Thermal conductivity type gas sensor for detecting sulfur hexafluoride leakage of GIS (Gas Insulated Switchgear) of transformer substation

Abstract

The invention relates to a thermal conductivity type gas sensor for sulfur hexafluoride leakage detection of a GIS (Gas Insulated Switchgear) of a transformer substation, and relates to the technical field of sensors in an electric power system. The thermal conductivity type gas sensor for detecting the sulfur hexafluoride leakage of the GIS of the transformer substation comprises a sensor main body; the sensor main body comprises a resistance wire frame body; the resistance wire frame body comprises an ellipsoidal frame body formed by winding a metal resistance wire; an insulating layer is arranged on the surface of the metal resistance wire; the heat conduction material shell is formed by wrapping the resistance wire frame body with a heat conduction material; wherein the heat conduction material is a composite material prepared by mixing nano-particles of carbon nano-tubes, boron nitride and aluminum nitride. By adopting the thermal conductivity type gas sensor for sulfur hexafluoride leakage detection of the GIS of the transformer substation provided by the invention, the gas detection effect can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of sensors in power systems, and in particular to a thermal conductivity gas sensor for detecting sulfur hexafluoride leakage in a substation GIS. Background Art

[0002] With the trend toward oil-free and miniaturized power system equipment, sulfur hexafluoride (SF6) has gained widespread adoption in power industries and systems worldwide, particularly in GIS (Gas-Insulated Switchgear) applications, thanks to its superior insulation, resistance to aging and deterioration, and arc-extinguishing properties. However, due to issues such as manufacturing quality, installation procedures, and aging of sealing components, SF6 gas leaks are inevitable. This colorless, odorless, and toxic gas poses a threat to worker safety and hinders the safe and reliable operation of power systems. Therefore, SF6 gas leak detection technology is crucial to the future development of power systems and the safety of workers, and cannot be ignored.

[0003] Currently, common methods for detecting SF6 gas concentrations include infrared absorption, electrochemical sensors, gas chromatography, and thermal conductivity sensors. While infrared absorption offers high accuracy, its equipment is expensive. Electrochemical sensors are susceptible to poisoning and ineffectiveness during use, and their sensitivity decreases with age. Gas chromatography is expensive and limited by laboratory conditions, making it impractical for on-site testing.

[0004] Therefore, current methods for detecting gas leaks in electrical equipment have the problems of high cost and low sensitivity, resulting in poor gas detection results. Summary of the Invention

[0005] Based on this, it is necessary to provide a thermal conductivity gas sensor, a sensor assembly and a matching preparation method for substation GIS sulfur hexafluoride leakage detection that can improve gas detection effects.

[0006] In a first aspect, the present application provides a thermal conductivity gas sensor for detecting sulfur hexafluoride leaks in a substation GIS, comprising:

[0007] The sensor body includes a resistance wire frame; the resistance wire frame includes an ellipsoidal frame formed by winding a metal resistance wire; an insulating layer is provided on the surface of the metal resistance wire;

[0008] The heat-conducting material shell is a shell formed by wrapping the resistance wire frame with a heat-conducting material; wherein the heat-conducting material is a composite material prepared by mixing carbon nanotubes, boron nitride and aluminum nitride nanoparticles.

[0009] In one embodiment, the resistance wire frame is filled with insulating material.

[0010] In one embodiment, the metal resistance wire includes at least any one of the following metal materials: platinum, palladium, rhodium, iridium, ruthenium, osmium, and tungsten.

[0011] In one embodiment, the carbon nanotubes are oxidized single-walled carbon nanotubes, oxidized double-walled carbon nanotubes, or oxidized multi-walled carbon nanotubes.

[0012] In one embodiment, the boron nitride is one of hexagonal boron nitride, rhombohedral boron nitride, cubic boron nitride and wurtzite boron nitride.

[0013] In one embodiment, the resistance wire frame includes at least two resistance coils wound from a metal resistance wire, and the resistance coils are arranged at a preset interval.

[0014] In the second aspect, the present application also provides a sensor assembly for detecting sulfur hexafluoride leaks in a substation GIS, comprising at least two thermal conductivity gas sensors as described in any one of the embodiments of the first aspect; wherein, one of the thermal conductivity gas sensors is used as a detection element of the sensor assembly, and the other thermal conductivity gas sensor is used as a compensation element of the sensor assembly.

[0015] In a third aspect, the present application further provides a preparation method for preparing the thermal conductivity gas sensor as described in any one of the embodiments of the first aspect, the method comprising:

[0016] A resistance wire frame is formed by winding the wire using a winding machine; the resistance wire frame includes an ellipsoidal frame formed by winding the metal resistance wire;

[0017] forming an insulating layer on the outer surface of the metal resistance wire;

[0018] Coating a thermally conductive material slurry on the surface of the resistance wire frame, and electrifying the metal resistance wire to sinter the thermally conductive material slurry to form a thermally conductive material shell;

[0019] The thermal conductive material slurry is prepared by mixing carbon nanotubes, boron nitride and aluminum nitride.

[0020] In one embodiment, forming an insulating layer on the outer surface of the metal resistance wire includes:

[0021] The sol-gel method was used to prepare α-Al2O3 nano-scale ultrafine powder materials;

[0022] The prepared α-Al2O3 material and glycerol are mixed in a weight ratio of 1:2, and ultrasonically dispersed to fully mix them to prepare an α-Al2O3 carrier slurry;

[0023] After the α-Al2O3 carrier slurry is coated on the metal resistance wire, it is sintered and molded by electricity to form the insulation layer of the metal resistance wire.

[0024] In one embodiment, the method further comprises:

[0025] The carbon nanotubes, the boron nitride, and the aluminum nitride are mixed in a volume ratio of 2:1:2, and the mixture is added to a xylene solution in a volume ratio of 1:200, and stirred to be uniformly dispersed to prepare a solution of a ternary composite material;

[0026] Centrifuging, washing and drying the solution of the ternary composite material to obtain the ternary composite material;

[0027] The ternary composite material and glycerol are mixed in a weight ratio of 1:2, and ultrasonic dispersion is performed to fully mix the mixture to obtain a ternary composite material slurry, which is used as the slurry of the thermal conductive material.

[0028] The above-mentioned thermal conductivity gas sensor for sulfur hexafluoride leak detection in substation GIS combines carbon nanotubes, boron nitride lattices and aluminum nitride nanoparticles as the sensitive material of the ellipsoidal sulfur hexafluoride thermal conductivity gas sensor, so that the sensitive material has a high specific surface area and thermal stability, which can greatly improve the heat exchange efficiency and temperature adaptability of the sensor. In addition, the use of ellipsoidal resistance wire can effectively improve the surface molding quality and uniformity of the bead-shaped sensitive element. The degree of uneven heating of the sensitive material during high-temperature sintering and the microcracks generated inside the material are reduced. At the same time, the gas sensor can form a uniform temperature field during operation, improving the reliability and service life of the gas sensor, thereby overcoming the problems of high cost and poor sensitivity of the gas leakage detection method in electrical equipment and improving the gas detection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Schematic diagram of the structure of a thermal conductivity gas sensor in one embodiment;

[0031] Figure 2is a schematic structural diagram of a thermal conductivity gas sensor in another embodiment;

[0032] Figure 3 is a schematic structural diagram of a sensor assembly in one embodiment;

[0033] Figure 4 Schematic diagram of the principle of the preparation method in one embodiment.

[0034] Explanation of reference numerals: 100 is the sensor body, 200 is the heat-conducting material shell, 110 is the resistance wire frame, 101 is the base, 102 is the metal protective cover, 300 is the sensor assembly, 310 is the detection element, and 320 is the compensation element. DETAILED DESCRIPTION

[0035] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0037] It will be understood that the terms "first," "second," etc. used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element.

[0038] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0039] It is understood that “at least one” refers to one or more, “a plurality” refers to two or more, and “at least a portion of an element” refers to a portion or all of an element.

[0040] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0041] In one embodiment, Figure 1 and Figure 2 As shown, a thermal conductivity gas sensor for detecting sulfur hexafluoride leakage in a substation GIS is provided, comprising: a sensor body 100 and a heat conductive material shell 200 , wherein the sensor body 100 comprises a resistance wire frame 110 .

[0042] Among them, the sensor body 100 refers to the other parts of the sensor except the thermal conductive material shell 200, such as the metal resistance wire in the resistance wire frame 110, the base 101 welded to the metal resistance wire, and the metal protective cover 102 with good air permeability connected to the base 101.

[0043] The resistance wire frame 110 includes an ellipsoidal frame formed by winding a metal resistance wire. Specifically, the metal resistance wire in the resistance wire frame 110 is in the shape of a hollow ellipsoid and has terminals at both ends for connecting to the terminals of the base 101.

[0044] Among them, the surface of the metal resistance wire is provided with an insulating layer, which is coated on the surface of the metal resistance wire. The insulating layer material can be α-Al2O3 nano-scale powder, which plays the role of isolating the resistance wire and the composite material to prevent heat / gas diversion between the two.

[0045] Among them, the thermal conductive material shell 200 is a shell formed by wrapping the resistance wire frame 110 with a thermal conductive material, that is, the metal resistance wire in the resistance wire frame 110 is wrapped by the thermal conductive material in the thermal conductive material shell 200, which makes it easier for the thermal conductive material to evenly transfer the heat of the external leaked gas to the metal resistance wire, thereby improving the sensitivity of the thermal conductivity type gas sensor.

[0046] Among them, the thermal conductive material is a thermal conductive composite material coated on the surface of the insulating layer and sintered together. The thermal conductive material is a composite material prepared by mixing carbon nanotubes, boron nitride and aluminum nitride nanoparticles. Since the thermal conductive material has three components, this composite material is also called a ternary composite material.

[0047] In the above-mentioned thermal conductivity gas sensor for sulfur hexafluoride leak detection in substation GIS, carbon nanotubes, boron nitride lattices and aluminum nitride nanoparticles are combined as the sensitive material of the ellipsoidal sulfur hexafluoride thermal conductivity gas sensor, so that the sensitive material has a high specific surface area and thermal stability, which can greatly improve the heat exchange efficiency and temperature adaptability of the sensor. In addition, the use of ellipsoidal resistance wire can effectively improve the surface molding quality and uniformity of the bead-shaped sensitive element. The degree of uneven heating of the sensitive material during high-temperature sintering and the microcracks generated inside are reduced. At the same time, the gas sensor can form a uniform temperature field during operation, improving the reliability and service life of the gas sensor, thereby overcoming the problems of high cost and poor sensitivity of the gas leakage detection method in electrical equipment and improving the gas detection effect.

[0048] In one embodiment, the resistance wire frame 110 is filled with an insulating material, which is an ellipsoidal α-Al2O3 insulating layer located in the inner core of the resistance wire, isolating the irregular flow of sulfur hexafluoride gas inside the resistance wire and improving the thermal stability of the sulfur hexafluoride thermal conductivity gas sensor.

[0049] In one embodiment, the metal resistance wire comprises at least any one of the following metal materials: platinum, palladium, rhodium, iridium, ruthenium, osmium, and tungsten. Preferably, the material of the metal resistance wire is platinum.

[0050] In one embodiment, the carbon nanotubes are oxidized single-walled carbon nanotubes, oxidized double-walled carbon nanotubes, or oxidized multi-walled carbon nanotubes. Preferably, the carbon nanotubes are oxidized multi-walled carbon nanotubes.

[0051] In one embodiment, the boron nitride is one of hexagonal boron nitride, rhombohedral boron nitride, cubic boron nitride and wurtzite boron nitride. Preferably, the boron nitride is hexagonal boron nitride.

[0052] In one embodiment, the aluminum nitride is micron ultrafine high-purity aluminum nitride powder.

[0053] Among them, carbon nanotubes are one-dimensional porous carbon nanomaterials that serve as pathways for gas exchange when the thermal conductivity gas sensor comes into contact with sulfur hexafluoride gas;

[0054] Among them, boron nitride has a tight lattice structure and high bonding strength between atoms, which enables heat to be effectively transferred in the lattice, so it has good thermal conductivity; aluminum nitride nanoparticles not only have good thermal conductivity, but also have good thermal stability, and can maintain good performance even at high temperatures without decomposition or deformation.

[0055] This application makes full use of the high specific surface area and high thermal stability of the ternary composite material, and the shaping guidance and homogenization agglomeration effect of the ellipsoidal resistance wire on the composite material, so that the sensitive element has a uniform temperature field and good heat exchange efficiency, shortens the response time, improves the detection accuracy, and extends the service life.

[0056] In one embodiment, the resistance wire frame 110 includes at least two resistance coils wound from a metal resistance wire, each of which is arranged at a predetermined spacing. Specifically, spacing is maintained between the coils of resistance wire, and the predetermined spacing between the resistance coils can be the same, thereby facilitating uniform temperature transfer.

[0057] In one embodiment, the thermal conductivity gas sensor can be used to detect gases including one or a mixture of SF6, He, and H2 gases.

[0058] In one embodiment, the present application further provides a sensor assembly 300 for detecting sulfur hexafluoride leakage in a substation GIS, comprising at least two thermal conductivity gas sensors according to any of the above embodiments.

[0059] One thermal conductivity type gas sensor is used as the detection element 310 of the sensor assembly 300 , and the other thermal conductivity type gas sensor is used as the compensation element 320 of the sensor assembly 300 .

[0060] like Figure 3 As shown, the sensor assembly 300 includes two sensor elements, namely a detection element 310 and a compensation element 320 .

[0061] As can be seen, the core components of sensor assembly 300 include a detection element 310 and a compensation element 320. The resistance of compensation element 320 must match that of detection element 310, and they are encapsulated in separate reaction gas chambers to improve detection accuracy. Detection element 310 and its paired compensation element 320 are packaged together in a metal casing. This casing has air holes for contact with the gas being measured. The packaged detection element 310 and compensation element 320 are then placed together in a powder metallurgy casing to achieve safety and explosion-proof properties.

[0062] When using the sensor assembly 300 to detect sulfur hexafluoride, the compensation element 320 and the detection element 310 can be paired and connected to the two arms of the Wheatstone bridge, and a DC voltage can be applied. When the gas being measured comes into contact with the sensor detection element 310, heat exchange occurs with the detection element 310, causing the resistance of the detection element 310 to change. The Wheatstone bridge loses balance and generates a changing voltage. The generated voltage is amplified by a signal amplifier and output. The output voltage signal can reflect the change in gas concentration.

[0063] The sensor assembly 300 provided in the embodiment of the present application has precise pairing, simple structure, good stability, easy portability, good real-time performance, high detection accuracy, high working reliability, strong practicality, reliable process, and is easy to mass produce, and can be widely used in sulfur hexafluoride leakage detection in substation GIS equipment.

[0064] In one embodiment, the present application also provides a preparation method for preparing a thermal conductivity gas sensor as in any of the above embodiments, the method comprising: using a winding machine to wind a resistance wire frame 110; forming an insulating layer on the outer surface of the metal resistance wire; coating the surface of the resistance wire frame 110 with a slurry of a thermal conductive material, and energizing the metal resistance wire to sinter the slurry of the thermal conductive material into a shape to form a thermal conductive material shell 200.

[0065] The resistance wire frame 110 includes an ellipsoidal frame formed by winding a metal resistance wire; the thermal conductive material slurry is made by mixing carbon nanotubes, boron nitride and aluminum nitride.

[0066] Specifically, refer to Figure 4 The preparation method provided in the embodiment of the present application includes the following steps: step (1): winding a Pt wire with a winding machine to form an ellipsoidal resistance wire; step (2): preparing slurries of the carrier α-Al2O3 and the ternary composite sensitive material respectively; step (3): spot welding the ellipsoidal resistance wire on the base 101; step (4): coating the carrier slurry on the ellipsoidal resistance wire, applying power to high-temperature sintering to form it; step (5): coating the ternary composite sensitive material slurry on the sintered carrier surface, applying power to high-temperature sintering to form it; step (6): symmetrically installing a protective cover on the base 101.

[0067] In one embodiment, an insulating layer is formed on the outer surface of a metal resistance wire, comprising: preparing an α-Al2O3 nano-scale ultrafine powder material using a sol-gel method; mixing the prepared α-Al2O3 material with glycerol in a weight ratio of 1:2, and ultrasonically dispersing the mixture to ensure sufficient mixing to prepare an α-Al2O3 carrier slurry; coating the α-Al2O3 carrier slurry on the metal resistance wire, and then applying electricity and sintering the slurry at a high temperature to form an insulating layer of the metal resistance wire.

[0068] In one embodiment, the method further includes: mixing carbon nanotubes, boron nitride, and aluminum nitride in a volume ratio of 2:1:2, adding the mixture to a xylene solution in a volume ratio of 1:200, stirring to uniformly disperse it, and preparing a solution of a ternary composite material; centrifuging, washing, and drying the solution of the ternary composite material to obtain a ternary composite material; mixing the ternary composite material with glycerol in a weight ratio of 1:2, ultrasonically dispersing them to fully mix them, and preparing a ternary composite material slurry as a slurry of a thermal conductive material.

[0069] Exemplarily, the preparation in step (2) comprises the following steps:

[0070] (a) Preparation of α-Al2O3 nano-scale ultrafine powder material by sol-gel method;

[0071] (b) preparing an α-Al2O3 slurry, comprising mixing the α-Al2O3 material prepared in step (a) with glycerol in a weight ratio of 1:2, and performing ultrasonic dispersion to ensure thorough mixing, thereby preparing an α-Al2O3 slurry;

[0072] (c) preparing a ternary composite material of carbon nanotubes / boron nitride / aluminum nitride nanoparticles, comprising: mixing carbon nanotubes, boron nitride, and aluminum nitride in a volume ratio of 2:1:2, adding the mixture to a xylene solution in a volume ratio of 1:200, and stirring to uniformly disperse the mixture to obtain a carbon nanotube / boron nitride / aluminum nitride ternary composite material solution; and centrifuging the solution, washing with water, and drying to obtain a carbon nanotube / boron nitride / aluminum nitride ternary composite material.

[0073] (d) preparing a carbon nanotube / boron nitride / aluminum nitride ternary composite material slurry, the process of which is as follows: mixing the carbon nanotube / boron nitride / aluminum nitride ternary composite material prepared in step (c) with glycerol in a weight ratio of 1:2, and ultrasonically dispersing the mixture to ensure thorough mixing, thereby preparing a carbon nanotube / boron nitride / aluminum nitride ternary composite material slurry.

[0074] In addition, the coating in step (4) includes the following steps: a) coating a layer of the prepared α-Al2O3 slurry on the ellipsoidal resistance wire to serve as a carrier; b) coating the surface of the carrier with the prepared ternary composite sensitive material slurry.

[0075] In addition, the high-temperature sintering molding in step (5) is achieved by the following process: under the protection of high-purity nitrogen, a DC voltage is applied to the semi-finished product, a sintering current of 230 mA is applied, the temperature is controlled at about 550°C, and the power is kept on for 30 minutes.

[0076] Compared to existing technologies, the thermal conductivity sensor method proposed in this application is a concentration-based sensor that responds to the difference in thermal conductivity between the measured component and the reference gas. This method offers advantages such as a wide detection range, high reliability, easy installation, and simplified maintenance, making it suitable for on-site testing of power systems. Furthermore, this application provides a preparation method compatible with this thermal conductivity gas sensor, describing its manufacturing process and operating method. This method is used to detect gas concentrations within a range of 0.02% to 100%, enabling wide-range gas concentration detection.

[0077] In the description of this specification, reference to the terms "some embodiments" or "other embodiments" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0078] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A thermal conductivity gas sensor for detecting sulfur hexafluoride leakage in a substation GIS, characterized in that: include: sensor body; The sensor body includes a resistance wire frame; The resistance wire frame includes an ellipsoidal frame formed by winding metal resistance wire; The surface of the metal resistance wire is provided with an insulating layer; The heat-conducting material shell is a shell formed by wrapping the resistance wire frame with a heat-conducting material; wherein the heat-conducting material is a composite material prepared by mixing carbon nanotubes, boron nitride and aluminum nitride nanoparticles.

2. The thermal conductivity gas sensor according to claim 1, wherein: The resistance wire frame is filled with insulating material.

3. The thermal conductivity gas sensor according to claim 1 or 2, characterized in that: The metal resistance wire comprises at least any one of the following metal materials: platinum, palladium, rhodium, iridium, ruthenium, osmium, and tungsten.

4. The thermal conductivity gas sensor according to claim 1 or 2, characterized in that: The carbon nanotube is one of oxidized single-walled carbon nanotube, oxidized double-walled carbon nanotube or oxidized multi-walled carbon nanotube.

5. The thermal conductivity gas sensor according to claim 1 or 2, characterized in that: The boron nitride is one of hexagonal boron nitride, rhombohedral boron nitride, cubic boron nitride and wurtzite boron nitride.

6. The thermal conductivity gas sensor according to claim 1 or 2, wherein: The resistance wire frame includes at least two resistance coils wound from a metal resistance wire, and the resistance coils are arranged at a preset distance from each other.

7. A sensor assembly for detecting sulfur hexafluoride leakage in a substation GIS, characterized in that: comprising at least two thermal conductivity gas sensors according to any one of claims 1 to 6; Among them, one of the thermal conductivity type gas sensors is used as a detection element of the sensor assembly, and the other thermal conductivity type gas sensor is used as a compensation element of the sensor assembly.

8. A preparation method, characterized in that: For preparing a thermal conductivity gas sensor according to any one of claims 1 to 6, the method comprises: A resistance wire frame is formed by winding the wire using a winding machine; the resistance wire frame includes an ellipsoidal frame formed by winding the metal resistance wire; forming an insulating layer on the outer surface of the metal resistance wire; Coating a thermally conductive material slurry on the surface of the resistance wire frame, and electrifying the metal resistance wire to sinter the thermally conductive material slurry to form a thermally conductive material shell; The thermal conductive material slurry is prepared by mixing carbon nanotubes, boron nitride and aluminum nitride.

9. The preparation method according to claim 8, characterized in that The step of forming an insulating layer on the outer surface of the metal resistance wire comprises: The sol-gel method was used to prepare α-Al2O3 nano-scale ultrafine powder materials; The prepared α-Al2O3 material and glycerol are mixed in a weight ratio of 1:2, and ultrasonically dispersed to fully mix them to prepare an α-Al2O3 carrier slurry; After the α-Al2O3 carrier slurry is coated on the metal resistance wire, it is sintered and molded by electricity to form the insulation layer of the metal resistance wire.

10. The preparation method according to claim 8, characterized in that The method further comprises: The carbon nanotubes, the boron nitride, and the aluminum nitride are mixed in a volume ratio of 2:1:2, and the mixture is added to a xylene solution in a volume ratio of 1:200, and stirred to be uniformly dispersed to prepare a solution of a ternary composite material; Centrifuging, washing and drying the solution of the ternary composite material to obtain the ternary composite material; The ternary composite material and glycerol are mixed in a weight ratio of 1:2, and ultrasonic dispersion is performed to fully mix the mixture to obtain a ternary composite material slurry, which is used as the slurry of the thermal conductive material.

Images