JPS646527B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention significantly improves the cooling effect by increasing the heat transfer coefficient on the insulating gas side and the air side of a radiator of a gas insulated transformer installed indoors.

For cooling this type of transformer, it is generally desirable to use a self-cooling type radiator to prevent noise generation, and the radiator increases the cooling effect and reduces the heat radiation area or unit quantity, and the entire transformer It is desirable to reduce the floor space of the building as much as possible.

The structure of a conventional transformer of this type and the ventilation equipment of the transformer room are as shown in FIGS. 1 and 2. A transformer tank 1 houses a winding 2 and an iron core 3 and is filled with an insulating gas 4. Reference numeral 5 indicates a high-pressure side bushing, and 6 indicates a low-pressure side bushing. The high-pressure side and low-pressure side lead wires are led out from the side wall of the tank 1 to external terminals 5a and 6b, respectively, and connected to the external terminals 5a and 6a. The lead wires (not shown) are connected to bus ducts 7a and 7, respectively.
It is located inside b. A plurality of self-cooling type radiators 8 are attached to the side wall of the transformer tank 1. The radiator 8 has a structure in which hollow panels are connected in parallel to upper and lower headers (none of which are shown), and the upper connecting pipe 8a and lower connecting pipe 8b are connected to the side wall of the transformer tank 1. It is supported integrally with the transformer tank 1.

In the transformer room 100 in which the above transformer is installed, a ventilation port 103 with a ventilation fan 102 is provided in the partition wall 101, and the ventilation port 103 has an opening equivalent to the floor area of the entire transformer. A shielding hood 105 suspended above the transformer is connected to the transformer through a ventilation duct 106.

Loss heat generated from the winding 2 and iron core 3 of this transformer is transferred to the insulating gas 4 in the tank 1,
The insulating gas 4 that has risen due to natural convection due to the temperature difference is guided into the radiator 8 from the upper connecting pipe 8a of the radiator 8, and is introduced into the transformer chamber 100 from the heat radiation surface (surface) of the hollow panel that constitutes the radiator 8. The transformer is cooled by dissipating heat into the tank 1, and then returning to the tank 1 via the lower connecting pipe 8b, repeating the circulation action to cool the transformer.

The air in the transformer room 100 is introduced into the shielding hood 105 by the ventilation fan 102 as shown by the arrow, and is sucked from the shielding hood 105 into the ventilation opening 103 through the ventilation duct 106, and is discharged to the outside from the ventilation opening 103. By doing so, the transformer room 100 is cooled by ventilation.

However, since the conventional shielding hood 105 is suspended with a large distance between the lower edge of its opening and the upper surface of the radiator 8, the ventilation fan 105
2 into the shielding hood 105, only a part of it passes through mainly in contact with the upper part of the heat radiating surface of the radiator 8; in such a ventilation path, the heat radiating surface of the radiator 8 The disadvantage was that the heat transfer coefficient on the air side was inevitably reduced, and the cooling effect was poor.

Furthermore, in a transformer that allows natural convection of insulating gas, the speed at which the insulating gas naturally convects due to temperature difference is determined by the center height of the radiator (cooling center height).
It is known that the heat transfer coefficient on the surface of the winding and the core is proportional to the natural convection speed of the insulating gas. Since the difference between the height of the cooling center and the height of the heating center of a conventional transformer is small, there is a limit to the increase in the heat transfer coefficient on the insulating gas side. This had the disadvantage that the cooling effect of the container was further reduced.

Additionally, in general, in self-cooled gas insulated transformers, when the transformer capacity increases from the viewpoint of cooling performance of the refrigerant gas, the number of radiators installed must be increased, or a cooling fan must be attached to make the transformer air-cooled. However, adding a radiator increases the size of the transformer as a whole, making it impossible to install it indoors where floor space is limited, and using a wind-cooled system poses problems in terms of noise prevention. Ta.

This invention eliminates the above drawbacks, increases the heat transfer coefficient on the insulating gas side and the air side of the self-cooling radiator of a gas insulated transformer, and greatly improves the cooling effect, making it suitable for indoor installation. The purpose of the present invention is to provide a gas insulated transformer with low noise and a small floor space.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a longitudinal sectional view showing an embodiment of the present invention, in which a plurality of ascending gas pipes 11 are vertically branched and provided at the center of the upper wall 10a of the transformer tank 10. Upper header pipe 1 at the upper end
Connect 2 horizontally. Transformer tank 10
A plurality of descending gas pipes 13 and 14 are branched vertically from the lower ends of the opposing side walls 10b and 10c, and a plurality of descending gas pipes 13 and 14 are provided at the same symmetrical position as the ascending gas pipe 11. Lower header pipes 16 and 18 are connected to the upper end in a horizontal direction.

The above-mentioned ascending gas pipe 11 and descending gas pipe 13,
14 and the top wall 10a and side walls 10b, 10c of the transformer tank 10, as well as between the ascending gas pipe 11 and the upper header pipe 12, and between the descending gas pipes 13, 14 and the lower header pipes 16, 18. The connections between the two are removable by means of flanges (not shown).

Above the top wall 10a of the transformer tank 10,
A plurality of self-cooling type radiators 80 are arranged in parallel and facing each other on both the left and right sides of the upper header pipe 12, and the upper connecting pipe 80a and the lower connecting pipe 80b of the radiator 80 are connected to the upper header pipe 12, respectively. It is detachably connected to the lower header pipes 16 and 18 via flanges (not shown).

Thus, the plurality of radiators 80 are disposed above the upper wall 10a of the transformer tank 10, supported by the upper header pipe 12 and the lower header pipes 16, 18, and are arranged in parallel with the transformer tank 10. It will be connected. Regarding the support of the radiator 80, a support stand may be placed between it and the upper wall 10a as necessary, and an appropriate fixing member may be interposed between it and the rising gas pipe 11 to ensure that the radiator 80 is fixed. The member may be welded to and supported by the radiator 80 and the rising gas pipe 11.

The shielding hood 105 hangs down to the vicinity of the lower end of the outer surface of each radiator 80 on both the left and right sides and both front and rear ends, and surrounds the outer surface of each radiator, so that the entire radiator is covered by the shielding hood 105. and covered from above. This shielding hood 105 is connected to the partition wall 101 of the transformer room 100 via the ventilation duct 106.
Connect to the ventilation port 103 of.

In this embodiment, a high voltage side bushing 50 and a low voltage side bushing 60 of the transformer winding 20 are provided on opposing side walls 10b and 10c of the transformer tank 10, respectively, and bus ducts 70b and 70c are provided on the side walls 10b and 10c, respectively. , and the radiator 80 is placed close to the top wall 10a of the transformer tank 10. However, if there is sufficient ceiling height in the transformer room 100, the bushings 50, 60 and bus ducts 70b, 70c may be installed. The heat radiator 80 may be attached to the upper wall 10a of the transformer tank 10 and placed above the bus duct.

When the heat radiator 80 is arranged as described above, the loss heat generated from the winding 20 and the iron core 30 is transferred to the insulating gas 40 in the transformer tank 10 and rises in the rising gas pipe 11 as shown by the arrow. Then, it reaches the upper header pipe 12, and is guided from the upper header pipe 12 to the radiator 80 via the upper connecting pipe 80a. The insulating gas cooled by dissipating heat from the heat radiating surface of the radiator 80 enters the lower header pipes 16 and 18 through the lower connecting pipe 80b, descends in the descending gas pipes 13 and 14, and enters the transformer tank 10. return.

The natural convection speed when the insulating gas circulates in this way is that the difference between the height of the cooling center and the height of the heating center is lower than that of a conventional transformer because the radiator 80 is placed above the transformer tank 10. The heat transfer rate on the insulating gas side on the surface of the windings and core increases significantly, and combined with the fact that a plurality of radiators 80 are connected in parallel to the transformer tank 10, rate increases significantly.

In addition, a shielding hood 105 is provided by the ventilation fan 102.
Since the shielding hood 105 surrounds the vicinity of the lower end of the outer surface of each radiator 80, the air introduced into the transformer chamber 100 passes through the lower end of each radiator 80 as shown by the arrow. The introduced air is then introduced into the shielding hood 105, and the introduced air can be brought into contact with the entire heat radiating surface of each radiator 80. Therefore, the heat transfer coefficient on the air side of the radiator 80 also increases significantly.

In the above embodiment, the radiator is a self-cooling type that naturally circulates insulating gas, but it is not limited to a self-cooling type, and as shown in FIG.
The same applies to a system in which a blower 90 is inserted into the insulating gas 14 to forcefully circulate the insulating gas.

As described above, this invention arranges a plurality of heat radiators of a gas insulated transformer in parallel and facing each other above the top wall of the transformer tank, and the lower ends of the front, rear, left and right outer surfaces of each heat radiator are It is surrounded by a shielding hood suspended from above, and the shielding hood is connected to the ventilation opening of the transformer room.

Therefore, according to the present invention, since the heat transfer coefficient on the air side increases as well as the heat transfer coefficient on the insulating gas side, there is no need to use an air-cooled radiator, and a self-cooling radiator can be used. As a result, the cooling performance is almost the same as that of an air-cooled type, and not only can a low-noise transformer suitable for indoor installation be obtained, but also the heat radiation area of the radiator is smaller than that of conventional transformers of the same capacity. Alternatively, the number of installations can be reduced, and the rated capacity of a self-cooling transformer can supply the same overload as an air-cooled type, making it possible to raise the limit of self-cooling capacity higher than before. becomes.

In addition, according to this invention, the floor space occupied by the radiator is reduced, and the floor space for the entire transformer is reduced. It has the advantage of being able to be installed even in places with narrow floor space.

The present invention is not limited to the gas insulated transformers described above, but can also be applied to gas insulated reactors, as well as oil-immersed transformers and oil-immersed reactors.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a conventional self-cooling gas insulated transformer and a transformer room, FIG. 2 is a plan view thereof, and FIG. 3 is a longitudinal sectional view showing an embodiment of the present invention. 4
The figure is a partial vertical sectional view showing an embodiment of a forced circulation gas insulated transformer. 10: Transformer tank, 10a: Top wall of tank, 10b, 10c: Side wall of tank, 11: Rising gas pipe, 12: Upper header pipe, 13, 14:
Descending gas pipe, 16, 18: Lower header pipe, 8
0: radiator, 100: transformer room, 103: ventilation opening, 105: shielding hood.

Claims (1)

[Claims] 1. In a gas insulated transformer installed indoors, a plurality of radiators are arranged in parallel and facing each other on both the left and right sides of the rising gas pipe that branches upward from the top wall of the transformer tank, and each radiator is placed in parallel. The ascending gas pipe and the descending gas pipe branched from the side wall of the transformer tank are connected to each other via an upper header pipe and a lower header pipe, and the pipes hang down to the lower end of the outer surface of the radiator and extend around the radiator. 1. A gas insulated transformer comprising: a shielding hood that surrounds the transformer from above, and the shielding hood is connected to a ventilation port that communicates with the outside of the transformer room.