JP2015222080A - Self-supporting rack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-supporting rack capable of reducing a side slip with respect to a floor surface by efficiently consuming energy produced by an earthquake.SOLUTION: A self-supporting rack 20A for being installed in water 11 includes: a stand box 22 which is installed in a self-supporting manner by a plurality of legs 24, on a floor surface 12a of a pit 12 for storing the water 11; a rack box 21 which houses a storage article and which is accommodated inside the stand box 22 with a clearance for interposing the water 11; and a plurality of lower elastic members 23 which are provided between a bottom plate 22a of the stand box 22 and a bottom plate 21a of the rack box 21 and which support the rack box 21.

Description

  The present invention relates to a self-supporting rack that is installed on a floor surface and stores stored items therein.

2. Description of the Related Art A self-supporting rack that is installed on a floor surface and stores stored items therein is known. This is because when the rack is fixed to the floor surface, the load at the time of the earthquake is applied to the rack as it is, and a large load is applied to the support portion of the rack. When the self-supporting type is used, the rack slides during an earthquake, so the acceleration of the rack is reduced, the load on the support part is reduced, damage to the support part can be suppressed, and the safety thereof can be improved.
An example of such a self-supporting rack is a self-supporting fuel assembly storage rack that stores a fuel assembly of nuclear fuel. Such a self-supporting rack is merely installed on the floor surface in a pit filled with water, for example, and the floor surface can be slid in the event of an earthquake in order to reduce the load during the earthquake. However, there are the following problems when the amount of skid during an earthquake is large.
(1) Pit walls and racks collide and are damaged.
(2) The rack legs are displaced from the predetermined position, and a large-scale layout correction work occurs after the earthquake.

JP2013-40871A

  For example, in Patent Document 1, the rack body (11) and the base plate (17) are separated via a universal joint (16A), a spring (15), and the like (see FIG. 2 of Patent Document 1). ), When the seismic horizontal force is transmitted to the rack main body (11) through the universal joint (16A), the rack main body (11) swings, so that the energy consumption by the damper (41) causes the base of the base plate (17). The side slip of (18) is reduced.

  However, since only the damper consumes energy due to the earthquake, the amount of side slip reduction (energy consumption) is small. In addition, the stored item jumps in the swing motion, and the speed of the upper part of the stored item increases due to the centrifugal force, and there is a concern about damage due to a collision with an adjacent rack or pit wall.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a self-supporting rack capable of efficiently consuming energy due to an earthquake and reducing side slip relative to the floor surface.

The self-supporting rack according to the first invention for solving the above-mentioned problems is
A self-supporting rack installed in a fluid,
A first box that is installed on a floor surface of the place where the fluid is stored by a plurality of legs; and
A second box for storing a stored item and accommodated inside the first box with a gap for interposing the fluid;
A plurality of elastic members are provided between the bottom plate of the first box and the bottom plate of the second box and support the second box.

The self-supporting rack according to the second invention for solving the above-mentioned problems is
In the self-supporting rack according to the first invention,
The second box between the bottom plate of the first box and the bottom plate of the second box, on the upper surface side of the bottom plate of the first box or on the lower surface side of the bottom plate of the second box. A first resistance plate extending toward the lower surface side of the bottom plate or the upper surface side of the bottom plate of the first box is provided.

A self-supporting rack according to a third invention for solving the above-mentioned problems is as follows.
In the self-supporting rack according to the second invention,
A plurality of the first resistance plates are arranged in a lattice shape as viewed from above, or a plurality of the first resistance plates are arranged radially.

A self-supporting rack according to a fourth invention for solving the above-described problems is as follows.
In the self-supporting rack according to any one of the first to third inventions,
A second resistance plate covering an outlet of a gap between the side wall of the first box and the side wall of the second box at the upper end of the side wall of the first box or the upper end of the side wall of the second box Is provided.

A self-supporting rack according to a fifth invention for solving the above-mentioned problems is as follows.
In the self-supporting rack according to any one of the first to fourth inventions,
Another elastic member is provided between the side wall of the first box and the side wall of the second box.

A self-supporting rack according to a sixth invention for solving the above-mentioned problems is as follows.
In the self-supporting rack according to any one of the first to fourth inventions,
It extends between the side wall of the first box and the side wall of the second box, and extends in the horizontal direction on the inner surface side of the side wall of the first box or the outer surface side of the side wall of the second box. The third resistance plate is provided.

  According to the present invention, the self-supporting rack is separated into the outer first box and the inner second box, and the energy at the time of the earthquake is efficiently used for the resistance energy of the fluid accompanying the horizontal displacement of the inner second box. Since the conversion is performed well, the side slip (horizontal displacement) with respect to the floor surface of the outer first box can be further reduced.

It is a perspective view which shows the state which has arrange | positioned the self-supporting fuel assembly storage rack used as one application example of the self-supporting rack which concerns on this invention in a pit. It is a figure which shows an example (Example 1) of embodiment of the self-supporting rack based on this invention, (a) is sectional drawing of the perpendicular direction, (b) is sectional drawing of the horizontal direction. . It is sectional drawing explaining a motion when the horizontal force by an earthquake acted on the self-supporting rack shown in FIG. It is sectional drawing which shows the modification of the self-supporting rack shown in FIG. It is a figure which shows another example (Example 2) of embodiment of the self-supporting rack which concerns on this invention, (a) is the sectional view of the perpendicular direction, (b) is the sectional view of the horizontal direction It is. It is sectional drawing explaining a motion when the horizontal force by an earthquake acted on the self-supporting rack shown in FIG. It is sectional drawing which shows the modification of the self-supporting rack shown in FIG. It is sectional drawing which shows the other modification of the self-supporting rack shown in FIG.

  Hereinafter, with reference to FIGS. 1-8, embodiment of the self-supporting rack based on this invention is described. In the following description, a self-supporting fuel assembly storage rack is illustrated as an example of a self-supporting rack. However, the present invention is not limited to this and can be applied to a self-supporting rack for other purposes.

Example 1
FIG. 1 is a perspective view showing a state in which a self-supporting fuel assembly storage rack, which is an application example of the self-supporting rack of this embodiment, is arranged in a pit. FIG. 2 is a diagram showing the self-supporting rack of the present embodiment, and FIG. 2A is a vertical sectional view (sectional view taken along line BB in FIG. 2B). 2 (b) is a horizontal cross-sectional view (cross-sectional view taken along line AA in FIG. 2 (a)). FIG. 3 is a cross-sectional view for explaining the movement when a horizontal force due to an earthquake acts on the self-supporting rack shown in FIG. FIG. 4 is a cross-sectional view showing a modification of the self-standing rack shown in FIG.

  As an application example of the self-supporting rack according to the present embodiment, for example, there is a self-supporting fuel assembly storage rack that stores a fuel assembly of nuclear fuel. As shown in FIG. 1, a large number of self-supporting fuel assembly storage racks 20 (hereinafter referred to as racks 20) are independently installed on the floor surface 12 a of the pit 12 where water 11 is stored, It is stored and stored in water 11. The rack 20 is only installed on the floor 12a and is not fixed. This is because the floor 12a can be slid in the event of an earthquake in order to reduce the load during the earthquake. Also, the racks 20 are not connected to each other. Therefore, if the amount of skid is large, as described above, the pit walls 12b and the racks 20 collide with each other and are damaged, or the legs of the racks 20 are displaced from the predetermined positions, and a large amount of layout correction work occurs after the earthquake. There is a bug to do.

  Therefore, in this embodiment, as shown in FIGS. 2A and 2B, the amount of skid is reduced by devising the structure of the rack 20A. 2 to 4 show only one rack 20A, the other racks 20A have the same structure.

  Specifically, as shown in FIGS. 2 (a) and 2 (b), the rack 20A has a storage box 22 (first box) installed on the floor surface 12a of the pit 12 and a stored item. It has a rack box 21 (second box) that is housed and accommodated inside the table box 22 with a gap for interposing the water 11 therebetween. The rack box 21 has a box shape with an upper opening, and similarly, the table box 22 has a box shape with an upper opening. A plurality of lower elastic members 23 are arranged between the bottom plate 21 a of the rack box 21 and the bottom plate 22 a of the table box 22, and the rack box 21 is supported on the upper surface of the bottom plate 22 a of the table box 22. A plurality of legs 24 are provided on the lower surface of the bottom plate 22a of the table box 22, and the racks 20A stand on the floor 12a by these legs 24. As the lower elastic member 23, for example, a laminated rubber or a spring used for seismic isolation of a building is used.

  Thus, the rack 20 </ b> A has a double structure in which the rack box 21 and the base box 22 are separated from each other. The rack 20 </ b> A allows relative horizontal displacement of the rack box 21 with respect to the base box 22 and supports the weight of the rack box 21. Therefore, the lower elastic member 23 having the vertical rigidity necessary for supporting the rack box 21 and the base box 22 is supported. Further, the side wall 21b of the rack box 21 and the side wall 22b of the base box 22 are arranged so as to face each other and have a gap for interposing the water 11, and here, the four side walls 21b of the rack box 21 are provided. On the other hand, the four side walls 22b of the table box 22 face each other and are arranged so as to surround the four sides, and a gap is provided.

  The side wall 21b of the rack box 21 and the side wall 22b of the table box 22 are not provided with openings such as holes in consideration of the fluid resistance described later, but the bottom plate 21a of the rack box 21 and the bottom plate 22a of the table box 22 are not provided. A plurality of small holes are provided, and water 11 circulates through these holes so that the fuel assemblies (contained items) stored in the rack box 21 can be cooled.

  In the rack 20A having the above-described structure, a movement when a horizontal force due to an earthquake is applied will be described with reference to FIG.

  For example, when the rack box 21 is displaced relative to the table box 22 in the horizontal displacement direction H with respect to the table box 22, the side wall 21b of the rack box 21 on the front side in the horizontal displacement direction H and the table box 22 are applied. The gap between the side walls 22b of the first and second side walls is reduced. Then, the flow of the water 11 passing up and down through the gap between the side wall 21b and the side wall 22b and the flow of the water 11 passing horizontally through the gap between the bottom plate 21a and the bottom plate 22a are generated (white arrow). reference). The same applies to the case where the rack box 21 is relatively displaced in the direction opposite to the horizontal displacement direction H. That is, when the rack box 21 is oscillated horizontally with respect to the table box 22 due to an earthquake, a flow of water 11 is generated between the rack box 21 and the table box 22.

  At this time, the energy of the earthquake is absorbed by the resistance of the fluid (water 11) between the side wall 21b and the side wall 22b, whereby the resistance of the fluid accompanying the horizontal displacement (horizontal vibration) of the rack box 21 is absorbed. It will be converted efficiently into energy.

  Thus, by effectively and effectively utilizing the fluid resistance generated by the horizontal displacement (horizontal vibration) of the rack box 21 and converting the energy from the earthquake into the resistance energy of the fluid, the floor surface of the table box 22 itself. It is possible to suppress the relative displacement with respect to 12a and suppress the amount by which the legs 24 slide on the floor surface 12a, that is, suppress the side slip of the table box 22 itself with respect to the floor surface 12a. This has the same effect and effect no matter which horizontal direction the rack box 21 is displaced. Therefore, it is possible to cope with horizontal forces due to earthquakes that do not know in which direction the vibrations are applied.

  Compared with the invention disclosed in the cited document 1, the energy consumption by the fluid resistance due to the horizontal movement causes the energy to be consumed more efficiently than the energy consumption by the damper, so in the rack 20A having the above-described structure, The skid with respect to the floor 12a of the leg 24 of the box 22 can be reduced from the invention of the cited document 1. Further, since the rack box 21 is housed in the base box 22, damage caused by the collision between the pit wall 12b and the rack 20A can be reduced as compared with the invention of the cited document 1.

  Furthermore, as shown in FIG. 4, a side elastic member 25 such as rubber or a spring may be sandwiched between the side wall 21 b of the rack box 21 and the side wall 22 b of the base box 22. By this side elastic member 25, energy due to the earthquake can be consumed, and the side slip of the legs 24 of the table box 22 with respect to the floor surface 12a can be further reduced, and the damage due to the collision between the pit wall 12b and the rack 20A is further reduced. can do. In the case where the side elastic member 25 is provided on the upper side of the side wall 21b and the side wall 22b, it can be expected to suppress the swing motion. Further, since the rack box 21 moves with respect to the table box 22, the consumption of fluid resistance energy can be used, and the amount that the rack 20A slides on the floor surface can be effectively reduced.

(Example 2)
FIG. 5 is a diagram showing the self-supporting rack of the present embodiment, and FIG. 5A is a vertical sectional view (cross-sectional view taken along the line DD in FIG. 5B), and FIG. b) is a horizontal cross-sectional view (cross-sectional view taken along the line CC of FIG. 5A). FIG. 6 is a cross-sectional view for explaining the movement when a horizontal force due to an earthquake acts on the self-supporting rack shown in FIG. 7 and 8 are sectional views showing modifications of the self-supporting rack shown in FIG.

  The rack 20B according to the present embodiment basically has the same structure as the rack 20A according to the first embodiment. However, by adding a structure for efficiently using the resistance energy of the fluid, the side slip can be achieved. The amount is further reduced. Therefore, the same reference numerals are given to the structures equivalent to the rack 20A of the first embodiment, and the redundant description will be omitted, and the rack 20B of the present embodiment will be described. 5 to 8, only one rack 20B is shown, but the other racks 20B have the same structure.

  Compared with the rack 20A of the first embodiment, a lower resistance plate 26 and an upper resistance plate 27 are further added to the rack 20B of the present embodiment.

  The lower resistance plate 26 is provided on the lower surface side of the bottom plate 21 a of the rack box 21, and is erected downward toward the upper surface side of the bottom plate 22 a of the table box 22. Here, a plurality of lower resistor plates 26 are arranged so as to form a lattice when viewed from above. The lower elastic member 23 is disposed on the lower surface side of the bottom plate 21a, and a predetermined gap (predetermined channel width) is secured between the bottom plate 21a and the bottom plate 22a of the base box 22, so The resistance plate 26 can be arranged in such a lattice shape with a high degree of freedom.

  This lower resistance plate 26 increases the fluid resistance by narrowing the gap (distance) with the upper surface of the bottom plate 22a of the table box 22, that is, by narrowing the flow path between the bottom plate 21a and the bottom plate 22a. I am letting. The bottom plate 21a and the bottom plate 22a are provided with a plurality of holes, which are small enough not to have a great influence on the increase in fluid resistance.

  The upper resistor plate 27 is provided at the upper end of the side wall 21b of the rack box 21 and extends upward from the upper side, and the upper end portion extends horizontally outward. In other words, it is formed in the shape of an L-shaped cross section, and is arranged so that its horizontal portion is higher than the upper end of the side wall 22b. With such a shape and arrangement, the upper resistor plate 27 covers the outlet of the gap between the side wall 21b of the rack box 21 and the side wall 22b of the base box 22, and the base box is moved when the rack box 21 is displaced. It does not come into contact with the 22 side. The upper resistor plate 27 may be provided on the entire circumference along the upper end of the side wall 21b of the rack box 21, but may be provided not only on the entire circumference but also on a part thereof.

  The upper resistor plate 27 covers the outlet of the gap between the side wall 21b and the side wall 22b, that is, covers the outlet of the flow path between the side wall 21b and the side wall 22b. Increases fluid resistance. It should be noted that the length of the upper resistor plate 27 extending outwardly is just above the upper end of the side wall 22b of the table box 22 so as to just cover the gap in the normal arrangement state (initial arrangement state). Just extend.

  The lower resistor plate 26 may be provided on the upper surface side of the bottom plate 22a of the table box 22 instead of the lower surface side of the bottom plate 21a of the rack box 21. In this case, the lower resistor plate 26 is provided on the bottom plate of the rack box 21. What is necessary is just to make it stand toward the upper surface toward the lower surface side of 21a. Similarly, the upper resistor plate 27 may be provided at the upper end of the side wall 22b of the table box 22 instead of the upper end of the side wall 21b of the rack box 21, and in this case, the upper end portion of the upper resistor plate 27 is directed inward. It should be extended toward. Furthermore, only one of the lower resistor plate 26 and the upper resistor plate 27 may be provided. Further, the lower resistor plate 26 may be extended in the vertical direction or the oblique direction, and the upper resistor plate 27 may be extended in the vertical direction and then horizontally, or from the beginning. You may extend toward the diagonal direction.

  In the rack 20B having the above-described structure, a movement when a horizontal force due to an earthquake is applied will be described with reference to FIG.

  For example, when the rack box 21 is displaced relative to the table box 22 in the horizontal displacement direction H with respect to the table box 22, the side wall 21b of the rack box 21 on the front side in the horizontal displacement direction H and the table box 22 are applied. The gap between the side walls 22b of the first and second side walls is reduced. Then, the flow of the water 11 passing up and down through the gap between the side wall 21b and the side wall 22b and the flow of the water 11 passing horizontally through the gap between the bottom plate 21a and the bottom plate 22a are generated (white arrow). reference). The same applies to the case where the rack box 21 is relatively displaced in the direction opposite to the horizontal displacement direction H. That is, when the rack box 21 is oscillated horizontally with respect to the table box 22 due to an earthquake, a flow of water 11 is generated between the rack box 21 and the table box 22.

  At this time, the energy of the earthquake is absorbed by the resistance of the fluid (water 11) in the gap between the side wall 21b and the side wall 22b, so that the resistance of the fluid accompanying the horizontal displacement (horizontal vibration) of the rack box 21 is achieved. It can be efficiently converted into energy.

  In addition, in the lower resistor plate 26, when the flow of the water 11 occurs, the direction in which the water 11 flows between the bottom plate 21a and the bottom plate 22a, and the horizontal displacement direction H of the lower resistor plate 26 erected in the vertical direction, Therefore, a large fluid resistance is generated in the lower resistor plate 26, and the energy caused by the earthquake can be more efficiently converted into the resistance energy of the fluid. In addition, since the lower resistor plate 26 is arranged in a grid pattern, a large fluid resistance can be generated in the lower resistor plate 26 erected in the vertical direction regardless of the horizontal force caused by the earthquake. .

  Further, even when the flow of water 11 occurs in the upper resistance plate 27, the upper resistance plate 27 covering the gap has a large resistance against the flow of water 11 passing upward through the gap between the side wall 21b and the side wall 22b. Therefore, a large fluid resistance is generated in the upper resistance plate 27, and the energy caused by the earthquake can be more efficiently converted into the resistance energy of the fluid.

  Thus, by effectively and effectively utilizing the fluid resistance generated by the horizontal displacement (horizontal vibration) of the rack box 21 and converting the energy from the earthquake into the resistance energy of the fluid, the floor surface of the table box 22 itself. The relative displacement with respect to 12a can be suppressed so that the legs 24 do not slide on the floor surface 12a, that is, the side slip of the table box 22 itself with respect to the floor surface 12a can be suppressed. This has the same effect and effect no matter which horizontal direction the rack box 21 is displaced. Therefore, it is possible to cope with horizontal forces due to earthquakes that do not know in which direction the vibrations are applied.

  In addition, in the rack 20B, since the lower resistance plate 26 and the upper resistance plate 27 are provided at positions that do not interfere with the vibration motion of the rack box 21, the rack 20A according to the first embodiment is not hindered. As a result, the fluid resistance becomes larger, and as a result, the energy due to the earthquake can be consumed more efficiently, and the side slip of the legs 24 of the table box 22 with respect to the floor surface 12a can be further reduced. Further, since a large fluid resistance is generated, the contact between the side wall 21b of the rack box 21 and the side wall 22b of the table box 22 can be prevented and suppressed when the rack box 21 is displaced.

  The arrangement of the lower resistor plate 26 is not limited to the lattice shape, but may be other than the lattice shape as long as the fluid resistance can be increased. In particular, a lower elastic member 23 is disposed on the lower surface side of the bottom plate 21 a of the rack box 21, and a predetermined gap (predetermined channel width) is provided between the bottom plate 21 a of the rack box 21 and the bottom plate 22 a of the base box 22. For this reason, the freedom degree of arrangement | positioning of the lower resistance board 26 is high. For example, as shown in FIG. 7, a plurality of lower resistor plates 28 may be arranged radially (like a letter C), for example, so as to narrow the flow path toward the center of the bottom plate 21 a.

  As described above, since the plurality of lower resistance plates 28 are arranged so as to narrow the flow path toward the center of the bottom plate 21a, the fluid resistance becomes larger than that of the rack 20A of the first embodiment. Energy can be consumed more efficiently, and the side slip of the legs 24 of the table box 22 with respect to the floor 12a can be further reduced.

  For example, as shown in FIG. 8, a side resistance plate 29 may be further provided in the gap between the side wall 21b and the side wall 22b.

  The side resistance plate 29 is provided on the inner wall side of the side wall 22b of the table box 22, and extends inward so as to narrow a gap between the side wall 21b and the side wall 22b. Further, the side resistance plate 29 may be provided on the entire circumference along the inner wall of the side wall 22b of the table box 22. The side resistance plate 29 increases the fluid resistance by narrowing the gap, that is, by narrowing the flow path between the side wall 21b and the side wall 22b. However, when the side resistor plate 29 is provided, the length of the side resistor plate 29 is set between the side wall 21b and the side wall 22b so that the side resistor plate 29 does not contact the rack box 21 when the rack box 21 is displaced. Or the gap between the side wall 21b and the side wall 22b needs to be set larger than the length of the side resistance plate 29. At this time, you may consider the displacement amount at the time of an earthquake.

  The side resistor plate 29 may be provided on the outer wall side of the side wall 22b of the rack box 21 in place of the inner wall side of the side wall 22b of the table box 22. In this case, the side resistor plate 29 faces inward. It should be extended.

  By this side resistance plate 29, energy due to the earthquake can be consumed, and the side slip of the leg 24 of the table box 22 with respect to the floor surface 12a can be further reduced, and the damage due to the collision between the pit wall 12b and the rack 20A is further reduced. can do.

  The present invention is suitable for a self-supporting rack called a free standing rack.

11 Water 12 Pit 12a Floor 12b Pit wall 20A, 20B Rack 21 Rack box 21a Bottom plate 21b Side wall 22 Base box 22a Bottom plate 22b Side wall 23 Lower elastic member 24 Leg 25 Side elastic member 26 Lower resistance plate 27 Upper resistance plate 28 Lower resistance Plate 29 Side resistance plate

Claims (6)

A self-supporting rack installed in a fluid,
A first box that is installed on a floor surface of the place where the fluid is stored by a plurality of legs; and
A second box for storing a stored item and accommodated inside the first box with a gap for interposing the fluid;
A self-supporting rack comprising a plurality of elastic members provided between a bottom plate of the first box and a bottom plate of the second box and supporting the second box. The self-supporting rack according to claim 1,
The second box between the bottom plate of the first box and the bottom plate of the second box, on the upper surface side of the bottom plate of the first box or on the lower surface side of the bottom plate of the second box. A self-supporting rack comprising a first resistance plate extending toward the lower surface side of the bottom plate of the first box or the upper surface side of the bottom plate of the first box. The self-supporting rack according to claim 2,
A plurality of the first resistance plates are arranged in a lattice shape as viewed from above, or a plurality of the first resistance plates are arranged radially. The self-supporting rack according to any one of claims 1 to 3,
A second resistance plate covering an outlet of a gap between the side wall of the first box and the side wall of the second box at the upper end of the side wall of the first box or the upper end of the side wall of the second box A self-supporting rack characterized by providing In the self-supporting rack according to any one of claims 1 to 4,
A self-supporting rack, wherein another elastic member is provided between a side wall of the first box and a side wall of the second box. In the self-supporting rack according to any one of claims 1 to 4,
It extends between the side wall of the first box and the side wall of the second box, and extends in the horizontal direction on the inner surface side of the side wall of the first box or the outer surface side of the side wall of the second box. A self-supporting rack characterized in that a third resistance plate is provided.

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