Uniform heating structure and manufacturing method thereof

Abstract

The invention discloses a uniform heating structure and a manufacturing method thereof, and belongs to the field of electric heating. The structure mainly comprises a supporting structure, a temperature equalizing layer, a heating layer, an electrode, an insulating layer, a heat conduction interface layer, a fastening structure and a heat preservation structure. Firstly, the supporting structure, the uniform temperature layer, the insulating layer and the heating layer are combined together through the heat conduction interface layer, then the electrodes are installed through pressing, welding and other methods, the device is fastened through a mechanical structure, then the outer side of the fastening structure is wrapped with the heat preservation structure, and finally a power line and the electrodes are connected and mechanically fixed through an insulating material. And a uniform electric heating structure is obtained. The structure prepared by the method adopts the uniform conductive film as a heating element, and the uniform temperature layer is laid, so that the overall temperature is more uniform. Meanwhile, a large number of heat conduction interface layers are used in the structure, so that the heat resistance is smaller, and the energy efficiency is higher. The structure also has the advantages of fast temperature rise, high reliability and the like.

Description

Technical Field

[0001] The invention belongs to the field of electric heating and relates to a uniform heating structure and a manufacturing method thereof. Background Art

[0002] Uniform heating has always been a difficulty in the field of industrial heating.

[0003] Traditional electric heating mostly uses resistance wire as the heating element, which has problems such as uneven heating, easy aging, and burning.

[0004] The present invention adopts a uniform conductive film as a heating element and lays a temperature-averaging layer, so that the heating temperature distribution is more uniform. Moreover, the present invention also adopts a thermal interface material, so that the thermal resistance of the system is smaller and the overall energy efficiency is higher. The present invention provides a method for uniform electric heating, which has the characteristics of simple process, low cost, energy saving, safety, uniform temperature, high reliability, etc. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art, adopt a uniform conductive film as a heating element and use a temperature-averaging layer, and use a thermal interface material between layers and structures, so that the thermal resistance of the system is smaller, and uniform, energy-saving and highly reliable electric heating is achieved.

[0006] The present invention proposes a manufacturing method for a uniform heating structure, and the detailed manufacturing steps are as follows: 1. A method for manufacturing a uniform heating structure, wherein the uniform heating structure is characterized in that the main components include: a support structure, a temperature-averaging layer, a heating layer, an electrode, an insulating layer, a thermally conductive interface layer, a fastening structure, and a thermal insulation structure. The manufacturing steps include: S01, laying the first temperature-averaging layer: uniformly coating the thermal interface layer on the surface of the support structure on one side of the heat source direction, and uniformly laying the first temperature-averaging layer on the surface of the thermal interface layer; S02, laying the first insulating layer: uniformly coating the thermal interface layer on the other side of the first temperature-averaging layer in S01, and uniformly laying the first insulating layer on the surface of the thermal interface layer; S03, laying the heating layer: uniformly coating the thermal interface layer on the other side of the first insulating layer in S02, and uniformly laying the heating layer on the surface of the thermal interface layer; S04, electrode installation: Coat the surface of two or more electrodes of a certain shape with conductive paste and fix them to the surface of the S03 heating layer, keeping a certain distance between the electrodes; S05, laying the second insulating layer: uniformly coating the thermal interface layer on the other side of the heating layer S04, and uniformly laying the second insulating layer on the surface of the thermal interface layer; S06, laying the second temperature-averaging layer: uniformly coating the thermal interface layer on the other side of the S05 insulation layer, and uniformly laying the second temperature-averaging layer on the surface of the thermal interface layer; S07, fastening structure installation: place the fastening structure on the other side of the S06 temperature-averaging layer and fasten it through a mechanical structure; S08, thermal insulation structure installation: place the thermal insulation structure on the other side of the S07 fastening structure and fix it; S09, power line connection: connect the power line to the electrode and use insulating material for mechanical fixation to obtain a uniform heating structure.

[0007] 2. Furthermore, it is characterized in that the support structure of step S01 is made of one or more of metal, ceramic, polymer and composite material, and its bottom surface shape is one or more of annular, rectangular, fan-shaped, elliptical, circular, polygonal, and the thickness ranges from 0.001m to 10m.

[0008] 3. Furthermore, it is characterized in that the thermal conductivity of the S01-S06 thermal conductive interface layer is 0.5 to 500 W / (m·K); the thermal conductive interface layer contains a resin matrix and a thermal conductive filler, the resin matrix includes one or more of epoxy resin, polyurethane, acrylic, silicone resin, fluorosilicone resin, polyimide, bismaleimide, phenolic resin, cyanate resin, and phthalonitrile resin, and the thermal conductive filler includes one or more of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, silicon, boron nitride, aluminum nitride, silicon nitride, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, graphite, and metal particles, and the particle size range of the thermal conductive filler is 0.01 to 200 μm.

[0009] 4. Further, it is characterized in that the thermal conductivity of the first temperature-averaging layer and the second temperature-averaging layer in steps S01 and S06 is 80 to 2000 W / (m·K), and the first temperature-averaging layer and the second temperature-averaging layer in steps S01 and S06 contain one or more of metal, silicon, boron nitride, aluminum nitride, silicon nitride, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, and graphite, and the thickness ranges from 0.01 mm to 10 mm.

[0010] 5. Furthermore, it is characterized in that the insulation strength of the first insulating layer and the second insulating layer in steps S02 and S05 is greater than 10 kV / mm, and the temperature resistance temperature is greater than 150°C. The first insulating layer and the second insulating layer in steps S02 and S05 contain one or more of epoxy resin, phenolic resin, polyimide, polyetheretherketone, polyphenylene sulfide, polysulfone, polytetrafluoroethylene, silicone, fluorine-containing silicone, mica, ceramic, glass, and rubber, and the thickness ranges from 0.01 mm to 8 mm.

[0011] 6. Further, it is characterized in that the heating layer in steps S03 and S04 is a thin film material with a thickness ranging from 0.01 mm to 1 mm, a square resistance less than 1000 Ω / □, and a maximum fluctuation range of the square resistance of ±15%. The heating layer in steps S03 and S04 contains one or more of carbon nanotubes, graphene, graphite nanosheets, graphite, carbon fiber, carbon black, metal, and semiconductor.

[0012] 7. Further, it is characterized in that the resistivity of the electrode in step S04 is less than 100µΩ·cm, the electrode in step S04 contains one or more of copper, aluminum, silver, and gold, the installation method is one or more of crimping and welding, and the conductive paste in step S04 is one or more of silver paste, aluminum paste, and carbon paste.

[0013] 8. Furthermore, it is characterized in that the material of the fastening structure in step S07 is one or more of metal, resin, ceramic fiber, and composite material, and its tensile strength is greater than 100 MPa and its temperature resistance is greater than 150°C.

[0014] 9. Furthermore, it is characterized in that, in the step S09, the connection method between the power line and the electrode is welding or crimping, and the insulating material used is one or more of high temperature resistant resin, ceramic, and insulating composite material.

[0015] 10. A uniform heating structure, characterized in that the uniform heating structure is prepared by any of the above methods, the heating temperature can reach 120-300°C, the temperature uniformity of the heating surface is good, the high and low temperature difference of the heating surface is less than 8°C, the heating rate is greater than 1°C / min, and it has a uniform electric heating function.

[0016] Compared with the prior art, the advantages of the present invention are: (1) The structure prepared by this method uses a uniform conductive film as a heating element and lays a temperature-averaging layer, so that the temperature of the heating surface is more uniform; (2) The structure prepared by this method uses a large amount of thermal conductive interface layer, so the thermal resistance is smaller and the energy efficiency is higher; (3) The structure prepared by this method has the advantages of fast heating and high reliability; (4) The method provided by the present invention can achieve uniform electric heating and has the characteristics of simple process, low cost, energy saving and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is the overall manufacturing flow chart of the present invention.

[0018] Attached Figure 2 It is a schematic diagram of the structure of the present invention, and the lower right corner is a partial enlarged schematic diagram.

[0019] Attached Figure 3Schematic diagram of temperature measurement position distribution in the embodiment.

[0020] Attached Figure 4 It is a scatter diagram of the temperatures measured at each temperature measuring point in the embodiment. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not have to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known structures, circuits, materials or methods are not specifically described.

[0022] Throughout the specification, references to "one embodiment", "an embodiment", "an example" or "an example" mean that a particular feature, structure or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment", "in an embodiment", "an example" or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures or characteristics may be combined in one or more embodiments or examples in any appropriate combination and / or subcombination. The present invention is described in detail below with reference to the accompanying drawings.

[0023] In the following description of the technical solution of the present invention in conjunction with the accompanying drawings, the size, proportion and position relationship of each element in the attachment are only exemplary, and the connection method between the illustrated elements is only for illustration and is not intended to limit the present invention.

[0024] Example

[0025] The embodiment described above illustrates the application of the method for manufacturing a uniform heating structure. The invention will be described in detail below in conjunction with the accompanying drawings: like Figure 2 As shown, the structure with uniform heating function mainly includes the following parts: a supporting structure 101, a thermal interface layer 102, a first temperature-averaging layer 103, a first insulating layer 104, a heating layer 105, a second insulating layer 106, a second temperature-averaging layer 107, a fastening structure 108, a thermal insulation structure 109, and an electrode 110; the resin matrix of the thermal interface layer is a temperature-resistant silicone resin, and the thermal conductive filler is boron nitride powder with a particle size of 1 to 100 μm and a thermal conductivity of 10 W / (m·K).

[0026] S01, laying of the first temperature equalizing layer: Figure 2As shown, the support structure 101 is 4Cr5MoSiV1 steel, the bottom surface is annular, the upper surface is annular, the inner radius of the upper surface is 0.43m, the inner radius of the lower surface is 0.513m, the outer diameters of the upper and lower surfaces are both 0.553m, the thickness of the upper surface ring is 0.123m, the thickness of the lower surface ring is 0.040m, and the height is 260mm. The surface of the support structure 101 on the heat source side is evenly coated with a thermal interface layer 102, and the first temperature-averaging layer 103 is a high-purity oxygen-free copper foil with a thermal conductivity of 385W / (m·K) and a thickness of 0.1mm. The first temperature-averaging layer 103 is evenly laid on the surface of the thermal interface layer; S02, laying the first insulating layer: uniformly coating the thermal interface layer 102 on the other side of the first temperature-averaging layer 103 in step S01, wherein the first insulating layer 104 is a polyimide film with a dielectric strength of 200 kV / mm, a temperature resistance of more than 240° C., and a thickness of 0.2 mm, and uniformly laying the first insulating layer 104 on the surface of the thermal interface layer; S03, laying the heating layer: uniformly coating the other side of the first insulating layer 104 in step S02 with the thermal interface layer 102, and uniformly laying the heating layer 105 on the surface of the thermal interface layer. The heating layer is a thin film material with a thickness of 0.1 mm and a square resistance of 5 Ω / □. The maximum fluctuation range of the square resistance is ±5%. The heating layer 105 contains graphite and phenolic resin. The heating layer is uniformly laid on the surface of the thermal interface layer. S04, electrode installation: The electrode 110 is a copper electrode with a resistivity of about 1.68µΩ·cm. There are two electrodes in total, with a thickness of 2mm, a width of 20mm, and a length of 300mm. The surface is coated with carbon paste. The installation method is crimping. The two electrodes are fixed to the surface of the heating layer 105 in step S03 in symmetrical positions, and the carbon paste is left to dry naturally. Figure 2 As shown; S05, laying the second insulating layer: uniformly coating the other side of the heating layer 105 in step S03 with the thermal interface layer 102, the second insulating layer 106 is a polyimide film with a dielectric strength of 200 kV / mm, a temperature resistance of more than 240° C., and a thickness of 0.2 mm, and uniformly laying the second insulating layer 106 on the surface of the thermal interface layer; S06, laying the second temperature-averaging layer: uniformly coating the other side of the second insulating layer 106 in step S05 with a thermally conductive interface layer, wherein the second temperature-averaging layer 107 is a high-purity oxygen-free copper foil with a thermal conductivity of 385 W / (m·K) and a thickness of 0.1 mm, and uniformly laying the second temperature-averaging layer 107 on the surface of the thermally conductive interface layer; S07, fastening structure installation: the fastening structure 108 is made of aluminum alloy, with a tensile strength greater than 120 MPa and a temperature resistance higher than 210° C. The fastening structure is placed on the other side of the second temperature-averaging layer 107 in step S06 and fastened by installing bolts and nuts; S08, installation of thermal insulation structure: the thermal insulation structure 109 is made of silica aerogel with a thickness of 50 mm and a surface covered with silicone cloth. The thermal insulation structure 109 is placed on the other side of the fastening structure 108 in step S07 and fixed; S09, power line connection: The power line and the electrode are connected by welding, the insulating material used is ceramic, and ceramic screws and nuts are used for mechanical fixation to obtain a uniform heating structure.

[0027] A 380V AC voltage is applied to the two electrodes of the uniform heating structure, and the heating element starts to work. The electrical energy is quickly converted into thermal energy on the membrane and transferred inward. The heat is transferred to the uniform temperature layer. Due to the uniform temperature characteristics of the uniform temperature layer, the heat is evenly transferred to the surface of the support structure, and finally the surface of the support structure away from the heat source is uniformly heated to 200±3℃. The temperature measurement points are taken on this surface. The coordinate system established is similar to some of the temperature measurement points. Figure 3 The x-axis is located on the heated upper surface. In the x-direction, a value is taken every 270.2 mm, for a total of 10 values. In the y-direction, a value is taken every 34.12 mm, for a total of 8 values. There are 80 temperature measurement points in total. The temperature measured at each temperature measurement point is as follows: Figure 4 The lowest temperature is 197℃, the highest temperature is 203℃, the difference between high and low temperature is 6℃, the temperature uniformity is good, and the rapid heating rate of 3℃ / min can be achieved.

[0028] Although the present invention has been described with reference to typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for manufacturing a uniform heating structure, characterized in that: The main components include: support structure, temperature-averaging layer, heating layer, electrode, insulation layer, thermal interface layer, fastening structure, and thermal insulation structure. The manufacturing steps include: S01, laying the first temperature-averaging layer: uniformly coating the thermal interface layer on the surface of the support structure on one side of the heat source direction, and uniformly laying the first temperature-averaging layer on the surface of the thermal interface layer; S02, laying the first insulating layer: uniformly coating the thermal interface layer on the other side of the first temperature-averaging layer in S01, and uniformly laying the first insulating layer on the surface of the thermal interface layer; S03, laying the heating layer: uniformly coating the thermal interface layer on the other side of the first insulating layer in S02, and uniformly laying the heating layer on the surface of the thermal interface layer; S04, electrode installation: Coat the surface of two or more electrodes of a certain shape with conductive paste and fix them to the surface of the S03 heating layer, keeping a certain distance between the electrodes; S05, laying the second insulating layer: uniformly coating the thermal interface layer on the other side of the heating layer S04, and uniformly laying the second insulating layer on the surface of the thermal interface layer; S06, laying the second temperature-averaging layer: uniformly coating the thermal interface layer on the other side of the S05 insulation layer, and uniformly laying the second temperature-averaging layer on the surface of the thermal interface layer; S07, fastening structure installation: place the fastening structure on the other side of the S06 temperature-averaging layer and fasten it through a mechanical structure; S08, thermal insulation structure installation: place the thermal insulation structure on the other side of the S07 fastening structure and fix it; S09, power line connection: connect the power line to the electrode and use insulating material for mechanical fixation to obtain a uniform heating structure.

2. The manufacturing method according to claim 1, characterized in that: The support structure of step S01 is made of one or more of metal, ceramic, polymer and composite material, and its bottom surface shape is one or more of annular, rectangular, fan-shaped, elliptical, circular and polygonal, and the thickness ranges from 0.001m to 10m.

3. The manufacturing method according to claim 1, characterized in that: The thermal conductivity of the S01-S06 thermal conductive interface layer is 0.5 to 500 W / (m·K); the thermal conductive interface layer contains a resin matrix and a thermal conductive filler, the resin matrix includes one or more of epoxy resin, polyurethane, acrylic, silicone resin, fluorosilicone resin, polyimide, bismaleimide, phenolic resin, cyanate resin, and phthalonitrile resin, the thermal conductive filler includes one or more of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, silicon, boron nitride, aluminum nitride, silicon nitride, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, graphite, and metal particles, and the particle size range of the thermal conductive filler is 0.01 to 200 μm.

4. The manufacturing method according to claim 1, characterized in that: The thermal conductivity of the first temperature-averaging layer and the second temperature-averaging layer in steps S01 and S06 is 80 to 2000 W / (m·K). The first temperature-averaging layer and the second temperature-averaging layer in steps S01 and S06 contain one or more of metal, silicon, boron nitride, aluminum nitride, silicon nitride, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, and graphite, and the thickness ranges from 0.01 mm to 10 mm.

5. The manufacturing method according to claim 1, characterized in that: The insulation strength of the first insulating layer and the second insulating layer in steps S02 and S05 is greater than 10kV / mm, and the temperature resistance temperature is greater than 150°C. The first insulating layer and the second insulating layer in steps S02 and S05 contain one or more of epoxy resin, phenolic resin, polyimide, polyetheretherketone, polyphenylene sulfide, polysulfone, polytetrafluoroethylene, silicone, fluorine-containing silicone, mica, ceramic, glass, and rubber, and the thickness ranges from 0.01mm to 8mm.

6. The manufacturing method according to claim 1, characterized in that: The heating layer in steps S03 and S04 is a thin film material with a thickness ranging from 0.01 mm to 1 mm, a square resistance less than 1000 Ω / □, and a maximum fluctuation range of the square resistance of ±15%. The heating layer in steps S03 and S04 contains one or more of carbon nanotubes, graphene, graphite nanosheets, graphite, carbon fiber, carbon black, metal, and semiconductor.

7. The manufacturing method according to claim 1, characterized in that: The resistivity of the electrode in step S04 is less than 100 µΩ·cm, the electrode in step S04 contains one or more of copper, aluminum, silver, and gold, the installation method is one or more of crimping and welding, and the conductive paste in step S04 is one or more of silver paste, aluminum paste, and carbon paste.

8. The manufacturing method according to claim 1, characterized in that: The material of the fastening structure in step S07 is one or more of metal, resin, ceramic fiber, and composite material, and has a tensile strength greater than 100 MPa and a temperature resistance greater than 150°C.

9. The manufacturing method according to claim 1, characterized in that: In the step S09, the power line and the electrode are connected by welding or crimping, and the insulating material used is one or more of high temperature resistant resin, ceramic, and insulating composite material.

10. A uniform heating structure, characterized in that: The uniform heating structure is prepared by the method of any one of claims 1 to 9, and its heating temperature can reach 120-300°C, the high and low temperature difference of the heating surface is less than 8°C, the heating rate is greater than 1°C / min, and it has a uniform electric heating function.

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