JPS6315609A - Apparatus for evacuation and gas filling of gas insulated switchgear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for evacuation and gas filling operations necessary for the assembly process of gas insulated switchgear.

In particular, the present invention relates to a vacuum evacuation and gas filling method suitable for a gas insulated switchgear which has a box-shaped container and whose gas pressure is close to atmospheric pressure.

[Conventional technology]

Conventionally, in order to seal insulating gas inside the container of a gas-insulated switchgear in which switching equipment such as a circuit breaker and a disconnector is housed inside a box-shaped container, for example, as seen in JP-A-60-152202, According to the six methods, there is a so-called displacement method that takes advantage of the fact that the specific gravity of insulating gas is greater than that of air. This had the effect of being able to fill insulating gas with a relatively high concentration.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, the amount of water contained in the gas poses a problem. In other words, in gas-insulated switchgear, in order to ensure the insulation performance of the insulating gas, it is necessary to reduce the moisture content in the gas to a very low value, and for this reason, a method of filling the gas with gas has generally been adopted. However, box-shaped containers use a low gas pressure with a rated gas pressure of around 0.5 kgldG, and when the inside is evacuated, the gas pressure from the outside can be reduced.

It will be subjected to a pressure of 1.0 kg/d, and its strength will be determined by the external pressure under vacuum, which is uneconomical.

The purpose of the present invention is to evacuate the inside of the container, sufficiently remove moisture inside the container, and evacuate the container.

To provide a vacuum evacuation and gas filling method for reducing the pressure applied to a container during gas filling to be less than the rated gas pressure of the insulating gas to be filled, and producing a lightweight and economical box-shaped container.

[Means for solving problems]

In the present invention, a box-shaped container is housed inside another container large enough to accommodate the box-shaped container, and each container is evacuated and filled with gas almost simultaneously by an independent pump connected to each container. By doing so, the work can be completed without applying pressure to the box-shaped container of the gas-insulated switchgear, and the purpose can be achieved.

[Effect]

The pump is connected to the box-shaped container of the gas-insulated switchgear, and contributes to evacuation and gas filling inside. On the other hand, the pump is connected to a container installed outside the box-shaped container, and the container that contributes to the vacuuming of this container has an airtight structure, so that gas does not move between the containers. When the pump 6 and the gas treatment device 3 are operated at the same time, the pressure in each container changes approximately in the same way, and therefore almost no pressure is generated in the box-shaped container.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a box-shaped container of a gas insulating device that houses switching equipment such as a circuit breaker and a disconnector. 2 is a valve attached to a box-shaped container by a method such as a flange, and 3 is a gas processing device equipped with a vacuum pump for evacuating the inside of the box-shaped container 1 and a pump for filling with insulating gas. , connected by a valve and a hose 4. on the other hand,
Reference numeral 5 denotes a separate container installed around the outer periphery of the box-shaped container 1, which is separable from the base of 5', and by disassembling 5, the box-shaped container can be easily assembled inside 5'.

5 and 5' are bolted together using airtight flanges. Further, the box-shaped container 1 itself has an airtight structure, so that there is no gas flow between it and the container 5, 5'. Reference numeral 6 denotes a vacuum pump for evacuating the inside of the containers 5 and 5'.
, 5'. Since it is not necessary to fill the insides of the containers 5 and 5' with gas, the container 6 only needs to be equipped with a vacuum pump.

Now, when the box-shaped container 1 is evacuated, if the vacuum pump in the gas processing device 3 and the vacuum pump 6 are operated at the same time, there will be a slight difference due to the difference in the capacity of each pump and the volume of the containers 1 and 5, 5'. However, the pressure in each container remains almost the same and becomes a vacuum, and the pressure acting on container 1, that is, the difference between the internal pressures of containers 1 and 5, 5', can always be suppressed to a value close to 0.

On the other hand, when filling the box-shaped container 1 with gas, the filling pump in the gas inlet processing device is operated, and the valve 9 is gradually opened. Valve 9 opens to the atmosphere;
When opened, the containers 5, 5' are filled with air.

As a result, air is sealed inside the containers 5 and 5' up to the maximum atmospheric pressure, and gas can be filled in the container 1 up to a rated gas pressure close to atmospheric pressure. By appropriately adjusting the valve 9, the pressure can be increased while keeping the pressure of both containers the same up to atmospheric pressure, and no pressure is applied to the box-shaped container 1. Above atmospheric pressure, the maximum container 1 Since it is only subjected to the rated gas pressure that it is originally subjected to, there is no problem in terms of design.

[Effects of the Invention] According to the present invention, the pressure generated in the box-shaped container can be reduced to below the rated gas pressure filled in the container, and in particular, when a vacuum is drawn, the pressure generated can be reduced to approximately O. Therefore, the design of a single box-shaped container can be made extremely easy, and a lightweight and economical gas insulated switchgear can be provided.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Box-shaped container of gas insulated switchgear, 3... Gas treatment device, 5.5'... Container, 6... Vacuum pump.

Claims (1)

[Claims] 1. In a gas insulated gas switchgear that evacuates the inside and then fills insulating gas, the outside of a box-shaped container is surrounded by a separate airtight container, and the box-shaped container has a first A gas treatment device equipped with a vacuum pump and a filling pump for filling gas is connected to the airtight container with a second vacuum pump and a valve, respectively, to reduce the pressure difference between the box-shaped container and the airtight container. A vacuum evacuation and gas filling device for a gas insulated switchgear, characterized in that a means is provided for filling the inside of the box-shaped container with an insulating gas while keeping the pressure always below the design pressure of the box-shaped container.