JPS6357754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vacuum wall piping penetration device for a nuclear fusion device.

[Technical background of the invention]

A conventional example will be explained with reference to FIGS. 1 to 3. FIG. 1 is a schematic diagram of a nuclear fusion device. In the figure, 1 indicates a vacuum container. This vacuum vessel 1 has a toroidal shape and confines plasma 2 therein to maintain a high vacuum. A blanket 3 is provided inside the vacuum vessel 1 so as to surround the plasma 2. A shield 4 is provided between the blanket 3 and the vacuum vessel 1. The blanket 3 contains lithium as a tritium breeding material therein, and is provided with a coolant channel 5 for cooling the lithium, as shown in FIG. Further, the blanket 3 reacts high-energy neutrons emitted from the plasma 2 with the lithium to generate tritium, and uses the thermal energy generated at this time to cool helium gas or the like flowing through the coolant flow path 5. It is constructed so that it can be taken out to the outside using a material. That is, the lithium is generally kept at a high temperature of 400 DEG C. to 1000 DEG C., and the multiplied tritium is sent out to the outside of the blanket 3 using the helium gas flow. The helium gas sent to the outside has a relatively high temperature, and when it passes through the relatively low temperature shield 4 and the vacuum wall 1a, there is a risk that thermal stress may be generated in the penetrating portion. Therefore, generally, the coolant passage 5 has a double piping structure, and high temperature helium gas is passed through the inner piping and low temperature helium gas is passed through the outer piping.

Next, the coolant flow path 5 having the above-mentioned double piping structure will be explained. A first outer tube 6 is disposed through the through hole 1A of the vacuum wall 1a with one end protruding outside the vacuum wall 1a. A second outer tube 7 is butt-welded to one end of the first outer tube 6. At the same time, a first inner tube 8 and a second inner tube 9 are disposed inside the first outer tube 6 and the second outer tube 7, respectively, and are welded and joined by butting. Then, the high temperature helium gas containing the multiplied tritium flows through the first inner tube 8 and the second inner tube 9, and the outside of the first inner tube 8 and the second inner tube 9 is kept at a low temperature. of helium gas flows through it. Therefore, a space exists between the shielding body 4 and the vacuum wall 1a, which are kept at a relatively low temperature, and the high temperature helium gas, so that generation of thermal stress can be prevented.

[Problems with background technology]

Generally, the blanket 3 is at risk of being damaged by neutrons and charged particles and requires periodic replacement. Furthermore, in the unlikely event that an accident occurs, the blanket 3 must be repaired or replaced. Therefore, the coolant flow path 5 must be cut and welded each time. However, the structure of the coolant flow path 5 does not have sufficient machining allowance, and in order to cut the inner pipe, it must be cut together with the outer pipe, or the outer pipe must be cut and one end removed, which is extremely difficult. There was a problem.

[Purpose of the invention]

The object of the present invention is to facilitate the repeated cutting and welding of double-structured piping, and to facilitate the use of automatic equipment such as automatic cutters and automatic welders for vacuum wall piping in nuclear fusion devices. The object of the present invention is to provide a penetration device.

[Summary of the invention]

In order to achieve the above object, the present invention includes a first outer tube that penetrates the vacuum wall of a vacuum container and has one end led out of the vacuum container; The first tube protrudes from the lead-out end of the first outer tube.
an inner tube, a second outer tube provided outside the vacuum container opposite to the first outer tube, and a second outer tube disposed within the second outer tube with one end protruding from the second outer tube. a second inner pipe which is welded to the first inner pipe; and a second inner pipe which is slidably provided to the second outer pipe and has one end welded and joined to the lead-out end of the first outer pipe. and a tubular welding seat welded to the second outer tube via an expansion joint.

That is, a space is provided between the first outer tube and the second outer tube, and a welding seat is connected to the second outer tube via an expansion joint and slides along the outer periphery of the second outer tube. When the first outer tube and the second outer tube are connected to each other, the welding seat is slid toward the first outer tube side and welded.
When separating, cut it and slide it to the second outer tube side.

Therefore, a sufficient cutting allowance can be provided at the joint between the first outer tube and the welding seat, making welding and cutting easier. In addition, by sliding the welding seat toward the second outer tube, it becomes possible to cut and weld the first and second inner tubes from the space, and also to cut and weld the first and second inner tubes from the space. Sufficient machining allowance can be provided to facilitate welding and cutting.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 4 to 6. In the figure, 101 indicates a vacuum container. This vacuum container 101 has a toroidal shape and confines plasma 102 therein to maintain a high vacuum. A blanket 103 is provided inside the vacuum vessel 101 so as to surround the plasma 102. A shield 104 is provided between the blanket 103 and the vacuum container 101. The blanket 103 contains lithium as a tritium breeding material inside, and a coolant channel 10 is provided to cool the lithium.
5. Further, the blanket 103 reacts high-energy neutrons emitted from the plasma 102 with the lithium to generate lithium, and the thermal energy generated at this time is transferred to a helium gas or the like flowing through the coolant flow path 105. It is configured to take out the coolant to the outside.

Therefore, the coolant flow path 105 is generally configured to have a double piping structure, with high temperature helium gas flowing through the inner piping and low temperature helium gas flowing through the outer piping.

Next, the configuration of the coolant flow path 105 will be explained. As shown in FIG. 5, a through hole 101A is provided in the vacuum wall 101a of the vacuum container 101, and one end (leading-out end) of the first outer tube 106 is led out of the vacuum container 101 through the through hole 101A. ing.
This first outer tube 106 has a flange portion 106A at one end outside the vacuum wall 101a. Outside the vacuum wall 101a, there is a second outer tube coaxially with the first outer tube 106 and having a space with the first outer tube 106.
An outer tube 107 is provided. This second outside 1
A weld seat 108 is slidably provided on the outer peripheral side of the weld 07, and one end is connected to the second outer tube 107 via a bellows 109. The other end has a flange portion 108A, which is welded to the flange portion 106A of the first outer tube 106. A first inner tube 110 and a flange portion 111 each have a flange portion 110A inside the first outer tube 106 and the second outer tube 107.
A second inner tube 111 is provided, and the flange portion 110 is disposed at the position of the space portion.
A and 111A are welded together.

In the above configuration, when cutting the coolant flow path 105, first the first outer tube 106 and the welding seat 1 are cut.
Cut the joint 08 using an automatic cutter or the like. As shown in FIG. 6, the weld seat 108 is attached to the second outer tube 1.
07 along the outer periphery to the second outer tube 107 side. Then, the joint between the first inner tube 110 and the second inner tube 111 is cut off from the space using an automatic cutter or the like. This completes the cutting of the coolant flow path 105.

On the other hand, when welding, the first inner pipe 1 is
Weld 10 and 111 using an automatic welder or the like. Then, the welding seat 108 is slid toward the first outer tube 106, and the flange portion 106A of the first outer tube 106 and the flange portion 108A of the welding seat 108 are brought into contact and welded using an automatic welder or the like. This completes the welding of the coolant flow path 105.

That is, the flange portions 106A, 108A and 110A, 111A provide sufficient machining allowance for cutting and welding, making welding and cutting extremely easy. In addition, by sliding the welding seat 108 toward the second outer tube 107, it becomes possible to cut and weld the inner tube from the space, making it easy to use automatic cutters and automatic welders for both the inner tube and the outer tube. . Furthermore, bellows 109
This makes it possible to absorb the expansion and contraction of piping due to heat, thereby improving safety. In the embodiment described above, the welding seat 108 and the bellows 109 were provided outside the second outer tube 107, but as shown in FIG.
9 may be provided inside the second outer tube 107. In this case, the welding seat 108 is the second outer tube 1
It slides along the inner peripheral surface of 07. Hereinafter, the cutting and welding procedure is the same as in the previous embodiment.

〔Effect of the invention〕

As explained above, the present invention provides a first tube that penetrates the vacuum wall of a vacuum container and has one end led out to the vacuum chamber body.
an outer tube, a first inner tube disposed within the first outer tube and having one end protruding from the lead-out end of the first outer tube, and a first inner tube located opposite the first outer tube and arranged in the vacuum container. a second outer tube provided outside; and a second inner tube disposed within the second outer tube with one end protruding from the second outer tube and welded to the first inner tube. is slidably provided on the second outer tube and has one end connected to the first outer tube.
A tubular welding seat is welded to the outlet end of the outer tube and the other end is welded to the second outer tube via an expansion joint. Cutting and continuous operations can be performed repeatedly, and blankets can be easily replaced during periodic inspections of the fusion device.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing conventional examples. Figure 1 is a schematic configuration diagram of a nuclear fusion device, Figure 2 is a partially enlarged view of Figure 1, and Figure 3 is a partially enlarged view of Figure 2. Figures 4 to 6 are diagrams showing one embodiment of the present invention.
5 and 6 are partially enlarged views of FIG. 4, and FIG. 7 is a sectional view showing another embodiment of the present invention. 101a...Vacuum wall, 101A...Through hole in vacuum wall, 106...First outer tube, 107...Second outer tube, 108...Weld seat, 109...Bellows,
110...first inner tube, 111...second inner tube.

Claims (1)

[Claims] 1. A first outer tube that penetrates the vacuum wall of the vacuum container and has one end led out of the vacuum container, and a first outer tube that is disposed within the first outer tube and has one end that protrudes from the lead-out end of the first outer tube. a second outer tube provided outside the vacuum container opposite to the first outer tube; and a second outer tube disposed inside the second outer tube and having one end connected to the second outer tube. a second inner tube protruding from the tube and welded to the first inner tube; and a second inner tube slidably provided to the second outer tube and having one end welded to the lead-out end of the first outer tube. A vacuum wall piping penetrating device for a nuclear fusion device, comprising a tubular welding seat whose other end is welded to the second outer tube via an expansion joint.