Dry-type transformer low-voltage winding structure adopting heat pipe for heat dissipation at air channel

Abstract

The invention belongs to the technical field of dry-type transformers, and particularly relates to a dry-type transformer low-voltage winding structure adopting a heat pipe to dissipate heat at an air channel, which comprises an iron core, a low-voltage coil is arranged on the outer edge of the iron core, a high-voltage coil is arranged on the outer edge of the low-voltage coil, and a stay curtain is arranged in the low-voltage coil; heat pipes are arranged in the supporting strip curtain, the lower ends of the heat pipes are arranged in supporting strips, insulating supporting strips are arranged outside the supporting strips, and supporting plates are arranged between the heat pipes. A liquid medium is arranged in the heat pipe; the stay curtain comprises insulation paper, and the whole stay curtain is arranged to be of an insulation paper-stay-insulation paper interlayer curtain-shaped structure. And the stay curtain is annularly arranged on the outer edge of the coil winding. The detachable heat pipe is placed at the low-voltage winding air channel of the dry-type transformer, and heat of the low-voltage winding is dissipated through gasification and heat absorption of a liquid medium in the heat pipe. The transformer has the advantages of high heat dissipation efficiency, no maintenance, convenience in disassembly and replacement and reduction of temperature rise of the low-voltage winding.

Description

Technical Field

[0001] The present invention belongs to the technical field of dry-type transformers, and particularly relates to a low-voltage winding structure of a dry-type transformer that uses heat pipes for heat dissipation at the air ducts. Background Art

[0002] The windings of dry-type transformers dissipate heat through surface air convection and radiation. The low-voltage windings are generally located inside the entire coil, with poor heat dissipation conditions, which easily leads to excessive temperature rise of the low-voltage windings and affects the insulation life of the transformer.

[0003] The voltage level of the low-voltage windings is relatively low, and the electric field strength between the air ducts is not high either. Heat pipes can be placed at the air ducts of the low-voltage windings of dry-type transformers. By using the phase-change heat dissipation principle of heat pipes, the heat dissipation efficiency can be greatly improved, and the self-cooling temperature rise of the low-voltage windings can be effectively reduced. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-voltage winding structure of a dry-type transformer that uses heat pipes for heat dissipation at the air ducts, which can place detachable heat pipes at the air ducts of the low-voltage windings of dry-type transformers, and dissipate the heat of the low-voltage windings through the vaporization and heat absorption of the liquid medium inside the heat pipes. It has the advantages of high heat dissipation efficiency, maintenance-free, convenient disassembly and replacement, and reduced temperature rise of the low-voltage windings.

[0005] The technical solution adopted by the present invention is specifically as follows:

[0006] A low-voltage winding structure of a dry-type transformer that uses heat pipes for heat dissipation at the air ducts, including an iron core, with a low-voltage coil arranged on the outer edge of the iron core, a high-voltage coil arranged on the outer edge of the low-voltage coil, and a support strip curtain arranged inside the low-voltage coil;

[0007] Heat pipes are arranged inside the support strip curtain, the lower ends of the heat pipes are arranged inside the support strips, insulating support strips are arranged outside the support strips, and support plates are arranged between the heat pipes;

[0008] Liquid medium is arranged inside the heat pipes;

[0009] The support strip curtain includes insulating paper, and the overall support strip curtain is arranged in a sandwich curtain structure of "insulating paper - support strip - insulating paper";

[0010] The support strip curtain is arranged in a ring shape on the outer edge of the coil winding.

[0011] In a preferred embodiment, the overall material of the support strip is made of high thermal conductivity material.

[0012] In a preferred embodiment, grooves are opened on both sides of the support strip, the inside of the grooves is connected to heat pipe 1, and the bottom of the grooves is not penetrated.

[0013] In a preferred embodiment, through grooves are provided at both ends of the stay bar, and the through grooves form a heat dissipation channel.

[0014] In a preferred embodiment, an elastic rubber pad is provided on the joint surface between the heat pipe and the stay bar.

[0015] In a preferred embodiment, methanol or ethanol is used as the heat dissipation liquid inside the heat pipe 1 for the liquid medium.

[0016] In a preferred embodiment, 1% of graphene is also added to the liquid medium as a thermal conductive filler.

[0017] In a preferred embodiment, the stay bar curtain is designed in a segmented manner. The length of each segment of the stay bar curtain matches the axial dimension of the coil air duct, and the spacing of the stay bars in the transverse direction is accurately positioned according to the installation requirements of the heat pipes.

[0018] In a preferred embodiment, the upper end of the heat pipe is a heat dissipation end, and a plurality of heat dissipation fins are provided on the outer edge of the upper end of the heat pipe.

[0019] In a preferred embodiment, a black antirust paint is sprayed on the surface of the heat dissipation end of the heat pipe.

[0020] The technical effects achieved by the present invention are as follows:

[0021] The present invention significantly improves the heat dissipation efficiency through the phase change heat dissipation principle of the heat pipe. The liquid medium (such as methanol or ethanol) inside the heat pipe quickly vaporizes when the low-voltage winding generates heat, absorbs heat and migrates to the heat dissipation end through steam, and uses the synergistic effect of the heat dissipation fins and the black antirust paint coating to enhance heat radiation and convective heat transfer. The condensed liquid medium flows back to form a cycle, effectively reducing the temperature rise of the low-voltage winding. At the same time, the liquid medium with 1% graphene further optimizes the thermal conductivity, reduces the thermal resistance and the risk of local overheating, and ensures the long-term stable operation of the transformer;

[0022] The present invention adopts the "insulating paper - stay bar - insulating paper" sandwich curtain-shaped stay bar curtain design, combined with the segmented installation process, to accurately match the stay bar curtain with the coil air duct, simplify the winding process and improve the structural fit. The heat pipe is installed in a pluggable manner through the grooves on both sides of the stay bar, and the elastic rubber pad is used to buffer the thermal expansion stress, which is not only convenient for maintenance and replacement, but also enhances the insulation performance. In addition, this structure supports the transformation of existing transformers. By installing heat pipes and stay plates at the air duct, the heat dissipation capacity can be improved without overall disassembly, significantly reducing the transformation cost;

[0023] In the present invention, the struts are made of high - thermal - conductivity materials (such as aluminum alloy or graphite composite materials) to accelerate heat transfer, and combined with the design of through - grooves to form a heat - dissipation channel, taking into account both lightweight and efficient heat dissipation. The black antirust paint coating at the heat - dissipation end of the heat pipe extends the service life of the equipment by enhancing the infrared radiation ability and corrosion resistance. The selection of the liquid medium and the addition of graphene fillers further optimize the starting efficiency and heat - transfer uniformity of the heat pipe, ensuring the reliability and low maintenance requirements of the system under complex working conditions. Brief Description of the Drawings

[0024] Figure 1 FIG. is a schematic diagram of the low - voltage winding structure of a dry - type transformer with heat - pipe heat dissipation at the air duct in an embodiment of the present invention;

[0025] Figure 2 FIG. is a schematic diagram of the heat - pipe heat - dissipation structure and heat - dissipation principle in an embodiment of the present invention;

[0026] Figure 3 FIG. is a structural diagram of the heat - pipe transformation applied to a finished transformer in an embodiment of the present invention;

[0027] Figure 4 FIG. is a structural diagram of the heat - pipe strut curtain in an embodiment of the present invention;

[0028] Figure 5 FIG. is a schematic diagram of the installation of the strut curtain in an embodiment of the present invention.

[0029] In the drawings, the list of components represented by each reference numeral is as follows:

[0030] 1. Heat pipe; 2. Heat - dissipation fin; 3. Elastic rubber pad; 4. Strut; 5. Liquid medium; 6. Insulating strut; 7. Iron core; 8. High - voltage coil; 9. Low - voltage coil; 10. Support plate; 11. Insulating paper; 12. Strut curtain; 13. Coil winding. Detailed Embodiment

[0031] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made in conjunction with the accompanying drawings of the specification.

[0032] In the following description, many specific details are set forth to facilitate a thorough understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0033] Secondly, the "one embodiment" or "embodiment" mentioned herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The "in a preferred embodiment" that appears in different places in this specification does not all refer to the same embodiment, nor is it an individual or selectively mutually exclusive embodiment with other embodiments.

[0034] Next, the present invention is described in detail in conjunction with schematic diagrams. When detailing the embodiments of the present invention, for the convenience of explanation, the cross-sectional views showing the device structure will be locally enlarged out of the general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0035] Please refer to Figures 1 to 5 As shown, the present invention provides a low-voltage winding structure of a dry-type transformer using heat pipes for heat dissipation at the air duct, including an iron core 7. A low-voltage coil 9 is arranged on the outer edge of the iron core 7, a high-voltage coil 8 is arranged on the outer edge of the low-voltage coil 9, and a support bar curtain 12 is arranged inside the low-voltage coil 9;

[0036] A heat pipe 1 is arranged inside the support bar curtain 12. The lower end of the heat pipe 1 is arranged inside the support bar 4. An insulating support bar 6 is arranged outside the support bar 4, and the insulating support bar 6 plays a role in fixing and protecting the support bar 4. A support plate 10 is arranged between the heat pipes 1;

[0037] A liquid medium 5 is arranged inside the heat pipe 1;

[0038] The support bar curtain 12 includes insulating paper 11. The overall support bar curtain 12 is set as a sandwich curtain structure of "insulating paper 11 - support bar 4 - insulating paper 11". Two layers of insulating paper 11 made of epoxy resin and several aluminum alloy support bars 4 are prefabricated by a vacuum pressure impregnation process to form a standardized support bar curtain 12 assembly;

[0039] The support bar curtain 12 is arranged in a ring shape on the outer edge of the coil winding 13.

[0040] During the coil winding process, the support bar curtain 12 is directly laid on the already wound coil winding 13, and then the subsequent low-voltage coil 9 and high-voltage coil 8 are continuously wound on the support bar curtain 12, so that the support bar curtain 12 is naturally embedded inside the coil structure. This process simplifies the installation process, improves the installation efficiency of the support bar 4, and at the same time ensures the close fit between the support bar 4 and the conductor layer, reducing the thermal resistance of the heat conduction path;

[0041] At the heat absorption end of the heat pipe 1, the Joule heat and eddy current heat generated during the operation of the low-voltage coil 9 are absorbed, causing the liquid medium 5 inside the heat pipe 1 to undergo a phase change and vaporize. The vapor of the liquid medium 5 migrates axially along the heat pipe 1 under the drive of the pressure difference to the upper end, and releases the latent heat through the heat exchange between the upper end of the heat pipe 1 and the external air, causing the vapor of the liquid medium 5 to condense into a liquid. Subsequently, the liquid medium 5 falls back into the lower end of the heat pipe 1 under the combined action of the capillary pump force and gravity, forming a closed reflux path for the liquid medium 5 and completing the continuous heat transport cycle.

[0042] Meanwhile, the solution can also be used to transform the existing finished transformer by adding the heat pipe 1 at the air duct to improve the temperature rise of the low-voltage winding. The specific measures are as follows: Insulating paper 11 is padded on both sides of the air duct, two heat pipes 1 are placed, a spacer 10 is driven between the heat pipes 1 to tighten them, and then they are glued firmly.

[0043] Please refer to Figure 2 As shown, the overall material of the spacer 4 is set as a high thermal conductivity material, such as aluminum alloy, copper alloy or graphite composite material, which can significantly optimize the overall thermal performance of the heat pipe 1. Taking aluminum alloy as an example, a thermal bottleneck is easily formed at the contact interface between the spacer 4 and the heat pipe 1, while the high thermal conductivity material can accelerate the longitudinal transfer of heat from the evaporation section to the condensation section, reduce the interface temperature difference, and avoid local heat accumulation.

[0044] Please refer to Figure 2 As shown, grooves are opened on both sides of the spacer 4, the inside of the grooves is connected to the heat pipe 1, and the bottom of the grooves is not through. Through the design of the grooves, a pluggable installation method of the heat pipe 1 is realized, enabling maintenance personnel to quickly replace or clean the heat pipe 1 without disassembling the transformer, reducing the maintenance cost and difficulty.

[0045] Please refer to Figure 2 As shown, through grooves are provided at both ends of the spacer 4, and the through grooves form a heat dissipation channel. On the basis of expanding the effective heat dissipation area, synchronously improving the heat radiation and convective heat transfer efficiency not only increases the heat dissipation area of the metal spacer 4, but also achieves the purpose of light weight. Moreover, when the spacers 4 are arranged adjacent to each other, an air flow channel can also be formed through the through grooves, further increasing the heat dissipation efficiency.

[0046] Please refer to Figure 2 As shown, an elastic rubber pad 3 is provided on the joint surface between the heat pipe 1 and the spacer 4. By virtue of the elastic rubber pad 3 having both the functions of an insulating medium and mechanical stress buffering, the potential transfer between the heat pipe 1 and the spacer 4 can be effectively inhibited, and at the same time, the thermal expansion difference of the heat pipe 1 is compensated through elastic deformation to improve the structural stability.

[0047] Please refer to Figure 2As shown, methanol or ethanol is used as the heat-dissipating liquid inside the heat pipe 1 for the liquid medium 5; the core advantage of using methanol or ethanol as the liquid medium 5 in the heat pipe 1 lies in its excellent phase-change characteristics and adaptability: the low boiling points of both, methanol at 64.7 °C and ethanol at 78.4 °C, can quickly vaporize and transfer heat in medium- and low-temperature scenarios, and combined with the low surface tensions of methanol at 22.1 mN / m and ethanol at 22.3 mN / m, it significantly enhances the capillary reflux ability and improves the start-up efficiency of the heat pipe 1.

[0048] Please refer to Figure 2 As shown, 1% of graphene is also added to the liquid medium 5 as a thermal conductive filler. Further, on the basis of using methanol or ethanol as the liquid medium of the heat pipe 1, adding 1% of graphene as a thermal conductive filler can significantly improve the performance of the heat pipe 1: the high thermal conductivity of graphene, about 5000 W / mK, builds a nano-thermal conductive network, greatly enhancing the heat conduction efficiency of the working fluid, reducing the thermal resistance and accelerating the phase-change cycle, thereby improving the thermal response speed and heat transfer uniformity and reducing the risk of local overheating.

[0049] Please refer to Figure 4 and Figure 5 As shown, the stay curtain 12 adopts a segmented design. The length of each stay curtain 12 matches the axial dimension of the coil air duct, and the spacing of the transverse stays 4 is accurately positioned according to the installation requirements of the heat pipe 1, so as to facilitate providing an accurate installation position during the installation of the heat pipe 1, and thus facilitate the operator to accurately install the heat pipe 1.

[0050] Please refer to Figures 1 to 5 As shown, the upper end of the heat pipe 1 is the heat-dissipating end, and multiple heat-dissipating fins 2 are provided on the outer edge of the upper end of the heat pipe 1. Multiple fins are evenly arranged to form a continuous heat-dissipating surface, which can optimize the air flow channel and increase the contact area between the heat pipe 1 and the air. Under natural convection conditions, it can not only strengthen the heat radiation ability but also promote air turbulent motion, thereby significantly improving the overall heat dissipation efficiency of the heat pipe 1. This structural design takes into account both heat dissipation performance and space utilization.

[0051] Please refer to Figures 1 to 5 As shown, the surface of the heat-dissipating end of the heat pipe 1 is sprayed with black anti-rust paint. After the surface of the heat-dissipating end of the heat pipe 1 undergoes multi-stage pretreatment, an advanced coating process is used to apply a dark protective coating;

[0052] This composite coating system is composed of a polymer resin substrate and a radiation-enhancing material, and forms a dense protective structure through a layered curing process;

[0053] The coating not only meets the anti-corrosion requirements in harsh environments, but its special surface morphology and material ratio significantly improve the infrared radiation characteristics;

[0054] On the surface of the heat dissipation end, the processed coating and the fin geometric features produce a synergistic effect, and through the dual action mechanisms of enhancing the heat radiation capacity and optimizing the convective heat transfer, the heat dissipation capacity of the heat dissipation system is integrally improved.

[0055] The working principle of the present invention is as follows: during the coil winding process, the support bar curtain 12 is directly laid on the already wound coil winding 13, and then the subsequent low-voltage coil 9 and high-voltage coil 8 are continuously wound on the support bar curtain 12, so that the support bar curtain 12 is naturally embedded inside the coil structure. This process simplifies the installation process, improves the installation efficiency of the support bar 4, and at the same time ensures the tight fit between the support bar 4 and the wire layer, reducing the thermal resistance of the heat conduction path;

[0056] At the heat absorption end of the heat pipe 1, the Joule heat and eddy current heat generated during the operation of the low-voltage coil 9 are absorbed, causing the phase change and vaporization of the liquid medium 5 inside the heat pipe 1. The vapor of the liquid medium 5 migrates axially along the heat pipe 1 to the upper end under the drive of the pressure difference, and releases the latent heat through the heat exchange between the upper end of the heat pipe 1 and the external air, so that the vapor of the liquid medium 5 condenses into a liquid. Subsequently, the liquid medium 5 falls back into the lower end of the heat pipe 1 under the combined action of the capillary pumping force and gravity, forming a closed return path of the liquid medium 5 to complete the continuous heat transport cycle.

[0057] At the same time, the solution can also be used to transform the existing transformer finished product by adding the heat pipe 1 at the air duct to improve the temperature rise of the low-voltage winding. The specific measures are as follows: insulating paper 11 is padded on both sides of the air duct, two heat pipes 1 are placed, a support plate 10 is driven between the heat pipes 1 to tighten, and then it is glued firmly.

[0058] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. The structures, devices, and operation methods not specifically described and explained in the present invention are implemented according to the conventional means in the art without special description and limitation.

Claims

1. A low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct, characterized in that: It includes an iron core (7), a low-voltage coil (9) is arranged on the outer edge of the iron core (7), a high-voltage coil (8) is arranged on the outer edge of the low-voltage coil (9), and a support strip curtain (12) is arranged inside the low-voltage coil (9); A heat pipe (1) is arranged inside the support strip curtain (12), the lower end of the heat pipe (1) is arranged inside a support strip (4), an insulating support strip (6) is arranged outside the support strip (4), and a support plate (10) is arranged between the heat pipes (1); A liquid medium (5) is arranged inside the heat pipe (1); The support strip curtain (12) includes insulating paper (11), and the whole support strip curtain (12) is arranged in a sandwich curtain structure of "insulating paper (11)-support strip (4)-insulating paper (11)"; The support strip curtain (12) is arranged in a ring shape on the outer edge of the coil winding (13).

2. The low-voltage winding structure of a dry-type transformer with heat pipe heat dissipation at the air duct according to claim 1, characterized in that: The whole material of the support strip (4) is set as a high thermal conductivity material.

3. The low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct according to claim 1, characterized in that: Grooves are opened on both sides of the support strip (4), the inside of the grooves is connected to the heat pipe 1, and the bottom of the grooves is not penetrated.

4. A low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct according to claim 1, characterized in that: Through grooves are arranged at both ends of the support strip (4), and the through grooves form a heat dissipation channel.

5. The low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct according to claim 1, characterized in that: An elastic rubber pad (3) is arranged on the joint surface between the heat pipe (1) and the support strip (4).

6. The low-voltage winding structure of a dry-type transformer that uses a heat pipe for heat dissipation at the air duct according to claim 1, characterized in that: The liquid medium (5) uses methanol or ethanol as the heat dissipation liquid inside the heat pipe 1.

7. A low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct according to claim 1, characterized in that: 1% of graphene is also added to the liquid medium (5) as a thermal conductivity filler.

8. The low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct according to claim 1, characterized in that: The support strip curtain (12) adopts a segmented design, the length of each support strip curtain (12) matches the axial dimension of the coil air duct, and the spacing of the horizontal support strips (4) is accurately positioned according to the installation requirements of the heat pipes (1).

9. The low-voltage winding structure of a dry-type transformer using a heat pipe for heat dissipation at the air duct according to claim 1, wherein: The upper end of the heat pipe (1) is a heat dissipation end, and a plurality of heat dissipation fins (2) are arranged on the outer edge of the upper end of the heat pipe (1).

10. The low-voltage winding structure of a dry-type transformer with heat pipe heat dissipation at the air duct according to claim 1, characterized in that: The surface of the heat dissipation end of the heat pipe (1) is sprayed with black antirust paint.

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