JPS5992710A - Method of laying shaft of direct water cooling line - 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 The present invention relates to a method for installing a vertical shaft portion of an electric cable line installed in an underground tunnel and directly cooled by cooling water.

It is known that high-voltage and ultra-high-voltage electrical cables installed underground in cities are subjected to forced cooling in order to increase the power transmission capacity per circuit. Types of forced cooling include direct pipe water cooling, in which cooling water is passed through the gap between the cable and the conduit in the electrical cable installed in the conduit, and cooling water is passed in the parallel path adjacent to the conduit housing the cable. An indirect pipe water cooling system in which water is passed through is known. Recently, it has become difficult to construct conduits for laying underground cables close to the ground surface due to congestion of buried objects.
As aLl ml+ became more popular, a method of constructing tunnels or V-yu common ditches deep underground in cities and laying multi-circuit cables within them has been adopted.

Such cables inside the tunnel also need to be cooled in the same way as mentioned above, and an experiment has been conducted on a direct water cooling system for the cable inside the tunnel, in which a conduit is installed inside the tunnel, and the cable is directly cooled with water after passing through the conduit. is being attempted.

The power transmission capacity of a power cable subjected to such forced cooling can be increased by about 30 to 50% with indirect cooling, and by about 100% with direct water cooling, compared to the case without cooling.

In the above-mentioned direct water cooling system, since the power cable is placed inside the cooling pipe, holding the cable directly at the IJ-1-i is a round trip.

For this reason, in cases where vertical tunnels (hereinafter referred to as shafts) have a large head, it is difficult to prevent cables from falling.

That is, in the case of uncooled cable lines, a vertical shaft installation method as shown in FIG. 1 (A1 and B) has conventionally been adopted.

The method shown in the figure is to
1 into a snake shape and at regular intervals, ri! This is a method in which the cable 1 is fixed with J-1 and 22, and the change in width of the swivel between the heat expansion and contraction beam 1)-) 22 and the crease 1 and 22, which occurs due to the rise in temperature of the cable 1, is used to absorb the change.

However, in direct water-cooled lines, the cable cannot be gripped directly with the cleat as shown in the diagram, but can only be gripped indirectly from above the cooling pipe. Therefore, even if a snake is installed, the cable will freely slide downward inside the snake-shaped cooling pipe.

Matanaka) The method shown in the figure is to firmly fix the non-cooled electric cable cable 21 at one point at the top of the shaft using a fixing device 23, and suspend the entire cable 21. In this case, all of the thermal expansion and contraction of the cable 21 is caused by the bending radius R1 at the lower end of the shaft.
It will be absorbed by the deformation of.

However, for direct water-cooled lines, this method had two problems. That is, (1) the cable cannot be fixed by the fixing device because there is a pull inside the cooling pipe. Also, if the cable is in the cooling pipe/caught, the bending radius R of the cable cannot be changed freely as shown by the dotted line (because there is a restriction on the inner diameter of the cooling pipe).

The present invention has been made to solve the above-mentioned problems, and provides a method of laying a water-cooled cable line directly into a vertical shaft, which can effectively absorb thermal expansion and contraction of the cable. That is.

The present invention provides a method in which a direct water-cooled electric cable (hereinafter referred to as water-cooled cable) is suspended from the top of a shaft, and is laid by bending it toward the bottom with a curvature at the bottom of the shaft.
The cooling pipes in the vertical part of the water-cooled pull are fixed to the vertical wall of the shaft at appropriate intervals, and the cooling pipes in the short section of the water-cooled cable are removed on the second side of the shaft, and the internal cables are removed. The cable portion is fixed to the upper surface of the shaft by exposing the cable portion, and a bypass pipe is provided for the cooling pipe, and the cooling pipe at the curved part of the water cooling cable is made thicker so that the inside of the cooling pipe is fixed to the upper surface of the shaft. This is a method of laying the shaft part of the iljl water tangent line, which requires that the cable can be freely deformed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below by way of embodiments with reference to the drawings.

FIG. 2 is a side view illustrating an embodiment of the method of the present invention. In the figure, 1 (l-i water cooling couple, cooling pipe (
For example, an internal cable 2 is inserted into a hard vinyl chloride pipe 3, and cooling water 11 is passed through the cooling pipe 3. The cooling pipes 3 in the vertical part of the water cooling cable 1 are fixed to the vertical wall iM+ 8 of the shaft by cooling pipe fixing creases 1 and 6 at appropriate intervals, and are laid in a straight line.

Next, in the 9th part of the second side of the shaft, the water cooling cable 1 is connected to the point p.
The cooling pipe 3 is removed for a short section (for example, about 1 trt), water stop devices 5, 5 are installed to stop water, the internal cable 2 is exposed, and this internal cable section is attached to a cable fixing device. 4 to the upper surface 9 of the shaft, and a bypass pipe 7 of the cooling pipe 3 is provided to allow the cooling water 11 to flow therethrough.

In addition, at the bottom 10 of the vertical shaft of the water-cooled cable 1, there is a bend, ``I
A bent portion 12 having an L diameter R is provided, and the bent portion 12 is bent in the direction of the bottom 1 nilO from the vertical direction. 6 is fixed at IJ -1-. In the present invention, the cooling pipe 1 of the water cooling portion 12 has a curvature of 10.
Make 3 thicker.

FIG. 3 is a side view showing an example of this bent portion 12.
(a) The figure shows the normal state, (b) shows the state during thermal expansion of the cable, and (c) shows the pipe diameter register and -za. The inner diameter of the cooling pipe 13 at this bent portion 12 is larger than that of the other portions of the cooling pipe 3, and is bulged on the outside of the bend, and the cross section [n] shape may be circular or elliptical. In order to connect this large-diameter pipe section and a normal narrow pipe section (c) pipe diameter register user 14 as shown in Figure 1.
is used. A hard vinyl chloride pipe similar to the cooling pipe 3 is used for the cooling pipe +3 and the pipe diameter register user 14.

With this configuration, the internal cable 2 of the water cooling cable 1
is fixed at point P on the upper surface of the shaft, and the cooling pipe 3 in the vertical part is fixed to the vertical wall surface 8, so expansion and contraction due to temperature changes in the cooling pipe 3 does not reach the curved part 12 at the bottom. For,
The internal cable 2 extends downward due to the temperature change, and the point P2 in the lower cable fixing creases 1 and 6 extends by a length Il+ at the point P2' trench in FIG. 3(b). This elongation m will reach the bending part 12 between points P2 and P3,
Since the diameter of the cooling pipe 13 in this part is large, the internal cable 2 in this part can be deformed into [1], and the amount of thermal expansion and contraction can be easily absorbed.

The shaft installation method of the present invention configured as described above has the following effects.

(B) Fix the cooling pipe in the vertical part of the water-cooled cable to the vertical wall of the shaft as shown in the previous I-Bo, and attach the internal cable part of the water-cooled cable to the top of the shaft (as described above)
- Because it is fixed on one side and a bypass pipe is provided, the vertical part (
1) When the internal cable is drawn into the cooling pipe, since it is in a straight line, there is less friction and less tension in the cable than in a snake-shaped cable, and the cable is easy to install.

(b) Also, the water-cooled cables are suspended like two series, and the cooling pipe at the bent part with the curvature of the -[: part is made thicker so that the internal cable can freely deform within the cooling pipe. Therefore, as shown in Figure 3 (b), the point P, −■
The amount of thermal expansion and contraction caused by temperature changes in the internal couple between the two can be easily absorbed, making it easy to install water-cooled cables in the vertical shaft.
It is 1 knife, and +74 construction is easy. (Point r'2-P
There is no need to insert an rlJ flexible cooling pipe between the two. )←9
Fix the internal cable directly at point PI on the second side of the shaft.
There is no risk of falling off.

2) Because the cooling pipes in the Taruichi area are fixed at appropriate intervals,
There is no need to consider thermal expansion and contraction of the cooling pipe.

In addition, the exposed section of the internal cable in point 1 is short (
For example, about 17 +

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are side views illustrating an example of a conventional method of laying a vertical shaft portion of an uncooled cable line, respectively. FIG. 2 is a side view for explaining an embodiment of the method of the present invention. Figures 3 (a) to (c) are side views showing an example of the bent portion shown in Figure 2, where (a) shows the normal state, (b) shows the state when the cable is thermally stretched, and ( c) The figure is a diagram showing a tube diameter reno user. 1 Direct water cooling cable, 2 Internal cable, 3.1
3. Cooling pipe, 4. Cable fixing device, 5. Water stop device,
6.16 Cooling pipe fixed cree-1, 7 bypass pipe,
8. Vertical wall surface, 9. Top surface of shaft, 1o Bottom surface of shaft, 11. Cooling water, 12. Bend part, I/l pipe bending radius.

Claims (1)

[Claims] (1) A method in which a direct water-cooled electric cable (hereinafter referred to as a water-cooled cable) is suspended from the top of a shaft, and bent at the bottom with a curvature at the bottom of the shaft to install an IJ. The cooling pipes of the vertical part of the water cooling cable are fixed at appropriate intervals to the vertical wall surface of the shaft, and at the second side part of the shaft, the cooling pipe of the outer section of the water cooling cable is removed and the internal cable is removed. Exposing the cable section to the shaft
It is fixed on two sides, and a bypass pipe is provided for the front 8-pin cooling pipe, and the cooling pipe at the bent part of the water cooling cable is made thicker so that the internal cable can be freely deformed within the cooling pipe. A method for installing a vertical shaft portion of a direct water-cooled line.