Test method for testing heat conductivity coefficient of refractory material by low-thermal-resistance plate method

Abstract

The invention discloses a test method for testing the heat conductivity coefficient of a refractory material through a low-thermal-resistance plate method and relates to the field of testing. The test method for testing the heat conductivity coefficient of the refractory material by the low-thermal-resistance flat plate method comprises the following steps: preparing the refractory material into hexagonal test pieces, and paving the hexagonal test pieces on the surface of a hexagonal boron nitride layer on a vapor chamber to form a flat plate, so that each edge of the hexagonal test piece positioned on the inner side is respectively clung to six adjacent hexagonal test pieces; embedding a hot surface thermocouple for detecting the temperature of the bottom surface of the hexagonal test piece on the inner side in the hexagonal boron nitride layer, placing the flat plate on a heating plate in a mold, and filling aerogel between the flat plate and the side wall of the mold; a cooling water jacket and a cold-surface thermocouple for detecting the temperature of the top surface of the hexagonal test piece are mounted on the top surface of the hexagonal test piece on the inner side; heating the vapor chamber and cooling the hexagonal test piece by using a heating plate and a cooling water jacket; and calculating the heat conductivity coefficient of the refractory material after the temperature of the vapor chamber is stable. The test method for testing the heat conductivity coefficient of the refractory material by the low-thermal-resistance plate method has the advantages of good reliability of test results, high precision and high efficiency.

Description

Technical Field

[0001] This application relates to the field of testing, and more specifically, to a test method for testing the thermal conductivity of refractory materials using a low thermal resistance plate method. Background Technology

[0002] Currently, the method for measuring the thermal conductivity of refractory materials generally adopts the water flow plate method, which has the advantages of simple principle, easy understanding and high accuracy. It is mainly used for the accurate measurement of solid insulating materials. Its core method is to establish a one-dimensional steady-state heat flow to heat the hot surface and cool the cold surface, so that the heat can only pass through the sample vertically to the cold surface. When the system reaches thermal equilibrium, that is, when the temperature and heat flow no longer change with time, the thermal conductivity is directly calculated by Fourier's law of thermal conductivity.

[0003] Current testing methods suffer from several drawbacks when measuring sample temperature. The hot-side thermocouple is subjected to thermal radiation from the heating element or heat spreader, and there is thermal resistance between it and the sample block. As a result, the measured temperature does not match the actual temperature of the hot-side surface of the test object. During the test, the heat flow of the sample block is not a straight-line transfer from the hot side to the cold side, but also dissipates heat towards the edge of the sample block, leading to large test errors. The test time is also very long, requiring multiple measurements to be taken every 10 minutes after the system reaches a steady state to obtain an average value, which is time-consuming.

[0004] Therefore, a testing method is needed that can accurately measure the hot surface temperature, has low system thermal resistance, can reduce or compensate for lateral heat dissipation, and is highly efficient. Summary of the Invention

[0005] The purpose of this application is to provide a test method for testing the thermal conductivity of refractory materials using a low thermal resistance plate method, which has the advantages of high reliability, high accuracy, and high efficiency in test results.

[0006] This application is implemented as follows: This application provides a test method for testing the thermal conductivity of refractory materials using a low thermal resistance flat plate method, comprising the following steps: Prepare at least five pairs of hexagonal test pieces of refractory material; A hexagonal boron nitride layer is laid on a heat spreader plate, and each hexagonal test piece is sequentially laid on the hexagonal boron nitride layer to form a flat plate, so that each side of the hexagonal test piece located on the inner side is tightly attached to six adjacent hexagonal test pieces. After removing the hexagonal specimen and embedding multiple hot-face thermocouples in the hexagonal boron nitride layer, the hexagonal specimen is laid back and compacted to obtain a flat plate sample. Each hot-face thermocouple is used to detect the temperature of the bottom surface of each hexagonal specimen located on the inner side. The flat plate sample is placed on the heating plate inside the mold, and aerogel is filled between the flat plate sample and the side wall of the mold. A cooling water jacket is installed on the top surface of each hexagonal specimen located on the inner side, and a cold-face thermocouple is provided on the bottom surface of the cooling water jacket for detecting the temperature of the top surface of the corresponding hexagonal specimen. The heating plate is used to heat the hot plate, and the cooling water jacket is used to cool the hexagonal test piece; After the temperature of the hot plate is stabilized, the thermal conductivity of the refractory material is calculated according to the temperatures measured by the hot face thermocouple and the cold face thermocouple, the water mass and the water temperature difference passing through the cooling water jacket, the area of the cooling water jacket, and the thickness of the hexagonal test piece.

[0007] In some optional embodiments, when the individual hexagonal test pieces are sequentially laid on the hexagonal boron nitride layer to form a flat plate, at least two hexagonal test pieces are located on the inner side.

[0008] In some optional embodiments, the temperature measuring points of the hot face thermocouple and the cold face thermocouple are located at the geometric centers of the bottom surface and the top surface of the corresponding hexagonal test piece.

[0009] In some optional embodiments, the hexagonal boron nitride layer is obtained by compacting and scraping the hexagonal boron nitride powder laid on the hot plate.

[0010] In some optional embodiments, when the individual hexagonal test pieces are sequentially laid on the hexagonal boron nitride layer to form a flat plate, the individual hexagonal test pieces are arranged in two or more layers from the inside to the outside.

[0011] In some optional embodiments, the hot plate is a boron nitride plate, a silicon carbide plate, a silicon nitride plate, a copper plate, or a silver plate.

[0012] In some optional embodiments, the cross section of the cooling water jacket is circular and coaxially arranged with the hexagonal test piece.

[0013] In some optional embodiments, the bottom surface of the cooling water jacket is provided with a mounting groove for accommodating the cold face thermocouple, and the inner wall of the mounting groove is provided with a hexagonal boron nitride insulation coating.

[0014] In some optional embodiments, the sizes of the individual hexagonal test pieces are the same.

[0015] In some optional embodiments, the thermal conductivity of the refractory material is calculated according to the following formula λ : ; In the formula, λ is the thermal conductivity of the refractory material; n is the number of hexagonal test pieces located on the inner side; m is the water mass passing through the cooling water jacket; is the water temperature at the outlet of the cooling water jacket; is the water temperature at the inlet of the cooling water jacket; is the temperature measured by the hot face thermocouple; is the temperature, flow rate, and water temperature difference measured by the cold face thermocouple; R is the radius of the cooling water jacket; and δ is the thickness of the hexagonal test piece.

[0016] The beneficial effects of the present application are: the test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method provided by the present application comprises the following steps: at least five pairs of hexagonal test pieces are made from the refractory material; a hexagonal boron nitride layer is laid on a heat plate, and each hexagonal test piece is sequentially laid on the hexagonal boron nitride layer to form a flat plate, so that each side of the hexagonal test piece located on the inner side is tightly attached to six adjacent hexagonal test pieces; the hexagonal test piece is taken down, a plurality of hot face thermocouples are embedded in the hexagonal boron nitride layer, and then the hexagonal test piece is laid back and compacted to obtain a flat plate sample, each hot face thermocouple is used to detect the bottom surface temperature of each hexagonal test piece located on the inner side; the flat plate sample is placed on the heating plate in the mold, and aerogel is filled between the flat plate sample and the side wall of the mold; a cooling water jacket is installed on the top surface of each hexagonal test piece located on the inner side, and a cold face thermocouple is arranged on the bottom surface of the cooling water jacket to detect the top surface temperature of the corresponding hexagonal test piece; the heat plate is used to heat the heat plate, and the cooling water jacket is used to cool the hexagonal test piece; after the temperature of the heat plate is stabilized, the thermal conductivity of the refractory material is calculated according to the temperature measured by the hot face thermocouple and the cold face thermocouple, the water quality and the water temperature difference passing through the cooling water jacket, the area of the cooling water jacket and the thickness of the hexagonal test piece. The test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method provided by the present application avoids the interference caused by direct heat radiation by embedding the hot face thermocouple in the hexagonal boron nitride layer, at the same time, each side of the hexagonal test piece located on the inner side is tightly attached to six adjacent hexagonal test pieces to form a horizontal heat dissipation compensation mechanism, which avoids the horizontal temperature difference from causing the horizontal heat loss in the inner test block, so that the heat is directionally conducted from the hot face to the cold face, and the reliability of the test result is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0018] Figure 1 The flowchart of the test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method provided by the present application is shown in the embodiment of the present application. Figure 2 The structure schematic diagram of positioning to form a flat plate by sequentially laying ten hexagonal test pieces on the hexagonal boron nitride layer in the test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method provided by the present application is shown in the embodiment 1 of the present application. Figure 3 The cross-sectional structure schematic diagram of using the heating plate to heat the heat plate and using the cooling water jacket to cool the hexagonal test piece in the test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method provided by the present application is shown in the embodiment 1 of the present application. Figure 4The test method for testing the thermal conductivity of refractory materials by the low thermal resistance flat plate method provided in Embodiment 2 of the present application is a schematic diagram of a flat plate structure formed by sequentially laying twelve hexagonal test pieces on a hexagonal boron nitride layer; Figure 5 The test method for testing the thermal conductivity of refractory materials by the low thermal resistance flat plate method provided in another embodiment of the present application is a schematic diagram of a flat plate structure formed by sequentially laying fourteen hexagonal test pieces on a hexagonal boron nitride layer.

[0019] In the figure: 100, hexagonal test piece; 110, hot plate; 120, hexagonal boron nitride layer; 130, hot face thermocouple; 140, heating plate; 150, aerogel; 160, cooling water jacket; 170, water inlet; 180, water outlet; 190, cold face thermocouple; 200, mounting groove; 210, mold. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0022] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0024] In addition, the terms "horizontal", "vertical", "overhang" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that it is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0025] In the description of the present application, it should be further pointed out that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0027] The features and performances of the test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method of the present application are further described in detail below in combination with embodiments.

[0028] As shown in Figure 1 The present application provides a test method for testing the thermal conductivity of refractory material by low thermal resistance flat plate method, which comprises the following steps: Step one, at least five pairs of hexagonal test pieces are made from refractory material; optionally, the length of each hexagonal test piece is 50-150mm, the thickness is 5-25mm, and the size is recorded; Step two, a copper heat plate with the same size and shape as the bottom of the mold is laid, a hexagonal boron nitride powder layer is formed on the heat plate, the hexagonal boron nitride powder is below 180 mesh, and the thickness of the hexagonal boron nitride layer is 2-8mm; each hexagonal test piece is sequentially laid and positioned on the hexagonal boron nitride layer to form a flat plate, so that at least two hexagonal test pieces are located on the inner side of the flat plate, and the other hexagonal test pieces are located on the outer side of the flat plate; three edges of each hexagonal test piece on the outer side are respectively tightly attached to three adjacent hexagonal test pieces, and six edges of each hexagonal test piece on the inner side are respectively tightly attached to six adjacent hexagonal test pieces; the thickness of the heat plate is 0.5-3mm; Step three, remove each hexagonal test piece and embed at least two hot surface thermocouples in the hexagonal boron nitride layer, then lay back each hexagonal test piece, compact the hexagonal boron nitride layer to obtain a flat plate sample, and each hot surface thermocouple is used to detect the temperature at the center of the bottom surface of the hexagonal test piece on the inner side; Step four, place the flat plate sample on the heating plate in the mold, so that the bottom surface of the heat plate is attached to the top surface of the heating plate, and fill the aerogel between the outer wall of the flat plate sample and the side wall of the mold; Step five, install a cooling water jacket on the top surface of each hexagonal test piece on the inner side, the cross section of the cooling water jacket is circular, the cooling water jacket is provided with a spiral cooling water pipe, the top surface of the cooling water jacket is provided with a water inlet and a water outlet connected with the cooling water pipe, and the bottom center of the cooling water jacket is provided with a mounting groove for accommodating a cold surface thermocouple. The inner wall of the mounting groove is provided with a hexagonal boron nitride insulation coating, and the cold surface thermocouple is installed in the mounting groove for detecting the temperature at the center of the top surface of the corresponding hexagonal test piece; Step six, heat the heat plate using the heating plate, pass the cooling water into the water inlet and out of the water outlet through the cooling water pipe, and cool the hexagonal test piece using the cooling water jacket; Step seven, after the temperature of the heat plate stabilizes, calculate the thermal conductivity of the refractory material according to the measured temperatures of the hot surface thermocouple and the cold surface thermocouple, the water mass and the water temperature difference passing through the cooling water jacket, the area of the cooling water jacket and the thickness of the hexagonal test piece. Optionally, the thermal conductivity of the refractory material is calculated according to the following formula λ In the formula, λ is the thermal conductivity of the refractory material; n is the number of hexagonal test pieces on the inner side; m is the water mass passing through the cooling water jacket; is the water temperature at the outlet of the cooling water jacket; is the water temperature at the inlet of the cooling water jacket; is the measured temperature of the hot surface thermocouple; is the measured temperature, flow rate and water temperature difference of the cold surface thermocouple; R is the radius of the cooling water jacket; and δ is the thickness of the hexagonal test piece.

[0029] In other optional embodiments, the number of hexagonal test pieces made of refractory material can also be 2N, N≥5.

[0030] In other optional embodiments, the heat plate can also be a boron nitride plate, a silicon carbide plate, a silicon nitride plate or a silver plate.

[0031] ​​In other optional embodiments, when each hexagonal specimen is sequentially laid on the hexagonal boron nitride layer to form a flat plate, the hexagonal specimens can also be arranged in two, three, or more layers from the inside out. The hexagonal specimen located on the inner side can be either the innermost hexagonal specimen or any layer of hexagonal specimens located inside the outermost hexagonal specimen.

[0032] In other alternative embodiments, when each hexagonal test piece is sequentially laid on the hexagonal boron nitride layer to form a flat plate, the number of hexagonal test pieces located on the inner side can also be two, three, four or more.

[0033] The low thermal resistance plate method for testing the thermal conductivity of refractory materials provided in this application embodiment involves laying hexagonal boron nitride powder on a heat spreader to form a hexagonal boron nitride layer. At least five pairs of hexagonal test pieces of refractory material are then sequentially laid on the hexagonal boron nitride layer to form a plate, with at least two hexagonal test pieces located on the inner side of the plate. Each side of the inner hexagonal test piece is in close contact with six adjacent hexagonal test pieces. A hot-face thermocouple for detecting the center temperature of the bottom surface of the inner hexagonal test piece is then embedded within the hexagonal boron nitride layer. The plate sample, consisting of the heat spreader, the hexagonal boron nitride layer, and the hexagonal test pieces, is then moved into a mold. After the heating plate is placed on the heat exchange plate, aerogel is filled between the outer wall of the flat plate sample and the side wall of the mold. A cooling water jacket is installed on the top surface of each hexagonal specimen located on the inner side. A cold-face thermocouple for detecting the center temperature of the top surface of the corresponding hexagonal specimen is installed in the mounting groove at the center of the bottom surface of the cooling water jacket. The heat exchange plate is heated by the heating plate and cooling water is introduced into the inlet of the cooling water jacket and then flows out from the outlet through the cooling water pipe to cool the hexagonal specimen. After the temperature of the heat exchange plate stabilizes, the thermal conductivity of the refractory material is calculated based on the temperature measured by the hot-face thermocouple and the cold-face thermocouple, the water mass and water temperature difference through the cooling water jacket, the area of ​​the cooling water jacket and the thickness of the hexagonal specimen.

[0034] The beneficial effects of the test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method provided in this application are: 1. After the refractory material is made into at least five pairs of hexagonal test pieces, they are laid sequentially on a hexagonal boron nitride layer to form multiple layers from the inside out. The outer hexagonal test pieces and the inner hexagonal test pieces are in the same heating system and have the same temperature along the same contour line in the thickness direction, forming a lateral heat dissipation compensation mechanism. This avoids the lateral loss of heat in the inner hexagonal test pieces due to lateral temperature differences, and allows the heat of the inner hexagonal test pieces to be directionally conducted from the hot surface to the cold surface, reducing test errors, expanding the applicability of the plate method, and improving the reliability of test results.

[0035] 2. The medium between the hot-surface thermocouple and the hexagonal test piece is made of hexagonal boron nitride with a thermal conductivity greater than 40 W / m·K, instead of air with a thermal conductivity of only about 0.03 W / m·K. Heat transfer through the highly thermally conductive and highly insulating hexagonal boron nitride can significantly reduce the thermal resistance of the system and improve the test accuracy.

[0036] Third, by using a hexagonal boron nitride layer and a heat spreader to heat the hexagonal specimen, a uniform heating effect is achieved, making the hot surface temperature of the hexagonal specimen more uniform. At the same time, the heat spreader also provides support and reinforcement for the hexagonal boron nitride layer.

[0037] Fourth, the hot-surface thermocouple is embedded in the hexagonal boron nitride layer, which avoids the interference of direct heat radiation from the heating plate and the heat spreader on the temperature detected by the hot-surface thermocouple, thus improving the test accuracy. At the same time, the hexagonal boron nitride powder with a mesh size of less than 180 has excellent lubricity. During the extrusion process, the particles slide and fill the gaps to achieve a compaction effect. It is also fine enough not to damage the hot-surface thermocouple. The hexagonal boron nitride can be reused, and the cost is controllable.

[0038] Fifth, the high thermal conductivity and insulation properties of the hexagonal boron nitride coating prevent short circuits between the cold-side thermocouple and the cooling water jacket, allowing the cooling water jacket to directly contact the cold side of the hexagonal test piece and reducing intermediate heat loss.

[0039] VI. By simultaneously testing multiple hexagonal specimens of the inner layers, the influence of uneven hexagonal specimens can be eliminated, and the testing efficiency can be effectively improved, reducing the testing time by 1-2 hours per test.

[0040] Example 1 like Figure 2 and Figure 3 As shown in the embodiments of this application, a test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method is provided, including the following steps: Step 1: Sample preparation; Prepare five pairs of hexagonal test pieces 100 from the refractory material. Each hexagonal test piece 100 has a side length of 100mm and a thickness of 20mm. Record the dimensions. Step 2: Lay a copper heat spreader 110 with the same shape and size as the bottom of mold 210. Hexagonal boron nitride powder (200 mesh) is then spread on the heat spreader 110 to form a hexagonal boron nitride layer 120, with a thickness of 5mm. Hexagonal test pieces 100 are then sequentially placed on the hexagonal boron nitride layer 120 and positioned to form a flat plate. Two hexagonal test pieces 100 are positioned inside the plate, and eight hexagonal test pieces 100 are positioned outside the plate. The two hexagonal test pieces 100 on the inner side are each attached to six adjacent hexagonal test pieces 100. The thickness of the heat spreader 110 is 0.5mm. Step 3: Remove each hexagonal specimen 100 and embed two hot-face thermocouples 130 in the hexagonal boron nitride layer 120. Then, lay the hexagonal specimen 100 back on and compact the hexagonal boron nitride layer 120 to obtain a flat plate sample. The two hot-face thermocouples 130 are used to detect the temperature of the center of the bottom surface of the two hexagonal specimens 100 located on the inner side. Step 4: Place the flat plate sample on the heating plate 140 inside the mold 210, and fill the space between the flat plate sample and the side wall of the mold 210 with aerogel 150. Step 5: Install a cooling water jacket 160 on the top surface of each hexagonal test piece 100 located on the inner side. The cooling water jacket 160 has a circular cross-section with a radius of 90mm. The cooling water jacket 160 is provided with a spiral cooling water pipe. The top surface of the cooling water jacket 160 is provided with an inlet 170 and an outlet 180 connected to the cooling water pipe. The bottom surface of the cooling water jacket 160 is provided with a mounting groove 200 for accommodating a cold-face thermocouple 190. The inner wall of the mounting groove 200 is provided with a hexagonal boron nitride insulating coating. The cold-face thermocouple 190 is installed in the mounting groove 200 to detect the center temperature of the top surface of the corresponding hexagonal test piece 100. Step 6: Heat the heat spreader 110 to 800°C using the heating plate 140, introduce cooling water into the inlet 170 and then out through the cooling water pipe from the outlet 180, and use the cooling water jacket 160 to cool the hexagonal test piece 100. Step 7: After the temperature of the heat spreader 110 stabilizes, measure the hot surface temperature of the bottom surface of the two inner hexagonal test pieces 100. They are respectively: 795℃, 795℃; the cold surface temperature of the top surface of the two inner hexagonal test pieces 100. The temperatures are 556℃ and 552℃ respectively; the radius R of the cooling water jacket 160 is 90mm; the masses m of the water flowing through the two cooling water jackets 160 are 492.8g and 495.3g respectively; the water temperature at the inlet 170 of the two cooling water jackets 160 is... The temperatures are 22.0℃ and 22.0℃ respectively, with the outlet water temperature of the two cooling water jackets at 160℃ being 180℃. The temperatures were 38.9℃ and 38.6℃, respectively; the thickness δ of the hexagonal specimen 100 was 20mm.

[0041] The thermal conductivity of refractory materials is calculated using the following formula. λ : .

[0042] Example 2 like Figure 4 As shown in the embodiments of this application, a test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method is provided, including the following steps: Step 1: Sample preparation; Prepare six pairs of hexagonal specimens from the refractory material. Each hexagonal specimen has a side length of 150 mm and a thickness of 10 mm. Record the dimensions. Step 2: Lay a silicon nitride heat spreader plate with the same shape and size as the bottom of the mold. Spread hexagonal boron nitride powder (200 mesh) onto the heat spreader plate to form a hexagonal boron nitride layer, with a thickness of 8mm. Place the hexagonal test pieces sequentially onto the hexagonal boron nitride layer to form a flat plate, with three hexagonal test pieces on the inner side and nine on the outer side. The three inner hexagonal test pieces should have their edges pressed tightly against six adjacent hexagonal test pieces. The thickness of the heat spreader plate should be 2mm. Step 3: Remove each hexagonal specimen and embed three hot-face thermocouples in the hexagonal boron nitride layer. Then, lay the hexagonal specimen back on and compact the hexagonal boron nitride layer to obtain a flat plate sample. The three hot-face thermocouples are used to detect the temperature of the center of the bottom surface of the three hexagonal specimens located on the inner side. Step 4: Place the flat plate sample on the heating plate inside the mold, and fill the space between the flat plate sample and the side wall of the mold with aerogel. Step 5: Install a cooling water jacket on the top surface of each hexagonal test piece located on the inner side. The cooling water jacket has a circular cross-section with a radius of 145mm. The cooling water jacket is equipped with a spiral cooling water pipe. The top surface of the cooling water jacket is equipped with an inlet and an outlet connected to the cooling water pipe. The bottom surface of the cooling water jacket is equipped with a mounting groove for accommodating the cold-face thermocouple. The inner wall of the mounting groove is equipped with a hexagonal boron nitride insulating coating. The cold-face thermocouple is installed in the mounting groove to detect the center temperature of the top surface of the corresponding hexagonal test piece. Step 6: Heat the heat spreader to 500°C using a heating plate. Then, introduce cooling water into the inlet and allow it to flow out through the outlet via the cooling water pipe. Use a cooling water jacket to cool the hexagonal specimen. Step 7: After the temperature of the heat spreader stabilizes, measure the hot surface temperature of the bottom surface of the three inner hexagonal test pieces. The temperatures are 492℃, 492℃, and 492℃ respectively; these are the cold surface temperatures of the top surfaces of the three inner hexagonal specimens. The temperatures are 326℃, 322℃, and 325℃ respectively; the radius R of the cooling water jacket is 145mm; the masses m of the water flowing through the three cooling water jackets are 958.6g, 955.3g, and 957.2g respectively; and the inlet water temperatures of the three cooling water jackets are... The outlet water temperatures of the three cooling water jackets are 22.0℃, 22.0℃, and 22.0℃, respectively. The temperatures were 35.9℃, 35.6℃, and 35.8℃, respectively; the thickness δ of the hexagonal specimen was 10mm.

[0043] The thermal conductivity of refractory materials is calculated using the following formula. λ : .

[0044] like Figure 5 As shown, in other optional embodiments, the refractory material can be made into seven pairs of hexagonal test pieces and sequentially laid on the hexagonal boron nitride layer to form a flat plate, with four hexagonal test pieces located on the inner side of the flat plate and ten hexagonal test pieces located on the outer side of the flat plate. Each side of the hexagonal test piece located on the inner side is respectively attached to six adjacent hexagonal test pieces.

[0045] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method, characterized in that, Includes the following steps: Prepare at least five pairs of hexagonal test pieces from the refractory material; A hexagonal boron nitride layer is laid on a heat spreader plate, and hexagonal test pieces are sequentially laid on the hexagonal boron nitride layer to form a flat plate, so that each side of the hexagonal test piece located on the inner side is tightly attached to six adjacent hexagonal test pieces. After removing the hexagonal test piece and embedding multiple hot-face thermocouples in the hexagonal boron nitride layer, the hexagonal test piece is laid back and compacted to obtain a flat plate sample. Each of the hot-face thermocouples is used to detect the temperature of the bottom surface of each of the hexagonal test pieces located on the inner side. The flat plate sample is placed on a heating plate inside the mold, and aerogel is filled between the flat plate sample and the side wall of the mold. A cooling water jacket is installed on the top surface of each of the hexagonal test pieces located on the inner side, and a cold-face thermocouple is provided on the bottom surface of the cooling water jacket for detecting the temperature of the top surface of the corresponding hexagonal test piece. The heating plate is used to heat the heat spreader, and the cooling water jacket is used to cool the hexagonal specimen. After the temperature of the heat spreader plate stabilizes, the thermal conductivity of the refractory material is calculated based on the temperature measured by the hot-side thermocouple and the cold-side thermocouple, the water mass and water temperature difference through the cooling water jacket, the area of ​​the cooling water jacket, and the thickness of the hexagonal test piece.

2. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, When the hexagonal test pieces are sequentially laid on the hexagonal boron nitride layer to form a flat plate, at least two of the hexagonal test pieces are located on the inner side.

3. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, The temperature measuring points of the hot-side thermocouple and the cold-side thermocouple are located at the geometric centers of the corresponding bottom and top surfaces of the hexagonal specimen.

4. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, The hexagonal boron nitride layer is obtained by compacting and smoothing the hexagonal boron nitride powder laid on the heat spreader.

5. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, When each hexagonal test piece is sequentially laid on the hexagonal boron nitride layer to form a flat plate, each hexagonal test piece is arranged in two or more layers from the inside out.

6. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, The heat spreader is a boron nitride plate, a silicon carbide plate, a silicon nitride plate, a copper plate, or a silver plate.

7. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, The cooling water jacket has a circular cross-section and is arranged coaxially with the hexagonal test piece.

8. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, The bottom surface of the cooling water jacket is provided with a mounting groove for accommodating the cold-side thermocouple, and the inner wall of the mounting groove is provided with a hexagonal boron nitride insulating coating.

9. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, All the hexagonal specimens described are the same size.

10. The test method for testing the thermal conductivity of refractory materials using the low thermal resistance plate method according to claim 1, characterized in that, The thermal conductivity of the refractory material is calculated using the following formula. λ : ； In the formula, λ denoted as , where is the thermal conductivity of the refractory material; n is the number of hexagonal test pieces located on the inner side; and m is the mass of water passing through the cooling water jacket. The outlet water temperature of the cooling water jacket; The inlet water temperature of the cooling water jacket; The temperature is measured by the thermocouple on the hot surface; The temperature, flow rate, and water temperature difference are measured by the cold-face thermocouple; R is the radius of the cooling water jacket; δ is the thickness of the hexagonal test piece.

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