JPH0314903Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a power transmission line such as a phase-separated busbar or a conduit aerial power transmission line.

[Problems that conventional technologies and ideas try to solve]

Both phase-separated busbars and conduit aerial power transmission lines have a conductor insulated and supported within a sealed pipe-shaped metal sheath, and the space between the conductor and the metal sheath is filled with air (phase-separated busbar). They were filled with insulating gas and SF ₆ (conduit aerial power transmission lines) to achieve the required electrical insulation.

By the way, in order to increase the current capacity in these power transmission lines, the above-mentioned electrically insulating gases were circulated, but since these gases have a small heat capacity, it is necessary to use gases to increase the current capacity. It was necessary to increase the amount of circulation, which led to larger railway lines.

Conventionally, as a solution to the above-mentioned drawbacks, it has been proposed to use an insulating liquefied refrigerant such as chlorofluorocarbon gas as the insulating gas (Japanese Patent Publication No. 57-56285).
issue).

However, in the above-mentioned proposed example, since the refrigerant supply path is provided outside the track, space for installing piping in addition to the track is required, and it cannot be said that there is an improvement in terms of economy.

An object of the present invention is to provide a power transmission line of this type that can eliminate the problems of the prior art described above, reduce the size of the power transmission line, and significantly increase the power transmission capacity.

[Means to solve the problem]

The evaporative cooling type power transmission line provided by this invention is
As shown in the accompanying drawings, cooling equipment 7 is attached via a pipe 6-1 communicating with the pipe-shaped conductor 1 and a pipe 6-2 communicating with the pipe-shaped metal sheath 2 that insulates and supports the pipe-shaped conductor 1. In addition, an expansion valve 9 is provided at a position distal to the connection position of the cooling equipment 7 to connect the pipe-shaped conductor 1 to a state where there is a differential pressure between the inside and the outside, and the space inside the pipe-shaped conductor 1 is 8-1 as the outgoing path, the insulating liquefied refrigerant supplied here is maintained in a liquid phase based on the restriction of the expansion valve 9, and the space 8-2 between the pipe-shaped conductor 1 and the pipe-shaped metal sheath 2 is This is characterized in that the refrigerant discharged from the expansion valve 9 is made to flow in a gas-liquid mixed state as the return path.

[Effect]

The insulating liquefied refrigerant cooled and liquefied in the cooling equipment 7 is sent to the space 8-1 in the pipe-shaped conductor 1, which is the outgoing path, through the pipe 6-1, and becomes the far end with respect to the pipe connection position. expansion valve 9 in position
released. The released refrigerant flows into the space 8-2 between the pipe-shaped conductor 1 and the pipe-shaped metal sheath 2.
It flows as a return route, returns to the cooling equipment 7 through the pipe 6-2, is cooled and liquefied again, and is circulated through the above-mentioned route.

In the flow of the refrigerant, the inner space 8-1 of the pipe-shaped conductor 1, which is the outward path, is under pressure with respect to the return path of the space 8-2 between the pipe-shaped conductor 1 and the pipe-shaped metal sheath 2 due to the restriction of the expansion valve 9. This allows the insulating liquefied refrigerant supplied through the pipe 6-1 to liquefy without being vaporized by the heat generated in the conductor or metal sheath due to track operation. It will be transported while maintaining the phase state.

Therefore, even in the inner space of the thin pipe-shaped conductor 1, it is possible to send the material over a long distance, that is, to the far end, while suppressing vaporization, that is, a gas-liquid two-layer flow, which causes significant pressure loss.

The refrigerant released from the expansion valve 9 vaporizes according to the amount of heat generated in the conductor or metal sheath, absorbs the heat with the latent heat at that time, and returns to the cooling equipment 7 in a gas-liquid mixed state. At this time, the refrigerant flows through a sufficiently wide space between the pipe-shaped conductor 1 and the pipe-shaped metal sheath 2, so that pressure loss due to vaporization can be prevented from becoming significant.

〔Example〕

FIG. 1 shows a preferred embodiment of an evaporative cooling type power transmission line, in which 1 is a pipe-shaped conductor and 2 is a pipe-shaped metal sheath.

Therefore, the pipe type conductor 1 has a post type insulator 3.
-1 and a cone spacer 3-2 and are insulated and supported within a pipe-shaped metal sheath. The terminal of the pipe-shaped conductor 1 is sealed, and the terminals of the pipe-shaped metal sheath 2 and the pipe-shaped conductor 1 are sealed with an insulator 5 to maintain an insulating state. Moreover, the space between both 1 and 2 is formed by a cone spacer 3-- which is provided at a predetermined distance with the post-type insulator 3-1 in between.
It is divided by 2.

In the line section thus partitioned, at one end (line end) side, a piping 6-1 connected to the pipe-shaped conductor 1 and communicated via an insulating tube 4 passing through the pipe-shaped metal sheath 2 is connected to the pipe-shaped conductor 1. Cooling equipment 7
Piping 6-2 is connected to the refrigerant delivery side of the pipe and connected to the pipe-shaped metal sheath 2. Cooling equipment 7
The pipe-shaped conductor 1 is connected to the refrigerant recovery side of
An expansion valve 9 is provided to communicate the inside and outside of the tank.

Therefore, the insulating liquefied refrigerant cooled and liquefied in the cooling equipment 7 flows through the inner space 8-1 of the pipe-shaped conductor 1 through the pipes 6-1 and 4, and passes through the expansion valve 9 at the far end. space 8-2 between the pipe-shaped conductor 1 and the pipe-shaped metal sheath 2.
The air flows through this space as a return route and is returned to the cooling equipment 7 via the pipe 6-2. The refrigerant flowing into the return space 8-2 is used for electrical insulation between the conductor 1 and the metal sheath 2.

The expansion valve 9 can sufficiently increase the pressure in the space 8-1 within the pipe-shaped conductor 1 by adjusting the throttle of the valve, and maintains the supplied insulating liquefied refrigerant in a liquid phase to the far end. It can flow to the side. Therefore, the refrigerant released from the expansion valve 9 and flowing through the wide space 8-2 inside the metal sheath 2 is vaporized by the heat generated due to the operation of the line, and the latent heat at that time is used to absorb the heat and perform the prescribed cooling. be exposed. The refrigerant whose vaporization has been promoted is returned to the cooling equipment 7 in a gas-liquid two-layer flow state, where it is liquefied again.

FIG. 2 shows an embodiment of a three-phase line in which three pipe-shaped conductors 1 are insulated and supported within a pipe-shaped metal sheath 2. According to the present invention, the internal space of each pipe-shaped conductor 1 is The configuration may be basically the same as that of the above-described embodiment except that 8-1 is used as the outward path for the refrigerant.

Although the expansion valve 9 is shown protruding outside the pipe-shaped conductor 1 into the space 8-2 serving as the return path, it is installed so as to be housed within the conductor in order to prevent flashover.

[Effect of idea]

As explained above, according to the evaporative cooling line of the present invention, the internal space of the pipe-shaped conductor through which the refrigerant goes out can maintain a sufficiently higher pressure than the space inside the metal sheath due to the restriction of the expansion valve. Even in the particularly narrow internal space, the refrigerant can be transported over a long distance from the refrigerant supply end to the far end while maintaining a liquid state without being vaporized, without making the flow path thicker. Transportation efficiency can be improved.

Furthermore, since the pressure in the space inside the pipe-shaped conductor on the outward path can be maintained high, the temperature at which the refrigerant is sent out can be increased, and there is no need to send the refrigerant at a low temperature.

It is possible to achieve the following effects.

Therefore, the intended purpose of significantly increasing the power transmission capacity while reducing the size of the power transmission line is fully achieved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional explanatory view showing one embodiment of an evaporative cooling type power transmission line according to the present invention, and FIG. 2 is a cross-sectional explanatory view showing another example of the power transmission line main body. In the symbols, 1 is a pipe-type conductor, 2 is a pipe-type metal sheath, 3-1 is a post-type insulator, 3-2 is a cone spacer, 4 is an insulating tube, 5 is an insulator, 6
-1 is piping (outward path), 6-2 is piping (return path), 7 is cooling equipment, 8-1 is space inside the conductor (outgoing path), 8-2
9 is a space within the metal sheath, and 9 is an expansion valve.

Claims (1)

[Scope of utility model registration request] For a power cable having a shape in which a pipe-shaped conductor 1 is insulated and supported within a pipe-shaped metal sheath 2, a pipe 6-1 communicating with the pipe-shaped conductor 1 and a pipe 6-2 communicating with the pipe-shaped metal sheath 2 are connected. A cooling equipment 7 is attached through the cooling equipment 7, and an expansion valve 9 is provided which communicates with the pipe type conductor 1 in a state where there is a pressure difference between the inside and outside at a position that is the far end with respect to the connecting position of the cooling equipment 7, The insulating liquefied refrigerant supplied thereto is maintained in a liquid phase state based on the restriction of the expansion valve 9 through the space 8-1 inside the pipe-shaped conductor 1, and is connected to the pipe-shaped conductor 1 and the pipe-shaped metal sheath. 2. An evaporative cooling type power transmission line characterized in that the refrigerant discharged from the expansion valve 9 is made to flow in a gas-liquid mixed state through the space 8-2 between the expansion valve 9 and the expansion valve 9.