JP2011082414A - Gas-insulated transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-insulated transformer that contributes to improvement in reliability by preventing a local temperature rise of a tank by introducing a high temperature insulation gas uniformly into a gas flow passage inside the tank. <P>SOLUTION: A vertical partition board 11 is provided between the inner wall surface of the tank 1 and a side portion of a winding 3. The partition board 11 is provided so as to be landscape over the longitudinal direction of the tank 1 so as to face the entire winding 3 inside the tank 1. Between the upper edge of the partition board 11 and the inner wall surface of the tank 1, a gap 13 is formed to allow an insulation gas 6 to pass through. A space between the inner wall surface of the tank 1 and the partition board 11 forms a gas flow passage 15 which allows the insulation gas 6 to flow. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas-insulated transformer having an improved flow path configuration of a cooling medium.

  The gas-insulated transformer is a tank in which a transformer main body is housed, in which a nonflammable insulating gas is sealed as a cooling and insulating medium, and is excellent in safety and compactness. Therefore, in recent years, gas-insulated transformers are increasing in substations and the like in urban areas in place of oil-filled transformers filled with insulating oil.

  Although the gas insulated transformer is inferior to the oil-filled transformer in terms of insulation performance, it cannot be denied that the cooling performance is lower than that of the oil-filled transformer due to the difference in the material properties of the medium. Since the insulating gas serving as the cooling medium has cooling characteristics inferior to the insulating oil, it is necessary to reduce the amount of heat generated from the transformer in order to cool the transformer with this insulating gas. However, if the amount of generated heat is reduced, the transformer is increased in size, which is not preferable.

  The heat source of the transformer is a transformer body composed of an iron core, windings, and the like, and efficiently cooling the transformer body leads to an improvement in cooling performance. Therefore, conventionally, a gas-insulated transformer that cools the insulating gas using a cooler and forcibly convects the insulating gas cooled by using a blower (blower) into the tank of the transformer has been proposed.

  A conventional example of a gas-insulated transformer including such a cooler and a blower will be specifically described with reference to FIGS. FIG. 7 is a sectional view of a conventional gas-insulated transformer, and FIG. 8 is a plan view of the same. As shown in FIG. 7, the gas insulated transformer is provided with a tank 1 having a circular cross section. In the center of the tank 1 is housed a transformer body composed of an iron core 2 and a winding 3 wound around the iron core 2. In addition, an insulating gas 6 which is a cooling and insulating medium is sealed inside the tank 1.

  Further, a gas outlet 7 and a gas inlet 8 are formed on the upper and lower sides of the side surface of the tank 1, and a pipe 9 through which the insulating gas 6 flows is joined to the gas outlet 7 and the gas inlet 8. . The pipe 9 has a cross-sectional area that can secure a sufficient gas flow rate of the insulating gas 6.

  A blower 4 forcing the insulating gas 6 into the tank 1 and a cooler 5 for cooling the insulating gas 6 are disposed in the middle of the pipe 9. Inside the tank 1, a partition plate 10 that divides the tank 1 in the vertical direction is horizontally attached near the lower surface of the winding 3.

  In the gas-insulated transformer having the above configuration, the insulating gas 6 in the tank 1 rises in the tank 1 while taking heat of the iron core 2 and the winding 3. The insulating gas 6 that reaches the upper part in the tank 1 passes through the gas outlet 7, passes through the pipe 9, descends the pipe 9, and enters the cooler 5.

  The insulating gas 6 in the cooler 5 is subjected to heat exchange with air, water, or the like, and the temperature decreases. The insulating gas 6 having a low temperature exits from the cooler 5, flows again into the tank 1 from the gas inlet 8 by the blower 4, and flows in from the lower part of the iron core 2 and the winding 3. At this time, the insulating gas 6 reaches the lower part of the iron core 2 and the winding 3 while being blocked by the partition plate 10 in the tank 1.

  Therefore, a differential pressure is generated between the gas inlet 8 side and the gas outlet 7 side, and the gas flow rate of the insulating gas 6 flowing to the iron core 2 and the winding 3 can be secured. The insulating gas 6 having a predetermined flow rate rises while taking heat from the iron core 2 and the winding 3, and again enters the cooler 5 through the gas outlet 7 and the pipe 9.

  As described above, a closed loop of the insulating gas 6 that circulates inside the tank 1 is configured, and the low-temperature insulating gas 6 can be forcedly convected into the tank 1. As a result, the insulating gas 6 can have a cooling characteristic equivalent to that of the insulating oil, and the gas-insulated transformer can ensure high cooling performance.

  However, in the gas-insulated transformer described above, since the pipe 9 is provided outside the tank 1, a space for installing the pipe 9 is required. Therefore, the volume occupied by the gas-insulated transformer at the substation is increased, which increases the installation area of the substation.

  Moreover, the pipe 9 extends from the upper part to the lower part of the tank 1, and the overall length of the pipe 9 is considerably long. For this reason, the installation work of the pipe 9 is troublesome, and it takes a lot of time to assemble the gas-insulated transformer, resulting in an increase in manufacturing cost. In order to solve these problems, a gas-insulated transformer in which a gas flow passage functioning as the pipe 9 is formed inside the tank 1 has been proposed.

  For example, in the gas-insulated transformer described in Patent Document 1, as shown in FIG. 9, the partition plate 11 close to the inner wall surface of the tank 1 is installed vertically from the upper surface portion of the tank 1. A gas flow passage 14 is formed by a space sandwiched between the partition plate 11 and the inner wall surface of the tank 1. A lower gap 12 is formed between the lower end of the partition plate 11 and the bottom surface of the tank 1.

  Further, on the upper surface of the tank 1, a gas outlet 7 is opened at the left edge and a gas inlet 8 is opened at the right edge. Among these, the gas flow passage 14 is communicated with the gas outlet 7 below. In the gas insulated transformer described in Patent Document 1, the cooler 4 is disposed above the upper surface of the tank 1.

  In the gas-insulated transformer as described above, the insulating gas 6 cooled by the cooler 4 descends the gas flow passage 14 through the gas inlet 8 and reaches the bottom of the tank 1 to reach the lower side. It passes through the gap 12 and flows into the lower part of the iron core 2 and the winding 3. That is, the gas flow passage 14 in the tank 1 plays the role of the pipe 9 shown in FIGS. For this reason, the piping 9 installed outside the tank 1 can be omitted, and the reduction of the manufacturing cost and the compactness of the transformer can be realized.

JP 7-226322 A

  However, the following problems have been pointed out for conventional gas-insulated transformers. That is, in the gas-insulated transformer described in Patent Document 1 and the conventional gas-insulated transformer shown in FIGS. 7 and 8, the insulating gas 6 is gas from the upper part of the iron core 2 and the winding 3 to the upper surface of the tank 1. Although it flows toward the outflow port 7, the insulating gas 6 has a small specific gravity and low viscosity unlike the insulating oil.

  For this reason, the insulating gas 6, which has become hot due to the removal of heat from the iron core 2 and the winding 3, concentrates on the gas outlet 7 and flows linearly into the pipe 9. As a result, a large amount of high-temperature gas is concentrated in the vicinity of the gas outlet 7, and the temperature in the vicinity of the gas outlet 7 (the portion indicated by the alternate long and short dash line in FIGS. 8 and 9) is higher than that of the other parts of the tank 1. It became high locally. When such a local temperature rise occurs in the tank 1, the performance of the transformer may become unstable, and an immediate improvement has been awaited.

  The present invention has been proposed in order to solve the above-described problems, and an object of the present invention is to provide a gas-insulated transformer that achieves cost reduction and compactness by forming an insulating gas flow passage inside the tank. Another object of the present invention is to provide a gas-insulated transformer that contributes to the improvement of reliability by preventing a local temperature rise of the tank by uniformly introducing a high-temperature insulating gas into the gas flow passage inside the tank.

  To achieve the above object, according to the present invention, a tank body contains a transformer body composed of an iron core and a winding wound around the iron core, and encloses an insulating gas which is a cooling and insulating medium. Has a gas outlet through which the insulating gas flows out of the tank and a gas inlet through which the insulating gas flows into the tank, and the insulating gas is provided at the gas outlet and the gas inlet. A gas-insulated transformer comprising: a cooler that joins a pipe through which the gas flows; and a cooler that takes in and cools the insulating gas through the pipe and a blower that feeds the insulating gas cooled by the cooler into the tank. A partition plate is installed vertically between the inner wall surface and the transformer body, and a gap through which the insulating gas passes is provided between the upper portion of the partition plate and the tank inner wall surface, A gas flow path through which the insulating gas flows is formed by a space sandwiched between the inner wall surface of the tank and the partition plate, and the gas flow path allows the insulating gas from the transformer body to flow from the gap to the gas flow path. It is configured to be introduced into the pipe through an outlet.

  According to the gas-insulated transformer of the present invention, when the insulating gas flowing out from the transformer body flows through the gap between the upper part of the partition plate and the inner wall surface of the tank, pressure loss occurs in the gas flow. It is possible to flow uniformly into the flow path, and thereby it is possible to avoid a local temperature rise due to the concentration of the high-temperature insulating gas, thereby improving the reliability.

1 is a front sectional view of a first embodiment according to the present invention. The top view of FIG. Front sectional drawing of the modification of 1st Embodiment. The front view of 2nd Embodiment which concerns on this invention. The top view of FIG. Front sectional drawing of 3rd Embodiment which concerns on this invention. Front sectional drawing of the conventional gas insulation transformer. The top view of FIG. Front sectional drawing of the conventional gas insulation transformer.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. In the following embodiment, the same members as those in the conventional example shown in FIGS. In any of the following embodiments, a transformer body composed of an iron core 2 and a winding 3 is housed in a tank 1, and an insulating gas 6 that is a cooling and insulating medium is sealed in the tank 1. 1 is applied to a gas-insulated transformer including a blower 4 forced to convection 1 and a cooler 4 that cools an insulating gas 6.

(1) First embodiment
[Constitution]
A first embodiment according to the present invention will be described with reference to FIGS. 1 and 2. In the first embodiment, a vertical partition plate 11 is provided between the inner wall surface of the tank 1 and the side surface portion of the winding 3. The partition plate 11 is provided horizontally in the longitudinal direction of the tank 1 so as to face all the windings 3 in the tank 1 (see FIG. 2). The lower end of the partition plate 11 is fixed on the horizontal partition plate 10.

  A gap 13 is provided between the upper end portion of the partition plate 11 and the inner wall surface of the tank 1 so that the insulating gas 6 can pass therethrough. Here, in order to distinguish from the lower gap 12 of the partition plate 11 shown in FIG. A gas flow passage 15 through which the insulating gas 6 flows is formed by a space sandwiched between the inner wall surface of the tank 1 and the partition plate 11. The gas flow passage 15 is configured to introduce the insulating gas 6 that has come out of the iron core 2 and the winding 3 into the pipe 9 from the upper gap 13 through the gas outlet 7.

  In the conventional example shown in FIG. 7, the gas outlet 7 is provided in the upper part of the tank 1, but the gas outlet 7 in the first embodiment is the inner wall surface of the tank 1 facing the vicinity of the lower end of the partition plate 11. Is located. On the other hand, the gas inlet 8 is opened at the lower part of the side surface of the tank 1 as in the conventional example shown in FIG. Accordingly, the gas outlet 7 and the gas inlet 8 are close to each other in the vertical direction, and the length of the pipe 9 that joins both can be short.

[Insulating gas flow]
In 1st Embodiment which has the above structure, the insulating gas 6 circulates through the tank 1 and the piping 9 as follows. In other words, the insulating gas 6 that has taken the heat of the iron core 2 and the winding 3 to a high temperature rises up the iron core 2 and the winding 3 and flows out from the upper portions thereof. The insulating gas 6 flowing out from the iron core 2 and the winding 3 flows in the horizontal direction toward the gap 13 between the inner wall surface of the tank 1 and the upper part of the partition plate 11 and passes through the gap 13.

  Further, the insulating gas 6 flows into the gas flow passage 15 from the gap 13, descends through the gas flow passage 7, and enters the pipe 9. The insulating gas 6 that has entered the pipe 9 is cooled by the cooler 5, flows again into the tank 1 from the gas inlet 8 by the blower 4, and flows in from the lower part of the iron core 2 and the winding 3.

[Effect]
The operational effects of the first embodiment are as follows. That is, the insulating gas 6 flowing out from the iron core 2 and the winding 3 flows toward the gap 13 above the partition plate 11, but the gap 13 extends in the longitudinal direction of the tank 1. (See FIG. 2).

  At this time, pressure loss occurs in the insulating gas 6 flowing through the gap 13. Therefore, the insulating gas 6 is less likely to flow linearly toward the pipe 9 and flows uniformly through the gas flow passage 15. Therefore, the high temperature insulating gas 6 does not concentrate on the inner wall surface of the tank 1 and the temperature rise of the tank 1 is made uniform. Thereby, generation | occurrence | production of the local temperature rise of the tank 1 can be prevented.

  In the first embodiment, since the gas flow passage 15 for lowering the insulating gas 6 is provided inside the tank 1, the position of the gas outlet 7 can be shifted downward compared to the conventional case. For this reason, it is possible to provide the gas outlet 7 and the gas inlet 8 at positions close to each other.

  Accordingly, the length of the pipe 9 that joins the gas outlet 7 and the gas inlet 8 can be greatly shortened. As a result, it is possible to reduce the amount of material required for the piping 9 and shorten the assembly time of the transformer, thereby reducing the manufacturing cost. Further, since the space occupied by the pipe 9 can be reduced, the transformer can be made more compact and contribute to the reduction of the substation installation area.

  By the way, although the flow path of the insulating gas 6 is provided in the tank 1 in the same manner as the above-mentioned Patent Document 1 and this embodiment, the temperature of the insulating gas 6 flowing through the flow path is greatly different. That is, in Patent Document 1, since the insulating gas that has gone out of the cooler 4 and has a low temperature descends the gas flow passage 14, the temperature of the tank 1 varies depending on the process of descending the gas flow passage 14. The insulating gas 6 that has been cooled is heated. Therefore, the temperature of the insulating gas 6 rises at the time when it passes through the lower gap 12 and flows into the lower part of the iron core 2 and the winding 3, and the cooling characteristics of the insulating gas 6 are deteriorated.

  On the other hand, in the first embodiment, since the insulating gas 6 that has gone out of the cooler 5 and has reached a low temperature immediately returns to the inside of the tank 1, the temperature of the insulating gas 6 before the iron core 2 and the winding 3 are cooled. Is not increased, and excellent cooling characteristics can be maintained. Therefore, the transformer body can be efficiently cooled, and excellent cooling performance can be obtained.

(2) Second embodiment
[Constitution]
Next, a second embodiment according to the present invention will be described with reference to FIGS. The basic configuration of the second embodiment is the same as that of the first embodiment.

  The second embodiment is characterized by the shape of the gap 13 above the partition plate 11. That is, as shown in FIGS. 3 and 4, the partition plate 11 is provided with an upper surface portion 11 a. Three gas passage ports 16a to 16c are opened in the upper surface portion 11a along the longitudinal direction of the tank 1 (see FIG. 4).

  Among the gas passage openings 16a to 16c, the gas passage opening 16b located at the center has a small opening area. Further, in FIG. 4, the gas passage ports 16a and 16c at the upper and lower ends have a large opening area. A gap 13 provided between the partition plate 11 and the inner wall surface of the tank 1 is configured by these gas passage ports 16a to 16c.

[Effect]
In the second embodiment as described above, the opening area of the central gas passage 16b located right above the pipe 9 is small, and the opening areas of the gas passages 16a and 16c at both ends away from the pipe 9 are large. ing. For this reason, the pressure loss in the gas passages 16a to 16c can be adjusted according to the distance between the pipe 9 and the gas passages 16a to 16c.

  Therefore, the gas flow rate of the insulating gas 6 passing through the gap 13 is made uniform over the longitudinal direction of the tank 1. As a result, the insulating gas 6 can be distributed and flowed almost uniformly in the upper gap portion arranged in the longitudinal direction of the tank 1. Thereby, the local temperature rise of the tank 1 by the high temperature insulating gas 6 hitting the inner surface of the tank 1 can be prevented more reliably.

(3) Other Embodiments The present invention is not limited to the above embodiment, and materials, dimensions, shapes, and the like of the respective constituent members can be appropriately selected. For example, the material of the partition plate 11 is an insulating material as long as the characteristics of the material maintain mechanical strength, temperature characteristics, and electrical characteristics necessary for flowing high-temperature gas inside the transformer. Even if it is a metal material, the material is not ask | required.

  Further, as shown in FIG. 5, the partition plate 11 and the gap 13 on the upper side of the partition plate 11 may be provided on both sides of the iron core 2 and the winding 3 in the tank 1. Further, the configuration of the transformer may be a three-phase configuration or a single-phase configuration, and the number of transformer phases to be applied is not limited.

  Moreover, it can change suitably also about the arrangement | positioning location of a structural member, and specifically, as shown in FIG. 6, the cooler 5 may be arrange | positioned inside the gas flow path 15. FIG. According to such embodiment, the installation area of a transformer can be reduced by arrange | positioning the cooler 5 in the tank 1 inside. Further, it is possible to omit the connection work between the tank 1 and the cooler 5 at the substation, and the time required for assembling the entire transformer can be shortened to reduce the cost.

  Further, an embodiment in which a connection lead between the windings 3 is arranged in the gas flow passage 15 and the connection lead is actively cooled by the insulating gas 6 flowing in the gas flow passage 15 is also included. A current flows through the connection lead during operation of the transformer. However, if the insulation is applied to the connection lead in order to improve the dielectric strength, the temperature of the connection lead is increased, resulting in problems such as overheating of the insulation coating.

  Therefore, by arranging the connection lead in the gas flow passage 15 and actively cooling the connection lead with the insulating gas 6 flowing therethrough, the temperature rise of the connection lead can be suppressed low. In addition, since the cooling efficiency of the connection lead is improved, the insulation coating of the connection lead can be made thicker than before, and the effect that the transformer is made compact by shortening the insulation dimension can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Iron core 3 ... Winding 4 ... Blower 5 ... Cooler 6 ... Insulating gas 7 ... Gas outlet 8 ... Gas inlet 9 ... Piping 10, 11 ... Partition plate 12 ... Lower gap 13 ... Upper side Gap 14, 15 ... Gas flow passages 16a-16c ... Gas passage 20 ... Insulating gas flow

Claims (6)

In the tank, a transformer body comprising an iron core and a winding wound around the iron core is housed, and an insulating gas which is a cooling and insulating medium is sealed, and the insulating gas flows out of the tank on the tank wall surface. A gas outlet for allowing the insulating gas to flow into the tank, and a pipe for flowing the insulating gas connected to the gas outlet and the gas inlet. In a gas insulation transformer having a cooler that takes in and cools an insulating gas, and a blower that sends the insulating gas cooled by the cooler into the tank,
A partition plate is installed vertically between the inner wall surface of the tank and the transformer body,
A gap through which the insulating gas passes is provided between the upper portion of the partition plate and the inner wall surface of the tank,
A gas flow path through which the insulating gas flows is formed by a space sandwiched between the inner wall surface of the tank and the partition plate,
The gas flow passage is configured to introduce the insulating gas from the transformer main body into the pipe through the gas outlet through the gap.   The gas-insulated transformer according to claim 1, wherein the partition plate is made of an insulating material.   The gap between the upper part of the partition plate and the inner wall surface of the tank is provided with an opening area adjusted so that the gas flow rate of the insulating gas passing through the gap is uniform over the longitudinal direction of the tank. The gas-insulated transformer according to claim 1, wherein: As the gap between the upper part of the partition plate and the inner wall surface of the tank, a plurality of gas passage ports through which the insulating gas passes are provided in the longitudinal direction of the tank,
4. The gas according to claim 3, wherein among the plurality of gas passage openings, the gas passage opening in the vicinity of the pipe has a reduced opening area, and the opening area of the gas passage opening far from the pipe is increased. Isolation transformer.   The gas insulated transformer according to any one of claims 1 to 4, wherein the cooler is disposed in the gas flow passage.   The gas-insulated transformer according to claim 1, wherein connection leads between the windings are arranged in the gas flow passage.

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