JPS6239806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to tanks for oil-filled electrical equipment such as transformers and reactors. The present invention relates to a tank for oil-filled electrical equipment having a heat sink with an overhanging oil chamber formed by a projecting portion.

Generally, in oil-filled electrical equipment, heat generated inside the equipment is radiated from the tank surface using insulating oil as a medium. For this reason, tanks for oil-filled electrical equipment usually have a structure that can enhance the heat dissipation effect in the following manner. In other words, there are two methods: attaching heat dissipation fins to the side plates, attaching heat dissipation pipes that communicate with the top and bottom to the side plates, seam welding the outer peripheries of two panel plates to form a panel element, and attaching the upper and lower headers to the tank. There are methods to expand the heat dissipation area by bending the material into a corrugated shape, and the latter two methods have been particularly popular in recent years.

By the way, a so-called panel type heat radiator (not shown) is constructed by welding and fixing a plurality of panel elements formed by seam welding the outer peripheries of the two panel plates according to the required amount of heat radiation. There are disadvantages such as the manufacturing process requires many steps and the manufacturing process takes a long time. In other words, the manufacturing process involves cutting the hoop material to predetermined dimensions, press forming, spot welding in the grooves in the panel plates, welding the outer circumference seam of the panel plates, correcting the twist of the panel elements, welding combinations between panel elements, inserting the header, and welding the header and the panel. , requires numerous steps such as welding the panel's external reinforcement and attaching the panel radiator to the tank.

In addition, the total length of welds such as panel panel outer circumference seam welding and stitch welding between panel elements is extremely long, and most of the welding areas involve resistance welding where the welding atmosphere is not necessarily sufficient, so there is a possibility of oil leakage due to welding defects. However, there are also problems such as a lack of reliability.

In addition, the radiator is subject to up-down, front-back,
Panel radiators must have the strength to withstand repeated fatigue caused by vibration acceleration in the left and right directions, but the panel radiator must have the strength to withstand the weight of the radiator including oil, the vibration acceleration applied to the center of gravity of the radiator, and the position of the center of gravity of the radiator from the side wall of the tank. A moment due to the multiplicative product of the distances is generated at the base of the header installed at the top and bottom of the radiator, that is, at the tank side wall attachment part, and composite forces such as bending, torsion, and shearing also act on the panel element connection welds. Therefore, in devices that generate a large amount of heat, a large number of panel elements and a large length are required, which can cause extremely large stress to occur in the above-mentioned parts, leading to damage during transportation. There is. Therefore, in order to suppress these generated stresses to below a permissible value, it is necessary to provide reinforcement to connect the panel radiator to the tank on the outside, which further increases the number of manufacturing steps.

Note that this type of heatsink is formed into a panel board by pressing, and the type of panel width, length, and pitch between panels is limited due to the press type. Therefore, the optimal panel width, length, and It also has drawbacks such as the inability to select the pitch between panels, and the degree of freedom in design is restricted, making it impossible to perform optimal design.

On the other hand, in a method of expanding the heat dissipation area by bending the side plates into a corrugated shape, a corrugated heat dissipation plate as shown in FIG. 1 is used. That is, as shown in the cross-sectional view in FIG. 2, a thin sheet-like steel plate 1 is bent into a wave shape to form fin-like protrusions 1a at regular intervals, and the tips of the fin-like protrusions 1a are bent. They are connected to each other by a plurality of reinforcing pieces 2, and the upper and lower edges of the protrusion are pressed together as shown in FIG. 3, for example.
They are fused together using MAG welding to form a single heat sink. When this heat sink is used to construct a tank for oil-filled electrical equipment, as shown in FIG. 5 by welding, etc.

In this case, if it is an open oil-filled tank for electrical equipment, there is an oil head as internal pressure applied to the tank, so
It is required that the stress and amount of deformation on the wall surface of the fin-like protruding portion of the heat sink be below a permissible value with respect to this tank internal pressure.

In addition, when using a sealed tank to prevent deterioration of the insulating oil, in addition to the oil head, the expansion of the insulating oil due to the rise in temperature of the contents and the rise in temperature inside the gas chamber will cause pressure in the gas chamber. It should be noted that residual strain will occur in the overhang when a rise occurs and the resulting pressure on a portion of the overhang exceeds its yield stress.

However, the stress in the overhang is proportional to the amount of overhang, that is, the square of the wave depth, and is inversely proportional to the square of the plate thickness, and the amount of deformation is proportional to the fourth power of the wave depth. It increases or decreases in inverse proportion to the cube of the plate thickness, so in order to keep the stress and deformation in the overhang below the respective allowable values, it is necessary to increase the plate thickness according to the size of the overhang. As the thickness increases, the material cost and product weight naturally increase.

Furthermore, in a structure in which corrugated heat dissipation plates are formed on the four side walls of the tank as shown in Figure 4, the fin-like protrusions must be provided at appropriate pitches from the viewpoint of heat dissipation efficiency. It is not possible to provide more than the amount corresponding to the tank size. If a larger amount of heat dissipation is required, the amount of protrusion of the fin-like protruding portions may be increased, but of course there are manufacturing limitations, so such a tank structure cannot be adopted.

In view of these points, the present invention has been developed to provide an oil-filled electrical appliance that is small, lightweight, and economical, with large mechanical strength and the ability to freely select the heat dissipation area without increasing the thickness of the fin-like protruding parts. The purpose is to provide equipment tanks.

Embodiments of the present invention will be described below with reference to FIGS. 5 to 15.

FIG. 5 is a plan cross-sectional view of the corrugated heat dissipation plate 10A constituting the long side wall of the tank, in which the sheet-like thin steel plate 11 is bent in a corrugated manner so that fin-like overhangs are formed at regular intervals. A plurality of portions 11a are continuously formed, and flat plate portions 12 and 13 having different sizes are provided at both ends of the portions, and the longer plate portion 13 has a tank side wall portion on the long side as described later. It consists of This wave-shaped heat sink 1
As shown in FIGS. 7 and 8, 0A has flat plate portions 12 and 13 at both ends further bent into an L-shape or a U-shape to secure it to another adjacent corrugated heat sink. A connecting end is formed. In addition,
The upper and lower edges of each fin-like projecting portion 11a are welded under pressure to form a bag-like shape, and serve as a heat-radiating oil chamber in which insulating oil circulates. Further, the fin-like projecting portions 11a are connected to each other by reinforcing pieces 14 fixed to their tips.

On the other hand, FIG. 6 is a plan cross-sectional view of a corrugated heat sink 10B constituting the side wall on the short side of the tank.
By bending the sheet-like thin steel plate 11 into a corrugated shape, a large number of fin-like protrusions 11a are continuously formed over almost its entire length, and a long side wall and a side wall are formed at both ends of the fin-like protruding parts 11a. A flat plate portion 15 for joining is formed. This wave-shaped heat sink 1
As shown in FIGS. 9 and 10, the flat plate portions 15, 15 of 0B are bent into a U-shape in a direction opposite to the direction in which the fin-like projecting portions 11a extend to form connection ends. .

In FIG. 11, the entire circumference is the above-mentioned corrugated heat sink 10A, 1.
0B is a plan cross-sectional view showing a side wall of a tank configured by four corrugated heat sinks 10.
A flat plate of adjacent corrugated heat sinks 10A, which is constructed by oil-tightly fixing the joints 16 or 17 between the connecting ends having the long flat plate portions 13 or the other connecting ends. By locating the shaped portion 13 on the innermost side, a tank side wall portion is formed, and by arranging the bases of the fin-like protruding portions of adjacent wave-shaped heat sinks 10A to face each other with a predetermined interval, the tank side wall portion is formed. An oil passage 20 extending outward from the oil passage 20 and a heat radiating oil chamber formed of a plurality of fin-like protrusions communicating perpendicularly to the oil passage 20 are formed. Further, on the tank side wall on the short side, a corrugated heat sink 10B is arranged between the two side walls on the long side, and the joint portion 17 between the connecting end of the corrugated heat sink and the connecting end of the corrugated heat sink 10A is connected to each other. The bases of the fin-like protrusions at both ends of the corrugated heat sink 10B are arranged to face the bases of the fin-like protrusions of the corrugated heat sink 10A with a predetermined distance therebetween. An oil passage 20 extending outward from the side wall of the tank and a heat radiation oil chamber formed of a plurality of fin-like protrusions communicating perpendicularly to the oil passage 20 are formed.
As shown in FIG. 12 and FIG.
9, and by welding and oil-tightly fixing the cover plates 21 to the upper and lower parts of the communication passages 20 formed between the respective fin-like protruding parts 11a whose bases face each other, one tank is constructed. be done.

In addition, in the above embodiment, the side wall on the short side of the tank is constructed of the corrugated heat sink 10B, but instead of the corrugated heat sink 10B, a flat plate, a curved plate, or a polygonal plate may be used. Furthermore, a plurality of corrugated heat sinks 10B may be used in the same manner as the side walls on the long sides, and the bases of the fin-like protruding portions of adjacent wave-shaped heat sinks may be arranged so as to face each other. It's okay.

Furthermore, the fixed parts between each wave-shaped heat sink are connected to the connection ends of each wave-shaped heat sink as shown in FIGS. 14a to 15h.
Welding can also be carried out in various shapes as shown in Figures a to f.

In the present invention, since the tank for oil-filled electrical equipment is configured as described above, the manufacturing process of the corrugated heat sink itself includes bending the hoop material into a corrugated shape, squeeze welding both edges of the corrugated portion, welding a reinforcing piece, and welding the corrugated portion. By bending the flat plate part of the shaped heat sink and assembling and welding the tank side plates, the process including the heat sink and tank can be manufactured at a low cost and in a short time with less than half the steps required for conventional tanks.

Also, the total length of the welded part is approximately 1/4 of that of a panel radiator.
The reliability of the welding area is increased, and it can be fixed by MAG welding in a good welding atmosphere using shielding gas, making the welding more reliable than resistance welding such as seam welding and stitch welding. will improve.

Furthermore, the length of the fin-like overhangs and the pitch between the fin-like overhangs can be selected to be optimal for each device without the need for a press mold dedicated to a specific size, greatly improving the degree of design freedom. It also has the great advantage of being able to

Furthermore, in the present invention, as in the embodiment shown in FIG. In other words, it is possible to measure the reduction in floor space.

On the other hand, with conventional tanks that use corrugated heat sinks, if the heat generated by the equipment increases, the amount of fin-like overhang (depth of the waves) can be increased, or the pitch of the waves can be reduced to dissipate the heat. Although it will increase the area,
The amount of overhang, that is, the depth of the waves, cannot be increased due to the limited capacity of manufacturing equipment in the wave forming process and the squeeze forming process for both edges of the fin-like overhangs, and the pitch of the waves on the fin-like overhangs cannot be increased due to In order to obtain effective heat dissipation characteristics on the side, it cannot be made too small, so it cannot be applied to models with a large amount of heat dissipation.

Moreover, in open type oil-filled electrical equipment, the pressure due to the oil head is added, and in sealed oil-filled electrical equipment, the expansion of the insulating oil due to the temperature rise in the contents and the rise in tank internal pressure due to the rise in gas chamber temperature are added. The stress and deformation of the fin-shaped overhanging portions relative to the internal tank pressure must be kept below the allowable values.For this reason, as the depth of the waves increases, the plate thickness must naturally be increased in accordance with the depth of the waves. However, it had the disadvantage of increased weight. However, in the present invention, the bases of the fin-like protrusions of the adjacent corrugated heat sinks 10A, 10A are arranged opposite to each other and extend outward from the tank side wall, and the oil passage 20 is perpendicular to the oil passage 20. Since the heat dissipation oil chamber is formed of a plurality of fin-like overhangs that communicate with each other in a manner that By lengthening the oil passage 20 outward and increasing the number of fin-shaped projecting parts, the required heat radiation area can be secured without being particularly limited by the tank size.

Moreover, in order to keep the stress and deformation of the fin-like overhangs below the allowable values depending on the tank internal pressure, the depth of the waves can be reduced without increasing the plate thickness when the tank internal pressure is large. This makes it possible to reduce the amount of materials used and make the product lighter compared to conventional tanks.

As explained above, in the present invention, the manufacturing process can be significantly reduced to less than half compared to conventional tanks, and the tank can be manufactured at low cost and in a short time. Additionally, compared to conventional tanks that have corrugated heat dissipation plates on all sides, the heat dissipation area can be easily increased, and in the case of tanks with the same amount of heat dissipation as conventional tanks, the plate thickness can be reduced, reducing material costs. This has the effect of reducing the amount of water, making the product smaller and lighter, and so on.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view of a conventional corrugated heat sink, Fig. 2 is a cross-sectional view of its protruding portion, Fig. 3 is a vertical cross-sectional view thereof, and Fig. 4 is an oil pump using the above-mentioned corrugated heat sink. A perspective view of a tank for incoming electrical equipment; Figures 5 and 6 are plan cross-sectional views of the corrugated heat sinks forming the long side walls and short side walls of the tank during manufacture; Figures 7 and 8 are long 9 and 10 are a plan sectional view and a side view of a corrugated heat dissipation plate constituting a side wall, and FIGS.
The figure shows the tank side wall assembly configuration using a corrugated heat sink.
FIG. 12 is a plan view of the oil-filled electrical equipment tank of the present invention, FIG. 13 is a sectional view taken along the line X--X in FIG. 12, and FIGS. 14 a to h and 15 a to f are wave shapes, respectively. It is a figure which shows the Example of the fixed part between heat sinks. 10A, 10B... Wave-shaped heat sink, 11a... Fin-shaped overhang, 12, 13, 15... Flat plate-shaped part, 18...
Upper side plate, 19...lower side plate and bottom plate.

Claims (1)

[Claims] 1. A sheet-like thin steel plate is bent into a corrugated shape to form a plurality of fin-like protruding parts, and connecting ends are formed on both sides of the fin-like protruding parts, and both upper and lower end edges of each of the fin-like protruding parts are A tank side wall is constructed by using multiple corrugated heat sinks that are oil-tightly closed and have a heat-radiating oil chamber in which insulating oil circulates, and the connecting ends of each corrugated heat sink are fixed in an oil-tight manner. In the above, each of the corrugated heat sinks has a flat plate-like part constituting the tank side wall on one connecting end side, and the connecting ends on the side having the flat plate-like part or the other connecting ends can be connected to each other. are oil-tightly fixed, and the tank side wall is formed by the flat plate portions of the adjacent wave-shaped heat sinks, and the bases of the plurality of fin-like protruding portions of the adjacent wave-shaped heat sinks are arranged to face each other. A heat-radiating oil chamber is formed by forming an oil passageway extending outward from the side wall of the tank and a plurality of fin-like protrusions communicating orthogonally with the oil passageway. Tank for electrical equipment.