JPS60157071A - Cooling structure of first wall for fusion reactor - 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 an improvement in the cooling structure of a first wall forming a plasma facing surface of a blanket for a nuclear fusion reactor.

First, an outline of a tokamak-type fusion reactor will be explained.

A tokamak-type fusion reactor is one in which an electric current is passed through the plasma generated in the circumferential direction, and the plasma is confined by the force of the magnetic field generated by this electric current. An inner blanket 2, an outer blanket 2', an internal air device 7, etc. are arranged in the inner blanket 2, outer blanket 2', and internal air device 7. A tokamak-type fusion reactor is generally composed of the equipment described above.
Among these, the inner and outer blankets 2゜2' have the function of converting the nuclear energy of neutrons generated by a nuclear fusion reaction in the container into thermal energy, and the reaction of the neutrons with lithium oxide in the container to generate nuclear energy. It is an important piece of equipment in a nuclear fusion reactor, as it has the ability to fully produce tritium (tritium), which is the fuel for the fusion reactor, and, together with a shield, to shield neutron radiation. The first wall is this blanket 2,2
A structure that constitutes the plasma facing surface of 1, which receives a large heat load directly from plasma 1.

Since it is under severe conditions where it is subjected to a particle load, it is required to have sufficient cooling performance.

Conventionally, as shown in Fig. 2, the first wall 8 of a tokamak reactor is cooled by a method in which the coolant flows in the poloidal direction, that is, in the direction of arrow A. However, since the first wall 8 has a torus shape, the cooling flow is limited. A problem arises in that the channel pinch varies in the flow direction.

In other words, the pitch of the cooling channel is maximum at the plasma center plane B, which receives the severest heat load, and the pitch is minimum at the upper or lower part, where the heat load is relatively small, resulting in uneven cooling, and the maximum temperature of the structural material and It is difficult to suppress internal thermal stress below the allowable value, and furthermore, since the first wall 8 is installed in front of the blanket container as a structure independent of the growth blanket container, the first wall 8 and the wall of the blanket vessel, neutron economy is poor and the tritium breeding performance of the blanket is adversely affected, and the support of the first wall 8 is under severe heat load and single particle loading conditions. There were difficult and other problems, and it was difficult to solve them.

In view of the above technical problems, the present invention aims to provide a cooling structure for the first wall of a nuclear fusion reactor that is excellent in cooling performance and neutron economy.

That is, the present invention provides a cooling structure in which the first wall is integrated with the container wall of a box-shaped blanket and serves as the first wall, in which the coolant flows along the blanket container wall in a direction parallel to the donut-shaped plasma, that is, in a tridal direction. A coolant manifold, which also serves as a reinforcing flange of the Plarequet container and which distributes and collects the first wall coolant flow path composed of a plurality of parallel heat transfer tube groups, is installed at the rear of the bracket container. A predetermined coolant outlet temperature in the poloidal direction inside the manifold,
It is characterized by being divided into an appropriate number of partitions depending on the size of the heat load, the size of the blanket container, etc., and the coolant is folded back through the manifold and sent into the first wall coolant flow path for cooling. It is something to do.

An embodiment of the present invention will be described in detail below. Fig. 3 shows a new box-shaped blanket having a first wall that integrates the front wall of the blanket and the first wall, 10 is the first wall that also serves as the outer peripheral wall of the blanket, and 11 is the first wall. 1, and is connected to left and right manifolds 12a and 12bK which also serve as reinforcement 74 flange 12 provided at the rear of the blanket.

A tritium breeder material 13 and a neutron moderator 14 are housed inside the blanket container integrated with the first wall 10, and a coolant flows in a voloidal direction at appropriate intervals between the moderators 14. Cooling channel 1 for blanket cooling
5 is placed. The cooling structure installed in the coolant flow path 11 of the first filO is as shown in the cooling conceptual diagram in FIG. From there, proceed through ■ and ■ until you reach ■ in the left manifold 12b. Since the inside of the manifold is appropriately divided in the voloidal direction, the coolant is bent here and passes through (1) and (3). In this way, the coolant makes a U-turn in the manifolds 12a and LZb via headers (not shown), and when passing through the first wall 10, the cooling flow path 11 is installed so that it always flows in a toroidal direction. The municipal waste material flow velocity in the flow path 11 is tAf:
In order to achieve this, the number of coolant channels 11 connected to the anifolds 12a and 12b is varied in the voloidal direction for each valley-divided manifold. That is, on the coolant inlet 16 side, the number of parallel coolant channels 11 is increased, and the coolant outlet 1
It is reduced on the 7 side. -Next, the operation of this embodiment configured as described above will be explained. Since the first wall 10 of the blanket in the fusion reactor is subjected to a severe heat load from the plasma, the temperature of the coolant for cooling the first wall 10 is lower than that while cooling the first wall 10 from the inlet 16 to the outlet 17. As a countermeasure, in order to ensure a particularly high heat transfer coefficient at the coolant outlet 170111, cooling is performed on the coolant inlet 16 side where the coolant temperature is relatively low. Increase the number of material flow paths, and set 1 coolant outlet.
On the 7 side, the flow rate is adjusted by reducing the number of channels. This allows the coolant inlet 16 to have a relatively small heat transfer coefficient.
On the side, the coolant flow velocity in each flow path becomes smaller, and on the coolant outlet 17 side, where a large heat transfer coefficient is required, a sufficiently large flow velocity can be secured. It has a large heat transfer coefficient and can keep pressure loss low.

Furthermore, in a tokamak-type fusion reactor, the thermal load on the first wall 10 is greatest at the plasma center plane and becomes considerably smaller above and below the first wall 10. Since the number of coolant flow paths 11 is selected so as to equalize the thermal protection of the first wall structural material, thermal deformation and thermal stress are less likely to occur. The cross-sectional shape of the coolant flow path 11 is not necessarily circular, but may be elliptical,
Shapes such as a circular shape and a rectangular shape can also be adopted, and furthermore, flow pipes having these shapes can be appropriately combined and used depending on the heat load distribution.

As detailed above, according to the cooling structure of the first wall of the present invention, the first wall and the outer surrounding wall of the blanket are integrated, the coolant channels are provided in the tridal direction, and the number of channels is separated from the plasma. Since the settings are made in accordance with the heat load of

[Brief explanation of drawings]

Figure 1 is a cross-section diagram showing the outline of a tokamak-type fusion reactor, Figure 2
The figure is a perspective view showing the general shape of the inner blanket/first wall, FIG. 3 is a sectional view of a box-shaped blanket showing an embodiment of the first cooling structure for a fusion reactor according to the present invention, and FIG. It is a cooling conceptual diagram of the 1mth cooling structure. 10... First wall 11... Coolant channel 12...
Reinforcement flanges 12a, 12b... Manifold applicant: Kawasaki Heavy Industries, Ltd. Figure 1 Figure 2 Figure 3 Comprehensive view

Claims (1)

[Claims] In the first wall cooling structure in which the container wall of the box-shaped blanket and the first wall are integrated and the coolant flows in a tridal direction, the first wall coolant flow path is composed of a plurality of parallel heat transfer tube groups; A coolant manifold that distributes and collects the coolant flow paths and also serves as a reinforcing flange for the blanket is installed behind the blanket, and the interior of the manifold is divided into a predetermined number of sections in the voloidal direction, and the coolant is divided into sections. 1. An operating structure for a first wall for a fusion reactor, characterized in that the first wall is folded back through a divided manifold and sent into the first wall coolant flow path for cooling.