JPS6050332B2 - oil impregnation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for promoting the impregnation of insulating oil into an oil-immersed insulator such as an oil-immersed transformer.

Conventionally, a configuration shown in FIG. 1 has been used to promote oil impregnation in transformers and the like. That is, after filling the main body tank 2 and expansion chamber 3 with insulating oil 9 which has been degassed by a device not shown, compressed air is supplied from the pressurizing device 10 to the air chamber 5 of the bellows 4 via the air valve 8. By applying pressure, the insulating oil 9
The pressure is increased to promote impregnation into the oil-immersed insulator 4. Note that 6 is a lower valve and 7 is an upper valve. In this case, even if the insulating oil 9 is heated in advance to reduce its viscosity coefficient, if the oil-immersed insulator 1 is
For products that require a very long impregnation time, such as No. 10, the oil temperature cools down to ambient temperature by the time the insulating material is impregnated, and the viscosity coefficient of the oil increases, so the impregnation is difficult. It must be facilitated solely by the hydraulic pressure provided by chamber 5.

However, since there is a limit to the strength of the main tank 2 and the expansion chamber 3, it is not possible to increase the pressure in the air chamber 5 beyond this limit to promote impregnation, and it takes several days or more to complete the impregnation. The disadvantage is that it takes time. The present invention has been made in view of these points, and it is an object of the present invention to provide an oil impregnation accelerator that can shorten the impregnation time and, therefore, shorten the construction period.

An embodiment of the present invention shown in FIG. 2 will be described below. In the figure, 1 to 9 are the same as those in FIG. 1, so their explanation will be omitted. As for the other configurations, as shown in the figure, from the oil drain valve 11 to the check valve 15, and the deaerator 12 with oil heater.
, the throttle valve 13, the flow rate control valve 16, and the lower valve 6 of the main body tank 2 constitute a closed circuit through which degassed insulating oil 9 heated to a predetermined temperature is circulated. At this time, bellows 4
The air chamber 5 is connected to an air pressure detector 17 via an air valve 8, and is filled with gas to maintain a predetermined positive pressure. If the amount of oil injected from the lower valve 6 is greater than the amount of oil discharged from the oil drain valve 11,
The amount of oil in the expansion chamber 3 increases, compressing the bellows 4 toward the air chamber 5, and increasing the internal pressure of the air chamber 5. This pressure is detected by the air pressure detector 17, and if the pressure exceeds the reference value, the flow control valve 16 is operated in the direction of closing by the output operation of the controller 18, and injection is performed from the lower valve 6. Reduce oil amount. These operations are continued while the internal pressure of the air chamber 5 is above the reference value, so the flow control valve 16 continues until the amount of oil injected from the lower valve 6 becomes less than the amount of oil discharged from the oil drain valve 11. will be gradually closed. Furthermore, if the amount of oil injected from the lower valve 6 is smaller than the amount of oil discharged from the oil drain valve 11, the amount of oil in the expansion chamber 3 decreases, and the bellows 4 is stretched and air-filled. The internal pressure of chamber 5 decreases. this,
It is detected by the air pressure detector 17, and when the pressure becomes lower than the reference value, the flow rate control valve 1 is activated by the output operation of the controller 18.
6 in the direction of opening to increase the amount of oil injected from the lower valve 6. These operations are continued while the internal pressure of the air chamber 5 is below the reference value, so the flow rate is increased until the amount of oil injected from the lower valve 6 becomes greater than the amount of oil discharged from the drain oil valve 11. The control valve 16 is gradually opened. In addition, throttle valve 1
3. The relief valve 1 and pressure gauge 20 are used in combinations where the discharge capacity of the oil heater-equipped deaerator 12 used in this system is excessive compared to the required average flow rate.

Specifically, if the flow rate of the oil circulation system via the main body tank 2 of the transformer is excessive, the oil pressure inside the main body tank 2 may rise too much due to the pressure loss in the pipeline. While monitoring a pressure gauge 20 installed nearby, a portion of the oil discharged by the throttle valve 13 is diverted from the relief valve 14 to limit the rise in internal pressure of the main body tank 2. In addition, when the discharge amount and the suction amount are not constant over the elapsed time as in a general deaerator, the discharge amount becomes larger than the suction amount, and the amount of oil discharged from the oil drain valve 11 and the amount of oil released are different. Valve 1
The total amount of oil diverted from 4 and returned is the oil deaerator 1.
When the suction capacity of 2 is exceeded, the check valve 15 closes,
This prevents the insulating oil 9 from flowing back into the oil drain valve 11. According to this invention, the heated insulating oil is pressurized to a predetermined pressure and continuously circulates around the insulation in the transformer to be impregnated, so that the viscosity at room temperature is lower as shown in Table 1. This method has the advantage that the insulating oil is continuously press-injected into the insulating material to be impregnated, and therefore the impregnation time can be shortened.

In addition, in the transformer tank, the insulating oil, which is an incompressible liquid, and the compressed gas are separated by a bellows and coexist, so the pressures of both follow each other, and the Z of them always behaves almost the same. This makes it possible to detect changes in oil pressure from the air chamber side, and even if the volume of the insulating oil sealed in the transformer tank increases or decreases, the air chamber side responds to the rigid body. Since the internal pressure of the nearby transformer tank can be constructed so as not to fluctuate rapidly, automatic or manual control of the pressurizing force within the transformer tank can be easily achieved. Furthermore, in the circulation system according to the present invention, the insulating oil in the transformer is discharged from the valve installed below the transformer.
The density of the insulating oil discharged is the highest in the transformer, and therefore the coldest insulating oil is discharged, so that the temperature of the insulating oil in the transformer increases almost uniformly. FIGS. 3 and 4 show another embodiment of the present invention, in which an oil pressure detector 21 is used instead of the air pressure detector to detect the pressure in the transformer tank. In this example as well, if the output of the oil pressure detector 21 is linked to the operation output of the controller 18, automatic continuous operation is possible as in the previous example. Furthermore, in the embodiment shown in FIG. 4, the injection route for the insulating oil 9 is not limited to the lower valve, but may be the upper valve 7 or any other route connected to the tank. This indicates that it is preferable for the discharge route to be located at the bottom of the tank. that's all,
The embodiments of the present invention have been described with reference to a configuration in which the device is operated automatically, but even if each function of each component is performed manually, the time for impregnation with insulating oil can be easily shortened. be able to. Since this invention is constructed as described above, instead of increasing the oil pressure of the insulating oil as in the past, the insulating oil that has been heated to have a lower viscosity coefficient is heated around the immersed insulator until the impregnation is completed. The impregnation process can be completed in a short time.

In addition, since the same insulating oil is degassed while being circulated in a closed circuit, the amount of dissolved gas and moisture in the insulating oil sealed in the transformer can be reduced by 1.
This can be significantly reduced compared to the case where deaerating and lubricating is performed in one process, and thereby high-quality deaerating and lubricating can be achieved at the same time.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional oil impregnation accelerator;
Figures 3 and 4 are cross-sectional views showing embodiments of the oil impregnation accelerator according to the present invention. In the figure, 1 is an oil-immersed insulator, 2 is a main body tank, 3 is an expansion chamber, 4 is a bellows, 5 is an air chamber of the bellows, 6 is a lower valve, 7
is the upper valve, 8 is the air valve, 9 is the insulating oil, 11 is the oil drain valve, 12
13 is a throttle valve, 14 is a relief valve, 15 is a check valve, 16 is a flow rate control valve, 17 is an air pressure detector, 18 is a controller, 19 is a valve driving power source , 20 is a pressure gauge,
211 is an oil pressure detector.

Claims (1)

[Scope of Claims] 1. A main body tank containing an oil-immersed insulator, an oil heating device, a device for circulating insulating oil between the main body tank and the heating device, and a device communicating with and disposed inside the main body tank. an expansion chamber that increases the pressure of the insulating oil by introducing gas above atmospheric pressure into an air chamber provided therein to expand the air chamber; An oil impregnation device characterized in that an insulating oil is circulated through a circulation pipe. 2. The oil impregnation device according to claim 1, wherein the amount of oil injected into the main body tank is adjusted according to changes in the internal pressure of the air chamber of the expansion chamber. 3. The oil impregnation device according to claim 1, wherein the amount of oil injected into the main body tank is adjusted according to changes in the oil pressure of the insulating oil in the main body tank. 4 The detected pressure change is linked by negative feedback to the flow control valve installed in the insulating oil circulation path, so that the oil pressure in the main tank is automatically adjusted to around a preset value. An oil impregnating device according to claim 2 or 3, characterized in that: