Structure for supporting vertically placed cylindrical container

Abstract

To enable improvement of the seismic resistance of even a structure for supporting a vertically placed cylindrical container on a foundation, using a lug, under any conditions.SOLUTION: The structure for supporting a vertically placed cylindrical container of the present invention is a structure for supporting a vertically placed cylindrical container that is installed on a foundation and supported by a plurality of lugs arranged on the foundation at predetermined intervals in a circumferential direction. A seismic-reinforcement support is installed between the plurality of lugs to restrain circumferential rotation at a root portion between the vertically placed cylindrical container and the lugs.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a support structure for a vertically placed cylindrical vessel, and more particularly to a support structure for a vertically placed cylindrical vessel suitable for supporting with lugs a vertically placed cylindrical vessel such as a heat exchanger installed vertically in a nuclear power plant, for example. [Background technology]

[0002] Generally, lug-supported vertical cylindrical vessels such as heat exchangers that are installed vertically on foundations in nuclear power plants are designed to be earthquake-resistant.

[0003] In recent years, for lug-supported vertical cylindrical vessels such as heat exchangers that are installed vertically on foundations within nuclear power plants, the Great East Japan Earthquake that occurred in March 2011 has prompted a review of earthquake intensity and the design of highly earthquake-resistant structures and tsunami countermeasure structures.

[0004] In particular, among the lug-supported vertical cylindrical containers mentioned above, some that have already been installed (existing) do not have a highly earthquake-resistant structure and will require earthquake-resistance reinforcement work.

[0005] Patent Document 1 can be cited as a prior art document relating to such an earthquake-resistant reinforcement structure for a lug-supported vertical cylindrical container.

[0006] Patent document 1 describes that in order to obtain a lug support structure for a can body that can maintain the rigidity of the can body when subjected to external forces such as earthquakes without increasing its thickness, stoppers are attached to a stand that receives support lugs protruding from the outer periphery of the can body so as to sandwich the support lugs from both sides. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-85590 Summary of the Invention [Problem to be solved by the invention]

[0008] When a lug-supported vertical cylindrical container is subjected to a horizontal external force such as an earthquake, the lug-supported vertical cylindrical container and the lug may rotate in a horizontal plane, twisting, which may cause excessive stress to be generated at the base of the lug, which is the attachment point between the lug-supported vertical cylindrical container and the lug.

[0009] To address this issue, if it is necessary to improve the earthquake resistance of lug-supported vertical cylindrical vessels already installed within nuclear power plants, earthquake-resistant reinforcement work must be carried out under limited conditions.

[0010] In the above-mentioned Patent Document 1, external forces such as earthquakes are dealt with by attaching stoppers to a stand that receives support lugs protruding from the outer periphery of the can body, clamping the support lugs from both sides to restrain their rotation.

[0011] However, the support structure for the lug-supported upright cylindrical container proposed in Patent Document 1 can only be applied when the lug is installed on a stand, and therefore cannot be applied under many conditions.

[0012] In particular, as mentioned above, when a lug-supported vertical cylindrical container is subjected to a horizontal external force such as an earthquake, the base of the lug-supported vertical cylindrical container and the lug may rotate in a horizontal plane, twisting, which may cause excessive stress.

[0013] One way to address this issue is to increase the wall thickness of the lug-supported vertical cylindrical container to increase its structural strength, but this approach is not feasible for existing lug-supported vertical cylindrical containers.

[0014] The present invention has been made in consideration of the above points, and its object is to provide a support structure for a vertical cylindrical container that can improve earthquake resistance under any conditions (for example, for an existing vertical cylindrical container), even if the vertical cylindrical container is supported on a foundation by lugs. [Means for solving the problem]

[0015] In order to achieve the above-mentioned object, the support structure for a vertically placed cylindrical container of the present invention is a support structure for a vertically placed cylindrical container in which a vertically placed cylindrical container placed on a foundation is supported by a plurality of lugs placed on the foundation at predetermined circumferential intervals, and is characterized in that a plurality of earthquake-resistant reinforcement supports are installed between the plurality of lugs to restrain circumferential rotation of the base of the vertically placed cylindrical container and the lugs. [Effects of the Invention]

[0016] According to the present invention, even if a vertical cylindrical container is supported on a foundation by lugs, the earthquake resistance can be improved under any conditions (for example, an existing vertical cylindrical container). [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a first embodiment of a support structure for a vertically placed cylindrical container according to the present invention. [Figure 2] FIG. 2 is a plan view of FIG. 1 as seen from above. [Figure 3] 3 is a view corresponding to FIG. 2 showing an example in which the lug rotates due to a horizontal external force caused by an earthquake or the like in the support structure for a vertically placed cylindrical container according to the first embodiment of the present invention. FIG. [Figure 4] 2A and 2B are diagrams showing a second embodiment of the support structure for a vertically placed cylindrical container according to the present invention, illustrating an example of avoidance when an obstruction is found at the installation position of the earthquake-resistant reinforcement support. DETAILED DESCRIPTION OF THE INVENTION

[0018] The support structure for a vertically placed cylindrical container of the present invention will be described below based on the illustrated embodiment. In each drawing, the same reference numerals are used for the same components. [Example]

[0019] 1 and 2 show a first embodiment of the support structure for a vertically placed cylindrical container of the present invention. Fig. 1 is a perspective view showing the support structure for a vertically placed cylindrical container of the first embodiment, and Fig. 2 is a plan view of Fig. 1 as seen from above.

[0020] As shown in the figure, the support structure for a vertically placed cylindrical container in Example 1 supports a vertically placed cylindrical container 1 placed on a foundation 7 with a plurality of lugs 2 (four in Example 1) placed on the foundation 7 at predetermined intervals in the circumferential direction, and in Example 1, earthquake-resistant reinforcement supports 3 are installed between the four lugs 2 placed at predetermined intervals in the circumferential direction to restrain circumferential rotation of lug base portions 6, which are the base portions between the existing vertically placed cylindrical container 1 and the lugs 2 (four earthquake-resistant reinforcement supports 3 are installed in Example 1). These four earthquake-resistant reinforcement supports 3 are installed with both ends adjacent to the lugs 2.

[0021] Each of the lugs 2 described above is fixed to the foundation 7 with foundation bolts 4, and each of the seismic reinforcement supports 3 described above is fixed to the foundation 7 with a plurality of additional foundation bolts 5. By fixing the seismic reinforcement supports 3 to the foundation 7 with the additional foundation bolts 5, the shear load of the lugs 2 is transmitted to the foundation 7, and rotation is restrained.

[0022] Furthermore, the lugs 2 and seismic reinforcement supports 3 are arranged so that they sandwich each other from both sides, which restricts the rotation of the lugs 2. Furthermore, each seismic reinforcement support 3 and each lug 2 are not welded together, but are simply in contact with each other.

[0023] Furthermore, the number of additional foundation bolts 5 installed can be changed according to the expected horizontal external force. In other words, by adjusting the number of additional foundation bolts 5 according to the expected horizontal external force, it is possible to withstand a large external force with an appropriate number of additional foundation bolts 5.

[0024] Furthermore, the bolt holes (not shown) for the additional foundation bolts 5 formed in the seismic reinforcement support 3 are elongated holes that are long in the radial direction of the lugs 2. That is, by making the bolt holes for the additional foundation bolts 5 elongated in the radial direction of the lugs 2, these elongated holes are able to absorb the thermal expansion of the lugs 2, preventing the generation of stress due to the thermal expansion of the lugs 2 while also restraining the circumferential rotation of the lugs 2. In other words, the seismic reinforcement support 3 and the additional foundation bolts 5 are shaped so that they do not come into contact with each other during thermal expansion of the lugs 2, but do come into contact during an earthquake, making it possible to simultaneously restrain the circumferential rotation of the lug base portions 6 between the vertical cylindrical container 1 and the lugs 2 and suppress stress due to thermal expansion of the lugs 2.

[0025] By adopting the configuration of this embodiment, earthquake resistance can be improved under any conditions (for example, for an existing vertical cylindrical container 1), even if the vertical cylindrical container 1 is supported on the foundation 7 by lugs 2.

[0026] Furthermore, when the vertical cylindrical container 1 is subjected to a horizontal external force such as an earthquake, the lug base 6 between the vertical cylindrical container 1 and the lug 2 may rotate in a horizontal plane so as to twist, as shown in Figure 3, which may cause excessive stress to be generated at the lug base 6.

[0027] One way to address this problem is to increase the structural strength by, for example, increasing the thickness of the vertical cylindrical container 1, but since such measures cannot be taken for existing vertical cylindrical containers 1, in this embodiment, earthquake-resistant reinforcement supports 3 are installed between the four lugs 2 to restrain the circumferential rotation of the lug base 6 and reduce the generated stress, making it possible to create a support structure that can be added to existing vertical cylindrical containers 1. [Example]

[0028] A second embodiment of the support structure for a vertically placed cylindrical container of the present invention will be described with reference to Fig. 4. Fig. 4 is a view corresponding to Fig. 2, showing an example of how to avoid an obstruction when an object is present at the installation position of an earthquake-resistant reinforcement support.

[0029] Nuclear power plants usually have many structures (such as piping) inside, so it is often difficult to install earthquake-resistant reinforcement devices as desired.

[0030] In the support structure for the upright cylindrical container of Example 1 described above, the earthquake-resistant reinforcement supports 3 are installed on the foundation 7 between the lugs 2, so there is less possibility of interference with existing structures compared to earthquake-resistant reinforcement devices with a three-dimensional structure. However, if an interfering object 8 exists between the lugs 2 and the earthquake-resistant reinforcement supports 3 cannot be installed as is, the shape of the earthquake-resistant reinforcement supports 3 can be changed to some extent as shown in Figure 4, so that the earthquake-resistant reinforcement supports 3 at the positions where the interfering object 8 exists can be shaped like deformed earthquake-resistant reinforcement supports 3a, without impairing their functionality, and the earthquake-resistant reinforcement supports can be installed even if an interfering object 8 exists between the lugs 2.

[0031] That is, in Example 2 shown in Figure 4, when an obstruction 8 exists between the lugs 2, the deformable seismic reinforcement support 3a installed at the position where the obstruction 8 exists is shaped to avoid the obstruction 8 (for example, a shape with a recess formed on the outer periphery so that the obstruction 8 can be accommodated) (other configurations are the same as those of Example 1).

[0032] With such a configuration of Example 2, the effect is of course the same as that of Example 1, and even if there is an interfering object (e.g., piping, etc.) 8 between the lugs 2, it is possible to install earthquake-resistant reinforcement supports between the lugs 2, and earthquake resistance can be improved under any conditions (e.g., an existing vertically placed cylindrical container 1).

[0033] In the above-described embodiment, the vertical cylindrical container 1 is described as an existing container, but it goes without saying that the present invention does not necessarily require the vertical cylindrical container 1 to be an existing container, and can also be applied to a newly installed vertical cylindrical container.

[0034] Furthermore, the present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to add part of the configuration of one embodiment to the configuration of another embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0035] 1...vertical cylindrical container, 2...lug, 3...earthquake-resistant reinforcement support, 3a...deformed earthquake-resistant reinforcement support, 4...foundation bolt, 5...additional foundation bolt, 6...base of lug, 7...foundation, 8...interfering object

Claims

1. A support structure for a vertically placed cylindrical container, in which a vertically placed cylindrical container placed on a foundation is supported by a plurality of lugs placed on the foundation at predetermined intervals in the circumferential direction, A support structure for a vertically placed cylindrical container, characterized in that earthquake-resistant reinforcement supports are installed between the multiple lugs to restrain circumferential rotation of the base of the vertically placed cylindrical container and the lugs.

2. The support structure for a vertically placed cylindrical container according to claim 1, A support structure for a vertically placed cylindrical container, characterized in that the lug and the earthquake-resistant reinforcement support are installed so as to sandwich each other from both sides.

3. The support structure for a vertically placed cylindrical container according to claim 2, A support structure for a vertically placed cylindrical container, characterized in that the earthquake-resistant reinforcement support and the lug are in contact with each other without being welded.

4. The support structure for a vertically placed cylindrical container according to claim 3, A support structure for a vertical cylindrical container, characterized in that the lug is fixed to the foundation with foundation bolts, and the earthquake-resistant reinforcement support is fixed to the foundation with additional foundation bolts.

5. The support structure for a vertically placed cylindrical container according to claim 4, A support structure for a vertical cylindrical container, characterized in that the number of additional foundation bolts installed can be changed to suit the expected horizontal external force.

6. The support structure for a vertically placed cylindrical container according to claim 5, A support structure for a vertical cylindrical container, characterized in that the bolt holes for the additional foundation bolts formed in the earthquake-resistant reinforcement support are elongated holes extending in the radial direction of the lugs.

7. The support structure for a vertically placed cylindrical container according to claim 1, A support structure for a vertically placed cylindrical container, characterized in that if an obstruction exists between the lugs, the earthquake-resistant reinforcement support installed at the position where the obstruction exists is shaped to avoid the obstruction.

8. The support structure for a vertically placed cylindrical container according to any one of claims 1 to 7, A support structure for a vertical cylindrical container, wherein the vertical cylindrical container is an existing vertical cylindrical container.

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