A device for measuring thermal conductivity of vacuum high-temperature insulation materials

Abstract

The embodiment of the present application provides a vacuum high-temperature insulation material thermal conductivity measurement device, which belongs to the field of insulation material thermal conductivity testing technology. The vacuum high-temperature insulation material thermal conductivity measurement device includes a base, a heat source, a hanging bracket, a vacuum system and a temperature measurement component; the hanging bracket is arranged on the base, the sample to be measured is installed on the hanging bracket, and the vacuum system is used to maintain the measurement area in a vacuum state; the temperature measurement component is installed on the hanging bracket, and the temperature measurement component is used to monitor the temperature in the measurement area. A heat source insulation layer is arranged on the surrounding side of the heat source on the base to radiate the heat of the heat source upward toward one side of the sample to be measured, and there is a gap between the heat source and the sample to be measured in the vertical direction. This vacuum high-temperature insulation material thermal conductivity measurement device can ensure the accuracy of its results, and can also measure the thermal conductivity of high temperature to above 1000°C under vacuum radiation insulation, and simulate the measurement of the thermal conductivity of real isotope radiation insulation materials in working state based on the insulation principle.

Description

Technical Field

[0001] The present application relates to the technical field of thermal conductivity testing of thermal insulation materials, and in particular to a device for measuring thermal conductivity of vacuum high-temperature thermal insulation materials. Background Art

[0002] Aerospace radiation insulation materials, especially multi-layer insulation structures (MLI), have extremely low thermal conductivity in a high vacuum environment. They are mainly used for the insulation of aircraft and large fuel tanks in a space environment. The multi-layer is mainly composed of a reflective layer with high reflectivity and a spacer material with low thermal conductivity. Increasing the number of reflective layers can reduce the amount of heat transferred by radiation heat transfer, while increasing the material of the reflective layer will increase the probability of physical contact between the reflective layers, thereby increasing the amount of heat transferred by the solid; increasing the spacer material can reduce the amount of heat transferred by the solid; gas phase medium heat transfer is related to the vacuum environment in the system. When the vacuum degree is high, most of the gas molecules in the system are removed. Therefore, compared with the first two heat transfer methods, the gas phase medium heat transfer is very small. Based on the above basic theories, domestic and foreign researchers have designed multiple layers with various structures. However, as people's pace of exploring space is accelerating, the current multi-layer performance can no longer meet people's needs, especially in the field of isotope batteries. Therefore, it is urgent to apply new materials and new technologies to develop new multi-layer thermal insulation materials and other aerospace radiation thermal insulation materials. A set of vacuum high-temperature insulation material thermal conductivity measurement devices with real working conditions and ideal accuracy is an indispensable measuring equipment in the process of developing new materials.

[0003] At present, the research and development of low-temperature multilayer test equipment in China is relatively mature, but the research and development of vacuum high-temperature insulation materials and their test equipment is relatively slow. High-temperature multilayer insulation materials are typical vacuum high-temperature insulation materials, which are mainly used for the insulation of isotope batteries. High-temperature multilayer is an important component of isotope batteries. The performance of high-temperature multilayer directly affects the thermal control performance of isotope batteries. In order to further improve the efficiency of isotope batteries and improve their insulation performance, the real radiation heat transfer structure is simulated to measure the vacuum high-temperature thermal conductivity, avoiding the influence of contact heat transfer on thermal conductivity in the protected hot plate method, heat flow meter and other methods, and more realistically simulating the change of thermal conductivity with temperature in the radiation environment. Summary of the invention

[0004] The embodiment of the present application provides a vacuum high-temperature insulation material thermal conductivity measurement device to achieve the above-mentioned purpose.

[0005] Based on the above purpose, the embodiment of the present application provides a vacuum high-temperature insulation material thermal conductivity measuring device, which is used to measure the thermal conductivity of a sample to be measured, and includes a base, a heat source, a hanging bracket, a vacuum system and a temperature measuring component; the heat source is arranged on the base, and the heat source is used to generate heat to provide heat to the hot end of the sample to be measured; the hanging bracket is arranged on the base and extends upward in the vertical direction, the sample to be measured is installed on the hanging bracket through the hanging component, and is suspended above the heat source, and the hanging bracket and the base are enclosed to form a measurement area; the vacuum system is installed below the base, and the vacuum system is used to maintain the measurement area in a vacuum state; the temperature measuring component is installed on the hanging bracket, and the temperature measuring component is used to monitor the temperature in the measurement area; wherein, a heat source insulation layer is arranged on the base around the heat source, and the heat source insulation layer is arranged around the heat source and the bottom to radiate the heat generated by the heat source upward toward one side of the sample to be measured, and there is a gap between the heat source and the sample to be measured in the vertical direction.

[0006] In this scheme, by setting a vacuum system under the base, a good vacuum environment is provided for the whole device, and by setting a gap between the heat source and the sample to be tested in the vertical direction, that is, compared with the traditional heat source contact heat transfer, this scheme simulates the real radiation heat transfer structure to perform vacuum high-temperature thermal conductivity measurement, which can more realistically simulate the change of thermal conductivity with temperature in the radiation environment, and avoid the thermal conductivity influence of contact heat transfer in the protective hot plate method, heat flow meter and other methods. And by setting a heat source insulation layer around the heat source, the heat source insulation layer can only radiate the heat generated by the heat source upward toward one side of the sample to be tested, so that the upper limit of the radiation temperature of the heat source to the sample to be tested can be increased, that is, the radiation temperature can be increased to more than 1000℃, and the thermal conductivity of the real isotope radiation insulation material in the working state can be simulated and measured from the insulation principle. This vacuum high-temperature insulation material thermal conductivity measurement device is of great significance for the rapid iteration of research and development and verification of vacuum high-temperature insulation materials, and can effectively reduce the research and development costs, and plays a key role in the development of vacuum high-temperature insulation materials in the fields of isotope thermal photovoltaic power generation systems.

[0007] In some embodiments, the temperature measuring component includes a first temperature measuring element, a second temperature measuring element and a third temperature measuring element. The first temperature measuring element is located below the sample to be measured to measure the temperature of the hot end of the sample to be measured. The second temperature measuring element is located above the sample to be measured to measure the temperature of the cold end of the sample to be measured. The third temperature measuring element is used to measure the temperature of a side surface of the heat source close to the sample to be measured.

[0008] In the above technical solution, by providing a first temperature measuring element, a second temperature measuring element and a third temperature measuring element, the temperature of the heat source surface, the hot end and the cold end of the sample to be measured can be measured, thereby providing temperature measurement data during the measurement process, which is convenient for the subsequent calculation of the thermal conductivity of the sample to be measured.

[0009] In some embodiments, the temperature measurement component further includes a fourth temperature measurement element, which is built into the interior of the heat source to measure the internal temperature of the heat source.

[0010] In the above technical solution, the temperature inside the heat source can be monitored by the fourth temperature measuring element, so that the temperature of the heat source can be adjusted according to the real-time measurement situation.

[0011] In some embodiments, a first guide beam and a second guide beam are horizontally arranged on the lifting bracket at positions corresponding to the first temperature measuring element and the second temperature measuring element, respectively. The first temperature measuring element is slidably arranged on the first guide beam through a first slider, and the second temperature measuring element is slidably arranged on the second guide beam through a second slider.

[0012] In the above technical solution, the first temperature measuring element is slidably disposed on the first guide beam through the first slider, and the position of the first temperature measuring element can be adjusted, which not only ensures the certainty of the measurement position of the first temperature measuring element, but also allows the measurement position of the first temperature measuring element to be changed at any time. Similarly, the second temperature measuring element is slidably disposed on the second guide beam through the second slider, and the position of the second temperature measuring element can be adjusted, which not only ensures the certainty of the measurement position of the second temperature measuring element, but also allows the measurement position of the second temperature measuring element to be changed at any time.

[0013] In some embodiments, the vacuum high-temperature insulation material thermal conductivity measuring device also includes a heat source bracket, which is used for installing the heat source. The heat source bracket includes a support plate and a plurality of heat source support columns. The support plate is installed on the base through a connecting piece. The plurality of heat source support columns are distributed in an array on the heat source bracket to support the heat source.

[0014] In the above technical solution, the support plate is installed on the base through a connecting piece, so that the support plate and the base can be set at a distance to prevent heat from being transferred to the base. In addition, the heat source is supported by multiple heat source support columns, that is, multi-point support is performed, so that the support effect of the heat source is better.

[0015] In some embodiments, the heat source support column penetrates the support plate and cooperates with the support plate thread, so that ends of the plurality of heat source support columns away from the base can be coplanar in the horizontal direction.

[0016] In the above technical solution, the heat source support column and the support plate are threaded together, and the heat source support column can be raised and lowered on the support plate by rotating the heat source support column, so that each heat source support column can be adjusted so that the heat source can be placed horizontally.

[0017] In some embodiments, a bearing plate is provided on one end of the multiple heat source support columns away from the base, and the bearing plate is used to contact the heat source to support the heat source; a horizontal monitoring element is provided on the support frame, and the horizontal monitoring element is used to monitor the horizontality of the bearing plate.

[0018] In the above technical solution, a bearing plate and a horizontal monitoring element are arranged on the heat source support column, so that the bearing plate can not only increase the supporting area of ​​the heat source, but also facilitate the precise leveling of multiple heat source support columns under the monitoring of the horizontal monitoring element.

[0019] In some embodiments, the heat source insulation layer includes a tray and a heat insulation cover. The tray is arranged on a support plate. The tray includes a bottom wall and side walls connected to the bottom wall. The side walls extend along a side away from the base to form a placement area. The heat insulation cover is arranged in the placement area on the tray. The heat source is located in the heat insulation cover. The heat insulation cover is open toward one side of the sample to be tested so that the heat generated by the heat source can be radiated upward to the hot end of the sample to be tested.

[0020] In the above technical solution, the tray can stabilize the heat insulation cover and assemble the heat insulation cover into a whole. The top of the heat insulation cover is open, so the heat generated by the heat source in the heat insulation cover can only be radiated from the top to the hot end of the sample to be tested above, thereby achieving directional radiation of heat in the direction of the sample to be tested, and the radiation effect is better.

[0021] In some embodiments, a molybdenum sheet layer is further disposed on the inner side of the heat insulation cover. The molybdenum sheet layer is disposed in contact with the inner side of the heat insulation cover, and a heat insulation gasket may be used to separate the molybdenum sheet layer from the heat insulation cover to increase the heat insulation effect.

[0022] In the above technical solution, a molybdenum sheet with a good roughness and the same size as the heat insulation cover is placed in the heat insulation cover, and the heat reflection ability of the molybdenum sheet is utilized to further improve the heat insulation capacity of the heat source insulation layer.

[0023] In some embodiments, the hanging assembly includes multiple hanging parts, one end of each hanging part is connected to one side of the mounting frame, and the other end is connected to one end of the sample to be tested. The multiple hanging parts cooperate together to make the sample to be tested horizontally above the heat source.

[0024] In the above technical solution, the sample to be tested can be suspended above the heat source through multiple hanging parts and placed horizontally, so as to avoid direct contact between the sample to be tested and the heat source, and can more realistically simulate the change of thermal conductivity with temperature in a radiation environment.

[0025] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the main structure of a vacuum high-temperature insulation material thermal conductivity measurement device provided in some embodiments of the present application;

[0028] Figure 2 A schematic diagram of the cross-sectional structure of AA of a vacuum high-temperature insulation material thermal conductivity measurement device provided in some embodiments of the present application;

[0029] Figure 3 A top view of a vacuum high-temperature insulation material thermal conductivity measurement device provided in some embodiments of the present application.

[0030] Icons: 100-measuring device; 10-base; 20-heat source bracket; 21-heat source support column; 22-support plate; 23-load-bearing plate; 24-hexagonal pillar; 30-heat source insulation layer; 31-heat insulation cover; 32-tray; 33-molybdenum sheet layer; 40-heat source; 50-lifting bracket; 51-crossbeam; 52-vertical beam; 60-sample to be measured; 70-lifting assembly; 71-lifting wire; 72-lifting bolt; 73-height adjustment part; 80-temperature measuring assembly; 81-first temperature measuring element; 82-second temperature measuring element; 83-third temperature measuring element; 84-ceramic tube; 85-first slider; 86-second slider; 87-first guide beam; 88-second guide beam; 90-vacuum system; 91-vacuum chamber base; 92-molecular pump. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the embodiments of the present application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0035] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] Example

[0037] The inventors have discovered that the performance evaluation of vacuum high-temperature insulation materials can only be achieved through traditional measurement methods or qualitative analysis of whole-machine tests. For the research on vacuum high-temperature insulation materials, it is almost impossible to quickly optimize and quantitatively evaluate the basic performance of the designed and produced vacuum high-temperature insulation materials. The entire testing process is long and costly.

[0038] In view of this, the embodiment of the present application provides a vacuum high-temperature insulation material thermal conductivity measurement device, which can realize accurate measurement of the thermal conductivity of vacuum high-temperature insulation materials, greatly improve the optimization efficiency and reduce the testing cost, especially for rapid optimization and quantitative evaluation of the measurement of thermal conductivity of vacuum high-temperature insulation materials.

[0039] See also Figure 1 , Figure 2 and Figure 3The vacuum high-temperature insulation material thermal conductivity measuring device 100 is used to measure the thermal conductivity of the sample 60 to be measured. The vacuum high-temperature insulation material thermal conductivity measuring device 100 includes a base 10, a heat source 40, a hanging bracket 50, a vacuum system 90 and a temperature measuring component 80; the heat source 40 is arranged on the base 10, and the heat source 40 is used to generate heat to provide heat to the hot end of the sample 60 to be measured; the hanging bracket 50 is arranged on the base 10 and extends upward in the vertical direction, and the sample 60 to be measured is installed on the hanging bracket 50 through the hanging component 70, and is suspended above the heat source 40, and the hanging bracket 50 is provided on the base 10. The frame 50 and the base 10 enclose a measuring area; the vacuum system 90 is installed below the base 10, and the vacuum system 90 is used to maintain the measuring area in a vacuum state; the temperature measuring component 80 is installed on the hanging bracket 50, and the temperature measuring component 80 is used to monitor the temperature in the measuring area; wherein, a heat source insulation layer 30 is arranged on the base 10 around the heat source 40, and the heat source insulation layer 30 is arranged around the side and bottom of the heat source 40 to radiate the heat generated by the heat source 40 upward toward one side of the sample to be measured 60, and there is a gap between the heat source 40 and the sample to be measured 60 in the vertical direction.

[0040] In this solution, a vacuum system 90 is provided under the base 10 to provide a good vacuum environment for the entire device, and a gap is provided between the heat source 40 and the sample to be tested 60 in the vertical direction, that is, compared with the traditional contact heat transfer of the heat source 40, this solution simulates the real radiation heat transfer structure to perform vacuum high-temperature thermal conductivity measurement, which can more realistically simulate the change of thermal conductivity with temperature in a radiation environment, and avoid the influence of contact heat transfer on thermal conductivity in methods such as the protected hot plate method and the heat flow meter. In addition, by providing a heat source insulation layer 30 around the heat source 40, the heat source insulation layer 30 can radiate the heat generated by the heat source 40 only upward toward one side of the sample 60 to be tested, thereby increasing the upper limit of the radiation temperature of the heat source 40 to the sample 60 to be tested, that is, the radiation temperature can be increased to above 1000°C, and the thermal conductivity of the sample 60 to be tested (real isotope radiation insulation material) under working conditions can be simulated and measured based on the insulation principle. This vacuum high-temperature insulation material thermal conductivity measurement device 100 is of great significance for the rapid iterative research and development and verification of vacuum high-temperature insulation materials, can effectively reduce research and development costs, and plays a key role in the development of vacuum high-temperature insulation materials in the fields of isotope thermal photovoltaic power generation systems.

[0041] Among them, the hot end of the sample 60 to be tested is the end close to the heat source 40, and the end away from the heat source 40 to be tested is the cold end. The sample 60 to be tested can be a variety of insulation materials, for example, it can be aerospace radiation insulation material, and it can also be radiation insulation material in isotope power supply. The heat source 40 can be a variety of heating structures. For example, the heat source 40 can adopt a high-temperature resistant aluminum oxide / zirconia ceramic wire heat source 40, and its surface is evenly distributed with U-shaped grooves with two holes. The heat source 40 is formed by adding two sufficiently long heating wires to connect these U-shaped grooves in series in an orderly manner, so that the heat source 40 is resistant to high temperatures and the thermal field is evenly distributed. But not limited to this, the heat source 40 can be replaced by any standard isotope electrical simulation heat source 40 that can work stably at 1600°C.

[0042] The hanging bracket 50 may be a rectangular frame or a square frame, and may be assembled from a plurality of vertical beams 52 and a plurality of horizontal beams 51, and the vertical beams 52 and the horizontal beams 51 may be connected by right-angle connectors. The vertical beams 52 and the horizontal beams 51 may be made of existing aluminum profiles, and the strength meets the requirements, and the cross-sectional shape of the aluminum profile may be square, rectangular, etc.

[0043] In addition, the vacuum system 90 may include a vacuum chamber base 91, a vacuum flange and a molecular pump 92, which provide a good vacuum environment for the entire device, because the entire device must be in a vacuum environment during measurement to better measure the true thermal insulation capacity of the sample to be measured 60. A circular hole is opened in the middle of the base 10, and the circular hole is consistent in size with the exhaust hole of the molecular pump 92, which is to ensure the efficiency of the molecular pump 92 in evacuating the vacuum.

[0044] In some embodiments, the temperature measuring component 80 includes a first temperature measuring element 81, a second temperature measuring element 82 and a third temperature measuring element 83. The first temperature measuring element 81 is located below the sample to be measured 60 to measure the temperature of the hot end of the sample to be measured 60. The second temperature measuring element 82 is located above the sample to be measured 60 to measure the temperature of the cold end of the sample to be measured 60. The third temperature measuring element 83 is used to measure the temperature of a side surface of the heat source 40 close to the sample to be measured 60.

[0045] By providing a first temperature measuring element 81, a second temperature measuring element 82 and a third temperature measuring element 83, the temperatures of the surface of the heat source 40, the hot end and the cold end of the sample 60 to be tested can be measured, thereby providing temperature measurement data during the measurement process, which is convenient for the subsequent calculation of the thermal conductivity of the sample 60 to be tested.

[0046] Among them, the first temperature measuring element 81, the second temperature measuring element 82 and the third temperature measuring element 83 can adopt thermocouples. Through thermal simulation, the temperature of the surface of the heat source 40 and the hot end of the sample to be tested 60 is about 1200 degrees Celsius, so the first temperature measuring element 81 and the third temperature measuring element 83 can adopt S-type thermocouples for temperature measurement; the temperature of the cold end of the sample to be tested 60 is about 260 degrees Celsius, so the second temperature measuring element 82 can adopt T-type thermocouple for temperature measurement.

[0047] In some embodiments, the temperature measuring assembly 80 further includes a fourth temperature measuring element (not shown in the figure), which is built into the heat source 40 to measure the internal temperature of the heat source 40. The temperature inside the heat source 40 can be monitored by the fourth temperature measuring element, so that the temperature of the heat source 40 can be adjusted according to the real-time measurement situation.

[0048] The internal temperature of the heat source 40 is 1400 degrees Celsius, so the fourth temperature measuring element can use a B-type thermocouple to measure the temperature.

[0049] In some embodiments, a first guide beam 87 and a second guide beam 88 are horizontally arranged on the lifting bracket 50 at positions corresponding to the first temperature measuring element 81 and the second temperature measuring element 82, respectively. The first temperature measuring element 81 is slidably arranged on the first guide beam 87 through the first slider 85, and the second temperature measuring element 82 is slidably arranged on the second guide beam 88 through the second slider 86.

[0050] The first temperature measuring element 81 is slidably disposed on the first guide beam 87 through the first slider 85, and the position of the first temperature measuring element 81 can be adjusted, which not only ensures the certainty of the measurement position of the first temperature measuring element 81, but also allows the measurement position of the first temperature measuring element 81 to be changed at any time. Similarly, the second temperature measuring element 82 is slidably disposed on the second guide beam 88 through the second slider 86, and the position of the second temperature measuring element 82 can be adjusted, which not only ensures the certainty of the measurement position of the second temperature measuring element 82, but also allows the measurement position of the second temperature measuring element 82 to be changed at any time.

[0051] Among them, in order to ensure the insulation of the thermocouple, a ceramic tube 84 can be sleeved on the outer peripheral side of the first temperature measuring element 81, the second temperature measuring element 82 and the third temperature measuring element 83, that is, the ceramic tube 84 is sleeved on the outer peripheral side of the corresponding temperature measuring element, thereby ensuring the insulation of the positive and negative poles of the corresponding temperature measuring element; the first temperature measuring element 81 and the second temperature measuring element 82 can be matched with the corresponding slider through the ceramic tube 84, and the ceramic tube 84 can play an insulating role.

[0052] In addition, a driving mechanism may be installed on the first guide beam 87 and / or the second guide beam 88, and the driving mechanism may drive the first slider 85 and / or the second slider 86 to slide on the guide beam 51, so that the position of the first temperature measuring element 81 and / or the second temperature measuring element 82 may be automatically adjusted without human intervention. The driving mechanism may use a variety of driving parts, for example, an electric push rod, a cylinder, a gear rack driving mechanism, a hydraulic cylinder, etc.

[0053] In some embodiments, the vacuum high-temperature insulation material thermal conductivity measurement device 100 further includes a heat source bracket 20, which is used for installing a heat source 40. The heat source bracket 20 includes a support plate 22 and a plurality of heat source support columns 21. The support plate 22 is mounted on the base 10 through a connector, and the plurality of heat source support columns 21 are distributed in an array on the heat source bracket 20 to support the heat source 40. The support plate 22 is mounted on the base 10 through a connector, so that the support plate 22 and the base 10 can be spaced apart to prevent heat from being transferred to the base 10. In addition, the heat source 40 is supported by a plurality of heat source support columns 21, that is, multi-point support is performed, so that the support effect of the heat source 40 is better.

[0054] Among them, the support plate 22 of the heat source bracket 20 can be connected to the base 10 through a hexagonal pillar 24 with a designated type of external threaded step portion at both ends, so that the heat source bracket 20 and the base 10 are separated by a certain distance in the vertical direction and a stable connection is achieved between the two. Four threaded holes are opened on the support plate 22 to facilitate the four heat source support columns 21 to cooperate with the threaded holes, so that the height of the heat source support column 21 can be adjusted by twisting it.

[0055] In some embodiments, the heat source support column 21 penetrates the support plate 22 and is threadedly engaged with the support plate 22, so that the ends of the plurality of heat source support columns 21 away from the base 10 can be coplanar in the horizontal direction. Through the threaded engagement between the heat source support column 21 and the support plate 22, the heat source support column 21 can be raised and lowered on the support plate 22 by rotating the heat source support column 21, so that each heat source support column 21 can be adjusted, so that the heat source 40 can be placed horizontally.

[0056] In some embodiments, a bearing plate 23 is provided at one end of the plurality of heat source support columns 21 away from the base 10, and the bearing plate 23 is used to contact the heat source 40 to support the heat source 40; a level monitoring element is provided on the support frame, and the level monitoring element is used to monitor the levelness of the bearing plate 23. By providing the bearing plate 23 and the level monitoring element on the heat source support column 21, the bearing plate 23 can not only increase the support area of ​​the heat source 40, but also facilitate the precise leveling of the plurality of heat source support columns 21 under the monitoring of the level monitoring element.

[0057] The number of the heat source support columns 21 can be three, four or five. In this embodiment, the number of the heat source support columns 21 is set to four, and the four heat source support columns 21 are distributed in a rectangular or square shape. In addition, the level monitoring element can use an existing level meter, which is installed on the bearing plate 23, so that the level meter can be used to realize the leveling monitoring of the four heat source support columns 21.

[0058] In some embodiments, the heat source insulation layer 30 includes a tray 32 and a heat shield 31. The tray 32 is disposed on the support plate 22. The tray 32 includes a bottom wall and side walls connected to the bottom wall. The side walls extend along a side away from the base 10 to form a placement area. The heat shield 31 is disposed in the placement area on the tray 32. The heat source 40 is located in the heat shield 31. The heat shield 31 is openly disposed toward a side of the sample to be tested 60 so as to allow the heat generated by the heat source 40 to radiate upward to the hot end of the sample to be tested 60. The tray 32 can stabilize the heat shield 31, assemble the heat shield 31 as a whole, and the top of the heat shield 31 is openly disposed. Therefore, the heat generated by the heat source 40 in the heat shield 31 can only be radiated from the top to the hot end of the sample to be tested 60 above, thereby achieving directional radiation of heat toward the sample to be tested 60, and the radiation effect is better.

[0059] Among them, the heat insulation cover 31 can adopt a modular structural design, that is, the heat insulation cover 31 can be assembled by five pieces of aerogel and then placed in the placement area of ​​the tray 32. This has low processing costs. Of course, avoidance holes are correspondingly opened on the tray 32 and the heat insulation cover 31 for the heat source support column 21 to pass through.

[0060] In some embodiments, a molybdenum sheet layer 33 is further provided on the inner side of the heat shield 31, and the molybdenum sheet layer 33 is provided on the inner side of the heat shield 31. By placing a molybdenum sheet with good roughness and the same size as the inner side of the heat shield 31, the heat insulation capacity of the heat source insulation layer 30 is further improved by utilizing the heat reflection ability of the molybdenum sheet.

[0061] The connection between the molybdenum sheet and the heat shield 31 can be achieved by providing a plurality of small holes on each side of the heat shield 31, and tying iron wires through the small holes to achieve the connection between the molybdenum sheet and the heat shield 31. In this solution, eight small holes are provided on each side of the heat shield 31.

[0062] In some embodiments, the hanging assembly 70 includes a plurality of hanging parts, one end of each of which is connected to one side of the mounting frame, and the other end of each of which is connected to one end of the sample 60 to be tested, and the plurality of hanging parts cooperate to make the sample 60 to be tested horizontally located above the heat source 40. The sample 60 to be tested can be suspended above the heat source 40 and placed horizontally by the plurality of hanging parts, thereby avoiding direct contact between the sample 60 to be tested and the heat source 40, and being able to more realistically simulate the change of thermal conductivity with temperature in a radiation environment.

[0063] The hoisting parts include a height adjustment part 73, a hoisting bolt 72 and a hoisting wire 71. The height adjustment part 73 is mounted on the hoisting bracket 50. The hoisting bolt 72 is rotatably mounted on the height adjustment part 73. One end of the hoisting wire 71 is connected to the hoisting bolt 72, and the other end is tied to the nut of the sample to be tested 60. The hoisting wire 71 can be made of nylon 66 or mullite fiber, which has high mechanical strength, low thermal conductivity and certain high temperature resistance. After the sample to be tested 60 is hoisted, if it is found that the sample to be tested 60 is not hoisted levelly or the distance between the sample to be tested 60 and the heat source 40 is not appropriate, the hoisting bolt 72 installed on the height adjustment part 73 can be screwed to achieve the hoisting level of the sample to be tested 60 or the appropriate distance between the sample to be tested 60 and the heat source 40.

[0064] The specific assembly process of the vacuum high-temperature insulation material thermal conductivity measuring device 100 is as follows:

[0065] At the beginning of the experiment, according to the experimental plan, the designated sample to be tested 60 is selected, and the vacuum chamber is opened to prepare for assembly. The entire assembly process includes assembling the base 10 and the heat source bracket 20, assembling the heat source 40, assembling the heat source insulation layer 30, assembling the sample to be tested 60, hoisting multiple layers, and installing the temperature measurement component 80. The process of assembling the base 10 and the heat source bracket 20 is relatively simple. First, the base 10 and the vacuum chamber base 91 are connected together by bolts, and then the heat source bracket 20 is installed on the base 10 through the designated hexagonal pillars 24 with external threaded step portions at both ends.

[0066] Then assemble the heat source 40. First, thread the heating wire, then install the six-sided tungsten radiator to the surface of the heat source 40 through the ceramic frame, and finally insert the fourth temperature measuring element (i.e., thermocouple B) into the interior of the heat source 40. Then, insert the positive and negative poles of the heat source 40 and the fourth temperature measuring element into the ceramic tube 84 respectively. The partial assembly of the heat source 40 is completed.

[0067] Then assemble the heat source insulation layer 30. First, install the four heat source support columns 21 on the support plate 22 on the heat source bracket 20. The heat source support columns 21 are threadedly matched with the support plate 22. Then install the tray 32 on the heat source bracket 20. Then install the bottom part of the heat insulation cover 31 in the tray 32, place the molybdenum sheet, and then place the assembled heat source 40 on the four heat source support columns 21. (Before placing the heat source 40, first place a flat supporting plate 23 (square sheet) on the four heat source support columns 21, and then place a spirit level on the supporting plate 23. By observing the state of the spirit level, the four heat source support columns 21 are leveled), finally, place the remaining four sides of the heat insulation cover 31 with the molybdenum sheet into the tray 32, and the assembly of the heat source insulation layer 30 is completed.

[0068] To assemble the sample 60 to be tested, it is only necessary to tie one end of the hanging wire 71 to the nut of the sample 60 to be tested; before hanging multiple layers, the hanging bracket 50 must first be assembled on the base 10, and then the height adjustment part 73 must be assembled on the hanging bracket 50, and then the hanging bolt 72 must be assembled on the height adjustment part 73, and then the other end of the hanging wire 71 must be tied to the hanging bolt 72 to monitor the levelness of the sample 60 to be tested. If it is found that the sample 60 to be tested is not hung levelly or the distance between the sample 60 to be tested and the heat source 40 is not appropriate, the hanging bolt 72 installed on the height adjustment part 73 can be screwed to achieve the levelness of the sample 60 to be tested or the appropriate distance between the sample 60 to be tested and the heat source 40.

[0069] Install the temperature measuring assembly 80, put the ceramic tube 84 on each temperature measuring element (thermocouple), and then connect the ceramic tube 84 to the corresponding slider, and adjust the position of the corresponding slider on the corresponding guide beam to adjust the thermocouple to the appropriate position for temperature measurement.

[0070] The thermal conductivity calculation method of the vacuum high temperature insulation material thermal conductivity measuring device 100 is as follows:

[0071] According to Fourier's law of thermal conductivity, the relevant thermal conductivity calculation formula is expressed as follows:

[0072]

[0073] Where: d is the thickness of the sample to be tested, unit: m; A is the upper and lower surface area of ​​the sample to be tested, unit: m2; Q is the net heat power through the multi-layer longitudinal path, unit: W; ΔT is the average temperature difference between the upper and lower surfaces of the sample to be tested, unit: K.

[0074] Among them, d and A can be obtained by intuitive measurement given the geometric dimensions of the sample to be tested.

[0075] The measurement and calculation of ΔT requires the average temperature of the material surface to calculate T. The temperature of the thermocouple's measuring point is not the average temperature of the upper and lower ends of the sample to be measured. In actual operation, a layer of 0.1 cm thick high thermal conductivity material, such as copper sheet, can be added to the upper and lower ends of the multi-layer. The temperature difference obtained by measurement and calculation is ΔT.

[0076] Measurement and calculation of Q: According to the temperature and emissivity of the top surface of the sample to be tested, the total heat W1 released by the multiple layers can be calculated. Then the heat W2 released to the top surface of the multiple layers by the ambient temperature is subtracted from the total heat W1 to obtain the net heat Q actually passing through the multiple layers. This value can be calibrated and calibrated according to other test methods based on the optimized simulation test device model to ensure that the Q value of the same type of test samples at different temperatures is objective and true.

[0077] This application example combines actual measurement, calibration of other measurement methods and simulation. The structure truly simulates the thermal conductivity measurement of the sample to be tested under the condition of radiation heat transfer, that is, non-contact heat transfer. A heat flow meter can also be added to measure and calibrate, all of which are within the protection scope of this application.

[0078] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0079] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A vacuum high-temperature insulation material thermal conductivity measuring device, used to measure the thermal conductivity of a sample to be tested. It is characterized in that include: Base; A heat source is disposed on the base, and is used to generate heat to provide heat to the hot end of the sample to be tested; A hanging bracket is arranged on the base and extends upward in the vertical direction. The sample to be tested is installed on the hanging bracket through a hanging assembly and suspended above the heat source. The hanging bracket and the base are enclosed to form a measuring area; A vacuum system is installed below the base, and is used to maintain the measuring area in a vacuum state; A temperature measuring component is installed on the hanging bracket, and the temperature measuring component is used to monitor the temperature in the measuring area; Wherein, a heat source insulation layer is arranged on the base around the heat source, and the heat source insulation layer is arranged around the heat source and the bottom to radiate the heat generated by the heat source upward toward one side of the sample to be tested, and there is a gap between the heat source and the sample to be tested in the vertical direction; The temperature measuring component includes a first temperature measuring element, a second temperature measuring element, a third temperature measuring element and a fourth temperature measuring element. The first temperature measuring element is located below the sample to be measured and is used to measure the temperature of the hot end of the sample to be measured. The second temperature measuring element is located above the sample to be measured and is used to measure the temperature of the cold end of the sample to be measured. The third temperature measuring element is used to measure the temperature of a side surface of the heat source close to the sample to be measured.

2. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 1, It is characterized in that The temperature measuring component also includes a fourth temperature measuring element, which is built into the heat source to measure the internal temperature of the heat source.

3. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 1, It is characterized in that The hanging bracket is horizontally provided with a first guide beam and a second guide beam at positions corresponding to the first temperature measuring element and the second temperature measuring element, respectively. The first temperature measuring element is slidably arranged on the first guide beam via a first slider, and the second temperature measuring element is slidably arranged on the second guide beam via a second slider.

4. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 1, It is characterized in that The vacuum high-temperature insulation material thermal conductivity measuring device also includes: A heat source bracket is used for installing the heat source, and the heat source bracket includes a support plate and a plurality of heat source support columns. The support plate is installed on the base through a connecting piece, and the plurality of heat source support columns are distributed in an array on the heat source bracket to support the heat source.

5. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 4, It is characterized in that The heat source support column penetrates the support plate and is threadedly matched with the support plate, so that ends of the plurality of heat source support columns away from the base can be coplanar in a horizontal direction.

6. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 5, It is characterized in that A bearing plate is arranged on one end of the plurality of heat source support columns away from the base, and the bearing plate is used to contact the heat source to support the heat source; a level monitoring element is arranged on the bearing plate, and the level monitoring element is used to monitor the levelness of the bearing plate.

7. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 4, It is characterized in that The heat source insulation layer comprises: A tray, disposed on the support plate, the tray comprising a bottom wall and side walls connected to the bottom wall, the side walls extending along a side away from the base to form a placement area; A heat shield is arranged in the placement area on the tray, the heat source is located in the heat shield, and the heat shield is open toward one side of the sample to be tested so as to radiate the heat generated by the heat source upward to the hot end of the sample to be tested.

8. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 7, It is characterized in that A molybdenum sheet layer is also arranged on the inner side of the heat insulation cover, and the molybdenum sheet layer is arranged in contact with the inner side of the heat insulation cover.

9. The device for measuring thermal conductivity of vacuum high-temperature insulation materials according to claim 1, It is characterized in that The hanging assembly includes a plurality of hanging parts, one end of each of which is connected to one side of the mounting frame, and the other end of each of which is connected to one end of the sample to be tested. The plurality of hanging parts cooperate together to make the sample to be tested horizontally located above the heat source.

Images