RU203974U1 - SEALED CASE OF A HIGH VOLTAGE DEVICE OPERATING IN A LIQUID DIELECTRIC MEDIUM - Google Patents

Abstract

Usage: the proposed utility model relates to electrical engineering and is used in high-voltage transformers, both power and measuring, in high-voltage dividers, high-voltage circuit breakers, in protective arresters, nonlinear protective resistances (varistors) and high-voltage power supplies with their electrical loads - X-ray tubes ... Essence: a sealed housing of a high-voltage device has rigid walls and at least one movable wall, filled with a liquid dielectric, is configured to accommodate a high-voltage device. The sealed body is divided by rigid fixed partitions into volumes, in one of which it is possible to accommodate a high-voltage device in a liquid dielectric under increased pressure, and other volumes have movable walls, while the fixed partitions contain at least two holes, where part of the holes of each fixed partition is made the possibility of connecting pumps that ensure the pumping of a liquid dielectric from volumes with movable walls into a volume with a high-voltage device, and the remaining openings of the fixed partitions are made with the possibility of connecting throttling devices that ensure the movement of the liquid dielectric in the opposite direction. 1 ill.

Description

The proposed utility model relates to electrical engineering and is used in high-voltage transformers, both power and measuring, in high-voltage dividers, high-voltage circuit breakers, in protective arresters, nonlinear protective resistances (varistors) and high-voltage power supplies with their electrical loads - X-ray tubes.

Known device, selected as a prototype, in which in a sealed rigid steel case 1 with a movable wall 3 and filled with a liquid dielectric 4 - transformer oil, there is a high-voltage device 2 - a high-voltage transformer. (Fig. 1). If the movable wall is located on top of the housing, then it may be absent altogether, and the function of the movable wall is performed by the free surface of the liquid dielectric, which separates the liquid dielectric from the surrounding atmospheric air.

In such devices, the pressure in the liquid dielectric is always equal to atmospheric pressure. With an increase in the temperature of the liquid dielectric, its volume increases and the movable wall of the rigid sealed body, moving, provides the necessary increase in volume without violating the integrity of the body structure and changing the pressure in it.

It is known that the specific electric strengths of a liquid dielectric and a gas depend on pressure and increase with pressure in them, therefore high-voltage devices designed to operate both in a liquid dielectric and in a gaseous one can have significantly less weight and dimensions when operating in an insulating medium. with increased pressure.

Known sealed high-voltage devices, where as an insulating medium, gas under pressure is used as an insulating medium. Such devices have a rigid metal case of constant volume. In this case, with an increase in the temperature of a gaseous dielectric, the pressure in it increases. This effect is widely used in hermetically sealed high-voltage gas-insulated devices, for example, based on SF6 gas, in which the internal volume of the device is filled with SF6 gas under increased pressure. This makes it possible to reduce the weight and size of such high-voltage devices.

It is also known that the specific thermal conductivity and heat capacity of gases are several orders of magnitude lower than those of liquid dielectrics, therefore, in powerful high-voltage devices, a liquid dielectric is usually used, which has higher performance properties, namely, higher thermal conductivity in comparison with gas and a large value of the coefficient of thermal expansion. providing additional efficient convection cooling of the heat-generating elements of the high-voltage structure of the device.

Thus, if the pressure above atmospheric pressure is increased in the sealed case of a high-voltage device filled with a liquid dielectric, then this will achieve a positive effect - an increase in the dielectric strength of the liquid dielectric, which makes it possible to reduce the size and weight of such a device.

The objective of this technical solution is to improve the weight and size characteristics of high-voltage devices designed to operate in a liquid dielectric medium by developing a rigid case design that increases the pressure in the liquid dielectric surrounding the high-voltage device.

To solve this problem, a sealed case of a high-voltage device is proposed, having rigid walls and at least one movable walls, filled with a liquid dielectric, made with the possibility of placing a high-voltage device.

Unlike the prototype, the sealed case is divided by rigid fixed partitions into volumes, in one of which it is possible to place a high-voltage device in a liquid dielectric under high pressure, and other volumes have movable walls, while the fixed partitions contain at least two holes, where part the openings of each fixed partition are capable of connecting pumps that provide the pumping of a liquid dielectric from volumes with moving walls to a volume with a high-voltage device, and the remaining openings of the fixed partitions are made with the possibility of connecting throttling devices that ensure the movement of the liquid dielectric in the opposite direction

The essence of the utility model is that there is a physical dependence for a liquid dielectric, namely, the higher the pressure in the liquid, the higher the dielectric strength of the liquid dielectric. Therefore, if in a sealed case we provide an increased pressure in a liquid dielectric, then we can place a high-voltage device of a smaller size and mass, and with higher specific parameters inside the sealed case, thereby solving the problem.

The essence of the utility model is illustrated by drawings:

in fig. 1 shows a prototype of a sealed case of a high-voltage device;

in fig. 2 shows the case of a high-voltage device with fixed partitions, where:

1 - sealed housing;

2 - high voltage device;

3 - movable wall;

4 - liquid dielectric;

5 - fixed partition;

6 - holes;

7 - pump;

8 - throttle device.

FIG. 2 shows a sealed case 1 with a high-voltage device 2. The sealed case 1 is divided into volumes by fixed partitions 5. In one of the volumes there is a high-voltage device 2 operating in a liquid dielectric 4 under high pressure. Other volumes have movable walls 3 that separate the dielectric liquid in these volumes from atmospheric air. In the fixed partitions 5 dividing the volumes of the rigid sealed body 1 there are holes 6 - two or more. In some of these holes 6, pumps 7 are installed, which provide pumping of the liquid dielectric 4 from the volumes with movable walls 3 to the volume with the high-voltage device 2, and throttling devices 8 are installed to the remaining holes 6 of the fixed partitions 5, which ensure the movement of the liquid dielectric 4 in the opposite direction. Additionally, the devices 7 and 8 installed in the fixed partitions 5 can provide sufficient heat exchange between the volumes of the rigid sealed housing 1 in the presence of significant heat generation during the operation of the high-voltage device 2.

The device, the construction of which is shown in FIG. 2, works as follows: when the pumps 7 are not working, then in all volumes of the sealed housing 1, the pressure in the liquid dielectric 4 is equal to atmospheric. After turning on the pumps 7, the liquid dielectric 4 is pumped from the volumes of the housing with movable walls 3 into the volume of the housing with the high-voltage device 2 and the pressure of the liquid dielectric 4 in this volume of the housing increases. The magnitude of the pressure of the liquid dielectric 4 is provided by adjusting the pressure drop using throttle devices 8, through which the liquid dielectric 4 returns to the volumes of the sealed housing 1, where the movable walls 3 are located and in which the pressure of the liquid dielectric 4 is always equal to atmospheric pressure. With an increase in the temperature of the liquid dielectric 4 during the operation of the high-voltage device 2, an increase in the volume of the liquid dielectric 4 leads to the movement of the movable walls 3 and the volume occupied by the liquid dielectric 4, respectively, increases. After switching off the high-voltage device 2 and pumps 7, the pressure in the liquid dielectric 4 in all volumes of the sealed housing 1 becomes the same, and, therefore, equal to atmospheric pressure, and as the high-voltage device 2 cools down, the movable walls 3 will return to their original position under the influence of atmospheric pressure ...

So, the proposed utility model solves the problem posed, namely, improving the weight and size characteristics of high-voltage devices intended for operation in a liquid dielectric environment by developing a design of a rigid sealed case of a high-voltage device that provides increased pressure in a liquid dielectric during operation of a high-voltage device.

Claims (1)

A sealed case of a high-voltage device operating in a liquid dielectric, having rigid walls and at least one movable wall, filled with a liquid dielectric, made with the possibility of placing a high-voltage device, characterized in that the sealed case is divided by rigid fixed partitions into volumes, in one of which is made the possibility of placing a high-voltage device in a liquid dielectric under increased pressure, and other volumes have movable walls, while the fixed partitions contain at least two holes, where it is possible to connect pumps to a part of the holes of each fixed partition, which provide pumping of a liquid dielectric from volumes with movable walls to the volume with the high-voltage device, and the remaining openings of the fixed partitions are made with the possibility of connecting throttling devices that provide the movement of the liquid dielectric in the opposite direction.

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