JPS6281013A - Natural cooling type gas insulated transformer - Google Patents

Abstract

PURPOSE:To reduce the size and the weight by providing a partition plate for partitioning a tank to form a core side gas passage and a winding side gas passage, the first heat sink for dissipating heat through insulating gas heated by the core, and the second heat sink for dissipating heat through insulating gas heated by insulating gas released from heat by the first heat sink and the winding, thereby suppressing a thermal influence to the winding by the core and reducing the sectional area of the core. CONSTITUTION:SF6 gas 16 heated by a core 12 is fed from a core side gas passage 18 into the first heat sink 20, cooled in the step of passing the heat sink, and then returned to a winding side gas passage 19. The gas 16 heated by a winding 14 to rise and the gas 16 cooled by the sink 20 are combined at the top of the passage 19, cooled in the second heat sink 24, and returned from a lower header 26 to the lower portion in a tank 15. When an insulator of the core 12 is composed of an insulating material of H species, the insulator of the winding 14 may be formed of an insulating material of E species having low thermal resistance section.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a self-cooled gas insulated transformer equipped with a radiator.

[Technical background of the invention and its problems] Generally, gas insulated transformers have excellent insulation properties and high thermal stability (said to be stable up to about 200°C even in the presence of moisture and metals). The main body of the transformer is insulated by filling the tank with SF6 gas. In this case, the cooling performance of SF6 gas due to natural convection is 1/3 to 1/1 compared to the case where insulating oil is used as the insulating cooling medium.
The situation is that it is low at around /4. For this reason, the current density of the winding and the magnetic flux density of the core must be lowered so that the temperature of the first winding of the core of the transformer body, which is the heating element, and its insulator do not exceed the maximum specified temperature. As a result, gas-insulated transformers have iron cores compared to oil-immersed transformers.

There are 11 reasons why the winding becomes larger, and the overall size and weight also increase.

Therefore, as shown in Japanese Utility Model Application Publication No. 59-185813, we used insulators of high heat resistance class H class (maximum operating temperature is 180'C) among insulating materials for the upper half of the iron core and windings. A transformer has been proposed in which the entire transformer is made smaller and lighter by increasing the temperature to about 180° C.2.

However, in this case, a large amount of expensive H type insulating material must be used as the insulating material.

Here, a specific conventional configuration is shown in FIG. In the figure, reference numeral 1 denotes a transformer body consisting of an iron core 2 and a winding 4 arranged around the core through an insulating cylinder 3, and 5 denotes an SF 6 for housing and disposing the transformer body 1 and for insulation. This is a tank filled with gas 6. A radiator 7 is provided outside the tank 5 and communicates with the inside of the tank 5 via an upper header 8 and a lower header 9. In this configuration, the heat generated in the iron core 2 and winding 4 of the transformer body 1 is transferred to the SF6 gas 6 in the tank 5, and this SF6 gas 6 flows into the tank 5 as shown by the arrow in the figure. It rises due to natural convection due to the temperature difference, passes through the upper header 8, enters the radiator 7, where it radiates heat and is cooled, and then returns to the upper part of the tank 1 through the lower header 9, where the circulation is repeated. , whereby the transformer main body 1 is cooled. By the way, in gas insulated transformers currently manufactured in Japan, polyethylene terephthalate film (hereinafter referred to as PET) is used as the main insulation material, which is relatively inexpensive and has excellent insulation properties in gas.
) is used. The heat resistance classification of PET is Class E (maximum operating temperature is 120'C), and the winding temperature has a temperature difference of several orders of magnitude (°C) with respect to the surrounding gas temperature. As shown in the gas temperature distribution in the tank in the figure, if the lower end position of the winding 4 is h1' and the upper end position of the winding 4 is h2', the gas temperature at the upper end position h2' of the winding 4 is 105 It is necessary to suppress the temperature to about ℃ (the ambient temperature is 40℃). So, as mentioned above, SF,
Since the cooling performance of gas is inferior to that of an insulating pool, in self-cooled gas insulated transformers, not only the current density of the winding but also the magnetic flux density of the iron core must be suppressed accordingly. The cross-section of the iron core becomes larger, and the diameter of the winding wire increases due to the increase in the cross-section size of the iron core, and the wire size determined by the current density increases, resulting in an overall increase in size and weight. It also gets bigger.

On the other hand, if the maximum allowable temperature is expanded to reduce the overall size and weight, as in the above-mentioned Utility Model Application Publication No. 59-185813, a large amount of expensive class H insulating material must be used, which increases the cost. There was a problem with the price being high.

[Purpose of the Invention] The present invention has been made in view of the above circumstances, and its 1:1 objective is to develop a self-cooling type that can reduce the overall size and weight as well as reduce costs. To provide gas insulated transformers.

[Summary of the Invention] The present invention is provided in the -L section of a tank in which a transformer main body is housed and filled with insulating gas, and the inside of this tank is separated from the core side gas flow path and the winding side gas flow path by a partition plate. A first partition that is partitioned to form a flow path, communicates with the iron core side gas flow path at the outer upper part of the tank, and passes the insulating gas heated by the iron core to radiate heat.
When a heat radiator is provided, the heat is radiated through the insulating gas that is communicated with the winding side gas flow path outside the tank and the insulating gas radiated by the first radiator and the insulating gas heated by the winding. It is characterized in that it has a configuration in which a second heat radiator is provided to return the heat to the lower part of the tank, thereby minimizing the effect of heat on the windings due to the iron core.

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to FIGS. 1 and 2. First, in FIG. 1, reference numeral 11 denotes a transformer body, which consists of an iron core 12 and a winding 14 disposed around the iron core with an insulating tube 13 interposed therebetween. Reference numeral 15 denotes a tank in which the transformer body 11 is housed and insulating SF6 gas 16 is sealed. Reference numeral 17 denotes a partition plate, which is located at the upper part of the tank 15 and is connected to the upper end of the insulating cylinder 13, and is connected to the core side gas flow path 18 and the winding side gas flow path 1 within the tank 15.
It is divided into 9 parts. Here, the insulating cylinder 13 and the partition plate 1
The insulators related to 7.1Ili and the iron core 12 are made of a heat-resistant class or H class insulating material, and the insulators related to the winding 14 are made of an E class insulating material. On the other hand, reference numeral 20 designates a first heat radiator disposed at the upper part of the outside of the tank 15, the upper header 21 of which communicates with the core-side gas passage 18 inside the tank 15 via the duct 22 of the tank 15, and the lower part of the first heat radiator 20. A header 23 communicates with two portions of the winding 14 of the winding gas flow path 19. The first heat radiator 20 is cooled by radiating heat through the SF6 gas 16 heated by the iron core 12 in the tank 15, and the cooled S
The F6 gas 16 is returned to the winding side gas flow path 19. In this case, the vertical length dimension H of this first heat radiation S20 is
Winding 14 with high lR SF, gas 16 heated by
The length is set to be necessary to cool the SF6 gas 16 at the upper end to the same level as the maximum temperature. Reference numeral 24 designates a second radiator located below the first radiator 20 and disposed on the external side of the tank 15, the upper header 25 of which communicates with the winding side gas flow path 19; Lower header 26 is winding 1
It communicates with the upper part of the tank 15 on the fourth side. The second radiator 24 is cooled by radiating heat through the SF6 gas 16 cooled by the first radiator 20 and the SF6 gas 16 heated by the winding 14,
The cooled SF and gas 16 are returned to the lower part of the tank 15.

1- In the case of the configuration described above, the S heated by the iron core 12
The F6 gas 16 rises inside the insulating cylinder 13 as shown by the arrow in the figure, and flows from the core side gas passage 18 to the duct 22. It enters the first radiator 20 through the upper header 21 and is cooled by radiating heat in the process of passing there, and is then returned from the lower header 23 to the winding side gas flow path 19 in the tank 15. Ru. In addition, the SF6 gas 16 heated and raised by the winding 14 and the SF gas 16 cooled by the first radiator 20 are combined in the second part of the winding side gas flow path 19'', and the combined SF6 gas 16 enters the second radiator 24 through the upper header 25, is cooled by radiating heat during the passage there, and is then returned to the lower part of the tank 15 from the lower header 26. By repeating such circulation, the transformer main body 11 is cooled. Here, the lower end position portion of the winding 14 and the iron core 12 is ht, and the upper end position portion of the winding 14 is 12+iron core 1.
When one end position of 2 is set as h3, the temperature distribution of the SF6 gas 16 at each position is as shown in FIG.

In the figure, a characteristic line a indicates the gas temperature of the SF6 gas 16 heated by the winding worker 4, and a characteristic line a indicates the gas temperature of the SF6 gas 16 heated by the iron core 12. That is, the SF6 gas 16 heated by the iron core 12 reaches a temperature of about 165° C. at the upper end of the iron core, but is cooled to about 105° C. at the upper end position h2 of the winding after passing through the first radiator 20. Ru.

As described above, according to this embodiment, although the temperature of the waste inside the tank 15 is about 165° C. near the upper end position h3 of the iron core, it is suppressed to about 105° C. near the upper end position h2 of the winding by the first radiator 20. Since the thermal influence of the iron core 12 on the winding 14 can be suppressed as much as possible, if the insulators related to the iron core 12 are made of H class insulating material,
Regarding the related insulators, it is possible to use insulating materials of class E, which have a lower heat resistance class. Therefore, the insulation 5 related to the iron core 12
By composing the object with H class insulating material, the iron core 12
In this case, it is possible to set a high magnetic flux density that is not much different from that of an oil-immersed transformer, and the cross section of the iron core 12 can be made smaller to make it smaller and lighter.
Since the diameter of the winding 14 can be reduced, the winding 14 can be made smaller and lighter, and the overall size can be made smaller.

Moreover, by using an insulating material such as PET, which is inexpensive and has excellent insulation properties of type E, for the insulator related to the winding 14, which requires a large amount of insulator, it is possible to reduce costs.

Note that the present invention is not limited to the above-mentioned embodiment, and for example, as shown in FIG. 3 as another embodiment of the present invention, there is a A common intermediate header 27 may be provided for these, and in this way, the number of sealing points between the link 15 and these first and second radiators 20, 24 is reduced, and gas leakage prevention is ensured. The heat radiator's overall length in the vertical direction can be shortened. Further, in this case, the first heat radiator 20 and the second heat radiator 24 are in linear communication via the intermediate header 27, and the first and second heat radiators 20.
SF at the upper header 21 part of the first heat radiator 20 and the upper header 26 part of the second heat radiator 24 within 24
Since the temperature difference between the six gases 16 is large, the SF6 gas 16 heated by the iron core 12 is transferred to the first and second radiators 20.
As a result, the gas pressure at the middle header 27 becomes lower than at one end of the winding 141 in the tank 15.
A force is generated to draw the SF6 gas 16 at the upper end of the header 27 into the intermediate header 27, thereby promoting the circulation of the SF6 gas 16 and further improving the cooling effect.

[Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to suppress the thermal influence of the iron core on the windings as much as possible. Insulating materials with a low heat resistance classification can be used for the windings, and the iron core can have a high magnetic flux density that is not much different from that of oil-immersed transformers, making the core and windings smaller and lighter as a whole. Moreover, by using an inexpensive insulation + A material with a low heat resistance class for winding-related insulation that requires a large amount of insulation, it has the excellent effect of reducing costs. It is something to play.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 show one embodiment of the present invention, Fig. 1 is a longitudinal sectional view, Fig. 2 is a gas 1M degree characteristic diagram, and Fig. 3 shows another embodiment of the present invention. Figure 1 is a scabbard drawing. 4 is a diagram corresponding to FIG. 1 showing a conventional configuration, and FIG. 5 is a diagram corresponding to FIG. 2 showing a conventional configuration. In the drawing, 11 is the transformer body, 12 is the iron core, 13 is the insulation direction, 14 is the winding, 15 is the tank, 16 is SF6 gas (insulating gas), 17 is the partition plate, 18 is the iron core side gas flow path, 19 2 is a winding side gas flow path, 20 is a first heat radiator, and 24 is a second heat radiator. Applicant: Toshiba Corporation 1-゛,--5 Agent: Patent attorney Tsuyoshi Sato. □、ノ、−′. 1st base hit Figure 1 Part 2

Claims (1)

[Claims] 1. A transformer body consisting of an iron core and a winding arranged around the core through an insulating cylinder, a tank that houses the transformer body and is filled with insulating gas, and a tank that contains an insulating gas. a partition plate located at an upper part and partitioning the inside of the tank so as to form a core-side gas flow path and a winding-side gas flow path; and a partition plate provided at an external upper part of the tank in communication with the core-side gas flow path and the iron core. The first heat dissipates through the insulating gas heated by the
a radiator, an insulating gas located below the first radiator and provided outside the tank in communication with the winding side gas flow path and radiated by the first radiator; A self-cooling type gas insulated transformer comprising: a second radiator that radiates heat through the insulating gas heated by the wire and returns the heat to the lower part of the tank.