JPS5939887B2 - Tank for oil-filled electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tank for oil-filled electrical equipment such as a transformer, and particularly to a corrugated radiator.

In general, a tank such as an oil-immersed transformer consists of a tank body for storing the contents (electrical equipment), and a radiator that is necessary to keep the temperature rise of the contents within a specified value due to the operation of the transformer. It is composed of.

There are various types of heat sinks, but one of the most efficient is a thin metal plate bent in a corrugated manner, with corrugated ribs provided at regular intervals.
A corrugated radiator with a flow path for flowing insulating oil, which is a cooling medium, is used. One advantage of the recent adoption of such wave-shaped heat sinks is that the wave height and pitch of the wave-shaped heat dissipation ribs can be freely manufactured, which improves the heat dissipation design of transformers, etc. , the disadvantages of conventional panel heatsinks, which allow free heat radiation area, limit the types of tanks for oil-filled electrical equipment such as transformers, and sometimes force unnecessary waste of materials, have been overcome. The reason is that it has been resolved. FIG. 1 is a front view of a tank structure for oil-filled electrical equipment using a corrugated radiator, and FIG. 2 is a perspective view showing the frame of the tank.

A corrugated heatsink is made by bending a continuous thin steel strip into a corrugated shape.
Wave-shaped protruding heat dissipating ribs are formed at regular intervals, and both ends of the ribs are pressed together by drawing, and sealed with, for example, arc solution. A required number of heat radiating ribs are successively formed to form one corrugated heat radiator. When arranging such a corrugated radiator around a tank, it is possible to continuously manufacture the corrugated radiator corresponding to each side, bend the corners, and manufacture them seamlessly. Problems with handling in a temporary state for assembly, problems with temporary storage space, corrugated radiators have thin plates due to their nature, and it is extremely difficult to weld the corrugated radiators together, workability of tank assembly, etc. Therefore, it is common to manufacture corrugated heat sinks for each side individually. When the above corrugated radiator is used to construct a tank for oil-filled electrical equipment, the upper side plate 1, intermediate side plate 2, lower side plate 3, bottom plate 4, and support column 5 provided with the tank flange portion 1a, As shown in FIG. 2, a tank frame is formed, and the peripheral edge of the corrugated heat radiator having the heat radiation ribs 6 is attached to the upper side plate 1 and the lower side plate 3.
The tank is constructed by welding 10 with the intermediate side plate 2 and welding 11 with the support 5. According to this method, it is possible to easily temporarily place and move the corrugated heat radiator and assemble the tank while avoiding difficult welding of thin steel plates together, and the problem of temporary storage space can also be solved. However, when welding 11 between the intermediate side plate 2 or the support column 5 and the corrugated heat sink, the surrounding area of the weld 11 may be deformed due to welding heat.

The struts 5 are made of a relatively rigid member, such as angle iron, but the expansion and contraction force due to welding heat also affects the heat radiation ribs 6, so the heat radiation ribs 6a at both outer ends of the corrugated radiator are There is a problem that the heat radiator is deformed into a wavy shape, narrowing the flow path of the insulating oil, deteriorating the function of the radiator, and significantly impairing the appearance quality. Although this problem is caused by the thinness of the plate of the heat dissipation rib, simply increasing the thickness of the plate increases the weight and is not a good idea. In view of the above-mentioned points, the present invention includes a wave-shaped heat radiator that suppresses deformation and distortion of heat radiation ribs, improves heat radiation function, and does not impair appearance quality.
The purpose is to provide tanks for oil-filled electrical equipment.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

Note that the same parts as in FIG. 1 are given the same reference numerals and the explanation thereof will be omitted. As described above, the heat dissipation rib 6 is made by sequentially bending a continuous thin steel strip into a wave shape, pressing the upper and lower edges of the strip by drawing to form a circulation path for insulating oil, and sealing by welding 12. are doing.

The number, wave height, and wave width of these heat radiation ribs 6 are determined by the amount of heat radiation of the oil-filled electrical equipment. As shown in FIG. 4, the wave height H2 of the heat radiation ribs 6a at both outer ends of the corrugated heat sink having a wave width L2 is made smaller than the wave height H2 of the other heat radiation ribs 6. In this case, the wave height H2 of the heat radiation ribs 6a at both outer ends of the corrugated radiator is appropriately set depending on the plate thickness of the corrugated radiator, the wave width, the plate thickness of the intermediate side plate 2, the struts 5, etc. The wave height of the heat dissipation rib 6 satisfies equation (1). NlHlL
l=(N2-2n12)L2H2+2m2h2L2...
...(1) Here, N2; Total wave number of the heat radiation ribs M2: Number of surfaces of the corrugated radiator L2: Wave width of the heat radiation ribs H2; Wave height H2 of the heat radiation ribs other than both outer ends of the corrugated radiator; Wave height n1 of the heat radiation ribs at both outer ends of the corrugated radiator: Total wave number L1 of the heat radiation ribs when all wave heights of the heat radiation ribs of the corrugated radiator are the same; All wave heights of the heat radiation ribs of the corrugated radiator Wave width H1 of the heat radiation ribs when they are the same: Wave height of the heat radiation ribs when the wave heights of the heat radiation ribs of the waveform radiator are all the same For example, in the case of L2 = Ll, nl - N2, both outside of the waveform radiator The wave height H2 of the heat radiation rib 6a at the end and the wave height H2 of the other heat radiation ribs are expressed by the following equation.

One of the reasons why corrugated heat sinks are used is that they can be made into heat dissipating ribs with any wave height. Even if the heat dissipation ribs have different wave heights only at the outer ends of the corrugated heat dissipator as shown above,
It is sufficient to input the data into the manufacturing machine in advance. Therefore, when a tank for oil-filled electrical equipment is configured in this way, when welding 11 between the intermediate side plate 2 or the support column 5 and the corrugated radiator during welding assembly, the heat radiating rib provided at a position close to the welded portion is removed. Welding deformation for 6a can be made very small.

The top portion 6c of the heat dissipation rib 6a is located at the free plate field 6d,
It has strong rigidity and restrains the free board field 6d. In other words, the free plate field 6d retains the top portion 6c even if it shrinks due to welding heat.
Bending deformation (waving) of the free board field 6d due to the restraint of
becomes smaller. Deformation due to load is generally proportional to the square of the free length and the reciprocal of the cube of the plate thickness. Therefore, as in the present invention, the welding contraction force is applied only to the heat radiation rib 6a at the outermost end of the corrugated heat sink. By taking into consideration and setting the wave height appropriately,
The buckling deformation of the free plate field 6d of the outermost heat dissipating rib 6a can be extremely reduced. However, in the past, due to buckling deformation of the free plate field 6d, a thin steel strip with a thickness greater than necessary was used to obtain the heat radiation rib 6 with a wave height determined from the heat radiation amount of oil-filled electrical equipment. However, the thickness can be reduced to the required thickness based solely on mechanical strength for other uses. In this case, the wave height H2 of the outermost heat radiation rib 6a of the corrugated heat sink and the wave height H2 of the other heat radiation ribs are set to satisfy equation (1), so the heat radiation area of the conventional corrugated heat sink is This ensures that the heat dissipation characteristics of oil-filled electrical equipment are not degraded in the slightest. As explained above, according to the tank for oil-filled electrical equipment according to the present invention, by setting the wave heights of the heat radiation ribs at both outer ends of the corrugated radiator to be lower than the other heat radiation ribs, It is possible to suppress buckling deformation, and in the past, a thin steel strip that was thicker than necessary was used to obtain the required heat dissipation ribs. Can be made thinner.

Further, it is possible to prevent the insulating oil flow path from being narrowed due to its buckling deformation. Furthermore, in order to make the wave height of the outermost heat dissipation rib smaller than the others, the outer corner of the oil-filled electrical equipment tank has an obtuse angle, which has the effect of avoiding damage during transportation and handling. play.

[Brief explanation of drawings]

Figure 1 is a front view of a tank for oil-filled electrical equipment using a corrugated radiator, Figure 2 is a schematic perspective view of the frame of the same tank, and Figure 3A
The figure is a schematic perspective view of the corrugated heat sink of the present invention, and FIG. 3B is a cross-sectional view of the corrugated portion of the same. 1... Upper side plate, 2... Middle side plate, 3
...Lower side plate, 4...Bottom plate, 5...
...Strut, 6a... Heat dissipation rib.

Claims (1)

[Claims] 1. In a tank for oil-filled electrical equipment having a radiator formed by continuously forming a band-shaped thin metal plate into a wave shape and providing corrugated protruding ribs, the wave height of the corrugated protruding ribs at both outer ends of the heat radiator is as follows: A tank for oil-filled electrical equipment characterized by having a wave height lower than that of other ribs.