JPS6130196B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to oil-filled electrical equipment, and particularly to the structure of a radiator.

Generally, in oil-immersed transformers, there is a tank part provided to house the transformer body, and a tank part provided to cool the transformer body, whose temperature rises when the transformer is operated, via insulating oil. The tank consists of a radiator and a radiator, and the radiator is usually attached to the tank.

There are a wide variety of radiators available, such as panel-type radiators made by joining two press-formed flat plates and welding their peripheries and connecting them to upper and lower headers, and pipes. Tubular heat radiators mainly composed of are widely used.

On the other hand, in recent years, thin sheet steel plates, etc., have been continuously and automatically formed into a corrugated shape, the upper and lower ends of the corrugations are crushed, and the tips are fixed in an oil-tight manner by, for example, arc welding, so that insulating oil can enter and exit the inside. A corrugated heat sink with many fin-like protrusions has been developed and is attracting attention as a heat sink. When constructing a tank such as a transformer using the above corrugated heat sink, the corrugated heat sink also serves as the tank side wall, and the lower side plate and bottom box are attached to the upper and lower openings of the tank side wall. These corrugated heat sinks are installed on one to four sides of the side wall depending on the amount of heat generated by the transformer, but as the capacity of the transformer increases and the amount of heat generated increases, the height of the protruding fin-like portions increases. It becomes necessary to increase the height or increase the width in the vertical direction.

However, depending on the manufacturing capacity, this corrugated heat sink is extremely thin (1.0 mm to 2.3 mm) in order to facilitate corrugation, so it can be fin-shaped to increase the heat dissipation area. If the protruding height of the protruding portion is increased, there is a problem that when insulating oil is poured into the tank, the thin steel plate is deformed by the internal pressure caused by the oil head, making it unusable. In addition, transformers are sometimes installed in sealed tanks to prevent deterioration of the insulating oil from the standpoint of no maintenance or inspections; however, in such cases, the insulation Since the internal pressure of the tank increases due to the expansion of the oil and gas, there is a problem that the fin-shaped projecting portions cannot withstand this increase in internal pressure. Therefore, the protruding height of the fin-like protruding portions of the corrugated heat sink cannot be increased due to manufacturing and strength constraints. Further, the vertical width of the fin-like protruding portion cannot be increased due to restrictions due to the sheet width of the thin steel plate.

Therefore, as the capacity of the transformer increases, even if a corrugated heat sink is installed around the entire circumference of the tank, there will be insufficient heat dissipation area.For this reason, the design of the transformer body must be changed to reduce the amount of heat generated by the transformer body. The tank itself had to be made larger to provide space for installing the corrugated heat sink, which increased the cost of the transformer.

In addition, a structure has been considered in which a corrugated heat sink is used to construct a unit type radiator independent of the tank, and this unit type radiator is communicated with the tank via an oil pipe, but the fin-like overhangs are If the number is increased, the weight will increase and the oil pipe will no longer be able to support it, and the outer diameter will increase.

Furthermore, as shown in Figure 1, there are two or three stages in the tank 3.
Stage... and multiple unit type unit heat sinks 5A, 5B
It is also possible to install the oil pipe 1 above and below.
It is necessary to provide a large number of holes 2 on the side wall of the tank 3 for attaching A, 1B, 1C, and 1D, and a lot of time is required for the installation. Also tank 3
The insulating oil 4 is heated in the tank 3 as shown by the arrow, flows into the upper unit radiator 5A through the upper oil pipe 1A, is cooled here, and descends through the lower oil pipe 1B. The oil that has flowed into the tank 3 is divided into two parts: one that rises and flows into the upper oil passage pipe 1A on the upper stage, and one that descends and flows into the upper oil passage pipe 1C on the lower stage. Therefore, the lower upper oil pipe 1C contains the heated oil near section a in the tank 3 and the upper unit radiator 5A mentioned above.
The average wall temperature (H) of the lower unit radiator 5B decreases because the cooled oil mixes with the oil and flows in. Even if the heat transfer coefficient (α) and the heat radiation area (A) are constant, the amount of heat radiation = α・A・Due to the relationship of H, the heat dissipation effect is significantly deteriorated, causing heating.

The present invention has been made in view of the above-mentioned points, and it is possible to obtain a large heat radiation area by using a corrugated heat radiation plate that is easy to manufacture without increasing the outer diameter, and has good heat radiation efficiency for oil-filled electrical equipment. The purpose is to provide equipment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking a radiator of an oil-immersed transformer as an example. In FIGS. 2 and 3, 15A and 15B are upper and lower unit type unit heat radiators, respectively, which are formed by forming sheet-like thin steel plates into corrugated shapes, and sealing the upper and lower ends of each corrugation in an oil-tight manner. It is formed using corrugated heat sinks 10a, 10a each having a large number of fin-like protrusions through which insulating oil enters and exits. That is, each unit heat radiator 15A, 15
In B, two corrugated heat sinks 10a, 10a are arranged at a predetermined interval so that the opening sides of the fin-like overhangs face each other, and the ends of the opposing corrugated heat sinks are connected with side plates 10b. They are connected to form a rectangular tube shape. Therefore, each unit heatsink 15A,1
5B has rectangular openings at its upper and lower ends, and has a large number of fin-like protrusions protruding from its side surfaces. In this case, the two corrugated heat sinks and the side plates may be constructed from one continuous thin steel plate. These two unit heat radiators 15A and 15B are stacked vertically, and the lower end rectangular opening of the upper unit heat radiator 15A is oil-tightly connected via a rectangular cylindrical connecting tube 16. An upper oil pipe 11A is connected to the container 15A, and a lower oil pipe 11B is connected to the lower unit radiator 15B. Each oil pipe 11
As shown in FIG. 4, A and 11B have a tubular part 12 attached to the tank and a half part 13 formed on one side of the tubular part 12, and a side plate 14 at the end of the half part 13.
It is constructed by fixing the Each oil pipe 11A, 1
1B is arranged such that the opening sides of the half-shaped parts 13 are opposed to each other at the top and bottom, and the unit heat radiators 15A and 15B connected through the connecting tube 16 are arranged between them.
The opening of the half-shaped part 13 of the upper oil pipe 11A, the upper rectangular opening of the upper unit radiator 15A, the lower rectangular opening of the lower unit radiator 15B, and the opening of the half part 13 of the lower oil pipe 11B. A unit type heat radiator is constructed by fixing the joints between the two in an oil-tight manner, for example, by welding or the like.

The unit type heatsink configured as described above is the fifth
As shown in the figure, the ends of each tubular portion 12 of the oil pipes 11A and 11B are inserted into the holes 2 provided in the upper and lower side walls of the tank 3 housing the transformer body and insulating oil.
For example, they are connected by being oil-tightly attached to each other by welding or the like.

The insulating oil 4 heated in the tank 3 flows into the upper unit heat radiator 15A through the upper oil pipe 11A as shown by the arrow, and then flows into the numerous fin-like protrusions of each corrugated heat sink. It cools down and descends. Furthermore, the insulating oil 4 flows into the upper stage unit radiator 15B through the intermediate connecting tube 16, where it is also cooled by a number of fin-like protrusions and descends. The insulating oil that has been sequentially cooled by each unit radiator 15A, 15B flows into the lower part of the tank 3 through the lower oil pipe 11B, is warmed in the tank 3, and rises.
It also circulates so as to flow into the upper oil passage pipe 11A.

Therefore, since there is no mixing of heated insulating oil and cooled insulating oil during circulation, the average wall temperature of the radiator increases, the natural convection circulation force increases, and the heat dissipation effect is very good in relation to the amount of heat dissipation mentioned above. Become. In addition, since the two unit heat sinks 15A and 15B use corrugated heat sinks, they are not only easy to manufacture, but even when stacked one on top of the other, the fin-like protruding portions serving as heat dissipation portions are located below the connecting tube 16. Since the fins are located so as to protrude from each other, air can flow smoothly in the vertical direction and heat can be exchanged efficiently from the multiple fin-like protrusions.

As described above, the present invention can provide a heat radiator for oil-filled electrical equipment that uses a corrugated heat sink that is easy to manufacture, has a large heat radiation area, and has good heat radiation efficiency. In addition, the radiator according to the present invention can be installed in oil-filled electrical equipment with less man-hours for drilling holes in the tank and less man-hours for installation, regardless of the capacity of the equipment body.Moreover, there is no need to increase the size of the tank, so it is inexpensive. Can be configured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a radiator for oil-filled electrical equipment using a conventional wave-shaped radiator, FIG. 2 is a perspective view showing a radiator for oil-filled electrical equipment according to the present invention, and FIG. Fig. 4 is a perspective view showing an oil pipe used in the radiator shown in Fig. 2, and Fig. 5 is a sectional view showing an oil-filled electrical equipment to which the radiator shown in Fig. 2 is attached. . 3...tank, 4...insulating oil, 10a...corrugated heat sink, 10b...side plate, 11A, 11B...oil pipe, 1
5A, 15B...Unit type unit heat radiator, 16...Connection tube.

Claims (1)

[Claims] 1. Using a corrugated heat dissipation plate formed by forming a corrugated shape on a thin steel plate and sealing the upper and lower ends of each wave in an oil-tight manner to form a number of fin-like protrusions through which insulating oil enters and exits,
Forming upper and lower unit heat radiators having square tubular shapes having openings at the upper and lower ends and having the plurality of fin-like protrusions protruding outward from edges of the opening, the upper unit heat radiator The lower end opening and the upper end opening of the lower unit radiator are oil-tightly connected via a connecting tube, and upper and lower passages are connected to the upper end opening of the upper unit radiator and the lower end opening of the lower unit radiator. A radiator for oil-filled electrical equipment in which oil pipes are connected in an oil-tight manner, and the upper and lower oil passage pipes are connected to the upper and lower parts of a tank, respectively.