JPH0922822A - Oil deterioration prevention device for oil-filled device - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the capacity limit of the insulating oil that can be packed and transported, and to reduce the transportation cost. [Structure] An oil deterioration preventing device 6 is composed of a cylindrical diaphragm 61 and an insulating plate 62 which is attached to one opening of this diaphragm 61 in an oil-tight manner with the opening being covered. By constructing a lid by oil-tightly attaching one opening to the lower surface of the upper wall of the container 1B, the height dimension during transportation becomes smaller than that of the conventional oil-filled device. Diaphragm 61 and container 1
To attach B to the lower surface of the upper wall, the flange portion at the end of the diaphragm 61 is sandwiched between the wall surface of the container and the pressing plate 63 and bolted, and the insulating plate 62 is also attached to the diaphragm 61 by the insulating plate 62 and the pressing plate 64. The diaphragm 61 is sandwiched by and bolted to form an attachment structure that maintains oil tightness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric appliance such as a transformer or a reactor, in which the contents of an iron core, a winding, and the like are stored in a steel plate container and insulating oil is sealed in the container. The present invention relates to an oil deterioration preventing device provided to absorb a change in volume of insulating oil and further prevent the insulating oil from being deteriorated by blocking the insulating oil from the atmosphere.

[0002]

2. Description of the Related Art FIG. 3 is a side view including a sectional view of a conventional oil-filled transformer. The container 1 is composed of an upper container 11, a lower container 12 and a base 13 made of a steel plate having a size of about 10 mm,
In the container 1, the contents 3 of the transformer mainly composed of the iron core 31 and the winding 32 are housed, and the insulating oil 41, which also serves as an insulating medium and a cooling medium, is enclosed to a depth larger than that for covering the contents 3. , A gas space 4 with nitrogen gas sealed in the space above it
2 are provided.

Coolers 2 are attached to both sides of the lower container 12 through pipes not designated by the reference numeral.
Thus, the insulating oil whose temperature has risen due to the heat generated by the contents 3 during operation is cooled. The above-mentioned pipe can be removed by a flange portion (not shown), and the cooler 2 can be removed from the container 1 by this flange portion.

When the temperature of the insulating oil 41 increases, the insulating oil 41 expands and its volume increases, so that the gas space 42 is compressed and the pressure in the container 1 rises. Therefore, if the volume of the gas space 42 is small, the change in internal pressure due to temperature change is large, and if the volume is large, the change is small. The nitrogen gas is sealed to prevent deterioration of the insulating oil 41 due to oxygen and moisture contained in the air, and the sealed structure is the simplest structure that prevents these from entering from the outside. That's why. The upper container 11 and the lower container 12 are kept airtight by a flange portion which is a connecting portion between them and which is not denoted by a reference numeral and packing which is provided on the flange portion and which is not described.

Although the internal pressure of the container 1 changes due to the temperature change of the insulating oil 41, if the internal pressure rises excessively, the container 1, the cooler 2 or their accessories may be damaged.
Increasing the allowable internal pressure value increases the mechanical strength of the container 1 and its accessory members, which increases the cost of the oil-filled transformer. On the other hand, to set the allowable internal pressure value low, the volume of the gas space 42 must be increased. That is, it is necessary to increase the height of the container 1, which also causes an increase in the cost of the oil-filled transformer. Therefore, considering these factors, the conditions are set so that the cost of the oil-filled transformer is minimized.

In the case of the nitrogen-sealed type, the insulating oil 41 is usually mixed with nitrogen gas in a state close to saturation.
As is well known, the higher the internal pressure, the larger the saturation amount of nitrogen gas mixed in the insulating oil. Therefore, when the temperature of the insulating oil 41 changes from the high state to the low direction, the pressure also changes from the high state to the low direction, so that the saturation amount of the nitrogen gas becomes small, and as a result, the state of oversaturation can be considered.
Actually, the temperature of the insulating oil changes slowly and is circulating, so that it is not oversaturated enough to generate bubbles inside. However, if a so-called oil-feeding type cooling system with an oil-feeding pump for forcibly circulating insulating oil is adopted, rotation of the pump creates a negative pressure in the pump. It is conceivable that air bubbles will be generated at this point and penetrate into the winding 32 to cause a decrease in the insulation strength. Due to such a problem, the oil feeding type is not adopted as the cooling system of the nitrogen sealed type oil-filled transformer as shown in FIG.

FIG. 4 is a side view including a partial cross-sectional view of an oil-filled transformer different from FIG. 3, and the same members as those in FIG. 3 are designated by the same reference numerals and duplicate description will be omitted. In this figure, container 1
A diaphragm-type conservator 5 as an oil deterioration preventing device is provided above A. Conservator 5 is lower case 5
1, a diaphragm 52, and an upper case 53, which are integrated by being fastened with a bolt shown by a line segment at a flange portion not denoted by a reference numeral. The figure shows a state during transportation, and a transportation cover 530 is attached instead of the upper case 53. The upper case 53 and the respirator 55 attached to the upper case 53, which are illustrated separately from each other, are sent separately.

When the temperature of the insulating oil 41 in the container 1 rises, the insulating oil 41 expands. Since the expansion coefficient of the insulating oil is larger than that of the steel material forming the main body container 1, the insulating oil 41 moves from the container 1 to the conservator 5 due to the temperature rise, and the volume of the insulating oil 41 in the conservator 5 is reduced. growing. Therefore, the diaphragm 52 bulges upward. On the contrary, when the temperature drops, the diaphragm 52 goes down.

The gas space 42A above the diaphragm 23 is a diaphragm 52.
A so-called breathing action is performed in which air increases or decreases depending on whether the air flows up or down, and air flows in and out through the respirator 55. A hygroscopic agent is enclosed in the respirator 55 so that the air containing moisture is not sucked in, and the air entering the inside is dehumidified by this hygroscopic agent. By the way, the configurations of the oil-filled transformers shown in FIGS. 3 and 4 assume a medium-capacity power transformer of about 10,000 kVA, and the height dimension of these figures is several meters. is there. Such an oil-filled device needs to be transported from the factory where it was manufactured to the installation site. Although there are various transportation methods, the most ideal method is a method in which all parts are attached and insulating oil is enclosed. In practice, there are transportation restrictions regarding size and weight, and for example, a bushing (not shown) attached to the upper container 11 is removed to reduce the height, insulating oil is removed and nitrogen gas is filled to reduce the transportation weight. Various measures are taken, such as transporting them. Then, if the parts are removed, the transportation cost for sending the parts separately is required, and it becomes necessary to install the parts again on the main body at the installation place, and the transportation cost including these is increased. If the insulating oil is removed and transported, it is necessary to degas nitrogen gas at the installation site and inject the insulating oil.The insulating oil at this time must be degassed and dehydrated. It needs to be transported, which also increases the amount of work on site.

In the nitrogen gas sealing system shown in FIG. 3, there is a high possibility that the height of the container 1 is increased to secure the gas space 42 and the transportation limit is exceeded. In the case of FIG. 4, the conservator 5 is used. The amount of protrusion from the upper surface of the container 1 is also likely to exceed the height limit. Therefore, as shown in the figure, the method of removing the upper case 53 and transporting is adopted. In this case, the insulating oil 41 is shielded from the outside air by the diaphragm 53, and since the insulating oil 41 corresponds to the volume change of the insulating oil due to the temperature change, the insulating oil 41 can be transported while being enclosed. Even in the state shown in FIG. 4, if the height exceeds the transportation limit, the lower case 51 must be removed, and then the insulating oil 41 cannot be transported while being enclosed.

[0011]

As described above, in the conventional oil deterioration preventing device for the oil-filled transformer, the height dimension often exceeds the transportation limit, and therefore, the insulating oil is sealed and many parts are mounted. There is a problem that the capacity limit of the transformer that can be transported in the state is limited to a low level. An object of the present invention is to solve such a problem, and to provide an oil deterioration preventing device for an oil-filled battery charger, which can increase the capacity limit in which insulating oil can be enclosed and can be transported to reduce the transportation cost. It is in.

[0012]

In order to solve the above problems, according to the present invention, a change in volume of the insulating oil sealed in the container according to the temperature is absorbed and the insulating oil is shielded from the air. An oil deterioration prevention device provided with a diaphragm for the above purpose may be provided in the upper space in the container. Further, the oil deterioration prevention device is assumed to be oil-tightly attached to this surface with the lower surface of the upper wall of the container as a part thereof. Further, the oil deterioration preventing device is composed of a tubular diaphragm and an insulating plate oil-tightly attached to one opening of the diaphragm with the opening covered, and the other opening of the diaphragm is a container. It is preferable that it is attached to the lower surface of the upper wall in an oiltight manner.

[0013]

In the structure of the present invention, the oil deterioration preventing device having the diaphragm is provided in the upper space in the container of the oil impregnating device, so that the oil deterioration preventing device of the nitrogen gas sealing type is provided as compared with the oil impregnating device. Since the volume of the gas space may be small, the height of the oil impregnator becomes small, and unlike the conventional diaphragm type conservator, there is no protruding member attached to the upper container. The size becomes smaller.

Further, the oil deterioration preventing device is oil-tightly attached to this surface by using the lower surface of the upper wall of the container as a part thereof, so that the diaphragm is opened at least on the side to be attached to the upper wall of the container, so that the conventional diaphragm is prevented. The shape is close to the diaphragm of the formula conservator. In addition, the oil deterioration prevention device is composed of a tubular diaphragm and an insulating plate that is oil-tightly attached to one opening of this diaphragm by covering this opening with the other opening of the diaphragm. The configuration of the diaphragm is attached to the lower surface of the upper wall of the container in an oil-tight manner to form a lid, so that the shape of the diaphragm is simplified.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is a side view of an oil impeller and an oil deterioration preventing apparatus therefor according to a first embodiment of the present invention. The same members as those in FIG. 3 are designated by the same reference numerals, and similar members are designated by a suffix B. Omit duplicate explanations. In this figure, the oil deterioration preventing device 6 is a container 1
Cylindrical diaphragm 6 attached to the lower surface of upper container 11B of B
1. An insulating plate 62 for oil-tightly closing the opening at the lower end of the diaphragm in the drawing, a pressing plate 63 for oil-tightly attaching the diaphragm 61 to the upper container 11B, and an insulating plate 62 for the diaphragm 61. It consists of a pressing plate 64 for tight attachment. Holding plate 6
3 is attached to the upper container 11B by sandwiching the end portion of the diaphragm 61 with attachment bolts simply shown by line segments, and the pressing plate 6
Similarly, the other end of the diaphragm 61 is connected to the insulating plate 62.
It can be attached by sandwiching it with.

The reason why the structure in which the insulating plate 62 is attached to the lower end is adopted is that the gas space 43 in which the air of the oil deterioration preventing device 6 enters has a uniform depth dimension.
That is, if the insulating plate 62 is also made of a diaphragm and has the same flexibility as the other portions, the diaphragm 61 has a shape that hangs when the volume of the gas space 43 becomes small. This is because there is a possibility of approaching the contents 3 and affecting the insulation characteristics.

As described above, in order to sandwich the diaphragm 61 between the pressing plates 63 and 64 and fix it in an oil-tight manner, the diaphragm 6 is used.
It is necessary that the sandwiched portion 1 is formed in a flange shape. Since such a shape is the same as the diaphragm 52 of FIG. 4, there is no problem in manufacturing the diaphragm 61. Instead of the combination of the diaphragm 61 and the insulating plate 62, in the case of adopting a flange-shaped peripheral portion and a shape capable of bulging downward like the diaphragm 52 of FIG. 4, the bottom is flat. The insulating plate may be attached to the lower surface of this portion as described above, or the insulating plate may be put inside so that the bottom surface becomes flat even when the gas space 42 becomes small.

FIG. 2 is a side view of the oil-filled battery charger including a partial cross-sectional view showing a second embodiment of the present invention. The same components as those in FIG. 1 are designated by the same reference numerals to omit redundant description. Also,
Since the oil deterioration preventing device 6 is exactly the same as that of FIG. 1, the reference numerals of the members constituting the oil deterioration preventing device 6 are omitted.
2 is different from FIG. 1 in that an oil feed pump 21 is provided in the middle of a pipe connecting the lower side of the lower container 12C of the container 1C and the cooler 20. The oil feed pump 21 serves to feed the insulating oil cooled by the cooler 20 into the container 1C, and a cooling system provided with such an oil feed pump 21 is called an oil feed type. There is. The cooler 20 is assumed to be a blower type cooler to which a fan for blowing air (not shown) is attached. Therefore, as shown in the drawing, the dimension in the left-right direction of the drawing is small. In some cases, a self-cooling cooler in which a fan is not installed even if an oil pump is installed is used.

As described above, in the case of the oil impregnated device of FIG. 3, the oil feed pump cannot be used in order to avoid the formation of bubbles. On the other hand, in the case of the oil deterioration preventing device 6 of FIG. 2, the insulating oil 41 is filled with degassed insulating oil as in the case of using the diaphragm type conservator of FIG. No bubbles are generated from the pump. Therefore, the oil pump can be used without providing a diaphragm-type conservator protruding above the container 1 as shown in FIG. Compact size and capacity can be achieved by using an oil pump. Then, during transportation, the dimension during transportation is smaller than that of any of the above-mentioned two conventional examples. Therefore, it becomes possible for an oil-filled device with a larger capacity to transport with insulating oil sealed in. Cost reduction can be achieved.

[0020]

As described above, according to the present invention, since the oil deterioration preventing device having the diaphragm is provided in the upper space of the container, the height of the oil impregnator becomes smaller than that of the conventional example. The height dimension when transported in a state where oil is enclosed is reduced, and as a result, a larger capacity can be transported by such a method, and the transportation cost is reduced. Also, when an oil pump is provided to increase the protein capacity and capacity of the oil impeller, it is not necessary to provide a diaphragm-type conservator projecting above the container. It is possible to contribute to cost reduction of the oil-filled electric device by eliminating the installation work on the oil-filled device.

Further, by attaching the oil deterioration preventing device to this surface with the lower surface of the upper wall of the container as a part thereof in an oil-tight manner, the diaphragm has a shape close to that of the conventional diaphragm type conservator. It is easy to manufacture, and the reliability to withstand long-term use can be easily ensured. In addition, the oil deterioration prevention device is composed of a tubular diaphragm and an insulating plate that is oil-tightly attached to one opening of this diaphragm by covering this opening with the other opening of the diaphragm. If the container is attached to the lower surface of the upper wall of the container in an oil-tight manner to form a lid, the shape of the diaphragm is simplified, which contributes to further cost reduction and maintenance and improvement of reliability.

[Brief description of drawings]

FIG. 1 is a side view including a partial cross-sectional view of an oil-filled battery charger and an oil deterioration preventing apparatus therefor according to a first embodiment of the present invention.

FIG. 2 is a side view including a partial cross-sectional view of an oil-filled battery charger and an oil deterioration preventing apparatus therefor according to a second embodiment of the present invention.

FIG. 3 is a side view including a partial cross-sectional view of a conventional oil impeller and its oil deterioration prevention device.

FIG. 4 is a side view including a partial cross-sectional view of a conventional oil-filled battery charger and its oil deterioration prevention device different from those in FIG. 3;

[Explanation of symbols]

1, 1A, 1B, 1C ... container, 11, 11A, 11B,
11C ... upper container, 12, 12A, 12B, 12C ... lower container, 2, 20 ... cooler, 3 ... contents, 31 ... iron core, 3
2 ... Winding, 41 ... Insulating oil, 42, 43 ... Gas space, 55
… Respirator, 5… Conservator (oil deterioration prevention device), 6…
Oil deterioration preventing device, 52, 61 ... diaphragm, 62 ... insulating plate, 6
3, 64 ... Holding plate,

Claims (3)

[Claims] 1. An oil deterioration preventing device provided with a diaphragm for absorbing a change in volume of insulating oil enclosed in a container depending on a temperature and for insulating the insulating oil from air is an upper space in the container. An oil deterioration prevention device for an oil-filled electric device, characterized in that it is provided in the. 2. An oil deterioration preventing device for an oil-filled battery charger according to claim 1, wherein the oil deterioration preventing device is oil-tightly attached to this surface with the lower surface of the upper wall of the container as a part thereof. . 3. An oil deterioration preventing device comprising a tubular diaphragm and an insulating plate oil-tightly attached to one opening of the diaphragm with the opening covered, and the other opening of the diaphragm. The oil deterioration preventing device for an oil-filled battery charger according to claim 2, wherein the portion is oil-tightly attached to the lower surface of the upper wall of the container.