JPH05166638A - Gas-insulated stationary induction apparatus - Google Patents

Abstract

PURPOSE:To prevent the wall of a tank from being locally heated at low costs without attaching a silicon-steel-plate shield. CONSTITUTION:In a gas-insulated stationary induction apparatus such as a transformer, a reactor or the like which has been filled with an insulating gas 2 such as SF6 gas or the like, chambers 12, 13 are installed on the inner face or the outer face of a tank, their inside is filled with a coolant liquid, its internal pressure is set to be nearly identical to that of the SF6 gas and the coolant liquid is circulated inside the chambers 12, 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated static inductor such as a transformer or reactor in which a transformer body composed of an iron core and a coil or a reactor body is housed in a pressure vessel filled with an insulating gas such as SF ₆ gas. ..

[0002]

2. Description of the Related Art Due to the advantages of non-combustibility and explosion proof, the oil-immersed transformer that has been used conventionally does not have to change its basic structure, and instead of insulating oil as an insulating medium, insulation is used. Attention has been focused on a gas-insulated transformer and a reactor that perform insulation and cooling of a transformer by using an insulating gas such as SF ₆ gas having excellent characteristics. Although it has already been put to practical use in small capacity transformers and reactors with relatively low voltage of several KV and several 100 KVA, in recent years, due to its excellent advantages, it has been applied to transformers and reactors with higher voltage and large capacity. Expansion is being studied.

In a large-capacity device, it is impossible to effectively cool a large amount of heat generated internally by SF ₆ gas cooling alone, so a liquid cooling system is adopted. FIG. 2 illustrates a separate type transformer as an example of this type of gas-insulated static inductor.

SF ₆ gas in the pressure vessel 1 is 4 kg / cm ² G
The heat generated from the coils 4 and 5 is cooled by the cooling panel 6 in the coils 4 and 5. Refrigerant is sent from the direction of the arrow in the figure to the in-coil cooling panel 6 by the pump 10 via the insulating hose 8 and is circulated and cooled in the circulation path returning to the cooler 11 via the insulating hose 9. Similarly, the iron core is cooled by the iron core cooling panel 7.

[0005]

A liquid-cooled transformer represented by a separate system is mainly intended to cool a coil and an iron core, and local overheating of tank 1 where liquid cooling cannot be expected is filled with SF ₆ gas. Due to the internal cooling and the natural circulation cooling of air from the outer surface, there was a limit to the capacity increase due to the poor cooling characteristics. Especially, the tank surface facing the coil and the large current lead is more likely to generate local overheating due to the leakage magnetic flux, and the larger the capacity, the higher the possibility. As a means for solving this, a measure to use the tank 1 as an aluminum tank that also serves as an electromagnetic shield has been put into practical use. However, there was a drawback that the cost was tripled compared to the iron tank. There is also a measure to attach a silicon steel plate shield that can reduce local loss of heat and prevent local overheating even if the magnetic flux leaks into the inner surface facing the coil of the tank. However, the shape of the cylindrical tank of the pressure vessel as shown in FIG. 2 becomes complicated,
Increasing costs is inevitable. It is an object of the present invention to realize a large capacity gas-insulated static inductor by preventing local overheating of the tank wall at low cost in the gas-insulated static inductor.

[0006]

The gas-insulated transformer of the present invention has a chamber for filling the inside or outside of the tank with a refrigerant on the surface of the tank facing the coil and the large current lead.
A structure is provided to prevent local overheating by forced cooling by flowing a refrigerant through it.

[0007]

With the structure of the present invention, it is possible to prevent local overheating even with a large capacity, and it is possible to realize a large-capacity gas-insulated transformer of 300 MVA with a steel tank without installing a silicon steel plate shield. ..

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIG. 1 using a gas insulation transformer as an example. The same members as those of the conventional type shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. The inner surface of the tank 1 facing the coil 5 is provided with chambers 12 and 13 filled with a refrigerant, and the refrigerant liquid is pumped by a pump 10.
Is sent to the chambers 12 and 13 via the manifold pipes 14 and 15, and is cooled to the cooler 11 via the manifold pipes 16 and 17.
Returning to the pump 10, it is circulated and cooled. The refrigerant liquid and the SF ₆ gas in the tank are adjusted to almost the same pressure by the same pressure device 20 in which a bellows or a rubber bag is arranged.

In the gas-insulated transformer of the present embodiment having such a structure, local overheating of the tank surface can be prevented by forced liquid cooling or evaporative cooling of the refrigerant in the chamber. Since the pressure in the chamber and the pressure in the tank are almost the same with the same pressure device 20, structural strength is simple, and because it is made of the same iron material as the tank in terms of material, effective local heating without increasing costs Can be prevented.

Although one embodiment of the present invention has been described with the configuration in which the chamber is provided on the inner surface of the tank, it goes without saying that the configuration in which the chamber is provided on the outer surface of the tank is also a modification of the present invention. In this case, the pressure difference between the pressure inside the chamber and the atmospheric pressure becomes large, and the structural strength of the chamber must be increased, but there is an advantage that it is easy to install.

Further, although the manifold pipes of the embodiment have been described with the structure outside the tank, the structure in which these pipes are arranged inside the tank is also a modified example in which weathering of the pipe can be effectively prevented.

Although the embodiment of the present invention has been described based on the concept of a chamber called a chamber, a configuration in which the pipe is meandered and welded to the inner or outer surface of the tank is also a modification of the present invention.

[0013]

As described above, according to the present invention, it is possible to effectively cool the local overheat of the tank of the large-capacity gas-insulated static inductor without increasing the cost, and the cost is low and the gas-insulated static is highly reliable. An inductor can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a gas insulated static inductor of the present invention.

FIG. 2 is a cross-sectional view showing the configuration of a conventional gas-insulated static inductor.

[Explanation of symbols]

1 ... Tank 2 ... SF ₆ gas 3 ... Iron core 4 ... Low-voltage coil 5 ... High-voltage coil 6 ... In-coil cooling panel 7 ... Iron-core cooling panel 8, 9 ... Insulation hose 10 ... Pump 11 ... Cooler 12, 13 ... Chamber 14 , 15, 16, 17 ... Manifold piping

Claims (1)

[Claims] 1. In a gas-insulated static inductor such as a transformer or a reactor filled with an insulating gas such as SF ₆ gas, a chamber is provided on the inner or outer surface of the tank, and the inside of the tank is filled with a refrigerant liquid so that the inner pressure is SF ₆ A gas-insulated static inductor characterized in that it is almost the same as gas and that a coolant liquid is circulated in the chamber.