H2 < H3 = H4.

7. A calibration method for a dual heat pipe surface temperature source, based on the dual heat pipe surface temperature source calibration device according to any one of the above claims 1-6, characterized in that, The calibration method includes: Step 1: Establish a one-dimensional heat conduction equations (2), (3) and (4) including the deduced temperature value T of the inner wall of the upper surface of the heat pipe surface temperature source housing, the first temperature T1, the second temperature T2, and the third temperature T3, that is, the first heat conduction model, specifically as follows: interface,n , the first heat conduction model, specifically as follows: where n is the number for calculating the estimated value of the temperature of the inner wall of the upper surface of the heat pipe surface temperature source housing by the linear method in different one-dimensional heat conduction equations, and the thermal conductivity of the heat pipe surface temperature source is λ; Step 2: Calculate the first estimated value T of the inner wall temperature of the upper surface of the heat pipe surface temperature source housing, the second estimated value T inter face，1 , the second estimated value T inter face，1 and the third estimated value T interface,3 ; Step 3: Calculate the average value of the three estimated values through the following formula (5) as the temperature value T of the inner wall of the upper surface of the heat pipe surface temperature source housing interface ; Step 4: Establish a one-dimensional heat conduction equation set (6), i.e., the second heat conduction model, including the inner wall temperature value T of the upper surface of the heat pipe surface temperature source housing interface and the outer wall temperature value T of the upper surface of the heat pipe surface temperature source housing surface as follows: In Equation (6), q is the power converted into heat measured by the power meter; λsteel is the thermal conductivity of the material of the heat pipe surface temperature source 9 housing; Step Five: Calculate the outer wall temperature value T of the upper surface of the heat pipe surface temperature source housing through the above formula (6). surface As the calibrated temperature value, compare it with the temperature measurement value to be calibrated to complete the calibration of the surface temperature sensor or the radiation thermometer.

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