A uniform heating structure and a manufacturing method thereof

Abstract

The application discloses a kind of uniform heating structure and manufacturing method thereof, belong to electric heating field.The structure mainly includes the following parts: support structure, temperature equalizing layer, heating layer, electrode, insulating layer, heat-conducting interface layer, fastening structure, heat preservation structure.First, by heat-conducting interface layer, support structure, temperature equalizing layer, insulating layer, heating layer are combined together, then install electrode by pressing, welding etc., and using mechanical structure is fastened to device, then the outside of fastening structure is coated with heat preservation structure, finally power cord is connected with electrode and using insulating material is mechanically fixed, obtains uniform electric heating structure.The structure prepared by this method uses uniform conductive film as heating element, and lays temperature equalizing layer at the same time, so the overall temperature is more uniform.At the same time, the structure also uses a large amount of heat-conducting interface layer, so the thermal resistance is smaller, and the energy efficiency is higher.The structure also has the advantages of fast heating, high reliability, etc.

Description

Technical Field

[0001] This invention belongs to the field of electrothermal technology and relates to a uniform heating structure and its manufacturing method. Background Technology

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

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

[0004] This invention employs a uniform conductive thin film as the heating element and lays a temperature-equalizing layer, resulting in a more uniform heating temperature distribution. Furthermore, this invention utilizes a thermal interface material, leading to lower system thermal resistance and higher overall energy efficiency. This invention provides a method for uniform electric heating, characterized by simple process, low cost, energy saving, safety, uniform temperature, and high reliability. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art. It adopts a uniform conductive thin film as a heating element and uses a temperature equalization layer. Thermal interface materials are used between layers and between structures, resulting in lower thermal resistance of the system and achieving uniform, energy-saving and highly reliable electric heating.

[0006] This invention proposes a manufacturing method for a uniform heating structure, the detailed steps of which are as follows:

[0007] 1. A method for manufacturing a uniform heating structure, wherein the prepared uniform heating structure is characterized by comprising the following main structural components: a support structure, a temperature homogenizing layer, a heating layer, electrodes, an insulating layer, a thermally conductive interface layer, a fastening structure, and a heat insulation structure. The manufacturing steps include:

[0008] S01, First temperature uniform layer laying: A thermally conductive interface layer is uniformly coated on the surface of the supporting structure on the side of the heat source direction, and the first temperature uniform layer is uniformly laid on the surface of the thermally conductive interface layer.

[0009] S02, First insulating layer laying: A thermally conductive interface layer is uniformly coated on the other side of the first temperature uniform layer in S01, and the first insulating layer is uniformly laid on the surface of the thermally conductive interface layer.

[0010] S03, Heating layer laying: A thermally conductive interface layer is uniformly coated on the other side of the first insulating layer in S02, and the heating layer is uniformly laid on the surface of the thermally conductive interface layer.

[0011] S04, Electrode installation: Coat the surfaces 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;

[0012] S05, Second insulation layer laying: A thermally conductive interface layer is uniformly coated on the other side of the S04 heating layer, and the second insulation layer is uniformly laid on the surface of the thermally conductive interface layer.

[0013] S06, Second temperature uniform layer laying: A thermally conductive interface layer is uniformly coated on the other side of the S05 insulating layer, and the second temperature uniform layer is uniformly laid on the surface of the thermally conductive interface layer.

[0014] S07, Fastening structure installation: Place the fastening structure on the other side of the S06 temperature equalization layer and fasten it with a mechanical structure.

[0015] S08, Installation of thermal insulation structure: Place the thermal insulation structure on the other side of the S07 fastening structure and fix it;

[0016] S09, Power cord connection: Connect the power cord to the electrode and use insulating material for mechanical fixation to obtain a uniform heating structure.

[0017] 2. Further, the supporting structure in step S01 is made of one or more of metal, ceramic, polymer and composite materials, and its bottom surface shape is one or more of annular, rectangular, fan-shaped, elliptical, circular, polygonal, and its thickness ranges from 0.001m to 10m.

[0018] 3. Further, characterized in that the thermal conductivity of the S01-S06 thermally conductive interface layer is 0.5 to 500 W / (m·K); the thermally conductive interface layer contains a resin matrix and a thermally conductive filler, the resin matrix including one or more of epoxy resin, polyurethane, acrylic acid, silicone resin, fluorosilicone resin, polyimide, bismaleimide, phenolic resin, cyanate ester resin, and phthalonitrile resin, the thermally conductive filler including 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, the particle size range of the thermally conductive filler is 0.01 to 200 μm.

[0019] 4. Further, characterized in that the thermal conductivity of the first and second temperature-equalizing layers in steps S01 and S06 is 80 to 2000 W / (m·K), and the first and second temperature-equalizing layers in steps S01 and S06 contain one or more of the following: metal, silicon, boron nitride, aluminum nitride, silicon nitride, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, and graphite, with a thickness ranging from 0.01 mm to 10 mm.

[0020] 5. Further, 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 is greater than 150℃, and the first insulating layer and the second insulating layer in steps S02 and S05 contain one or more of epoxy resin, phenolic resin, polyimide, polyether ether ketone, polyphenylene sulfide, polysulfone, polytetrafluoroethylene, silicone, fluorosilicone, mica, ceramic, glass, and rubber, and the thickness ranges from 0.01mm to 8mm.

[0021] 6. Further, 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 sheet resistance of less than 1000 Ω / □, and a maximum sheet resistance fluctuation range 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.

[0022] 7. Further, 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 pressing and welding, and the conductive paste in step S04 is one or more of silver paste, aluminum paste, and carbon paste.

[0023] 8. Further, the fastening structure in step S07 is characterized in that the material 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.

[0024] 9. Further, in 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.

[0025] 10. A uniform heating structure, characterized in that the uniform heating structure is prepared by any of the above methods, and its heating temperature can reach 120-300℃, the heating surface temperature uniformity is good, the high and low temperature difference of the heating surface is <8℃, the heating rate is >1℃ / min, and it has a uniform electric heating function.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] (1) The structure prepared by this method uses a uniform conductive film as the heating element and a uniform temperature layer is laid at the same time, so that the temperature of the heating surface is more uniform.

[0028] (2) The structure prepared by this method makes extensive use of thermally conductive interface layers, thus resulting in lower thermal resistance and higher energy efficiency;

[0029] (3) The structure prepared by this method has the advantages of rapid heating and high reliability;

[0030] (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. Attached Figure Description

[0031] Appendix Figure 1 This is a flowchart of the overall manufacturing process of the present invention.

[0032] Appendix Figure 2 This is a structural schematic diagram of the present invention, with a partially enlarged schematic diagram in the lower right corner.

[0033] Appendix Figure 3 This is a schematic diagram of the temperature measurement location distribution in the embodiment.

[0034] Appendix Figure 4 This is a scatter plot of the temperatures measured at each temperature measurement point in the example. Detailed Implementation

[0035] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known structures, circuits, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0036] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The invention will now be described in detail with reference to the accompanying drawings.

[0037] In the following description of the technical solution of the present invention in conjunction with the accompanying drawings, the dimensions, proportions and positional relationships of the various elements are merely exemplary, and the connection methods between the illustrated elements are only for illustration and are not intended to limit the present invention.

[0038] Example

[0039] The embodiments described illustrate the application of this method for manufacturing a uniform heating structure. The invention will now be described in detail with reference to the accompanying drawings:

[0040] like Figure 2 As shown, the structure with uniform heating function mainly includes the following parts: support structure 101, thermally conductive interface layer 102, first temperature uniform layer 103, first insulation layer 104, heating layer 105, second insulation layer 106, second temperature uniform layer 107, fastening structure 108, heat preservation structure 109, and electrode 110; the resin matrix of the thermally conductive interface layer is heat-resistant silicone resin, and the thermally conductive filler is boron nitride micro powder with a particle size of 1-100μm and a thermal conductivity of 10W / (m·K).

[0041] S01, First temperature equalization layer laying: as follows Figure 2 As shown, the support structure 101 is made of 4Cr5MoSiV1 steel. Its bottom and upper surfaces are both annular, with an inner radius of 0.43m for the upper surface and 0.513m for the lower surface. Both surfaces have an outer diameter of 0.553m. The upper surface ring has a thickness of 0.123m, the lower surface ring has a thickness of 0.040m, and the height is 260mm. A thermally conductive interface layer 102 is uniformly coated on the surface of the support structure 101 on the side facing the heat source. The first heat-equalizing layer 103 is made of high-purity oxygen-free copper foil with a thermal conductivity of 385W / (m·K) and a thickness of 0.1mm. The first heat-equalizing layer 103 is uniformly laid on the surface of the thermally conductive interface layer.

[0042] S02, First insulation layer laying: The thermal interface layer 102 is uniformly coated on the other side of the first temperature uniform layer 103 in step S01. The first insulation layer 104 is a polyimide film with an insulation strength of 200kV / mm, a temperature resistance of over 240℃, and a thickness of 0.2mm. The first insulation layer 104 is uniformly laid on the surface of the thermal interface layer.

[0043] S03, Heating layer laying: A thermally conductive interface layer 102 is uniformly coated on the other side of the first insulating layer 104 in step S02, and a heating layer 105 is uniformly laid on the surface of the thermally conductive interface layer. The heating layer is a thin film material with a thickness of 0.1 mm, a sheet resistance of 5 Ω / □, and a maximum sheet resistance fluctuation range of ±5%. The heating layer 105 contains graphite and phenolic resin. The heating layer is uniformly laid on the surface of the thermally conductive interface layer.

[0044] S04, Electrode Installation: Electrode 110 is a copper electrode with a resistivity of approximately 1.68 µΩ·cm. There are two electrodes in total, each 2 mm thick, 20 mm wide, and 300 mm long. The surface is coated with carbon paste. The installation method is crimping. The two electrodes are symmetrically fixed to the surface of the heating layer 105 from step S03, and the carbon paste is allowed to dry naturally. Figure 2 As shown;

[0045] S05, laying the second insulation layer: uniformly coat the other side of the heating layer 105 in step S03 with a thermally conductive interface layer 102. The second insulation layer 106 is a polyimide film with an insulation strength of 200kV / mm, a temperature resistance of over 240℃, and a thickness of 0.2mm. The second insulation layer 106 is uniformly laid on the surface of the thermally conductive interface layer.

[0046] S06, Second temperature uniform layer laying: A thermally conductive interface layer is uniformly coated on the other side of the second insulating layer 106 in step S05. The second temperature uniform 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. The second temperature uniform layer 107 is uniformly laid on the surface of the thermally conductive interface layer.

[0047] S07, Fastening structure installation: The fastening structure 108 is made of aluminum alloy with a tensile strength greater than 120MPa and a temperature resistance higher than 210℃. The fastening structure is placed on the other side of the second temperature equalization layer 107 in step S06 and fastened by mounting bolts and nuts.

[0048] S08, Installation of thermal insulation structure: The thermal insulation structure 109 is made of silica aerogel with a thickness of 50mm and the surface is covered with silicone cloth. Place the thermal insulation structure 109 on the other side of the fastening structure 108 in step S07 and fix it.

[0049] S09, Power cord connection: The power cord is connected to the electrode by welding. The insulating material used is ceramic. Ceramic screws and nuts are used for mechanical fixation to obtain a uniform heating structure.

[0050] A 380V AC voltage is applied to the two electrodes of the aforementioned uniform heating structure, and the heating element begins to operate. Electrical energy is rapidly converted into heat energy on the film and transferred inwards. The heat is transferred to the temperature homogenization layer. Due to the temperature homogenization layer's uniform temperature characteristics, the heat is uniformly transferred to the surface of the supporting structure. Ultimately, the surface of the supporting structure away from the heat source direction can be uniformly raised to 200±3℃. Temperature measurement points are taken on this surface, and the established coordinate system and some temperature measurement points are shown below. Figure 3 As shown in the figure. The constructed x-axis is located on the heated upper surface. Ten values ​​are taken every 270.2 mm in the x-direction, and eight values ​​are taken every 34.12 mm in the y-direction, for a total of 80 temperature measurement points. The measured temperature at each point is shown in the figure. Figure 4 As shown. The lowest temperature is 197℃, the highest temperature is 203℃, the difference between the high and low temperatures is 6℃, the temperature uniformity is good, and it can achieve a rapid heating rate of 3℃ / min.

[0051] Although the invention has been described with reference to exemplary embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the invention can be embodied in many 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. Therefore, all variations 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 structural components include: a support structure, a heat spreader layer, a heating layer, electrodes, an insulating layer, a thermally conductive interface layer, a fastening structure, and a thermal insulation structure. The manufacturing steps include: S01, First temperature uniform layer laying: A thermally conductive interface layer is uniformly coated on the surface of the supporting structure on the side of the heat source direction, and the first temperature uniform layer is uniformly laid on the surface of the thermally conductive interface layer. The thickness of the first temperature uniform layer is 0.01mm to 10mm. S02, First insulating layer laying: A thermally conductive interface layer is uniformly coated on the other side of the first temperature uniform layer in S01, and the first insulating layer is uniformly laid on the surface of the thermally conductive interface layer. The thickness of the first insulating layer is 0.01mm to 8mm. S03, Heating layer laying: A thermally conductive interface layer is uniformly coated on the other side of the first insulating layer in S02, and the heating layer is uniformly laid on the surface of the thermally conductive interface layer. S04, Electrode Installation: Coat the surfaces of two or more electrodes of a certain shape with conductive paste and fix them to the surface of the heating layer in S03, keeping a certain distance between the electrodes. The electrodes in step S04 contain one or more of copper, aluminum, silver, and gold, and the conductive paste in step S04 is one or more of silver paste, aluminum paste, and carbon paste. S05, Second insulation layer laying: A thermally conductive interface layer is uniformly coated on the other side of the S04 heating layer, and a second insulation layer is uniformly laid on the surface of the thermally conductive interface layer. The thickness of the second insulation layer ranges from 0.01mm to 8mm. S06, Second temperature uniform layer laying: A thermally conductive interface layer is uniformly coated on the other side of the S05 insulating layer, and the second temperature uniform layer is uniformly laid on the surface of the thermally conductive interface layer. The thickness of the second temperature uniform layer is 0.01mm to 10mm. S07, Fastening structure installation: Place the fastening structure on the other side of the S06 temperature equalization layer and fasten it with a mechanical structure. S08, Installation of thermal insulation structure: Place the thermal insulation structure on the other side of the S07 fastening structure and fix it; S09, Power cord connection: Connect the power cord to the electrode and use insulating material for mechanical fixation to obtain a uniform heating structure. The connection method between the power cord and the electrode is welding or crimping. The insulating material used is one or more of high-temperature resistant resin, ceramic, and insulating composite material.

2. The manufacturing method according to claim 1, characterized in that, The support structure in step S01 is made of one or more of metal, ceramic, polymer and composite materials, and its bottom shape is one or more of ring, rectangle, sector, ellipse, circle and polygon, with a thickness ranging from 0.01m to 1m.

3. The manufacturing method according to claim 1, characterized in that, The thermal conductivity of the S01-S06 thermally conductive interface layer is 0.5–500 W / (m·K); the thermally conductive interface layer contains a resin matrix and a thermally conductive filler. The resin matrix includes one or more of epoxy resin, silicone resin, fluorosilicone resin, polyimide, bismaleimide, phenolic resin, cyanate ester resin, and phthalonitrile resin. The thermally 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. The particle size range of the thermally conductive filler is 0.01–200 μm.

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

5. The manufacturing method according to claim 1, characterized in that, The insulation strength of the first and second insulating layers in steps S02 and S05 is greater than 10kV / mm and the temperature resistance is greater than 150℃. The first and second insulating layers in steps S02 and S05 contain one or more of epoxy resin, phenolic resin, polyimide, polyether ether ketone, polyphenylene sulfide, polysulfone, polytetrafluoroethylene, silicone, fluorosilicone, mica, ceramic, glass, and rubber.

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 sheet resistance of less than 1000 Ω / □, and a maximum sheet resistance fluctuation range of ±15%. The heating layer in steps S03 and S04 contains one or more of the following: 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 100µΩ·cm, and the installation method is one or more of crimping and welding.

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

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

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