JPH0218907A - Gas-insulated transformer - Google Patents

Abstract

PURPOSE:To provide excellent cooling performance in a group operation of cooling circuits by disposing a reverse flow preventive device on the way in a gas circuit in which gas flows through a gas cooler. CONSTITUTION:Reverse gas flow preventing devices 7a, 7b are respectively added to a plurality of cooling circuits. That is, since a plurality of gas coolers 4a, 4b are provided and the devices 7a, 7b are respectively provided in the gas circuits of the coolers 4a, 46, even if the coolers 4a, 4b are groupoperated, the gas flow always passes a heat generator. Thus, even when the plurality of cooling circuits are provided, the gas flow generated at the time of group operation is controlled thereby to improve the cooling performance of a transformer.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a gas insulated transformer, and particularly to a gas insulated transformer that is cooled using a plurality of gas coolers.

(Conventional technology) In recent years, oil-filled transformers have replaced transformers due to demands for nonflammability, weight reduction, and simplified on-site construction and maintenance.

Gas insulated transformers using gas insulating media such as SFG gas are increasingly being adopted.

The uses of gas insulated transformers are becoming more diverse, and dual rating specifications and group operation of gas coolers are now required for the purpose of reducing loss of auxiliary equipment.

An example of such a gas insulated transformer is shown in FIG.

In FIG. 3, reference numeral 1 denotes a tank containing contents 2 mainly consisting of iron cores and windings, and the inside of this tank 1 is filled with SF and gas for the purpose of insulation and cooling. tank 1
A gas stopper 3 is provided between and the contents 2 so that a gas flow is effectively generated in the heat generating portion of the contents 2. Further, a gas blower 5 and gas piping 6 of the gas cooler 4 are provided to cool the gas in an amount corresponding to one calorific value. The gas cooler 4 is designed for maintenance, reduction of auxiliary equipment loss, space compression, etc.
Divided into multiple units, 4a-5a-6a and 4b-
A plurality of cooling circuits such as 5b-6b are configured.

(Problem to be Solved by the Invention) In a gas insulated transformer configured in this way, when the first capacity of the double rated capacity or the load factor is low, only one of the plurality of cooling circuits is operated. However, gas blower 5
The gas blown from a does not only flow through the gas flow path of the contents 2, but also flows through the cooling circuit 4 on the side of the stopped gas blower 5b.
It begins to pass through b-5b-6b (reverse flow).

This is because the pressure loss in the gas cooling circuit is about 2"3 smaller than the pressure loss in the gas flow path of Content 2. In order to reverse this relationship, it is necessary to configure Content 2. It is necessary to enlarge the gas flow paths in the core and windings, but this increases the core size and increases the winding size, which not only results in an extremely uneconomical design, but also increases the dimensions of the transformer itself. .As mentioned above, the gas that flowed back is 4a -5 again.
It circulates through the cooling circuit on the a-6a side, making it difficult for gas flow to occur in the contents 2 of the heat-generating section that is originally desired to be cooled.

The purpose of the present invention was to solve the above-mentioned problems, and to provide a gas-insulated transformer that has excellent cooling performance even in group operation of the cooling circuit without increasing the transformer size. be.

[Structure of the invention]

(Means for Solving Problem 111) In the present invention, in order to solve the above problems, a device for preventing backflow of gas is added to each of the plurality of cooling circuits.

(Function) According to the present invention, even when a plurality of cooling circuits are installed together, it is possible to control the gas flow generated during group operation and improve the cooling performance of the transformer.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, parts that are the same as those in the prior art are designated by the same reference numerals, and their explanation will be omitted.

In FIG. 1, 7 is a backflow prevention device, and this device has a damper function that rotates in response to gas flow.

The backflow prevention device 7 is configured to open only in one direction due to the gas flow generated by the operation of the gas blower 5. In a conventional gas insulated transformer, the backflow prevention device 7 is configured to open in only one direction due to the gas flow generated by the operation of the gas blower 5. cuts off the gas flow. Therefore, even when a gas insulated transformer having multiple coolers and their gas circuits is operated as a group of coolers, the entire gas flow will always pass through the heat generating part 2, and the cooling characteristics will not be impaired. do not have.

In Fig. 1, the backflow prevention device 7 is provided for each gas cooler circuit, but if the operation type of the gas cooler section to be operated in groups is determined for some reason, the cooling in the first group of operation order is required. It is also possible to omit this backflow prevention device in the device circuit.

1. As an embodiment of the present invention, the backflow prevention device 7 is provided in the middle of the gas pipe 6 as shown in FIG. 1. However, as another embodiment, as shown in FIG. 1
It may be provided at the connection part of the gas piping 6 in the interior (the part where the gas piping from the gas blower 5 is connected to the tank 1 and the gas flow is blown into the tank 1). In this case, the gas piping 6 can be simplified. This makes it possible to compress the space.

Furthermore, as mentioned above, gases such as SF and gas play an important role not only in the cooling function but also in the insulation function. Therefore, it is necessary to prevent the backflow prevention device 7 from generating substances harmful to insulation.Specifically, this includes foreign substances such as metal powder. By constructing the insulating material, it is possible to suppress the generation of foreign substances that are harmful in terms of insulation.

In particular, when it is installed inside the tank 1 as in the embodiment shown in FIG. When the backflow prevention device 7 is made of an insulating material, it is significant in terms of insulation design, and a highly reliable transformer can be provided.

〔Effect of the invention〕

As described above, according to the present invention, by having a plurality of gas coolers and providing a backflow prevention device in the gas circuit of each gas cooler, the gas flow can be prevented even when the gas coolers are operated in batches. The gas always passes through the heat generating part, making it possible to provide a compact and highly reliable gas insulated transformer with improved cooling performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIG. 2 is a sectional view showing another embodiment, and FIG. 3 is a sectional view showing a conventional gas insulated transformer. 1...Tank 2...Contents 3...Gas stop 4...Gas cooler 5...Gas blower 6...Gas piping 7...Backflow prevention device

Claims (1)

[Claims] (1) A gas insulated transformer equipped with a plurality of gas blowers and a gas cooler, characterized in that a backflow prevention device is disposed in the middle of the gas circuit flowing through the gas cooler.