Thermal conductivity testing device and method for spherical refractory materials

Abstract

A device and method for testing the thermal conductivity of spherical refractory materials relate to the field of thermal conductivity measurement. The device and method for testing the thermal conductivity of spherical refractory materials include a test box, a liquid storage tank, and an integrated test tube corresponding to the liquid storage tank. The test box is provided with a test cavity, a heating cavity, and a heat-conducting medium disposed in the test cavity and the heating cavity. The test cavity and the heating cavity are connected by at least one connecting hole. The test box is connected to a heating element for heating the heating cavity and a sample holder disposed in the test cavity. The surface of the spherical refractory material is provided with a test hole extending through the center of the sphere and a spherical temperature sensor. The integrated test tube is inserted into the test hole and extends into the center of the sphere and is connected to a spherical temperature sensor for detecting the center temperature of the sphere and a liquid guide mechanism. The liquid guide mechanism is used to drive the test medium to circulate between the integrated test tube and the corresponding liquid storage tank. The device and method for testing the thermal conductivity of spherical refractory materials can avoid interference with the measurement results caused by thermal radiation and heat loss, and obtain accurate test results for spherical refractory materials.

Description

Technical Field

[0001] The present application relates to the field of thermal conductivity measurement, and in particular to a device and method for testing the thermal conductivity of spherical refractory materials. Background Art

[0002] Refractory materials, as commonly used kiln lining materials in industrial kilns, are one of the indispensable structural and functional materials. The design, configuration, construction and application of refractory materials as well as related process and equipment conditions together have an impact on the life, production capacity and energy consumption of industrial kilns.

[0003] The thermal conductivity of refractory materials is closely related to their chemical and mineral composition, microstructure, and temperature. The more complex the chemical composition of a refractory and the greater the impurity content, the more significantly the thermal conductivity decreases. The presence of pores within the refractory also reduces thermal conductivity. For some multiphase composite refractory materials with significant anisotropy and widely varying thermal expansion coefficients, high internal stresses can cause microcracks to form along grain boundaries, hindering heat flux and significantly reducing the material's thermal conductivity.

[0004] For example, patent CN107860228B discloses a test furnace and method for testing the thermal conductivity of refractory materials. This method involves placing a sample of refractory bricks into a specified size within a test chamber, heating one side while measuring the temperature with infrared light on the other. The measured sample temperature and time are used to plot a thermal conductivity curve for the refractory material. This method is suitable for testing the thermal conductivity of heterogeneous and composite refractory materials at ultra-high temperatures. However, the furnace chamber utilizes silicon-molybdenum rods for radiation heating, while the test chamber utilizes infrared temperature measurement. For some materials, the measured target temperature and surface temperature may not match, leading to significant errors in the test results.

[0005] The national standard GB / T 5990 uses the hot wire method, which involves embedding a hot wire in a groove cut into the surface of a refractory material. The material is heated to a specific temperature, and the dynamic temperature rise at a specific location over a certain period of time is measured to calculate the thermal conductivity. Although this method is applicable to a wide range of thermal conductivity coefficients, the analysis error is large. This is because the heating effect of the hot wire source, which constantly raises the temperature of the refractory material, is affected by the surface flatness of the refractory material, the thickness of the material, the stability of the hot wire heating power coefficient, the stability of the ambient temperature, and even the length and diameter of the hot wire, the material of the hot wire, and the placement of the hot wire and the temperature measuring thermocouple. These factors have a significant impact on the test results, leading to inaccurate test results and making it difficult to test spherical refractory materials.

[0006] Therefore, a testing device and method for accurately measuring the thermal conductivity of spherical refractory materials are needed. Summary of the Invention

[0007] The purpose of the present application is to provide a device and method for testing the thermal conductivity of spherical refractory materials, which can avoid the interference of thermal radiation insulation and heat dissipation loss on the measurement results, thereby obtaining accurate test results of spherical refractory materials.

[0008] This application is implemented as follows:

[0009] The present application provides a device for testing the thermal conductivity of spherical refractory materials, which includes a test box, at least one liquid storage tank containing a test medium, and an integrated test tube corresponding to the liquid storage tank. The test box is provided with a test cavity and a heating cavity arranged in an upper and lower interval and a heat-conducting medium filled in the test cavity and the heating cavity. The test cavity and the heating cavity are connected through at least one connecting hole. The test box is connected to a heating element for heating the heating cavity. At least one sample holder for fixing the spherical refractory material is provided in the test cavity. The surface of the spherical refractory material is provided with a test hole extending radially to the center of the sphere and at least one spherical temperature sensor. The center of the spherical refractory material is provided with a spherical cavity connected to the test hole. The bottom of the integrated test tube is inserted into the test hole and extends into the corresponding spherical cavity. The integrated test tube is connected to at least one spherical center temperature sensor for detecting the temperature of the inner wall of the spherical cavity and a liquid guide mechanism. The liquid guide mechanism is used to drive the test medium to circulate between the integrated test tube and the corresponding liquid storage tank.

[0010] In some optional embodiments, the heat transfer medium and / or the test medium is one of water, heat transfer oil or molten salt.

[0011] In some optional embodiments, the liquid guiding mechanism includes a liquid guiding tube and a circulation pump connected to the liquid guiding tube, and both ends of the liquid guiding tube extend into corresponding liquid storage tanks.

[0012] In some optional embodiments, the diameter of the spherical refractory material is 100-200 mm, and the spherical cavity and the spherical refractory material share the same center and have a diameter of 10-20 mm.

[0013] In some optional embodiments, the sample holder includes a clamping ring for clamping the spherical refractory material and a plurality of supporting legs connecting the clamping ring and the test box.

[0014] In some optional embodiments, the liquid storage tank is connected to a heating device for heating the test medium and a test medium temperature sensor for detecting the temperature of the test medium.

[0015] In some optional embodiments, the integrated test tube is connected to a spherical center temperature sensor located on its central axis and a plurality of spherical center temperature sensors arranged at intervals along the circumference of its inner wall.

[0016] The present application also provides a method for testing the thermal conductivity of a spherical refractory material, which is performed using the above-mentioned thermal conductivity testing device for a spherical refractory material, and comprises the following steps:

[0017] The refractory material is made into a spherical refractory material and fixed on a sample holder in the test chamber;

[0018] At least one spherical temperature sensor is attached to the surface of the spherical refractory material, the bottom of the integrated test tube is inserted into the test hole of the spherical refractory material and extended into the corresponding spherical cavity, and the spherical center temperature sensor connected to the integrated test tube is used to detect the temperature of the inner wall of the spherical cavity;

[0019] Using a heating element to heat a heat transfer medium to a preset temperature so as to transfer heat to the spherical refractory material in the test cavity;

[0020] A liquid guide mechanism is used to drive the test medium to circulate between the integrated test tube and the corresponding liquid storage tank until the temperature of the inner wall of the spherical cavity is stable;

[0021] The temperature difference per unit time between the spherical surface temperature sensor, the spherical center temperature sensor and the test medium in the liquid storage tank is obtained to calculate the thermal conductivity of the spherical refractory material.

[0022] In some optional embodiments, the following formula is used to calculate the thermal conductivity of the spherical refractory material:

[0023]

[0024] In the formula; λ is the thermal conductivity w / m·K; Q is the heat flux, Q=C×m×(t2-t1), J; C is the specific heat capacity of the test medium, J / kg·K; m is the mass of the test medium, kg; t1 is the temperature of the test medium at the beginning of a single test after the temperature of the inner wall of the spherical cavity is stable, K; t2 is the temperature of the test medium at the end of a single test after the temperature of the inner wall of the spherical cavity is stable, K; R represents the radius of the spherical refractory material, m; r represents the radius of the spherical cavity, m; T2-T1 represents the temperature gradient difference between the spherical surface and the center of the spherical refractory material, that is, the temperature difference between the temperatures detected by the spherical surface temperature sensor and the temperature sensor at the center of the spherical cavity after the temperature of the inner wall of the spherical cavity is stable, expressed in K; s represents the time interval between the two temperature measurements t1 and t2, expressed in seconds.

[0025] In some optional embodiments, when the heat-conducting medium is heated to a preset temperature using a heating element, the heat-conducting medium is first heated to 50-100°C below the preset temperature at a heating rate of 10-30°C / min, and then the heat-conducting medium is continued to be heated to the preset temperature at a heating rate of 3-5°C / min.

[0026] The beneficial effects of the present application are as follows: the thermal conductivity testing device for spherical refractory materials provided by the present application includes a test box, at least one liquid storage tank containing a test medium, and an integrated test tube corresponding to the liquid storage tank; the test box is provided with a test cavity and a heating cavity arranged in an upper and lower interval and a heat-conducting medium filled in the test cavity and the heating cavity; the test cavity and the heating cavity are connected by at least one connecting hole; the test box is connected with a heating element for heating the heating cavity; at least one sample rack for fixing the spherical refractory material is provided in the test cavity; a test hole and at least one spherical temperature sensor extending radially to the center of the sphere are provided on the surface of the spherical refractory material; a spherical cavity connected to the test hole is provided at the center of the sphere of the spherical refractory material; the bottom of the integrated test tube is inserted into the test hole and extends into the corresponding spherical cavity; the integrated test tube is connected with at least one spherical center temperature sensor for detecting the temperature of the inner wall of the spherical cavity and a liquid guide mechanism; the liquid guide mechanism is used to drive the test medium to circulate between the integrated test tube and the corresponding liquid storage tank. The thermal conductivity testing device and method of spherical refractory materials provided in the present application can avoid interference of thermal radiation insulation and heat dissipation loss on the measurement results, thereby obtaining accurate test results of the spherical refractory materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 relevant drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic cross-sectional view of a thermal conductivity testing device for spherical refractory materials provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of the cross-sectional structure of a spherical refractory material tested by the thermal conductivity testing device for spherical refractory materials provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of a partial cross-section of the connection between a liquid storage tank, a liquid guide tube, and an integrated test tube in a thermal conductivity testing device for spherical refractory materials provided in an embodiment of the present application;

[0031] Figure 4 Schematic diagram of the partial structure of the integrated test tube in the thermal conductivity coefficient testing device of spherical refractory materials provided in an embodiment of the present application.

[0032] In the figure: 100, test box; 110, test cavity; 120, heating cavity; 130, heat-conducting medium; 140, connecting hole; 150, heating element; 160, sample rack; 161, retaining ring; 162, support leg; 170, partition; 200, liquid storage tank; 210, test medium; 220, heating device; 230, test medium temperature sensor; 300, integrated test tube; 400, spherical refractory material; 410, test hole; 420, spherical temperature sensor; 430, spherical cavity; 440, spherical center temperature sensor; 450, liquid guide tube; 460, circulation pump; 470, corundum sleeve. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, 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.

[0034] 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 protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0035] 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, it does not need to be further defined or explained in subsequent drawings.

[0036] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0038] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0039] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0040] The features and performance of the thermal conductivity testing device and method of the spherical refractory material of the present application are further described in detail below in conjunction with the embodiments.

[0041] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, the embodiment of the present application provides a thermal conductivity test device for spherical refractory materials, which includes a test box 100, two liquid storage tanks 200 each containing a test medium 210, and two integrated test tubes 300 corresponding to the liquid storage tanks 200. The test box 100 is divided into a test chamber 110 and a heating chamber 120 arranged in an upper and lower interval by a partition 170. The test chamber 110 and the heating chamber 120 are filled with a heat-conducting medium 130. Both the heat-conducting medium 130 and the test medium 210 are molten salt. The partition 170 is used to separate the test chamber 110 and the heating chamber 120. 0 is respectively provided with a connecting hole 140 connecting the test chamber 110 and the heating chamber 120. The test box 100 is connected to two heating elements 150 for heating the heating chamber 120. The heating elements 150 are heating tubes and pass through the heating chamber 120. Two sample racks 160 for fixing the spherical refractory material 400 are provided in the test chamber 110. The sample rack 160 includes a clamping ring 161 for clamping the spherical refractory material 400 and four supporting legs 162 connecting the clamping ring 161 and the partition 170.

[0042] The surface of the spherical refractory material 400 is provided with a test hole 410 extending radially to the center of the sphere and a spherical temperature sensor 420. The spherical temperature sensor 420 passes through the top of the test box 100 and extends out of the test box 100. The center of the spherical refractory material 400 is provided with a spherical cavity 430 connected to the test hole 410. The spherical cavity 430 and the spherical refractory material 400 share the same spherical center. The bottoms of the two integrated test tubes 300 respectively pass through the top of the test box 100 and are inserted into the two sample holders 160. The test hole 410 of the fixed spherical refractory material 400 extends into the corresponding spherical cavity 430. Each integrated test tube 300 is connected to five spherical center temperature sensors 440 for detecting the inner wall temperature of the spherical cavity 430 and a liquid guide mechanism. The liquid guide mechanism is used to drive the test medium 210 to circulate between the integrated test tube 300 and the corresponding liquid storage tank 200. The liquid guide mechanism includes a liquid guide tube 450 provided in the integrated test tube 300 and a liquid guide tube 450 extending from the integrated test tube 300. One end of the integrated test tube 300 is connected to a circulating pump 460. Both ends of the liquid guide tube 450 extend through the top of the test box 100 and then extend into the corresponding liquid storage tank 200. The liquid storage tank 200 is connected to a heating device 220 for heating the test medium 210 and a test medium temperature sensor 230 for detecting the temperature of the test medium 210. The heating device 220 is a heating tube. The integrated test tube 300 is connected to a corundum sleeve 470 located on its central axis and four circumferentially spaced apart along the integrated test tube 300. Corundum sleeves 470 are arranged at intervals and connected to the inner wall of the integrated test tube 300. Each corundum sleeve 470 houses a spherical center temperature sensor 440. The spherical center temperature sensor 440 secured to the corundum sleeve 470 on the central axis of the integrated test tube 300 extends 1 mm beyond the bottom spherical surface of the integrated test tube 300. The spherical center temperature sensor 440 secured to the corundum sleeve 470 on the inner wall of the integrated test tube 300 extends beyond the junction of the bottom spherical surface of the integrated test tube 300 and the cylindrical sidewall. In this embodiment, the diameter of the spherical refractory material 400 is 200 mm, and the diameter of the spherical cavity 430 is 20 mm. The test medium temperature sensor 230, the spherical temperature sensor 420, and the spherical center temperature sensor 440 are all thermocouples. The top of the integrated test tube 300 is made of insulating alumina ceramic material, and the bottom is made of copper.

[0043] The present application also provides a method for testing the thermal conductivity of a spherical refractory material using the above-mentioned device for testing the thermal conductivity of a spherical refractory material, comprising the following steps:

[0044] Step 1: The refractory material is formed into a spherical refractory material 400, dried, and calcined at a temperature above 600° C. to remove crystal water, and then fixed on the sample holder 160 in the test chamber 110;

[0045] Step 2: A spherical temperature sensor 420 is attached to the surface of the spherical refractory material 400 to detect the surface temperature of the spherical refractory material 400. The top of the spherical temperature sensor 420 is passed through and extends out of the top of the test box 100. The bottom of the integrated test tube 300 is passed through the top of the test box 100 and inserted into the test hole 410 of the spherical refractory material 400 and extends into the corresponding spherical cavity 430. The five spherical temperature sensors 440 connected to the integrated test tube 300 are respectively pressed against the inner wall of the spherical cavity 430 to detect the inner wall temperature of the spherical cavity 430.

[0046] Step three: Use the heating element 150 to heat the heat-conducting medium 130 to melt and raise the temperature to a preset temperature, so that the molten heat-conducting medium 130 that submerges the spherical refractory material 400 transfers heat to the spherical refractory material 400 in the test cavity 110, and the height difference between the liquid surface of the heat-conducting medium 130 and the top surface of the spherical refractory material 400 is 100 mm; optionally, when using the heating element 150 to heat the heat-conducting medium 130 to a preset temperature, first heat the heat-conducting medium 130 to 50-100°C lower than the preset temperature at a heating rate of 10-30°C / min, and then continue to heat the heat-conducting medium 130 to the preset temperature at a heating rate of 3-5°C / min.

[0047] Step 4: Use the heating device 220 to heat and melt the test medium 210 in the liquid reservoir 200, and use the circulation pump 460 to drive the test medium 210 to circulate along the liquid guide tube 450 between the integrated test tube 300 and the corresponding liquid reservoir 200 until the temperature of the inner wall of the spherical cavity 430 rises to a stable temperature and stops changing;

[0048] Step 5: Obtain the real-time temperature changes detected by the spherical temperature sensor 420 and the spherical center temperature sensor 440, and obtain the temperature of the test medium 210 in the liquid reservoir 200 at the beginning of the test after the inner wall temperature of the spherical cavity 430 stabilizes, the temperature of the test medium 210 in the liquid reservoir 200 at the end of the test after the inner wall temperature of the spherical cavity 430 is stabilized, and the time interval between the two temperature measurements of the test medium 210, and calculate the thermal conductivity of the spherical refractory material 400. The following formula is used to calculate the thermal conductivity of the spherical refractory material 400:

[0049]

[0050] In the formula, λ is the thermal conductivity w / m·K; Q is the heat flux Q=C×m×(t2-t1), expressed in J; C is the specific heat capacity of the test medium, J / kg·K; m is the mass of the test medium, kg; t1 is the temperature of the test medium at the beginning of a single test after the inner wall temperature of the spherical cavity 430 is stabilized, K; t2 is the temperature of the test medium at the end of a single test after the inner wall temperature of the spherical cavity 430 is stabilized, K; R represents the radius of the spherical refractory material 400, m; r represents the radius of the spherical cavity 430, m; T2-T1 represents the temperature gradient difference between the spherical surface and the center of the spherical refractory material 400, that is, the temperature difference detected by the spherical temperature sensor 420 and the spherical center temperature sensor 440 after the inner wall temperature of the spherical cavity 430 is stabilized, expressed in K; s represents the time interval between the two temperature measurements t1 and t2, expressed in seconds. The temperature detected by the sphere center temperature sensor 440 refers to the average value of the temperatures detected by each sphere center temperature sensor 440 in the integrated test tube 300 .

[0051] The thermal conductivity testing device and method of spherical refractory materials provided in the embodiment of the present application uses a partition 170 with a connecting hole 140 to separate the test box 100 into a test chamber 110 and a heating chamber 120 arranged in an upper and lower manner. The heating element 150 can be used to heat the heat-conducting medium 130 in the heating chamber 120, thereby indirectly heating the spherical refractory material 400 in the test chamber 110, avoiding the interference of the heat radiation of the heating element 150 on the surface temperature measurement of the spherical refractory material 400, thereby ensuring that the heating temperature of the spherical surface of the spherical refractory material 400 is more uniform, and that there is no heat loss during the heating process of the spherical refractory material 400 from the outside to the inside, thereby improving the detection accuracy during the thermal conductivity testing of the spherical refractory material 400. A test hole 410 is provided on the surface of the spherical refractory material 400 and extends radially to the center of the sphere. The bottom of the integrated test tube 300 is inserted into the test hole 410 of the spherical refractory material 400 and extends into the corresponding spherical cavity 430 to connect the spherical center temperature sensor 440 for detecting the inner wall temperature of the spherical cavity 430 and the liquid conduction mechanism for circulating heat dissipation, so as to facilitate the experimenter to test the temperature of the surface and center of the spherical refractory material 400 and calculate its thermal conductivity. By heating the outer spherical surface of the spherical refractory material 400, the heat is conducted to the inner spherical surface, ensuring that there is no heat loss during the entire detection process. Compared with traditional inner spherical surface heating, it is easier to accurately measure the temperature. Compared with the flat plate thermal conductivity model, there is no side heat dissipation loss, thereby effectively improving the measurement and calculation accuracy of the thermal conductivity.

[0052] The test chamber 110 may be provided with a plurality of sample holders 160 for fixing the spherical refractory materials 400 respectively, so as to ensure that a plurality of spherical refractory materials 400 can be tested simultaneously in one heating process, thereby effectively improving the test efficiency.

[0053] In other optional embodiments, the diameter of the spherical refractory material 400 can also be between 100-200 mm, such as 120 mm, 140 mm, 150 mm, 160 mm, and 180 mm; the diameter of the spherical cavity 430 can also be 12 mm, 14 mm, 15 mm, 16 mm, and 18 mm.

[0054] In other optional embodiments, the number of the integrated test tubes 300 and the one-to-one corresponding sample racks 160 can be one, three, or more than three, respectively, so as to test different numbers of spherical refractory materials 400 at the same time.

[0055] In other optional embodiments, the number of spherical temperature sensors 420 provided on the surface of the spherical refractory material 400 may also be two, three, four or more, and the two or more spherical temperature sensors 420 are arranged at intervals along the circumference of the spherical refractory material 400;

[0056] In other optional embodiments, the number of the spherical center temperature sensors 440 connected in the integrated test tube 300 can also be one, two, three, four, five or more than five.

[0057] In other optional embodiments, the heat-conducting medium 130 may also be water or heat-conducting oil, and the test medium 210 may also be water.

[0058] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, 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 this field without making creative efforts are within the scope of protection of this application.

Claims

1. A thermal conductivity testing device for spherical refractory materials, characterized in that: It includes a test box, at least one liquid storage tank containing a test medium and an integrated test tube corresponding to the liquid storage tank. The test box is provided with a test cavity and a heating cavity arranged in an upper and lower interval and a heat-conducting medium filled in the test cavity and the heating cavity. The test cavity and the heating cavity are connected through at least one connecting hole. The test box is connected to a heating element for heating the heating cavity; at least one sample rack for fixing spherical refractory materials is provided in the test cavity, the surface of the spherical refractory material is provided with a test hole extending radially to the center of the sphere and at least one spherical temperature sensor, the center of the spherical refractory material is provided with a spherical cavity connected to the test hole, the bottom of the integrated test tube is inserted into the test hole and extends into the corresponding spherical cavity, the integrated test tube is connected with at least one spherical center temperature sensor for detecting the temperature of the inner wall of the spherical cavity and a liquid guide mechanism, the liquid guide mechanism is used to drive the test medium to circulate between the integrated test tube and the corresponding liquid storage tank.

2. The thermal conductivity testing device for spherical refractory materials according to claim 1, characterized in that: The heat transfer medium and / or the test medium is one of water, heat transfer oil or molten salt.

3. The thermal conductivity testing device for spherical refractory materials according to claim 1, characterized in that: The liquid guiding mechanism includes a liquid guiding tube and a circulation pump connected to the liquid guiding tube, and both ends of the liquid guiding tube extend into the corresponding liquid storage tank.

4. The thermal conductivity testing device for spherical refractory materials according to claim 1, characterized in that: The diameter of the spherical refractory material is 100-200 mm, and the spherical cavity and the spherical refractory material share a common center and have a diameter of 10-20 mm.

5. The thermal conductivity testing device for spherical refractory materials according to claim 1, characterized in that: The sample rack includes a clamping ring for clamping the spherical refractory material and a plurality of supporting legs connecting the clamping ring and the test box.

6. The thermal conductivity testing device for spherical refractory materials according to claim 1, characterized in that: The liquid storage tank is connected to a heating device for heating the test medium and a test medium temperature sensor for detecting the temperature of the test medium.

7. The thermal conductivity testing device for spherical refractory materials according to claim 1, characterized in that: The integrated test tube is connected to a spherical center temperature measuring sensor located on the central axis thereof and a plurality of spherical center temperature measuring sensors arranged at intervals along the circumferential direction of the inner wall thereof.

8. A method for testing the thermal conductivity of spherical refractory materials, characterized in that: The method is carried out using the thermal conductivity testing device for spherical refractory materials according to any one of claims 1 to 7, and comprises the following steps: The refractory material is made into a spherical refractory material and fixed on a sample holder in the test chamber; At least one spherical temperature sensor is attached to the surface of the spherical refractory material, the bottom of the integrated test tube is inserted into the test hole of the spherical refractory material and extended into the corresponding spherical cavity, and the spherical center temperature sensor connected to the integrated test tube is used to detect the temperature of the inner wall of the spherical cavity; heating a heat-conducting medium to a preset temperature using a heating element to conduct heat to the spherical refractory material in the test cavity; Using a liquid guide mechanism to drive the test medium to circulate between the integrated test tube and the corresponding liquid storage tank until the temperature of the inner wall of the spherical cavity stabilizes; The temperature changes per unit time of the spherical surface temperature sensor, the spherical center temperature sensor, and the test medium in the liquid storage tank are obtained to calculate the thermal conductivity of the spherical refractory material.

9. The method for testing thermal conductivity of spherical refractory materials according to claim 8, characterized in that: The following formula is used to calculate the thermal conductivity of the spherical refractory material: ； Where; λ is the thermal conductivity; Q is the heat flux, ; C is the specific heat capacity of the test medium; m is the mass of the test medium; t1 is the temperature of the test medium at the beginning of a single test after the temperature of the inner wall of the spherical cavity is stabilized; t2 is the temperature of the test medium at the end of a single test after the temperature of the inner wall of the spherical cavity is stabilized; R represents the radius of the spherical refractory material; r represents the radius of the spherical cavity; T2-T1 represents the temperature gradient difference between the spherical surface and the center of the spherical refractory material, that is, the temperature difference between the temperatures detected by the spherical temperature sensor and the temperature sensor at the center of the spherical cavity after the temperature of the inner wall of the spherical cavity is stabilized; s represents the time interval between the two temperature measurements t1 and t2.

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