JPH0362291B2 - - Google Patents

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention uses a condensable liquid as an insulation and cooling medium for a coil portion, and a non-condensable insulating gas for insulation and cooling of a portion other than the coil portion. This invention relates to an evaporative cooling induction electric appliance used as a cooling medium.

(Prior art) Evaporative cooling uses the heat of vaporization required when condensable liquids such as fluorocarbons change from liquid phase to gas phase to cool induction electric appliances such as transformers and reactors. It is well known that there are induction electric devices. There are roughly two types of methods for cooling heat generating parts such as coils and iron cores in such evaporative cooling induction electric appliances, such as evaporative cooling transformers (hereinafter abbreviated as transformers). Part 1
One method is to fill a tank with a condensable liquid and immerse the transformer body therein, and the other method is to spray the condensable liquid from the top of the transformer body to the heat generating part. The former is because the heat-generating parts of the transformer are completely covered with condensable liquid, so all heat-generating parts are evenly cooled, and the condensable liquid has a higher dielectric strength in its liquid state than when it becomes a gas. Although it has the advantage of being good for insulation, it has the disadvantage that it requires a large amount of condensable liquid, which increases the weight of the entire transformer. On the other hand, in the latter case, the minimum amount necessary for cooling needs to be sprayed onto the heat generating part, so the amount of condensable liquid is small and the weight is light.

(Problem to be solved by the invention) However, especially for devices with complex internal structures such as high-voltage transformers, it is difficult to evenly supply condensable liquid to the heat generating parts. This may cause an imbalance in the temperature distribution. In addition, this method relies on vaporized condensable liquid for internal insulation, so when the transformer is not energized and the main body is cold, the transformer is not filled with vaporized condensable liquid, so the transformer Immediately after applying electricity, the insulating medium is very thin. To prevent this, generally a non-condensable insulating gas (for example, SF ₆ , etc.) is mixed in with the condensable liquid to share insulation during cold conditions. However, condensable liquids have the property that phase change from gas phase to liquid phase is difficult to occur when non-condensable insulating gases are present.
Cooling performance will be significantly reduced. To prevent this, the non-condensable insulating gas is collected and separated into a special container when the temperature inside the transformer rises and the vaporized condensable liquid fills the inside so that it can perform its insulating function sufficiently. It is desirable to do so, and there are some examples of doing so, but the disadvantage is that the structure becomes complicated.

The object of the present invention is to house the coil part of an induction electric device that generates a large amount of heat in a container that is kept airtight from other parts of the tank, and to cool and insulate it with a condensable liquid filled in this container. It is an object of the present invention to provide an evaporative cooling inductor which has a simplified structure and improved cooling performance by cooling and insulating a portion with a relatively small amount of heat generation with a non-condensable insulating gas.

[Structure of the invention]

(Means and effects for solving the problems) In the evaporative cooling induction electric appliance of the present invention, an iron core and a coil forming the electric appliance body are housed in a tank, and only this coil is placed in an airtight insulating container. The space is filled with a condensable liquid, the space inside and outside the container in the tank is filled with a non-condensable insulating gas, and the condensable liquid is circulated through a heat exchanger. It consists of

In the evaporative cooling induction electric appliance of the present invention, the coil of the electric appliance body, which generates a relatively large amount of heat, is immersed in a condensable gas and the heat of vaporization is used to perform evaporative cooling, and other parts such as the iron core are cooled. For this purpose, we used a non-condensable insulating gas to cool the
In addition to being able to effectively cool the coil without using large amounts of condensable liquid, the insulation of the internal space does not deteriorate even when the inside of the appliance is cold.
It is possible to provide an evaporatively cooled induction electric appliance that is economical and has excellent cooling and insulation performance.

(Example) An example of the present invention will be described below with reference to an evaporative cooling transformer shown in the figure. In the figure, reference numeral 1 indicates a transformer tank, and the tank 1 accommodates an iron core 2 forming a main body of the transformer and a coil 3 wound around the core. The coil 3 is housed in an airtight insulating container 4 with a sufficient space 4a around it. The container 4 is filled with a condensable liquid 5 such as Freon 113, and the upper part of the container 4 is filled with a condensable liquid 5 that has been vaporized by cooling the coil 3.
Pipes 6a and 6b are provided for discharging the vapor and introducing the condensable liquid 5, which has condensed and liquefied again, into the container 4. A heat exchanger 7 for condensing the vapor of the condensable liquid 5 is provided in the upper part of the tank 1, and the inlet and outlet of the heat exchanger 7 are connected to the pipes 6a and 6b of the container 4.
On the other hand, in the space other than the container 4 in the tank 1, there is a non-condensing material such as SF ₆ , which is in a gaseous state at room temperature and which cools heat-generating parts other than the coil 3 (iron core 2, etc.) and increases the dielectric strength of the internal space. It is filled with insulating gas 8. In the illustrated structure, the clamp fittings for tightening the iron core 2, the insulating members of the coil 3, and the insulating members supporting them from above and below are omitted for the sake of brevity. Each coil 3 is formed from a large number of coil sections, but since it is not possible to illustrate all of them, each coil section is shown in a simplified manner.

Next, the operation of the above transformer will be explained. When heat is generated in the coil 3 in the container 4, the condensable liquid 5 in contact with the coil 3 is heated and vaporized, cooling the coil 3 at this time. As a result, the vapor that becomes bubbles rises in the condensable liquid 5, accumulates in a vapor reservoir 9 at the upper part of the container 4, and further enters the heat exchanger 7 at the upper part of the tank 1 through pipes 6a and 6b. heat exchanger 7
is equipped with a plurality of heat exchange pipes (not shown), and the vapor of the condensable liquid 5 that enters the heat exchanger 7 is deprived of heat while passing through the heat exchange pipes, cools and liquefies, and the liquefied condensate The liquid 5 returns from the heat exchanger 7 to the container 4 via tubes 6a, 6b. The coil 3 is cooled by this circulation.

On the other hand, the heat generating parts other than the coil 3 portion (iron core 2, etc.) are cooled by removing heat from the non-condensable insulating gas 8 filled in the space other than the container 4 in the tank 1.
The non-condensable insulating gas 8 heated by taking heat from the iron core 2 and the like enters an external cooler (not shown) provided as needed, cools down, and then returns to the tank 1, repeating the cycle. Generally, the amount of heat generated by the iron core 2 is about a fraction of that of the coil 3, so it is possible to cool it sufficiently by natural circulation due to convection of the non-condensable insulating gas 8. However, as mentioned above, it is necessary to Depending on the situation, an external cooler can be installed to increase the cooling effect.

〔Effect of the invention〕

As described above, according to the present invention, a coil is immersed in a condensable liquid for a tank that generates a relatively large amount of heat in the main body of an electric appliance, and evaporative cooling is performed using the heat of vaporization. By using non-condensable insulating gas to cool the coil, the coil can be effectively cooled without using large amounts of condensable liquid. It is possible to provide an economical evaporative cooling induction electric appliance with excellent cooling and insulation performance without deterioration of performance.

[Brief explanation of drawings]

The drawing is a partially cutaway vertical sectional view showing an embodiment of the evaporative cooling induction electric appliance according to the present invention. DESCRIPTION OF SYMBOLS 1...tank, 2...iron core, 3...coil, 4...container, 4a...space, 5...condensable liquid, 6a, 6b...
Tube, 7... Heat exchanger, 8... Non-condensable insulating gas, 9...
Steam reservoir.

Claims (1)

[Claims] 1. The iron core and coil that form the main body of the electrical appliance are housed in a tank, and only this coil is housed in an airtight insulating container with a space provided therein, and the space is filled with a condensable liquid, and the tank is filled with a condensable liquid. An evaporative cooling induction electric appliance characterized in that a space other than the inside of the container is filled with a non-condensable insulating gas, and the condensable liquid is circulated through a heat exchanger.