JP2019096782A - Oil-filled transformer - Google Patents

Abstract

To provide an oil-filled transformer that improves heat radiation efficiency and cooling performance by arranging a material with good heat conduction efficiency in a tank of the oil-filled transformer.SOLUTION: An oil-filled transformer 1 includes: an iron core 12; a coil 11 wound around the iron core 12; a tank 14 containing the iron core 12 and the coil 11; and an insulating oil 13 put in tank 14 so as to immerse the iron core 12 and the coil 11. A heat transfer plate 21 having a thermal conductivity higher than that of the insulating oil 13 is provided between the coil 11 and the inside of the tank 14.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cooling structure of an oil-filled transformer.

Oil-filled transformers mainly consist of iron cores, coils, insulating oil and tanks.
Heat is generated due to resistance loss in the coil section and iron loss in the iron core section, and the temperature inside the transformer rises. The heat generated in the coil or core moves to the tank wall by the convection of the insulating oil, and is dissipated to the outside by the convection of air from the surface of the tank.

  In order to improve the cooling performance, it is conceivable to change the number and height of the wave ribs formed on the tank wall to increase the heat radiation area, but this means increasing the size of the transformer and increasing the mass Lead to

  In order to improve the cooling performance, in the oil-filled transformer disclosed in Patent Document 1, the heat collecting portion immersed or floating in the electrically insulating oil inside the tank and the outside of the cover provided on the upper portion of the tank A structure has been proposed in which the heat in the tank is dissipated to the outside of the tank by a heat dissipating mechanism constituted by a heat dissipating portion disposed in the heat dissipating portion and a heat dissipating portion transferring the heat collected by the heat collecting portion to the heat dissipating portion.

JP, 2017-135324, A

Patent Document 1 describes a cooling structure constituted by a heat dissipating portion at the top of the cover, a heat collecting portion at the bottom of the cover, and a heat transfer portion for transferring the heat collected by the heat collecting portion to the heat dissipating portion.
However, changing the appearance of the transformer is highly difficult for product application. In addition, since there is a connecting wire in the space from the upper part of the coil to the lower part of the cover, it is difficult to secure the occupied area of the heat collecting portion from securing the insulation distance.

  An object of the present invention is to provide an oil-impregnated transformer that improves heat dissipation efficiency and cooling performance by arranging a material with high thermal conductivity in a tank of a transformer.

If an example of the "oil-filled transformer" of the present invention for solving the above-mentioned subject is mentioned,
An oil-filled transformer comprising: an iron core; a coil wound around the iron core; a tank for containing the iron core and the coil; and an insulating oil placed in the tank so as to immerse the iron core and the coil. Inside the tank, a heat transfer plate having a thermal conductivity higher than that of the insulating oil is provided between the tank and the coil.

  According to the present invention, in the oil-filled transformer, the heat transfer efficiency can be enhanced and the cooling performance can be improved by arranging the heat transfer plate having a thermal conductivity better than the insulating oil in the tank.

  Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

BRIEF DESCRIPTION OF THE DRAWINGS Front sectional drawing which shows the oil-impregnated transformer of Example 1 of this invention. FIG. 2 shows a heat transfer plate of the oil-impregnated transformer of the first embodiment. The top view and front sectional view which show an example of the fixing method of a heat exchanger plate. The top sectional drawing which shows the oil-impregnated transformer of Example 2 of this invention. The figure which shows the heat exchanger plate of the oil-impregnated transformer of Example 2. FIG. The plane sectional view showing the oil immersion transformer of Example 3 of the present invention. The figure which shows the heat exchanger plate of the oil-impregnated transformer of Example 3. FIG. The plane sectional view which shows the oil-impregnated transformer of Example 4 of this invention. The side sectional drawing which shows the oil-impregnated transformer of Example 4 of this invention. FIG. 14 is an enlarged plan cross-sectional view showing the heat transfer plate portion of Example 4; The top sectional drawing which shows the oil-impregnated transformer of Example 5 of this invention. The figure which shows the heat exchanger plate of the oil-impregnated transformer of Example 5. FIG. The figure which shows the oil-impregnated transformer of Example 6 of this invention. The figure which shows the other example of the oil-impregnated transformer of Example 6 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the drawings for explaining the embodiments, the same components are denoted by the same names and reference numerals, and the repetitive description thereof will be omitted.

  Hereinafter, an oil-filled transformer according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 is a schematic front cross-sectional view of the oil-filled transformer of the first embodiment. The oil filled transformer 1 includes an iron core 12, a coil 11, an insulating oil 13 and a tank 14. The tank 14 contains an iron core-coil assembly and is filled with an insulating oil 13 so as to dip the iron core-coil assembly. A cover 15 is provided on the top of the tank 14 so as to cover the opening. The tank 14 is formed of, for example, a steel plate, and the side surface portion of the tank 14 is configured of a flat side plate portion 141 and a wave rib portion 142 formed in a wave shape.

  In the present embodiment, the heat transfer plate 21 is disposed from the upper portion to the lower portion of the tank 14 so as to be in full or partial contact with the inside of the side plate portion 141 of the tank. The heat transfer plate 21 is configured using a metal material such as aluminum or copper whose thermal conductivity is better than that of the insulating oil 13.

During the operation of the oil-filled transformer, the temperature of the upper part of the insulating oil 13 is higher than that of the lower part in the tank 14. By providing the heat transfer plate 21 from the upper portion to the lower portion of the tank 14, the heat of the insulating oil 13 in the upper layer inside the tank is dissipated to the lower layer to disperse the high temperature portions of the insulating oil. The cooling efficiency of the
Further, by providing the heat transfer plate 21 inside the tank, the heat of the heat source such as the coil 11 and the iron core 12 is collected by the heat transfer plate 21 through the insulating oil 13 and brought into contact with the inner wall surface of the tank. Since heat can be transferred from the plate 21 to the tank wall, the heat radiation efficiency can be enhanced and the cooling performance can be improved.
The tank can be applied to any of round and rectangular tank shapes.

  FIG. 2 shows the structure of the heat transfer plate of the first embodiment. Fig.2 (a) shows the plane sectional view of the oil-impregnated transformer which attached the heat-transfer plate, FIG.2 (b) (c) shows the front view and top view of the heat-transfer plate divided into two respectively. As shown in FIG. 2 (a), the tank has a round tank shape, one side of the tank is provided with a wave rib, and the other side is not provided with a wave rib. The heat transfer plate is composed of divided heat transfer plates 21 a and 21 b so that the attachment work to the tank 14 can be easily performed. 2B shows the heat transfer plate 21a overlapping the side wall not provided with the wave rib portion, and FIG. 2C shows the heat transfer plate 21b overlapping the side wall provided with the wave rib portion 142. In the heat transfer plate 21b overlapping the wave rib portion 142, the opening portion 211 is provided at a position corresponding to the wave rib so as not to inhibit the flow of the insulating oil 13 into the hollow portion of the wave rib. As a result, heat can be dissipated by the wave rib portion 142 without inhibiting the convection of the insulating oil 13.

  FIG. 3 shows an example of a method of attaching the heat transfer plate. Fig.3 (a) is the plane sectional view which attached the heat exchanger plate 21, FIG.3 (b) shows front sectional drawing. The heat transfer plate 21 is inserted between the guide 31 provided on the tank bottom plate portion 143 and the stopper 32 provided on the tank side plate portion 141 and between the inner wall surface of the tank and the studs and nuts 33 provided on the tank side plate portion 141 The heat transfer plate 21 is then tightened and fixed. In the illustrated example, one side of the heat transfer plate 21 is supported by a stopper 32 and the other side is fixed by a stud and a nut 33. By providing a plurality of fixed portions, the adhesion between the heat transfer plate 21 and the tank 14 can be enhanced, and the heat transfer efficiency can be enhanced. In addition, the attachment method of a heat exchanger plate is not restricted to this.

  According to this embodiment, in the oil-impregnated transformer, the heat transfer efficiency is improved and the cooling performance is improved by arranging the heat transfer plate having a thermal conductivity better than the insulating oil so as to be in contact with the inside of the side plate portion of the tank. It can be done.

  A second embodiment of the present invention will be described with reference to FIGS. 4A and 4B. The second embodiment is the same as the first embodiment in that the heat transfer plate is provided on the inner wall portion of the tank, but differs in the structure of the heat transfer plate.

  FIG. 4A shows a plan sectional view of the oil-impregnated transformer to which the heat transfer plate of the present embodiment is attached, and FIG. 4B shows the structure of the heat transfer plate of the present embodiment. A central portion of the heat transfer plate 21 is formed in a shape along the outer periphery of the coil 11, and the heat transfer plate 21 is closer to the coil 11 as a heat generating portion. The end of the heat transfer plate 21 is in contact with the inner wall of the tank 14 and is configured to be able to transfer heat to the tank 14. As shown in FIG. 4B, a large number of openings 211 are provided in the central portion of the heat transfer plate 21. The insulating oil can pass through the openings and is configured not to inhibit convection.

  According to the present embodiment, the heat transfer plate 21 has a shape along the outer periphery of the coil 11 and is disposed close to the coil, whereby the heat transfer plate collects heat near the heat source portion via the insulating oil, and the tank wall The heat can be efficiently transferred to the part, the heat radiation efficiency can be enhanced, and the cooling performance can be improved.

  A third embodiment of the present invention will be described with reference to FIGS. 5A and 5B. The third embodiment is the same as the first and second embodiments in that the heat transfer plate is provided on the inner wall portion of the tank, but differs in the structure of the heat transfer plate.

  FIG. 5A shows a plan sectional view of the oil-impregnated transformer to which the heat transfer plate of this embodiment is attached, and FIG. 5B shows the structure of the heat transfer plate of this embodiment. A folded portion 212 obtained by folding the heat transfer plate into a corrugated shape is provided at the central portion of the heat transfer plate 21, and the folded portion 212 is disposed so as to approach the coil 11 which is a heat generating portion. The end of the heat transfer plate 21 is in contact with the inner wall of the tank 14 and is configured to be able to transfer heat to the tank 14.

  According to the present embodiment, the heat transfer plate can be used as a heat transfer medium to efficiently transfer heat near the heat source to the tank wall by providing the heat transfer plate as a heat transfer medium. Thus, the heat dissipation efficiency can be enhanced and the cooling performance can be improved. In addition, since the surface area is increased by forming the corrugated folding shape, the heat transfer efficiency is improved.

  A fourth embodiment of the present invention will be described with reference to FIGS. 6A to 6C. The fourth embodiment is the same as the first, second, and third embodiments in that a heat transfer plate is provided on the inner wall of the tank, but differs in the structure of the heat transfer plate.

  6A shows a plan sectional view of the oil-impregnated transformer to which the heat transfer plate of the present embodiment is attached, FIG. 6B shows a side sectional view, and FIG. 6C shows an enlarged plan sectional view of the heat transfer plate portion. In the present embodiment, one side of the plate-like heat transfer plate 21 is contained in the hollow portion of the wave rib 142 provided on the side wall of the tank, and the other side of the heat transfer plate 21 is close to the coil 11 which is a heat generating portion. It extends. The heat generated by the coil 11 and the like is transferred to the heat transfer plate 21 via the insulating oil 13, transferred to the wave rib portion 142 of the tank by the heat transfer plate 21, and dissipated from the wave rib portion to the outside.

  FIG. 6C shows an enlarged plan sectional view of the heat transfer plate portion. The heat transfer plate 21 is fixed by pressing and caulking with the press jig 41 in a state in which the heat transfer plate 21 is inserted in the hollow portion of the wave rib portion 142.

  According to this embodiment, the heat transfer plate can be used as a heat transfer medium to efficiently transfer the heat in the vicinity of the heat source to the wave rib, so that the heat radiation efficiency can be enhanced and the cooling performance can be improved.

  A fifth embodiment of the present invention will be described with reference to FIGS. 7A and 7B. The fifth embodiment is the same as the first embodiment in that a heat transfer plate is provided on the inner wall of the tank, but differs in the shape of the tank.

  FIG. 7A shows a plan sectional view of the oil-impregnated transformer to which the heat transfer plate of the present embodiment is attached, and FIG. 7B shows the structure of the heat transfer plate of the present embodiment. In the present embodiment, the shape of the tank is rectangular (in the plan sectional view, rectangular). Then, a flat heat transfer plate 21 shown in FIG. 7B is closely attached to the flat portion of the wall surface of the tank 14. The heat transfer plate 21 is provided with an opening 211 at a position corresponding to the wave rib so as not to inhibit the flow of the insulating oil 13 into the hollow portion of the wave rib. As shown to FIG. 7A, the heat exchanger plate 14 can be closely approached to the coil 11 which is a heat source by making a tank into a rectangular shape.

  According to this embodiment, by making the shape of the tank rectangular, it is possible to bring the heat transfer plate close to the coil and efficiently transfer the heat generated by the coil etc. to the wall of the tank, thereby enhancing the heat radiation efficiency. , Cooling performance can be improved.

  A sixth embodiment of the present invention will be described with reference to FIGS. 8A and 8B. The sixth embodiment is the same as the first embodiment in that a heat transfer plate is provided on the inner wall of the tank, but differs in the shape of the tank.

  In this embodiment, it has a tank shape without wave ribs. The round tank 43 without a wave rib is shown to FIG. 8A, (a) is a plane sectional view, (b) is a side sectional view. Further, FIG. 8B shows a rectangular tank 44 without a wave rib, (a) is a plan sectional view, and (b) is a side sectional view. Even in a tank without a wave rib, by providing the heat transfer plate 21 between the coil and the inside of the tank, the heat near the heat source can be efficiently transferred to the tank wall.

  In each of the above embodiments, a single-phase transformer has been described as an example, but the present invention may be used for other oil-filled transformers such as a three-phase tripod type or a three-phase five-leg type three-phase transformer it can.

Reference Signs List 1 oil filled transformer main body 11 coil 12 iron core 13 insulating oil 14 tank 141 tank side plate 142 wave rib 143 tank bottom plate 15 cover 21 heat transfer plate (aluminum plate)
211 opening portion 212 folding portion 31 guide 32 stopper 33 stud, nut 41 pressing jig

Claims (14)

An oil-filled transformer comprising: an iron core; a coil wound around the iron core; a tank for containing the iron core and the coil; and an insulating oil placed in the tank so as to immerse the iron core and the coil.
An oil filled transformer provided with a heat transfer plate having a thermal conductivity higher than that of the insulating oil between the inside of the tank and the coil. In the oil-filled transformer according to claim 1,
The material of the heat transfer plate is aluminum or copper. In the oil-filled transformer according to claim 1,
The oil-filled transformer, wherein the heat transfer plate is provided in close contact with the whole surface or a part of the inner wall surface of the tank. In the oil-filled transformer according to claim 3,
The side of the tank has a plurality of wave ribs,
An oil-filled transformer characterized in that an opening portion through which insulating oil passes is provided in a portion overlapping the hollow portion of the wave rib of the heat transfer plate. In the oil-filled transformer according to claim 1,
The oil-filled transformer, wherein the heat transfer plate partially has a shape along a coil shape, and a shape portion along the coil shape of the heat transfer plate is disposed close to the coil. In the oil-filled transformer according to claim 5,
An oil-filled transformer characterized in that an opening through which the insulating oil passes is provided in a portion of the heat transfer plate along the coil shape. In the oil-filled transformer according to claim 1,
An oil-filled transformer characterized in that the heat transfer plate has a corrugated fold so as to approach the coil. In the oil-filled transformer according to claim 1,
The side of the tank has a plurality of wave ribs,
One side of the heat transfer plate is disposed in the hollow portion of the wave rib, and the other side of the heat transfer plate is disposed so as to extend toward the coil. In the oil-filled transformer according to claim 8,
An oil-impregnated transformer characterized in that one side of the heat transfer plate is sandwiched in the hollow portion of the wave rib and crimped and fixed. In the oil-filled transformer according to claim 1,
An oil filled transformer characterized in that the shape of the tank is a round tank. In the oil-filled transformer according to claim 1,
An oil-filled transformer characterized in that the shape of the tank is a rectangular tank. In the oil-filled transformer according to claim 1,
An oil filled transformer characterized in that the heat transfer plate is constituted by a plurality of divided heat transfer plates. In the oil-filled transformer according to claim 1,
A guide provided on a tank bottom plate for guiding insertion of the heat transfer plate, and a stopper provided on a tank side plate;
An oil filled transformer comprising a stud and a nut provided on a tank side plate portion for clamping and fixing the heat transfer plate. An oil-impregnated transformer comprising: an iron core; a coil wound around the iron core; an insulating oil covering the iron core and the coil; and a tank covering the insulating oil,
An oil-filled transformer characterized in that a metal member having a thermal conductivity higher than that of the insulating oil is disposed between the iron core and the coil and the inner wall of the tank so as to contact the insulating oil. .

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