JPH0974650A - Compressed gas insulated transmission line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the increase of diameters of ducts of a compressed gas insulated transmission line even if a transmission capacity is increased by a method wherein gas outlets through which insulating gas is introduced out are formed in the upper parts and lower parts of the respective ducts of the transmission line which form gas spaces and respective gas inlets are connected to each other with a gas pipe through which insulating gas flows. SOLUTION: A compressed gas insulated transmission line is installed in a tunnel 11 horizontally. A gas outlet 7 through which insulating gas is introduced out is formed in the upper part of a metal vessel 1 in one gas space 6 divided by the two cone spacers 4 of the compressed gas insulated transmission line. A gas inlet 8 through which insulating gas is introduced is formed in the lower part of the metal vessel 1. A gas pipe 9 through which insulating gas can flow is provided between the gas outlet 7 and the gas inlet 8. A heat exchanger 10 which performs heat exchange is provided in a part of the gas pipe 9. In the soil 12, the heat exchanger 10 is placed at a position higher than the position of the metal vessel 1. As a result, stable cooling can be performed all through a year, so that the transmission capacity can be increased without the significant increase of a cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground power transmission line, and more particularly to a gas-insulated pipeline air power transmission line capable of large-capacity power transmission.

[0002]

2. Description of the Related Art Conventionally, an underground power transmission line uses a cross-linked polyethylene cable (CV) or the like, and therefore has a poor heat dissipation performance and a small power transmission capacity as compared with an overhead power transmission line. In order to do, it was necessary to have multiple lines. Therefore, the extraction and transformation equipment is complicated and the cost is increased. Therefore, a gas-insulated pipeline air transmission line that has the same transmission capacity as an overhead line has been adopted.

FIG. 4 is a structural view in the longitudinal direction of a pipeline air transmission line in which a conductor housed in a metal pipe is insulated by an insulating gas, and FIG. 5A is a side view of a cone spacer portion. 5B is a sectional view of the main circuit conductor portion.

4 and 5, 1 is a metal container, 2
Is a bellows which forms a part of the metal container 1 and absorbs mechanical and thermal deformations, 3 is a main circuit conductor, 4 is a cone for supporting the main circuit conductor 3 and at the same time dividing a space filled with an insulating gas Spacers 5 are columnar spacers for supporting the main circuit conductor 3, and 6 is an insulating gas space. Although a single-phase conductor is shown in the figure, the structure is basically the same in the case of a three-phase configuration except that the three-phase conductor is arranged.

[0005]

Generally, in a pipeline air transmission line, if each transmission voltage and transmission capacity are determined, the diameter of the main circuit conductor is determined by the allowable temperature rise value of the conductor due to the main circuit current, and The basic diameter of the container is designed by the electric field value determined by the relationship with the diameter of the main circuit conductor due to the transmission voltage and the allowable value of the temperature rise of the metal container. This is because the diameters of the main circuit conductor and the metal container increase as the transmission voltage and transmission capacity increase.

On the other hand, since the construction cost of the pipeline air transmission line increases as the transmission capacity increases due to the large size of the main circuit conductor and the metal container as described above, the size of the pipeline metal container must be increased. It was necessary to develop a pipeline air transmission line capable of increasing the transmission capacity.

The present invention has been made in view of the above circumstances, and an object thereof is to increase the pipeline diameter of the pipeline airborne transmission line accordingly, even if the transmission capacity is increased due to the necessity of increasing the transmission capacity of the system. It is to provide a pipeline air transmission line that can cope without doing so.

[0008]

In order to achieve the above object, the first aspect of the present invention relates to a pipeline air transmission line having a gas space partitioned by insulating gas partition spacers at predetermined intervals. The pipeline air transmission line is installed horizontally in the cave installed in a horizontal direction, and the pipeline air transmission line is installed at the upper part of each pipeline forming one gas space of the pipeline air transmission line. Forming a gas lead-out portion for leading out the insulating gas in the pipeline, forming a gas introducing portion in the lower portion of the pipeline, and the gas lead-out portion and the gas introducing portion are connected to each other by a gas pipeline through which the insulating gas flows. It is characterized by being

A second aspect of the present invention is, in the pipeline air transmission line of claim 1, connected to a gas lead-out portion and a gas introduction portion for leading out and introducing an insulating gas in the pipeline air transmission line. A heat exchanger capable of exchanging heat of insulating gas is installed in the gas pipeline.

According to a third aspect of the present invention, in the pipeline air transmission line according to the second aspect, the heat exchanger for exchanging heat with the insulating gas is in the soil around the cave where the pipeline air transmission line is installed. And the heat exchanger is installed at a position higher than the gas outlet.

According to a fourth aspect of the present invention, in a pipeline air transmission line having a gas space partitioned by insulating gas partition spacers at predetermined intervals, the pipeline air transmission line is installed in a vertical direction. It is installed vertically in the cave and guides the insulating gas in the pipeline to the vicinity of the segment spacer in the axial upper part of each pipeline that forms one gas space of the pipeline air transmission line. And a gas introducing part for introducing the derived insulating gas into the conduit in the vicinity of the partition spacer at the lower part of the conduit, and the gas guiding part and the gas introducing part are insulated from each other. It is characterized in that they are connected to each other by a gas pipeline through which gas flows.

According to a fifth aspect of the present invention, in the pipeline air transmission line according to the fourth aspect, it is connected to a gas lead-out portion and a gas introduction portion for leading out and introducing an insulating gas in the pipeline air transmission line. A heat exchanger capable of exchanging heat of insulating gas is installed in the gas pipeline.

According to a sixth aspect of the present invention, in the pipeline air transmission line according to the first and fourth aspects, the gas pipeline is forced to circulate an insulating gas and the insulating gas is forcibly cooled. It is characterized by installing a cooling unit.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a gas-insulated pipeline air transmission line which is a first embodiment (corresponding to claim 1, claim 2 and claim 3) of the present invention.

As shown in the figure, the gas-insulated pipeline air transmission line is similarly installed horizontally in the cave 11 installed in the horizontal direction. A gas lead-out portion 7 for leading out an insulating gas is formed in the upper part of the metal container 1 in one gas space 6 divided by the two cone spacers 4 of the pipeline air transmission line, and in the lower part of the metal container 1. A gas introduction part 8 for introducing an insulating gas is formed in the. There is a gas pipeline 9 through which an insulating gas can flow between the gas outlet 7 and the gas inlet 8, and a heat exchanger 1 for exchanging heat in a part of the gas pipeline 9.
0 is formed. A soil 12 is provided outside the cavern 11 where the pipeline air transmission line container 1 is installed, and a heat exchanger 10 is installed in the soil 12 at a position higher than the metal container 1.

In general, the temperature of the soil 12 has a small variation throughout the year and is kept substantially constant. Also, soil 1
Since No. 2 has a large heat capacity, it has a large effect of cooling the heat source.
Therefore, the cooling effect is constant without being affected by the change in the outside air temperature, so that the insulating gas whose temperature has risen is cooled in the heat exchanger 10. A natural convection loop is formed in which the cooled insulating gas descends through the gas pipe 9 and returns from the insulating gas introducing portion 8 formed in the lower portion of the metal container 1 into the metal container 1.

Although the soil temperature varies depending on the location, it is lower than the outside air temperature and changes little. For example, at a certain point, the temperature of the soil is 1 even if the outside temperature is -3 ° C in winter.
The temperature of the soil is around 0 ° C, and the temperature of the soil is 2
It is around 0 ° C, and the amount of annual change is small with respect to the outside air.
The temperature design of a normal pipeline air transmission line is an outside air temperature of 40 ° C.
It is designed with dimensions that can be obtained from the allowable temperature rise of each part based on.

In the example of the above area, the conventional design outside air temperature is 40 ° C., but in this embodiment, the soil temperature in the summer is 20 ° C.
Therefore, it is possible to design in consideration of the cooling effect due to the difference of 20 ° C., and it is possible to increase the transmission capacity or reduce the pipe diameter.

FIG. 2 is a block diagram of a pipeline air transmission line which is a second embodiment (corresponding to claim 4 and claim 5) of the present invention. In this embodiment, the pipeline air transmission line is installed in the cave 11 installed in the vertical direction. In this case,
In order to achieve natural convection, the insulating gas lead-out part 7 is formed near the partition spacer 4 installed at the upper part of the metal container, and the insulating gas lead-in part 8 is formed near the partition spacer 4 installed at the bottom of the metal container. ing. When installed in this way, the heated insulating gas accumulates in the vicinity of the partition spacers 4, so that the temperature rises more than other portions, but in this embodiment, the temperature rise is suppressed by cooling the insulating gas. .

By the way, in the conventional pipeline air transmission line,
The temperature rise of the conductor due to the current flowing in the main circuit conductor is dissipated outside the power transmission line through the metal container by heat transfer through the insulating gas around the main circuit conductor. It is set so that the rise is kept within the allowable value.

On the other hand, in this embodiment, as described above, the insulating gas which is cooled by the heat exchange with the external space by introducing the insulating gas to the outside of the pipeline air transmission line is again fed into the pipeline air transmission line. By introducing it, the temperature rise of the main circuit conductor is suppressed. Since the insulating gas rises when heated by the temperature of the conductor, heat exchange occurs naturally by placing the heat exchange part above the pipeline air transmission line, and after heat exchange, pipeline air transmission is performed. Natural convection that returns to the inside of the pipeline occurs from the introduction part provided at the bottom of the pipeline of the track. It is also possible to install a circulation pump and a forced cooler to forcibly circulate the insulating gas. As a result, it is possible to increase the current flowing in the main circuit conductor within the specified temperature rise allowable range, and increase the transmission capacity.

FIG. 3 is a configuration diagram of a pipeline air transmission line which is a third embodiment (corresponding to claim 6) of the present invention. In the present embodiment, a circulation pump 20 for forcibly circulating the insulating gas and a cooling unit 21 for forcibly cooling the insulating gas are installed in the gas pipeline 9 through which the insulating gas in FIG. 1 flows. This embodiment is adopted by considering its economical efficiency when a larger capacity is required. It is also possible to install only the circulation pump 20 and perform cooling with the heat exchanger 10 installed in the soil 12.

[0023]

As described above, according to the present invention,
Since a heat exchanger that cools the insulating gas is installed outside the pipeline air transmission line in the soil, a certain amount of cooling can be performed throughout the year, so the transmission capacity can be increased without a significant increase in cost. In addition, since it is possible to transmit the same capacity with a pipeline air transmission line having a pipeline diameter smaller than that determined by the conventional design standard, it is possible to reduce the construction cost.

Further, when a larger capacity power transmission is required, it can be easily dealt with by installing a circulation pump and a cooling unit. In this case, it is necessary to calculate the overall economic effect such as the installation of circulation pumps and cooling units, but since the diameter of the pipeline does not become large, it is not necessary to create a cave that occupies a large weight in terms of cost. Effect is very large.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a pipeline air transmission line that is a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a pipeline air transmission line that is a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a pipeline air transmission line in which a circulation pump and a forced cooling unit according to a third embodiment of the present invention are installed.

FIG. 4 is a configuration diagram of a conventional gas-insulated pipeline air transmission line.

5A is a side view of the cone spacer portion of FIG. 4, and FIG. 5B is a cross-sectional view of the main circuit conductor portion of FIG.

[Explanation of symbols]

1 ... Metal container for pipeline air transmission line, 2 ... Bellows, 3 ...
Main circuit conductor of pipeline air transmission line, 4 ... Cone spacer,
5 ... Columnar spacer, 6 ... Insulating gas filling space, 7 ... Gas lead-out part, 8 ... Gas introducing part, 9 ... Gas distribution line, 10 ... Heat exchanger, 11 ... Cave, 12 ... Soil, 20 ... Circulation pump Two
1 ... Cooling unit.

Claims (6)

[Claims] 1. A pipeline air transmission line having a gas space partitioned by insulating gas partition spacers at predetermined intervals,
The pipeline air transmission line is installed horizontally in a cave installed in a horizontal direction, and each pipeline forming one gas space of the pipeline air transmission line has an upper portion above each pipeline. A gas lead-out portion for leading out an insulating gas in the pipe is formed, a gas inlet is formed in a lower portion of the pipe, and the gas lead-out portion and the gas inlet are connected to each other by a gas pipe through which an insulating gas flows. A transmission line in the air. 2. The pipeline air transmission line according to claim 1,
A heat exchanger capable of exchanging heat of the insulating gas is installed in the gas conduit connected to the gas outlet and the gas inlet for guiding and introducing the insulating gas in the pipeline air transmission line. The pipeline air transmission line. 3. The pipeline air transmission line according to claim 2,
A heat exchanger for exchanging heat with the insulating gas is buried in the soil around the cave where the pipeline air transmission line is installed, and the heat exchanger is installed at a position higher than the gas outlet. A pipeline air transmission line characterized by. 4. A pipeline air transmission line having a gas space partitioned by insulating gas section spacers at predetermined intervals,
The pipeline air transmission line is installed vertically in a cave installed in the vertical direction, and each pipeline axial upper part of each pipeline forming one gas space of the pipeline air transmission line A gas lead-out portion for leading out the insulating gas in the pipeline is formed near the partition spacer, and a gas lead-in portion for introducing the lead-out insulating gas into the pipeline near the partition spacer under the pipeline. And the gas outlet and the gas inlet are connected to each other by a gas pipeline through which an insulating gas flows. 5. The pipeline air transmission line according to claim 4,
A heat exchanger capable of exchanging heat of the insulating gas is installed in the gas pipeline connected to the gas outlet and the gas inlet for guiding and introducing the insulating gas in the pipeline air transmission line. Line air transmission line. 6. The pipeline air transmission line according to claim 1 or 4, wherein a circulation pump for forcibly circulating an insulating gas and a cooling unit for forcibly cooling the insulating gas are installed in the gas pipeline. A pipeline air transmission line characterized by.