JPH0226181Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical field of the invention] The invention relates to an indirect cooling line within a tunnel. [Technical background of the invention and its problems] In order to lay an ultra-high voltage cable inside a tunnel, the ultra-high voltage cable must be placed at the bottom of the trough installed inside the tunnel.
For example, they are arranged in three bales, and a water-cooled pipe is installed in the upper part of the trough to provide indirect cooling inside the trough. When performing a line cooling design as described above, various conditions regarding temperature are given. An example of this is as follows.

[Table] However, if the heat load due to the energization of a 22 to 66 kV class CV cable, i.e. a secondary cable, installed in a tunnel alongside an ultra-high voltage cable indirectly cooled in the trough, the following problems may occur. There is. That is, the secondary cable is installed outside the trough, and is cooled by a water-cooled pipe installed inside the trough. Therefore, cooling of the secondary system cable is performed via a trough with large thermal resistance, and the cooling efficiency is poor and the temperature inside the trough increases due to the heat load on the secondary system cable, and it is necessary to keep it below the limit value. It is difficult to maintain. [Purpose of the invention] The present invention was made based on the above circumstances, and aims to obtain an indirect cooling line in a tunnel that can maintain the temperature in the tunnel within a limit value when the heat load of the secondary cable is large. The purpose is [Summary of the invention] The indirect cooling line in a tunnel of the present invention connects a water-cooled pipe, which is installed together with a cable in a trough inside a tunnel, to the outside of the trough in an area where there is a large heat load due to the heat generated by the secondary cable installed outside the trough. It is characterized in that it is placed near the secondary system cable. [Embodiment of the invention] In FIG. 1, a trough 1 accommodates a cable (not shown) and two water-cooled pipes 2, only one of which is shown in the figure. In this figure, 3 is a tunnel, R ₁ and R ₂ are areas with a small heat load on the secondary cable, and R ₃ is an area with a large heat load on the secondary cable sandwiched between these areas. Thus, the water-cooled pipe 2 is connected to the trough 1 in the area _R3 .
It hangs outside and is close to the secondary cable.
By doing the above, the secondary cable, which has a large load, is cooled by the hanging water-cooled pipe without going through a trough with large thermal resistance, so it is efficiently cooled and the temperature rise in the tunnel is suppressed. be done. FIG. 2 shows a comparison between the temperature of the tunnel and the conductor of the inventive line having the above structure during an accident and during normal operation, compared with those of a conventional line cooled with the same amount of water. In this figure, the broken line is the line of the present invention, and the dotted line is the conventional line. From this figure, it can be seen that in the conventional line, although the conductor temperature has a sufficient margin with respect to the limit value, the temperature inside the tunnel exceeds the limit value. In contrast, it can be seen that the temperature inside the tunnel is kept lower in the invented line than in the conventional line. Note that in this case, the conductor temperature rises more than in the conventional line, but remains within the limit value. FIG. 3 shows another embodiment of the invention. This embodiment is applied when the heat load of the secondary cable cannot be predicted at the line design stage. In this diagram,
The water-cooled pipe 2 arranged in the trough is divided into unit water-cooled pipes 2a of a certain length, and the divided unit water-cooled pipes 2
comrades a are connected by header 4. In addition, a unit water cooling pipe 5a is installed outside the trough with a header 6.
A water-cooled pipe 5 for cooling the secondary system cable connected with
are provided, and the opposing headers 4 and 6 are connected by a connecting pipe 7. Between the opposing headers 4, 4,
There are valves 8, 9, 10, 1 on both sides of the connection point and on the connection pipe 7 of the pipeline connecting between 6 and 6.
1 and 12 are provided. In the above configuration, if the valve 12 of the connecting pipe 7 is closed and the valves 8 and 9 are opened, the water will be transferred to the water cooling pipe 2.
Flows only within. On the other hand, if valve 9 on the right and valve 10 on the left of the connection on the left in FIG. Cooling water does not flow into the unit water-cooled pipes 2a, but flows into the unit water-cooled pipes 5a between the connecting parts. In addition, by operating the valve, it is also possible to have a plurality of unit water cooling pipes in which the cooling water does not flow or flows. Therefore, in areas where the heat load on the secondary cable becomes large after the line is completed, cooling water can be made to flow into the unit water cooling pipes outside the trough as described above, so the implementation shown in Figure 1 can be used. You can achieve the same effect as in the example. [Effects of the invention] As is clear from the above, according to the present invention, even when the heat load on the secondary cable is large, the increase in temperature within the tunnel can be suppressed, which is beneficial in terms of railway safety. Note that if the cooling effect is similar to that of conventional lines, the required amount of cooling water may be small, and the capacity of the refrigerator may be small, making it possible to design the equipment economically.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of one embodiment of the present invention, FIG. 2 is a graph explaining its effects, and FIG. 3 is a piping diagram of another embodiment. 1...Trough, 2...Water cooling pipe.

Claims (1)

[Scope of utility model registration request] A water-cooled pipe laid in a trough in a tunnel together with a cable is brought out of the trough in an area where there is a large heat load due to heat generated by the secondary cable laid outside the trough, and placed near the secondary cable. An indirect cooling line in a tunnel featuring: