JPS6043807A - Oil-immersed apparatus with terminal box - Google Patents

Abstract

PURPOSE:To allow improvement in cooling performance and control of temperature rise, especially at bushings by providing vents on a bottom surface and an upper part of a terminal box covering the upper part of a heat dispersion part and equipping a blast means for circulation of cooled air flow. CONSTITUTION:A terminal box 4 for concealing bushings 3 is provided over an electrical device itself and a tank 1 containing insulating oil therein and having a heat dissipating part 2 such as a wave-shaped rib on the side thereof, and cables 6 are drawn out of lower parts of the both sides. A slit-like vent 8 is provided on the lower surface of the terminal box 4 and a hand hall is provided over the terminal box 4. A propeller fan 10 is mounted on a cover 5 of the hand hall and a vent 9 having a drip-proof cover is provided over the cover. Thus, external air is drawn up from the vent 8 and warmed air in the inside is exhausted from the upper vent 9 to promote heat-dissipation in the bushings 3. Upward air flow due to convection along the surface of the heat dissipation part is accelerated in the heat dissipation part 2.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to oil-filled electrical equipment, such as transformers and reactors, in which a terminal box is provided above a tank that houses the contents of electrical equipment and insulating oil and has a heat dissipation section on the side. Regarding.

[Background of the invention]

Recent oil-filled electrical equipment often has a structure in which a terminal box is installed above the tank to hide the charged part (bushing) in order to protect the charged part (bushing) on the tank from salt damage and ensure maintenance safety. .

FIG. 1 shows an example of a conventional oil-filled electrical device with a terminal box. 1
is a tank that stores the contents of electrical equipment and insulating oil and has a heat dissipation part 2 such as a corrugated lip on the side, 3 is a bushing, 4 is a terminal box,
5 is a hand hole cover, 6 is a cable, and heat radiation from the heat radiation part 2 is performed by natural convection of air and heat radiation shown by arrows.

FIG. 2 shows another example of a conventional oil-filled electrical device with a terminal box.

In this example, a blower 7 that generates an upward air curtain airflow as shown by the arrow is installed under the heat radiating section 2 to perform forced air cooling, and the other configurations are the same as in FIG. 1.

However, in either case, since the terminal box 4 is provided to cover the upper part of the heat radiating section 2, the natural convection of air and the flow of forced air cooling along the heat radiating section 2 are obstructed by the terminal box 4. ,
In particular, the amount of heat dissipated from the portion near the upper end where the temperature is highest of the heat dissipation section 2 decreased, and a sufficient cooling effect could not be obtained. Also,
Since the terminal box 4 is sealed and there is no air circulation, the temperature of the bushing 3 tends to rise, leading to problems such as thermal deterioration of the sealing material between the bushing and the tank. Therefore, it was necessary to use expensive bushings with large current capacity to prevent temperature rises.Oil-filled electrical equipment with terminal boxes that improve dynamic performance, especially the temperature rise of bushings, and are highly reliable. It's about getting.

[Summary of the invention]

The present invention provides an oil-filled electrical equipment with a terminal 'f', in which ventilation holes are provided in the lower surface of the terminal box that covers the top of the tank heat radiation part and in the upper part of the terminal box, and through these ventilation holes, the tank heat radiation part and the terminal box are connected. It is characterized by being provided with a blower means for circulating cooling air inside.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG. In this embodiment, a terminal box 4 that hides a bushing 6 is provided above a tank 1 that stores the contents of electrical equipment and insulating oil and has a heat dissipation part 2 such as a corrugated lip on the side, and a cable 6 is connected from the bottom of both sides of the terminal box 40. It is similar to the conventional example shown in FIG. 1 in that it is marked in black, but a slit-shaped ventilation hole 8 is provided in the lower surface of the terminal box 4 that covers the top of the tank heat radiating section 2. In addition, a hand hole is provided at the top of the terminal box 4 for connection work and maintenance inspection inside the terminal box, and a propeller fan 10 is attached to the hand hole cover 5, and a ventilation port 9 with a drip-proof cover is provided above the hand hole. It is a provision.

In this way, by the action of the propeller fan 10, external air is sucked in through the ventilation opening 8 on the bottom of the terminal box 4 as shown by the arrow in the figure, and the warm air inside is exhausted through the ventilation opening 9 on the top. Therefore, heat dissipation from the bushing B can be promoted. In addition, this ventilation action works on the heat dissipation section 2 located below the ventilation opening 8 so as to promote upward airflow due to convection along the heat dissipation surface, so the cooling effect of the heat dissipation section 2 is improved, especially at high temperatures. This is effective in increasing the amount of heat dissipated near the upper end of the heat dissipating section 2.

Another embodiment of the invention is shown in FIG. This embodiment is applied to a forced-air-cooled oil-filled electrical equipment with a terminal box in which the blower 7 is installed directly below the tank heat radiating section 2, similar to the conventional example shown in FIG. Ventilation holes 8 and 9 are provided on the lower surface of the covering terminal box 4 and on the upper part of the terminal box 4, respectively, and the blower 7 is also used as an air blowing means for ventilating the terminal box 4. The blower 7 may be a propeller fan, a sirocco fan, an inertia fan, or even a combination of these. After passing through, a part of it enters the terminal box 4 through the ventilation hole 8 above the heat dissipation section 2, flows around the bushing 6, and is finally discharged from the ventilation hole 9 with a drip-proof cover at the top of the terminal box. .

Therefore, the cooling air from the blower l is not obstructed by the terminal box 4 as in the conventional case, and the air flows easily between the waveform lips of the heat dissipation section 2. In addition to increasing the amount of heat dissipation and enhancing the cooling effect,
The inside of the terminal box 4 is also effectively cooled by promoting ventilation.

The power supply for the propeller fan y10 and the blower 7 in the above embodiments may be obtained from the load side of the equipment or from a separate power supply, and furthermore, the power may be supplied by a thermoelectric generating element using FeEIi2 or the like.

It is also possible to further enhance the cooling effect by detecting the load current and temperature of the equipment and activating these air blowing means only when the load is above a certain level or when the temperature is high, and relying on natural convection at other times. It is. If the above embodiments are followed, the inside of the terminal box is cooled, so the current capacity of the bushing can be reduced, making it possible to reduce the size and weight of the equipment and reduce the cost.

〔Effect of the invention〕

According to the present invention, ventilation holes are provided on the upper and lower surfaces of the terminal box provided above the tank heat radiating section, and the structure is configured to forcefully ventilate the tank heat radiating section and the terminal box, thereby cooling the tank heat radiating section. The effectiveness is improved, and in particular heat dissipation from the bushing is promoted, so the temperature rise is small and thermal deterioration of the sealing material interposed between the bushing and the tank can be prevented, resulting in a highly reliable oil-filled electric root unit with terminal box. be able to.

[Brief explanation of the drawing]

Figure 1 shows a conventional self-cooling type oil-filled electrical equipment with a terminal box, in which (a) is a front view, (b) is a partially cutaway side view,
Figure 2 is a diagram showing a conventional forced air cooling type oil-filled electrical converter with a terminal box, (a) is a front view, (b) is a side view with a part cut away, and Figure 3 is a diagram showing one example of the present invention. In the example diagrams, (a) is a plan view, (
b) is a partially cutaway front view, (c) is a plan view of the main part seen from the direction of arrow A, and FIG. 4 is a diagram of another embodiment of the present invention, and (a) is a partially cutaway view. A front view, and ('b) a partially cut side view. 1: Tank, 2: Tank heat dissipation section, 6: Bushing, 4
:Terminal box, 8.9 Two ventilation openings, 7.10: Feed (In

Claims (1)

[Claims] In oil-filled electrical equipment in which a terminal box is installed above a tank that houses the contents of the electrical equipment and insulating oil and has a heat radiating section on the side, ventilation is provided to the bottom surface of the terminal box that covers the top of the tank's heat radiating section and the top of the terminal box. 1. An oil-filled electrical device with a terminal box, characterized in that a vent is provided and a blowing means is provided for circulating cooling air through the ventilation port into the tank heat radiating section and the inside of the terminal box.