Gas-filled, oil-filled electrical equipment

Abstract

To provide gas-filled, oil-filled electrical equipment that facilitates the standardization of piping for pressure measurement. [Solution] The gas-filled oil-filled electrical equipment comprises an electrical equipment body, a tank housing the electrical equipment body, an insulating medium filled in the tank so that the entire electrical equipment body is submerged, a gas sealed in a positive pressure state in an upper space located above the insulating medium in the tank, a pressure gauge located outside the tank to measure the pressure of the gas, and piping connecting the pressure gauge and the upper space. The tank has a through hole formed in the thickness direction through the side of the tank below the liquid level of the insulating medium. The piping extends vertically within the tank. The upper end opening of the piping is located above the liquid level. The lower end of the piping protrudes outside the tank through the through hole.

Description

Technical Field

[0001] This embodiment of the present invention relates to a gas-sealed oil-filled electrical apparatus.

Background Art

[0002] For example, static induction apparatuses such as oil-filled insulating transformers are configured by housing a static induction apparatus main body having windings and an iron core in a tank together with an insulating medium such as insulating oil. Some of these apparatuses are configured such that a gas such as nitrogen gas is sealed at a positive pressure in the upper space inside the tank to prevent deterioration of the insulating medium. In this type of oil-filled transformer, if gas leakage occurs in the upper space inside the tank, there is a concern about deterioration of the insulating oil. Accordingly, a pressure gauge for measuring the pressure of the gas in the upper space of the tank is provided, to confirm that the pressure fluctuates within an appropriate range according to changes in oil temperature, and to periodically inspect that contact with the outside air is completely blocked.

[0003] In the case of a relatively large-sized oil-filled electrical apparatus, the height of the tank is large, so that the upper space inside the tank is located far above the eye level of a worker. Therefore, in the case of such a large tank, in order to facilitate visual confirmation of the pressure gauge by a worker, a pipe whose upper end communicates with the upper space is provided along the outer wall of the tank so as to extend downward, and the pressure gauge is provided at the lower end of the pipe.

[0004] For example, Patent Document 1 discloses an oil-filled electrical apparatus including: a tank in which an electrical apparatus main body is housed; insulating oil filled in the tank; an antioxidant gas sealed in a positive pressure state in a space above the insulating oil in the tank; a first pipe communicating with the upper space of the tank and extending to the outside of the tank; a sealed second pipe to which a distal end portion of the first pipe is connected; a third pipe configured to have a smaller diameter than the second pipe, extending in the vertical direction so as to airtightly penetrate a lower portion of the second pipe, and having an upper end portion positioned at an upper portion inside the second pipe; and a pressure gauge connected to the third pipe and configured to measure the pressure of the gas in the upper space of the tank.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-100407 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In the conventional configuration described in Patent Document 1, the piping for pressure measurement extends vertically from the height of the upper space to a height visible to the operator outside the tank. Typically, other components such as radiators and cable ducts are located outside the tank. To prevent interference between these components and the external piping, the arrangement and shape of the piping must be considered for each oil-filled electrical device, depending on the arrangement and dimensions of the other components.

[0007] Therefore, we provide a gas-filled, oil-filled electrical device that facilitates the standardization of piping for pressure measurement. [Means for solving the problem]

[0008] The gas-filled oil-filled electrical equipment of this embodiment comprises an electrical equipment body, a tank housing the electrical equipment body, an insulating medium filled in the tank so as to completely immerse the electrical equipment body, a gas sealed in a positive pressure state in an upper space located above the insulating medium within the tank, a pressure gauge positioned outside the tank to measure the pressure of the gas, and piping connecting the pressure gauge and the upper space. The tank has a through hole formed in the thickness direction through the side of the tank below the liquid level of the insulating medium. The piping extends vertically within the tank. The upper end opening of the piping is located above the liquid level. The lower end of the piping protrudes outside the tank through the through hole. [Brief explanation of the drawing]

[0009] [Figure 1]Schematic front view of an example in which a gas-filled oil-filled electrical device according to the first embodiment is applied to a transformer. [Figure 2] Longitudinal cross-sectional view shown along line II-II in Figure 1 [Figure 3] A schematic plan view showing the oil-filled transformer according to the first embodiment with the cover member removed. [Figure 4] A schematic perspective view partially showing the oil-filled transformer according to the first embodiment with the cover member removed. [Figure 5] Enlarged longitudinal cross-sectional side view showing the configuration around the first pipe in Figure 2. [Figure 6] A schematic perspective view partially showing the oil-filled transformer according to the second embodiment with the cover member removed. [Figure 7] A diagram showing the area around the first piping for the oil-filled transformer of the second embodiment (equivalent to Figure 5). [Figure 8] A diagram showing the area around the first piping for the oil-filled transformer of the third embodiment (equivalent to Figure 5). [Modes for carrying out the invention]

[0010] The following describes examples of applying gas-filled, oil-filled electrical equipment of multiple embodiments to transformers with reference to the drawings. In each embodiment, the same components are denoted by the same reference numerals and their descriptions are omitted.

[0011] (First Embodiment) The first embodiment will be described with reference to Figures 1 to 5. The transformer 10 shown in Figure 1 is, for example, an oil-filled transformer. In this embodiment, the transformer 10 is an oil-filled transformer, but is not limited to this. In the following description, the vertical direction with respect to the direction of gravity when the transformer 10 is installed on the floor in the position shown in Figure 1 will be referred to as the vertical direction of the transformer 10, the direction perpendicular to the plane of the paper in Figure 1 will be referred to as the front-to-back direction of the transformer 10, and the left-to-right direction in Figure 1 will be referred to as the left-to-right direction of the transformer 10.

[0012] As shown in Figures 1 and 2, the transformer 10 comprises a transformer body 11 as the main body of the electrical equipment, a tank 20, and a heat sink 30. The transformer body 11 is housed in a sealed tank 20. The heat sink 30 is configured in multiple units and is arranged on the side of the tank 20.

[0013] The transformer body 11 is composed of an iron core 12 and, for example, a three-phase coil 13 mounted on the iron core 12.

[0014] As shown in Figures 1 and 2, the tank 20 is formed in a generally rectangular box shape that is long in the front-to-back direction and houses the transformer body 11 inside. The tank 20 is composed of a tank body 21, a lid member 22, and a plurality of bushings 23. As shown in Figure 2, the tank body 21 is formed in a generally rectangular container shape with an open top. The tank body 21 has side portions 24 that form the front, rear, left, and right walls. The lid member 22 is formed in a plate shape that extends generally in the horizontal direction. The lid member 22 is detachably attached to the tank body 21 and opens and closes the opening at the top of the tank body 21. The lid member 22 may also be fixed to the tank body 21 by welding. The tank body 21 and the lid member 22 are made of metal members such as steel plates. The plurality of bushings 23 are arranged on the upper surface of the lid member 22 and connect lead wires (not shown) extending from each coil 13 of the transformer body 11 to external wires. Multiple bushings 23 may be arranged on the side surface 24 of the tank body 21.

[0015] The tank 20 is filled with an insulating medium M so that the entire transformer body 11 is submerged. The insulating medium M has insulating and cooling functions. The insulating medium M may be an insulating oil containing, for example, mineral oil or vegetable oil such as rapeseed oil, or it may be liquid silicone. Gas G is sealed in the space above the insulating medium M in the tank under positive pressure. Gas G is a gas that prevents oxidation of the insulating medium M, and is an inert gas such as nitrogen gas.

[0016] A through hole 25 is formed in the side surface portion 24 of the tank main body 21. The through hole 25 is an opening formed to penetrate the side surface portion 24 in the thickness direction. In the present embodiment, the through hole 25 is formed in the vertical middle portion of the front side surface portion 24. In this specification, the term "middle portion" is not necessarily limited to the center with respect to the vertical length dimension, and means a range including the relevant center. That is, the middle portion refers to at least a range that is not an edge portion.

[0017] The radiator 30 cools the insulating medium M in the tank 20 by heat exchange. The radiator 30 is configured to include an upper header 31, a lower header 32, and a plurality of heat radiation panels 33. The upper header 31 forms an inner hollow cylindrical shape extending in the left-right direction, and its distal end portion is connected to the upper end portion of each heat radiation panel 33. The lower header 32 forms an inner hollow cylindrical shape extending in the left-right direction, and its distal end portion is connected to the lower end portion of each heat radiation panel 33. The heat radiation panel 33 is formed in a thin sealed box shape in the left-right direction.

[0018] The base end portion 311 of each upper header 31 is connected to the side surface portion 24 at the upper part of the tank main body 21, below the liquid surface of the insulating medium M. The base end portion 321 of each lower header 32 is connected to the side surface portion 24 at the lower part of the tank main body 21, below the base end portion 311 of each upper header 31. The insulating medium M warmed by the heat generated by the transformer main body 11 inside the tank 20 flows into each heat radiation panel 33 through each upper header 31 of the radiator 30 by convection. The insulating medium M is cooled by exchanging heat with external air while descending inside the heat radiation panel 33. The insulating medium M that has flowed from the heat radiation panel 33 into the lower header 32 is returned into the tank 20 through the lower header 32. In this way, as the insulating medium M circulates, the insulating medium M in the tank 20 is cooled, and in turn the transformer main body 11 is cooled.

[0019] The transformer 10 further includes a pressure gauge 40. The pressure gauge 40 measures the pressure of the gas G sealed in the upper portion inside the tank 20. By confirming that the pressure of the gas G is appropriate, it can be indirectly verified that deterioration of the insulating medium M due to moisture absorption and oxidation is prevented. The pressure gauge 40 can be provided outside the tank 20, for example, at a position in front of the radiator 30 that is visible to an operator. In the present embodiment, the pressure gauge 40 is provided at an intermediate portion in the vertical direction of the radiator 30 on the right side.

[0020] The transformer 10 further includes a pipe 50. The pipe 50 connects from the upper space of the tank 20 to the pressure gauge 40 outside the tank 20, and guides the gas G to the pressure gauge 40 at a constant pressure. The pipe 50 is made of, for example, a metal member having high temperature resistance. In other embodiments, the pipe 50 may be made of, for example, a resin member having high temperature resistance.

[0021] As shown in Figure 2, the pipe 50 is configured to include a first pipe 51, a second pipe 52, a third pipe 53, a fourth pipe 54, and a branch pipe 55. The first pipe 51, the second pipe 52, the third pipe 53, the fourth pipe 54, and the branch pipe 55 are connected in this order, and communicate the upper space inside the tank 20 with the pressure gauge 40.

[0022] The first pipe 51 is a pipe extending from the upper space of the tank 20 to the outside of the tank 20. Regarding the flow of gas inside each of the pipes 51, 52, 53, 54, the portion closer to the upper space is referred to as a base end portion, and the portion closer to the pressure gauge 40 is referred to as a tip end portion. The base end portion of the second pipe 52 is connected to the tip end portion of the first pipe 51 protruding to the outside of the tank 20, and the tip end portion of the second pipe 52 is connected to the base end portion of the third pipe 53. In the present embodiment, the second pipe 52 is bent at approximately 90 degrees so as to change its path to the right from the tip end portion of the first pipe 51 that extends perpendicularly to the side surface portion 24, that is, forward. In other embodiments, the second pipe 52 may be bent at approximately 90 degrees so as to change its path to the left from the tip end portion of the first pipe 51.

[0023] The tip of the third pipe 53 is connected to the base end of the fourth pipe 54. In this embodiment, the third pipe 53 is bent at approximately 90 degrees from the tip of the second pipe 52, which extends horizontally in this case to the right, so as to change its course downwards. The tip of the fourth pipe 54 is connected to the pressure gauge 40. In this embodiment, the fourth pipe 54 is bent at approximately 90 degrees from the tip of the third pipe 53, which extends downwards, so as to change its course horizontally in this case forwards.

[0024] The branch pipe 55 branches downward from the middle of the forward portion of the fourth pipe 54. Since the branch pipe 55 is formed to protrude below each of the pipes 51, 52, 53, and 54 connected to the pressure gauge 40, even if insulating medium M enters the pipe 50, the invading insulating medium M is received by the branch pipe 55. By removing the detachable closing cap 56 that seals the end of the branch pipe 55, the invading insulating medium M can be discharged. In other words, the insulating medium M does not block each of the pipes 51, 52, 53, and 54. Therefore, the pressure gauge 40 can always measure the correct pressure.

[0025] As shown in Figures 3 and 4, the first pipe 51 is positioned in the corner C of the tank 20, indicated by the diagonal lines. Corner C is the corner of the rectangular tank 20 in a plan view, and is a part that does not overlap with the transformer body 11 in a plan view. Since the tank 20 is rectangular, while the coils 13 that make up the transformer body 11 are generally cylindrical, corner C is not used to house the tank body 21. By positioning the first pipe 51 in corner C, a sufficient insulation distance L can be secured between the transformer body 11 and the first pipe 51. Specifically, the first pipe 51 is positioned along the right side surface 24. The first pipe 51 may be fixed to the side surface 24 by welding or the like. This prevents the first pipe 51 from moving unintentionally.

[0026] As shown in Figures 4 and 5, the first pipe 51 extends vertically within the tank 20 from the upper space of the tank 20 to the through hole 25. The first pipe 51 is composed of a vertical section 511, a bent section 512, and a through section 513. The vertical section 511 is the portion that extends vertically downward from the upper space of the tank 20. An upper end opening 514 is formed at the upper end of the vertical section 511. The upper end opening 514 opens upward, connecting the inside of the first pipe 51 to the upper space of the tank 20. The lower end of the vertical section 511 is located below the liquid level of the insulating medium M. The bent section 512 connects the lower end of the vertical section 511 to the through section 513. The bent section 512 bends the lower end of the vertically extending first pipe 51 by approximately 90 degrees, so that it is directed horizontally, in this case forward. The base end of the through-section 513 is connected to the lower end of the bent section 512, and the tip of the through-section 513 is connected to the base end of the second pipe 52. The through-section 513 is formed to extend horizontally, in this case in the front-to-back direction, and is inserted into the through-hole 25, extending from the inside of the tank 20 to the outside of the tank 20.

[0027] At least the vertical portion 511, the bent portion 512, and the through portion 513 are integrally formed. In this case, integrally formed means that the individual parts, which are separated, are not connected by welding, fittings, inserts, etc., but are formed integrally from the beginning. This suppresses the risk of the insulating medium M entering the first pipe 51 in the portion immersed in the insulating medium M. In this embodiment, the vertical portion 511, the bent portion 512, and the through portion 513 are integrally formed by bending. In other embodiments, the vertical portion 511, the bent portion 512, and the through portion 513 may be integrally formed by machining or other methods.

[0028] The first pipe 51 and the second pipe 52, the second pipe 52 and the third pipe 53, the third pipe and the fourth pipe 54, the fourth pipe 54 and the pressure gauge 40, and the fourth pipe 54 and the branch pipe 55 may each be formed integrally, or they may be connected by welding, fittings, inserts, etc. In this embodiment, the first pipe 51 and the second pipe 52, the second pipe 52 and the third pipe 53, the third pipe and the fourth pipe 54, and the fourth pipe 54 and the pressure gauge 40 are connected by fittings. The fourth pipe 54 and the branch pipe 55 are connected by welding.

[0029] The upper opening 514 is located above the liquid level of the insulating medium M in the stationary transformer 10, at a distance greater than a predetermined distance. In this case, the predetermined distance can be set considering the rise in liquid level due to the operation of the transformer 10, vibrations and shocks during transportation and handling, and shaking due to earthquakes after installation. In other words, the upper opening 514 is located above the set maximum liquid level of the insulating medium M. The set maximum liquid level refers to the highest liquid level within the temperature range expected due to the operation of the transformer 10.

[0030] In this embodiment, the upper end opening 514 is formed such that the shape of the cut surface is generally horizontal. Since the cut is made perpendicular to the direction in which the first pipe 51 extends, the cutting work is easy and less material is wasted during cutting.

[0031] According to the embodiment described above, the transformer 10 as a gas-filled oil-filled electrical device comprises a transformer body 11 as the main body of the electrical device, a tank 20, an insulating medium M, a gas G, a pressure gauge 40, and piping 50. The tank 20 houses the transformer body 11 inside. The insulating medium M is filled into the tank 20 so that the entire transformer body 11 is submerged. The gas G is sealed in the upper space located above the insulating medium M within the tank 20 under positive pressure. The pressure gauge 40 is located outside the tank 20 to measure the pressure of the gas G. The piping 50 connects the pressure gauge 40 to the inside of the tank 20. A through hole 25 is formed in the side portion 24 of the tank 20, penetrating the side portion 24 in the thickness direction below the liquid level of the insulating medium M. The piping 50 extends vertically within the tank 20. The upper end opening 514 of the piping 50 is located above the liquid level. The lower end of the pipe 50 protrudes outside the tank 20 through the through hole 25.

[0032] According to this, the majority of the vertically extending piping 50 is located inside the tank 20. Therefore, the piping 50 is less likely to interfere with other components such as the heat sink 30 or cable ducts (not shown). Thus, a gas-filled oil-filled electrical device is provided in which the configuration of piping for measuring the pressure of the sealed gas can be standardized without relying on other components.

[0033] The tank 20 is formed in the shape of a rectangular box in plan view. The piping 50 is arranged extending vertically at the corner C inside the tank 20.

[0034] According to this, the dead space in the corners of the tank 20 can be effectively utilized. Furthermore, by arranging the piping 50 in the corners, the insulation distance between the transformer body 11 and the piping 50 can also be ensured.

[0035] In this configuration, where the piping 50 is immersed in the insulating medium M within the tank 20, there is a non-zero possibility that the insulating medium M may enter the piping 50 through welds, joints, or connections made by fittings. On the other hand, since most of the piping 50 is located inside the sealed tank 20, inspection of the connection points is not easy.

[0036] In contrast, the piping 50 has at least a vertical section 511 extending vertically within the tank 20, a through section 513 inserted into the through hole, and a bent section 512 connecting the vertical section 511 and the through section 153. The vertical section 511, the bent section 512, and the through section 513 are formed integrally.

[0037] According to this, since the tank 20 is connected at least from the upper space to the outside by a first pipe 51 that is integrally formed, it is possible to suppress the intrusion of the insulating medium M into the first pipe 51 inside the tank 20. Therefore, the effort required to inspect the pipe 50, especially the first pipe 51, can be reduced.

[0038] (Second Embodiment) A second embodiment will be described with reference to Figures 6 and 7. In this embodiment, the first pipe 51 is configured to include a vertical section 511, a bent section 512, a through section 513, and an additional upper bent section 515.

[0039] The upper bent section 515 is provided on the base end side of the first pipe 51 and is connected to the upper end of the vertical section 511. The upper bent section 515 is formed to extend approximately 180 degrees from the upper end of the vertical section 511, which extends in the vertical direction. In this embodiment, the upper bent section 515 is formed in an inverted U shape. The entire upper bent section 515 is located in the upper space.

[0040] An upper end opening 516 is formed at the tip of the upper bent portion 515. The upper end opening 516 connects the inside of the first pipe 51 to the upper space. In this embodiment, the upper end opening 516 opens downward. The upper end opening 516 is located at a predetermined distance or more above the liquid level of the insulating medium M in a stationary state. This prevents the insulating medium M from entering the inside of the pipe 51 from the upper end opening 516. In this embodiment, the upper end opening 516 is formed such that the shape of the cut surface is generally parallel to the horizontal direction.

[0041] In this embodiment, the vertical portion 511 and the upper bent portion 515 are integrally formed. However, if the connection point between the vertical portion 511 and the upper bent portion 515 is located above a predetermined distance above the liquid surface of the insulating medium M, the vertical portion 511 and the upper bent portion 515 may be connected by welding or the like.

[0042] The embodiment described above also achieves the same effects as the embodiment described above.

[0043] According to the gas-filled oil-filled transformer 10 of this embodiment, the piping 50 has at least a vertical portion 511 extending vertically within the tank 20 and an upper bent portion 515 that bends in an inverted U shape between the vertical portion 511 and the upper end opening 516. The upper end opening 516 opens downward.

[0044] According to this, even if the upper end opening 516 were to come into contact with the insulating medium M, since the upper end opening 516 opens downwards, the insulating medium M would be discharged from the upper end opening 516 to the outside of the piping 51. Therefore, the intrusion of the insulating medium M into the piping 50 is suppressed.

[0045] (Third embodiment) A third embodiment will be described with reference to Figure 8. In this embodiment, the first pipe 51 has an upper end opening 517 at the upper end of the vertical portion 511.

[0046] The upper end opening 517 opens upward, connecting the inside of the first pipe 51 to the upper space. Furthermore, the upper end opening 517 is formed so that the shape of its cut surface is not parallel to the lower surface of the lid member 22. In this way, even if the upper end opening 517 is located very close to the lower surface of the lid member 22, the entire surface of the upper end opening 517 does not come into contact with the lower surface of the lid member 22, thereby preventing the communication between the first pipe 51 and the upper space from being obstructed. In this embodiment, while the lower surface of the lid member 22 extends horizontally, the shape of the cut surface of the upper end opening 517 is formed to be inclined with respect to the horizontal direction. In other embodiments, the cut surface of the upper end opening 517 may be provided with irregularities so that the cut surface of the upper end opening 517 is not flat. This also prevents the entire surface of the upper end opening 517 from coming into contact with the lower surface of the lid member 22.

[0047] The embodiment described above also achieves the same effects as the embodiment described above.

[0048] According to this embodiment, the upper end opening 517 is formed facing upward and forms an inclined surface with respect to the ceiling surface of the tank, that is, the lower surface of the lid member.

[0049] According to this, the entire surface of the upper end opening 517 does not come into contact with the lower surface of the lid member 22, thus preventing the first pipe 51 from being obstructed from communicating with the upper space due to contact between the upper end opening 517 and the lid member 22. Therefore, communication between the pipe 50 and the upper space can be ensured, and the pressure of the gas G can be accurately detected.

[0050] Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0051] 10... Transformer (gas-filled, oil-filled electrical equipment), 11... Transformer body (electrical equipment body), 20... Tank, 21... Tank body, 24... Side section, 25... Through hole, 40... Pressure gauge, 50... Piping, 51... First piping (piping), 511... Vertical section, 512... Bent section, 513... Through section, 514... Upper end opening, 515... Upper bend section, 516... Upper end opening, 517... Upper end opening

Claims

1. The electrical equipment itself, A tank that houses the main body of the aforementioned electrical equipment, An insulating medium is filled into the tank so that the entire body of the electrical equipment is submerged, A gas is sealed in a positive pressure state in the upper space located above the insulating medium within the tank, A pressure gauge placed outside the tank to measure the pressure of the gas, The system includes a piping that connects the pressure gauge and the upper space, A through hole is formed in the side surface of the tank, below the liquid level of the insulating medium, and penetrating the side surface in the thickness direction. The aforementioned piping extends vertically within the tank, The upper end opening of the aforementioned pipe is located above the liquid level. The lower end of the aforementioned pipe protrudes outside the tank through the through hole. Gas-filled, oil-filled electrical equipment.

2. The tank is formed in the shape of a rectangular box in plan view, The aforementioned piping is arranged to extend vertically at the corners within the tank. The gas-filled, oil-filled electrical equipment according to claim 1.

3. The piping has at least a vertical portion extending vertically within the tank, a through portion inserted into the through hole, and a bent portion connecting the vertical portion and the through portion. The vertical portion, the bent portion, and the through portion are formed integrally. The gas-filled, oil-filled electrical equipment according to claim 1.

4. The piping has at least a vertical portion extending vertically within the tank and an upper bent portion that bends in an inverted U shape between the vertical portion and the upper end opening. The upper end opening opens downwards. The gas-filled, oil-filled electrical equipment according to claim 1.

5. The upper end opening is formed facing upward and forms a surface that is inclined with respect to the ceiling surface of the tank. The gas-filled, oil-filled electrical equipment according to claim 1.

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