JPH03101112A - Gas insulated transformer - Google Patents

Abstract

PURPOSE:To enhance balance of gas flow rate by a method wherein a first partition sheet is installed between the lower part of an iron core and the inner wall of a tank, a second partition sheet is installed between the lower part and the inner wall of the tank, the inside of the tank is divided into a lower chamber, a middle chamber and an upper chamber and a plurality of radiators for insulating-gas cooling are divided and connected to the individual divided chambers. CONSTITUTION:When an insulating gas 1a is made to flow to a gas insulated transformer, a gas cooled by means of a radiator 4a is made to flow into the lower chamber A of a tank 1 through a lower-part radiator pipe 6a. While the gas is cooling a gas route formed inside an iron core 2, temperature thereof is raised and the gas is returned to the radiator 4a through an upper-part radiator pipe 5a. The gas cooled by means of a radiator 4b is made to flow into a middle chamber B through a lower-part radiator pipe 6b. While the gas is cooling a gas route formed inside a winding 3, temperature thereof is raised and the gas is returned to the radiator 4b through an upper-part radiator pipe 5b. That is to say, the flow route which cools the iron core 2 and the flow route which cools the winding 3 are separated by using a first partition sheet 7 and a second partition sheet 8 thus making the cooling operation effective.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas insulated transformer that insulates and cools equipment using an insulating gas such as SF6 gas.

(Prior Art) Conventionally, a gas insulated transformer is configured as shown in FIG. That is, an iron core 2 made of laminated silicon steel plates is placed inside a tank 1.
A winding 3 is wound around the main leg portion of the iron core 2, and an insulating gas 1a such as SF6 gas is injected into the tank 1. A plurality of radiators 4 for cooling the insulating gas 1a are provided outside the tank 1, and the tank 1 and the radiators 4 are communicated through upper and lower radiator pipes 5 and 6.

The insulating gas 1aFi cooled by the radiator 4 passes through the lower radiator piping 6 9 and flows into the lower part of the tank 1, and then is divided into gas passages provided inside the iron core 2 and the winding 3, and then flows through the iron core 2 and the winding 3. 3 and returns to the radiator 4 through the upper part of the tank 1 and the upper radiator pipe 5.

(Problem to be Solved by the Invention) However, in the gas insulated transformer having the above structure, the width of the gas passage provided inside the core 2 must be made small in order to increase the space factor of the winding. The gas path provided inside the line 3a needs to be widened for insulation reasons.

Furthermore, since the winding 3 is wound around the main leg of the iron core 2, the horizontal length for one gas path is the winding +
The gas path in the iIs is longer, and the number of gas paths in winding 3 is generally larger. Therefore, the cross-sectional area of the gas passage, expressed as (horizontal length) x (width) x (number of pipes), is usually 5 to 10 times larger for winding 3 than for iron core 2, and for the tank than for radiator 4. Most of the insulating gas 1& that has flowed into the lower part also flows through the gas path inside the winding 3. Further, the frictional resistance Δh in the gas path can be expressed by the following equation.

Here, d is the fluid diameter and is approximately proportional to the width of the gas value. Also, t is high and V is the flow velocity. The height t of the gas passage in the iron core 2 is larger than that in the winding 3, and the width of the gas passage is smaller as described above. Since the knob υd is small, the frictional resistance in the gas path will be greater in the iron core 2 when the flow velocity is the same.

Therefore, it can be seen that the insulating gas 1a does not easily flow through the gas path inside the iron core 2.

Due to the above gas path cross-sectional area and frictional resistance, it becomes difficult for the insulating gas 1a to flow into the iron core 2, and the temperature rise of the iron core 2 becomes considerably larger than that of the winding 3, which deteriorates the insulation of the iron core 2. This has the disadvantage of shorting the life of the transformer. As a countermeasure for such a mass-market product, it is possible to make the iron core 2 larger to lower the magnetic flux density, or to make the gas passage section att in the iron core 2 thicker. There are drawbacks to this. Another possibility is to reduce the cross-sectional area of the gas passage inside the winding 3 in order to equalize the balance of branched flow between the gas passage inside the iron core 2 and the gas passage inside the winding 3. Disadvantages include increased temperature rise and insulation problems.

The present invention eliminates the above-mentioned drawbacks, secures the minimum necessary insulating gas flow rate for cooling each of the core and windings without increasing the size, and provides effective and uniform cooling with good flow rate and grance. The purpose is to obtain a gas insulated transformer that can be used.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above objects, the present invention provides a gas insulated transformer in which an iron core and a winding are housed inside a tank, and a radiator and radiator piping are provided outside the tank. A first partition plate is installed between the upper part of the iron core and the tank inner wall, and a second partition plate is installed between the upper part of the iron core and the tank inner wall to divide the inside of the tank into a lower chamber, a middle chamber, and an upper chamber. The plurality of radiators for cooling insulating gas are divided into two, and the lower radiator piping connected to one radiator is connected to the lower chamber of the tank, the upper radiator piping is connected to the upper chamber of the tank, and the other radiator is connected to the lower chamber of the tank. The tank is characterized in that upper and lower radiator pipes communicating with the tank are respectively connected to the middle chamber of the tank.

(Function) This makes it possible to independently secure the minimum gas flow rates necessary for cooling the core and the windings, and to perform effective cooling with a well-balanced flow rate.

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

In the figure, the same parts as in FIG. 3 are designated by the same reference numerals. The gas insulated transformer of the present invention stores an iron core 2 and a winding 3 together with an insulating gas 1a in a tank 1, and has a plurality of radiators 4m, 4b and upper and lower radiators outside the tank 1 for cooling the insulating gas 1a. Piping 51L.

It is equipped with 5bs6m and 6b. A first partition plate 7 is installed between the lower part of the iron core 2 and the inner wall of the tank 1, and a second partition plate 8 is installed between the upper part of the iron core 2 and the inner wall of the tank 1. The interior is divided into lower chamber A, middle chamber B, and upper chamber C.

Here, the lower radiator piping 6a communicating with one of the radiators 4a of the plurality of radiators for cooling insulating gas divided into two is connected to the lower chamber A of the tank 1, and the upper radiator piping 5a't--the upper radiator piping 5a't of the tank 1. connected to the upper chamber C,
The upper and lower radiator pipes 6*j6b communicating with the other radiator 4b are connected to the middle chamber B of the tank 1, respectively.

In the gas insulated transformer configured in this way, when the insulating gas IIL flows, the insulating gas cooled by the radiator 4a flows into the lower chamber A of the tank 1 through the lower radiator piping 6a, and flows into the iron core 2. The gas rises while being cooled through the gas path provided in the upper radiator pipe 5a and returns to the radiator 4a. In addition, the insulating gas cooled by the radiator 4b passes through the lower radiator pipe 6b.
It flows into the middle chamber B of the tank 1, rises while being cooled through the gas path provided in the winding 3, passes through the upper radiator piping 5b, and returns to the radiator 4b. It is possible to independently secure a gas flow path for cooling the iron core 2 and an amount of gas flowing to the winding 2 and the winding 3 for cooling the winding 3 by the picks and the first and second partition plates 7 and 8. This allows for effective cooling with a well-balanced flow rate. This makes it possible to make the iron core smaller and increase the magnetic flux density, improving the cooling effect and making it smaller and lighter.

By the way, as mentioned above, the gas path in the iron core 2 and the gas path in the winding 3 have a larger frictional resistance, making it difficult for gas to flow. Tip p5: If the design is done under the same conditions, the cooling of the iron core will be worse. Therefore, the amount of heat w radiated by the surface area S1 of the radiator 4a for cooling the iron core
The amount of heat W radiated by the surface area S2 of the radiator 4b for cooling the windings is the ratio of co□ (wcoag/sl). It is conceivable to make the ratio of OIL smaller than the ratio of OIL (WCOIL/”2). In other words, S t / 82≧Wco m w
/We or L may be established.

Additionally, in general, when the radiator is installed at a higher location, the insulating gas becomes heavier at the higher location, which increases the amount of insulating gas circulated and the flow rate. Therefore, in order to allow more insulating gas to flow through the gas path in the core 2, which has a large frictional resistance, it is possible to raise the installation position of the radiator 4a for cooling the core to the same level or higher than the radiator 4b for cooling the windings. desirable.

Furthermore, by installing monitoring devices such as temperature needles in both of the two gas spaces separated by the second partition plate 8, it is possible to independently monitor the temperature of the iron core and winding. Nana 9
, it becomes possible to know the occurrence and location of defects, etc. before they occur.

〔Effect of the invention〕

As described above, according to the present invention, an iron core made of laminated silicon steel plates is provided in a tank, the main leg portion of this iron core winds a winding, an insulating gas is stored in the tank, and the insulating gas is placed outside the tank. In a gas insulated transformer equipped with a plurality of radiators for cooling gas and radiator piping communicating the tank and the radiators, a first partition plate is provided between the lower part of the iron core and the inner wall of the tank, A second partition plate is installed between the upper part of the iron core and the inner wall of the tank to divide the inside of the tank into a lower chamber, a middle chamber, and an upper chamber, and further divide the plurality of radiators for insulating gas cooling into two. Then, connect the lower radiator piping that communicates with one radiator to the lower chamber of the tank, the upper radiator piping to the upper chamber of the tank, and connect the upper and lower radiator piping that communicates with the other radiator to the middle chamber of the tank. Therefore, it is possible to obtain a gas insulated transformer that is small, has a well-balanced flow rate, and can perform effective and uniform cooling by ensuring the minimum required gas flow rate for each of the core and windings.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 3 is a side view showing the tank body, and FIG. 3 is a sectional view showing a conventional gas insulated transformer. 1...tank, 1a...insulating gas, 2...iron core,
3...Winding, 4a, 4b...Radiator, 5hj5
b... Upper radiator piping, 7, 8... Partition plate, A
...lower chamber, B...middle chamber, C...upper chamber.

Claims (1)

[Claims] An iron core made of laminated silicon steel plates is provided inside a tank, a winding is wound around the main leg portion of this iron core, an insulating gas is stored inside the tank, and the insulating gas is cooled outside the tank. In a gas insulated transformer including a plurality of radiators and radiator piping communicating the radiators and the tank, a first partition plate is provided between the lower part of the iron core and the inner wall of the tank, and a first partition plate is provided between the lower part of the iron core and the inner wall of the tank. A second partition plate is installed between each inner wall to divide the inside of the tank into a lower chamber, a middle chamber, and an upper chamber, and the plurality of radiators for cooling insulated gas are
Split the lower radiator piping that communicates with one radiator to the lower chamber of the tank, connect the upper radiator piping to the upper chamber of the tank, and connect the upper and lower radiator piping that communicates with the other radiator to the middle chamber of the tank. A gas insulated transformer characterized by: