JP2023100407A - Oil containing electric apparatus - Google Patents

Abstract

To always measure correct pressure by a pressure gauge by preventing an insulation oil from intruding into a piping in an oil containing electric apparatus provided with the pressure gauge for measuring the pressure of gas sealed in an upper space in a tank.SOLUTION: An oil containing electric apparatus includes: a tank storing an electric apparatus body; an insulation oil filled in the tank; gas for antioxidation sealed in an upper space above the insulation oil in the tank in a positive pressure state; first piping communicating with the upper space in the tank and extending outside the tank; sealed second piping with a tip part of the first piping connected thereto; third piping configured with a diameter smaller than that of the second piping and vertically extending so as to hermetically penetrate a lower part of the second piping with an upper end positioned on an upper part of the second piping; and a pressure gauge connected to the third piping to measure the pressure of the gas in the upper space in the tank.SELECTED DRAWING: Figure 1

Description

An embodiment of the present invention relates to an oil-filled electrical device in which an electrical device body is housed in a tank together with insulating oil.

In oil-filled electrical equipment, such as oil-filled transformers for high-voltage power receiving and distributing equipment, the main body of the transformer is housed in a sealed tank together with insulating oil, and the upper space in the tank prevents deterioration of the insulating oil. There is a configuration in which nitrogen gas is sealed at a positive pressure for the purpose (see, for example, Patent Literature 1). In this type of oil-filled transformer, if nitrogen gas leaks from the upper space in the tank, the insulating oil will deteriorate. Therefore, a pressure gauge for measuring the pressure of the nitrogen gas in the upper space of the tank is provided, and it is regularly checked that the pressure gauge detects a positive pressure state.

In this case, in the case of a relatively small tank, even if the pressure gauge is installed on the outer wall of the tank, the operator can check it as it is. Due to the increase in size, the upper space comes to a position considerably above the height of the operator's line of sight. Therefore, in the case of such a large tank, in order for the operator to visually check the pressure gauge, a pipe whose upper end communicates with the upper space is provided so as to extend downward along the outer wall of the tank. A pressure gauge has been provided at the lower end of the pipe.

Japanese Utility Model Laid-Open No. 56-132719

However, in the above-described conventional configuration, there is a risk that the insulating oil may enter the pipe leading to the pressure gauge due to fluctuations or inclinations of the oil surface due to vibrations during transportation or earthquakes. If insulating oil intrudes into the piping, problems such as inability to measure correct pressure and damage to the pressure gauge occur.

Therefore, in those equipped with a pressure gauge that measures the pressure of the gas enclosed in the upper space in the tank, it is necessary to prevent problems caused by the intrusion of insulating oil into the piping and always measure the correct pressure with the pressure gauge. To provide an oil-filled electrical device capable of

An oil-filled electrical device according to an embodiment includes a tank in which a main body of the electrical device is housed, an insulating oil filled in the tank, and an oxidizer sealed in a space above the insulating oil in the tank in a positive pressure state. a gas for prevention, 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 the tip of the first pipe is connected, the second pipe A third pipe having a diameter smaller than that of the second pipe, extending vertically so as to airtightly penetrate the lower portion of the second pipe, and having an upper end positioned above the second pipe. and a pressure gauge connected to the third pipe for measuring the pressure of the gas in the upper space of the tank.

FIG. 1 shows an embodiment, and is a front view schematically showing the overall configuration of an oil-immersed transformer. Enlarged front view of upper part of piping Enlarged front view of the lower part of the piping part

An embodiment applied to an oil-filled transformer, which is an oil-filled static induction device for high-voltage power receiving and distribution equipment, will be described below with reference to the drawings. FIG. 1 shows the overall configuration of an oil-filled transformer 1 (hereinafter simply referred to as "transformer 1") as an oil-filled electrical device according to this embodiment. This transformer 1 is constructed by housing a transformer main body 2 as an electrical equipment main body in a sealed tank 3, and on the left and right sides of the tank 3 in FIG. A heat sink 4 is connected.

Although not shown in detail, the transformer main body 2 has a well-known configuration including an iron core and three-phase coils attached to the iron core. The tank 3 is in the shape of a rectangular box slightly elongated in the front-rear direction in the drawing, and is filled with insulating oil M such as mineral oil for insulation and cooling so that the entire transformer main body 2 is immersed therein. ing. At this time, the tank 3 is positioned in the upper space 5 of the insulating oil M, and a gas for preventing oxidation of the insulating oil M, such as nitrogen gas, is sealed in a positive pressure state. A plurality of bushings 6 for connecting each coil of the transformer main body 2 and the outside are provided on the upper surface of the tank 3 .

Each unit of the radiator 4 is for cooling the insulating oil M in the tank 3 by heat exchange. It is provided with a plurality of heat radiation panels 9 that connect the . Among them, the upper header 7 has a shape of a cylindrical pipe extending in the horizontal direction in the drawing, and the tip side thereof is connected to the upper end portion of each heat radiation panel 9 . The lower header 8 is also shaped like a cylindrical pipe extending in the left-right direction in the drawing, and the tip side thereof is connected to the lower end of each heat radiation panel 9 . The heat radiation panel 9 has a thin closed box shape in the horizontal direction in the figure.

The base end of each upper header 7 is connected to a portion lower than the upper space 5 at a portion closer to the upper part of the side surface of the tank 3 , and the base end of each upper header 7 is connected to the side surface of the tank 3 . connected to the lower end of the Thus, the insulating oil M heated in the tank 3 by the heat of the transformer main body 2 flows into each radiator panel 9 through each upper header 7 of the radiator 4 by convection. The insulating oil M descends inside the heat radiation panel 9 and is cooled by heat exchange with the outside. Thereafter, circulation is performed such that the liquid is returned from the heat radiation panel 9 to the tank 3 through the lower header 8 . By circulating the insulating oil M in this manner, the insulating oil M in the tank 3 is cooled.

Now, in the oil-filled transformer 1 of this embodiment, a pressure gauge 10 having a well-known structure is provided for measuring the pressure of the nitrogen gas in the upper space 5 in the tank 3 and checking for leakage. be done. At this time, the pressure gauge 10 is provided on the front surface of the radiator 4 on the right side at a height corresponding to the operator's line of sight, in this case, at the middle part in the height direction of the radiator 4. . In this embodiment, a piping structure for introducing the pressure of the nitrogen gas in the upper space 5 of the tank 3 to the pressure gauge 10 positioned below outside the tank 3 is provided as follows.

That is, as shown in FIG. 1, in this piping structure, a first piping 11, a second piping 12, a third piping 13, and a branch piping 14 are provided. As shown in FIG. 2, the first pipe 11 has a base end connected to the side wall of the tank 3 in communication with the upper space 5, and a tip side extending substantially horizontally to the right. . The tip of the first pipe 11 is airtightly connected to the lower outer peripheral surface of the second pipe 12 and communicates with the second pipe 12 . The connection position of the tip of the first pipe 11 is positioned slightly above the bottom of the second pipe 12 . The second pipe 12 has a diameter larger than that of the first pipe 11 and the third pipe 13, and has a vertically elongated cylindrical shape.

The third pipe 13 has a diameter smaller than that of the second pipe 12, and extends vertically so as to airtightly penetrate the bottom surface of the second pipe 12. It is positioned in the upper part of the pipe 12, slightly lower than the ceiling wall. At this time, in the present embodiment, as shown in FIG. 2, the upper end opening 13a of the third pipe 13 is obliquely cut. The lower end of the third pipe 13 extends to a position slightly lower than the height position of the pressure gauge 10, as shown in FIG.

In this embodiment, the opening at the lower end of the third pipe 13 serves as an oil drain port 15, and a lid 16 is provided to openably close the oil drain port 15. As shown in FIG. The space between the oil drain port 15 and the lid 16 is normally hermetically closed by aligning the flanges and tightening the bolts 17 . The lower end of the branch pipe 14 is airtightly connected to the right side slightly above the oil drain port 15 in the lower part of the third pipe 13, and extends upward while bending from there. The pressure gauge 10 is connected to .

As a result, the pressure of the nitrogen gas for preventing oxidation of the insulating oil M sealed in the upper space 5 in the tank 3 in a positive pressure state reaches the second pipe 12 through the first pipe 11, and reaches the second pipe 12. From the upper end opening 13a located in the upper part of the pipe 12, it reaches the inside of the third pipe 13 and reaches the pressure gauge 10 through the branch pipe 14. As shown in FIG. At this time, since the pressure gauge 10 is arranged at a relatively low position corresponding to the eye level of the operator, the pressure indicated by the pressure gauge 10 can be visually checked by the operator when inspecting for nitrogen gas leakage. It becomes possible to easily confirm.

According to this embodiment, the following functions and effects can be obtained. That is, in the oil-filled transformer 1 of the present embodiment, the deterioration due to oxidation of the insulating oil M can be suppressed by the nitrogen gas enclosed in the upper space 5 within the tank 3 . At this time, if nitrogen gas leaks from the tank 3, the anti-oxidation effect is lowered. Therefore, for example, inspections for nitrogen gas leaks are performed periodically. In this inspection, as described above, the pressure of the nitrogen gas in the upper space 5 reaches the pressure gauge 10 through the first pipe 11, the second pipe 12, the third pipe 13, and the branch pipe 14, and the pressure gauge 10 allows the pressure of the nitrogen gas in the headspace 5 to be monitored.

Here, if the oil surface of the insulating oil M in the tank 3 is shaken or tilted, the oil surface of the insulating oil M exceeds the height of the mouth on the base end side of the first pipe 11, and the upper part There is a possibility that the insulating oil M may enter the first pipe 11 from the space 5 . The insulating oil M that has leaked from the tank 3 into the first pipe 11 passes through the first pipe 11 and accumulates in the lower part of the second pipe 12 . However, since the inlet of the third pipe 13, that is, the upper end opening 13a is located in the upper part of the second pipe 12, the insulating oil M is prevented from entering the third pipe 13. FIG.

Therefore, even if the insulating oil M leaks from the tank 3 into the first pipe 11, the leaked insulating oil M only accumulates at the bottom of the second pipe 12, and the first pipe 11 to the pressure gauge 10 is not blocked. As a result, the pressure of the nitrogen gas in the upper space 5 can be directly guided to the pressure gauge 10, and the leaked insulating oil M does not interfere with the measurement of the pressure of the nitrogen gas. can measure the correct pressure of nitrogen gas.

As a result, according to the present embodiment, the problem caused by the intrusion of the insulating oil M into the piping, which is provided with the pressure gauge 10 for measuring the pressure of the nitrogen gas sealed in the upper space 5 in the tank 3, is and the pressure gauge 10 can always measure the correct pressure.

In the present embodiment, the upper end opening 13a of the third pipe 13 is obliquely cut. As a result, even if the upper end of the third pipe 13 is arranged near the ceiling of the second pipe 12, the upper end opening 13a of the third pipe 13 is obliquely cut. As a result, the upper end opening 13a of the third pipe 13 is prevented from coming into contact with the ceiling surface of the second pipe and being blocked due to a dimensional error or the like during assembly. As a result, the upper end opening 13a of the third pipe 13 is always open, and the state of communication between the second pipe 12 and the third pipe 13 can always be ensured.

Particularly, in this embodiment, a branch pipe 14 is provided above the lower end of the third pipe 13 and branches, and the pressure gauge 10 is connected to the branch pipe 14 . As a result, even if, for example, a large amount of insulating oil M leaks and the insulating oil M enters the third pipe 13, the insulating oil M only accumulates at the lower end of the third pipe 13. , the communication state of nitrogen gas reaching the pressure gauge 10 through the branch pipe 14 can be ensured. Therefore, the nitrogen gas pressure can be correctly led to the pressure gauge 10 through the branch pipe 14 without clogging the third pipe 13 with the insulating oil M, and the correct pressure can always be measured.

Further, at the lower end of the third pipe 13, an oil drain port 15 and a lid 16 for closing the oil drain port 15 so as to be able to open and close are provided. As a result, if the insulating oil M should enter the third pipe 13, the insulating oil M accumulated at the lower end can be easily removed by opening the lid 16 to open the oil drain port 15. can be discharged to

In the above-described embodiment, the upper end opening 13a of the third pipe 13 is cut obliquely. Also good. In the above embodiment, the branch pipe 14, the oil drain port 15, and the cover 16 are provided, but a pressure gauge may simply be provided at the lower end of the third pipe. Furthermore, in the above embodiment, mineral oil was used as the insulating oil M, but general insulating oils other than mineral oil, liquid silicone, and the like may also be used.

The anti-oxidation gas is not limited to nitrogen gas, and other inert gas or the like can also be used. As for the overall configuration of the transformer, various modifications may be made, such as a circulating pump for forcibly circulating the insulating oil M to the radiator, a fan device for forced cooling, and the like. It is possible. In addition, although an oil-filled transformer was used as an example, the oil-filled electrical equipment is not limited to transformers, but can also be applied to other stationary induction equipment such as reactors, switches, circuit breakers, relays, etc. can.

Although embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. The novel embodiments can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

In the drawings, 1 is an oil-filled transformer (oil-filled electrical equipment), 2 is a transformer body (electrical equipment body), 3 is a tank, 4 is a radiator, 5 is an upper space, 10 is a pressure gauge, 11 is the first 12 is a second pipe, 13 is a third pipe, 13a is an upper end opening, 14 is a branch pipe, 15 is an oil drain port, 16 is a lid, and M is insulating oil.

Claims (4)

a tank in which the main body of the electrical equipment is accommodated;
insulating oil filled in the tank;
an anti-oxidation gas sealed in a space above the insulating oil in the tank under positive pressure;
a first pipe that communicates with the upper space of the tank and extends outside the tank;
A sealed second pipe to which the tip of the first pipe is connected;
A third pipe having a diameter smaller than that of the second pipe, extending vertically so as to airtightly penetrate the lower portion of the second pipe, and having an upper end positioned above the second pipe. piping and
and a pressure gauge connected to the third pipe for measuring the pressure of the gas in the upper space of the tank. 2. The oil-filled electrical equipment according to claim 1, wherein the upper end opening of said third pipe is obliquely cut. 3. The oil-filled electrical device according to claim 1, wherein a branch pipe is provided above the lower end of said third pipe and branched, and said pressure gauge is connected to said branch pipe. 4. The oil-filled electrical equipment according to claim 3, wherein an oil drain port and a lid for openably closing the oil drain port are provided at the lower end of the third pipe.

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