JP2023090159A - horizontal cylindrical tank - Google Patents

Abstract

To provide a horizontal cylindrical tank capable of suppressing deformation of a tank body due to bulging vibration by a simple reinforcement structure (a reinforcement member).SOLUTION: A horizontal cylindrical tank includes: a cylindrical tank body which is horizontally installed to store liquid; a tank support member for fixing the tank body to a foundation; and a reinforcement frame which is installed inside the tank body, and transmits a contact load to an inner wall surface of the tank body, and is installed like a coil spring.SELECTED DRAWING: Figure 1

Description

The present invention relates to a horizontal cylindrical tank.

Cylindrical tanks that store liquids such as water and fuel oil are required to maintain a self-supporting state without collapsing and to prevent liquid leakage even when an earthquake occurs. In addition, since the cylindrical tank may be damaged due to seismic vibrations, it is necessary to prevent damage to the tank body.

As a background art in such a technical field, there is Japanese Patent Laying-Open No. 2019-147563 (Patent Document 1).

In this patent document 1, a torus (doughnut)-shaped reinforcing frame is installed inside the tank body with a gap from the inner wall surface of the tank body, and is composed of a hollow pipe in which gas is sealed, and a tank body. a positioning device installed inside, one end of which is connected to a buoyancy body located on the liquid surface of the tank body, the other end of which is connected to a connection jig located below the tank body, and a positioning device for retaining the reinforcing frame; tank is mentioned.

Patent Document 1 describes a cylindrical tank that suppresses bulging vibration generated in the tank body from inside the tank body and suppresses deformation in the radial direction (horizontal direction) of the tank body.

JP 2019-147563 A

Patent Literature 1 describes a vertical cylindrical tank (flat-bottomed cylindrical tank) that suppresses bulging vibration. A vertical cylindrical tank having a reinforcing frame and a positioning device described in Patent Document 1 suppresses bulging vibration.

However, Patent Document 1 does not describe a horizontal cylindrical tank. Further, the horizontal cylindrical tank cannot be provided with a reinforcing frame and a positioning device as described in Patent Document 1.

In addition, if there is space outside the tank body of the horizontal cylindrical tank and there are no construction restrictions, reinforcing ribs can be installed on the outside of the tank body. However, existing horizontal cylindrical tanks, which have limited construction work due to lack of space outside the tank body of the horizontal cylindrical tank, cannot be provided with reinforcing ribs on the outside of the tank body.

In addition, when reinforcing ribs are installed inside the tank body of a horizontal cylindrical tank, the additional fluid mass that affects the natural vibration mode of the horizontal cylindrical tank, which determines the behavior of the horizontal cylindrical tank when an earthquake occurs, increases. There is fear.

Accordingly, the present invention provides a horizontal cylindrical tank that suppresses deformation of the tank body due to bulging vibration by means of a simple reinforcing structure (reinforcing member).

In order to solve the above-described problems, the horizontal cylindrical tank of the present invention is installed horizontally and has a cylindrical tank body for storing liquid, a tank support member for fixing the tank body to a foundation, and a tank body inside the tank body. and a reinforcing frame installed in the shape of a coil spring for transmitting a contact load to the inner wall surface of the tank body.

According to the present invention, it is possible to provide a horizontal cylindrical tank that suppresses deformation of the tank body due to bulging vibration with a simple reinforcing structure (reinforcing member).

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a schematic bird's-eye view illustrating a horizontal cylindrical tank 2 having a reinforcing frame 1 described in Example 1. FIG. FIG. 4 is a schematic cross-sectional bird's-eye view illustrating a torus-type cylindrical tank 22 having a reinforcing frame 1 described in Example 2; FIG. 11 is a schematic explanatory diagram illustrating a horizontal cylindrical tank 2 having a reinforcing frame 1 described in Example 3; FIG. 11 is a partial schematic diagram illustrating a horizontal cylindrical tank 2 having a reinforcing frame 1 described in Example 4;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, substantially the same or similar configurations are described using the same reference numerals, and when the description overlaps in each drawing, the overlapping description may be omitted.

First, the horizontal cylindrical tank 2 having the reinforcing frame 1 described in Example 1 will be described.

FIG. 1 is a schematic bird's-eye view illustrating a horizontal cylindrical tank 2 having a reinforcing frame 1 described in Example 1. FIG.

A horizontal cylindrical tank 2 described in Example 1 stores a liquid 10 .

The horizontal cylindrical tank 2 has the following configuration.
(1) A cylindrical tank body 23 that stores the liquid 10 and is placed horizontally so that the horizontal cross section is rectangular (the vertical cross section is circular);
(2) Tank support legs (tank support members) 4 for fixing the tank body 23 to a strong foundation 3 connected to the ground,
(3) Installed inside the tank body 23 to transmit the contact load (the load acting on the inner wall surface of the tank body 23 from the reinforcing frame 1) to the inner wall surface of the tank body 23 (cylindrical plate forming the tank body 23). The reinforcement frame 1 is installed in a spiral shape (spiral shape, coil spring shape) along the inner wall surface of the tank body 23 .

Such horizontal cylindrical tanks 2 are, for example, 16 horizontal cylindrical tanks 2 arranged in a circular shape in the horizontal direction (each connecting part is formed obliquely), and are part of the containment vessel of the nuclear reactor. , forming a suppression chamber that holds pool water that condenses the steam released when the reactor coolant is lost.

The tank body 23 is made of steel having a diameter of about 7 m, a longitudinal (axial) length of about 15 m, and a thickness of about 15 mm, for example.

The tank support leg 4 is, for example, a tank support member that extends vertically with respect to the foundation 3 from below the tank body 23 , and firmly installs the tank body 23 on the foundation 3 . The tank support legs 4 are installed on the lower left and right sides of a circle (the cross section in the vertical direction of the tank body 23 and perpendicular to the longitudinal direction of the tank body 23 is circular). be done.

In addition, the tank support leg 4 itself, the connecting portion between the tank support leg 4 and the foundation 3, and , the connecting portion between the tank supporting leg 4 and the tank body 23 is taken measures.

In addition, although the tank support legs 4 are used in the description of the first embodiment, the tank support legs 4 may be any tank support member that firmly installs the tank body 23 on the foundation 3. It is not limited.

The reinforcing frame 1 is installed along the inner wall surface of the tank body 23 and is a reinforcing member made of, for example, steel in the shape of a coil spring having an outer diameter larger than the inner diameter of the tank body 23 . The reinforcing frame 1 is, for example, a reinforcing member in the shape of a coil spring having a circular or square cross section, a diameter or a side length of 90 to 100 mm, and 5 to 10 turns.

Then, the reinforcing frame 1 is compressed to have an outer diameter smaller than the inner diameter of the tank body 23 , is inserted into the tank body 23 , and is installed inside the tank body 23 . The reinforcing frame 1 applies a contact load (contact reaction force) to the inner wall surface of the tank body 23 in the direction from the inside to the outside (outward) by the reaction force (reaction force). That is, the reinforcing frame 1 supports the inner wall surface of the tank body 23 by contact load.

Further, the reinforcing frame 1 is fixed to the tank body 23 by welding only at its ends, and is not fixed to the tank body 23 except for only the ends. As a result, the reinforcement frame 1 can slide and move in the longitudinal direction of the tank body 23 even when a horizontal load is applied to the reinforcement frame 1 due to earthquake vibrations.

Even if an earthquake occurs, the tank body 23 needs to be protected from damage caused by earthquake vibrations. When an earthquake occurs, the liquid 10 stored in the tank body 23 exerts a tensile load on the inner wall surface of the tank body 23 that pulls the inner wall surface of the tank body 23 inward. A dynamic pressure load) acting on the inner wall surface of the barrel 23 is generated.

Therefore, in the first embodiment, the coil spring-shaped reinforcing frame 1 is installed inside the tank body 23, and even if a tensile load is generated on the inner wall surface of the tank body 23, the contact load of the reinforcing frame 1 , support the inner wall surface of the tank barrel 23 .

In other words, the reinforcing frame 1 generates a contact load on the inner wall surface of the tank body 23 in the direction from the inside to the outside due to its repulsive force. The contact load of the reinforcement frame 1 supports the inner wall surface of the tank body 23 that is radially deformed by the negative dynamic pressure of the liquid 10 caused by the vibration of the earthquake.

In this way, the horizontal cylindrical tank 2 described in Embodiment 1 is installed horizontally, has a cylindrical tank body 23 that stores the liquid 10, and has tank support legs (tank support legs) that fix the tank body 23 to the foundation 3. member) 4, and a reinforcing frame 1 which is installed inside the tank body 23, transmits a contact load to the inner wall surface of the tank body 23, and is installed in the shape of a coil spring.

As a result, particularly in the horizontal cylindrical tank 2, the inner wall surface of the tank body 23 is supported by a low-cost and simple reinforcing structure (reinforcing member), and the bulging that occurs in the tank body 23 due to earthquake vibrations can be prevented. ) suppresses vibration, suppresses excitation (generation) of an oval vibration mode due to bulging vibration, and suppresses radial deformation of the tank barrel 23 .

In addition, even if a horizontal load is applied to the reinforcement frame 1 due to earthquake vibrations, the reinforcement frame 1 slides and moves in the longitudinal direction of the tank body 23. It is possible to suppress an increase in the fluid added mass that affects the natural vibration mode of the horizontal cylindrical tank 2 that determines the behavior when it occurs. Furthermore, since the reinforcing frame 1 slides and moves in the longitudinal direction of the tank body 23, a damping effect is generated, and the response acceleration can be reduced.

Further, the reinforcing frame 1 can be easily installed even in the existing horizontal cylindrical tank 2 .

Next, a torus-type cylindrical tank 22 having the reinforcing frame 1 described in Example 2 will be described.

FIG. 2 is a schematic cross-sectional bird's-eye view illustrating a torus-type cylindrical tank 22 having the reinforcing frame 1 described in the second embodiment.

The torus-shaped cylindrical tank 22 described in the second embodiment is a torus (doughnut)-shaped horizontal cylindrical tank 2, and basically has the same configuration as the horizontal cylindrical tank 2 shown in FIG. Therefore, detailed description is omitted. Note that the water surface 10 is omitted.

The torus-shaped cylindrical tank 22 includes a torus-shaped tank body 23 that stores the liquid 10, and a reinforcement that is installed inside the tank body 23, transmits a contact load to the inner wall surface of the tank body 23, and is installed like a coil spring. a frame 1;

In other words, the torus-shaped cylindrical tank 22 has the coil spring-like reinforcing frame 1 installed inside the torus-shaped tank body 23 .

When an earthquake occurs, the liquid 10 stored in the tank body 23 tends to flow in one direction. As a result, the effect of reducing the additional fluid mass for the mode in which the entire torus-shaped cylindrical tank 22 moves can be expected.

Further, in the torus-type cylindrical tank 22, the ends of the reinforcing frame 1 can be connected together. Thereby, the repulsive force of the reinforcement frame 1 can be adjusted.

Next, the horizontal cylindrical tank 2 having the reinforcing frame 1 described in Example 3 will be described.

FIG. 3 is a schematic explanatory diagram illustrating a horizontal cylindrical tank 2 having a reinforcing frame 1 described in Example 3. FIG.

The horizontal cylindrical tank 2 described in Example 3 has the same configuration as the horizontal cylindrical tank 2 shown in FIG. Therefore, detailed description is omitted. Note that the water surface 10 is omitted.

In Example 3, the reinforcing frame 1 is composed of a hollow pipe. The hollow pipe is for example made of steel with a diameter of 100-150 mm and a thickness of 5-8 mm.

The reinforcing frame 1 is a hollow pipe in the form of a coil spring, and since the hollow pipe has a long overall length, the reinforcing frame 1 made of the hollow pipe has a large outer diameter by applying internal pressure to the hollow pipe. As a result, the contact load on the inner wall surface of the tank body 23 is increased from the inside to the outside. Thereby, this contact load can be further increased.

One end of the reinforcing frame (hollow pipe) 1 is connected to a pipe (pressurizing pipe) 7 through which air for applying internal pressure to the reinforcing frame 1 flows, and the other end is sealed. A pressurizing device 6 for pressurizing the air flowing through the pipe 7 is connected to the pipe 7 .

A pressure control valve 5 is installed in the pipe 7 to control the flow rate of air flowing through the pipe 7 and to control the internal pressure of the reinforcing frame 1 .

By applying internal pressure to the reinforcing frame 1, the reinforcing frame 1 increases the contact load on the inner wall surface of the tank body 23 from the inside to the outside. The inner wall surface of the tank body 23 is supported by the contact load of the reinforcing frame 1 .

The tank support leg (tank support member) 4 of the horizontal cylindrical tank 2 is provided with a support leg accelerometer (support member accelerometer) 8 for measuring the acceleration of the tank support leg (tank support member) 4 caused by the vibration of an earthquake. is installed, and a tank-body accelerometer 81 is installed on the tank body 23 of the horizontal cylindrical tank 2 to measure the acceleration of the tank body 23 caused by the vibration of an earthquake.

The pressure control valve 5 and the pressurizing device 6 are connected to the pressure control valve 5 and the pressurizing device 6 based on the measurement results (signals) of the supporting leg accelerometer (supporting member accelerometer) 8 and the tank trunk accelerometer 81. A control signal is transmitted from a control device 9 that controls the device 6 .

That is, in Example 3, the internal pressure of the reinforcing frame 1 is controlled based on the measurement results of the supporting leg accelerometer (supporting member accelerometer) 8 and the tank trunk accelerometer 81 . By controlling the internal pressure of the reinforcing frame 1 based on the measurement results of the supporting leg accelerometer (supporting member accelerometer) 8 and the tank trunk accelerometer 81, the internal pressure of the reinforcing frame 1 can be actively controlled. .

Thus, in Example 3, the horizontal cylindrical tank 2 further includes the pipe 7 for circulating air that applies internal pressure to the reinforcing frame 1, the pressurizing device 6 for pressurizing the air circulating through the pipe 7, the pipe A pressure control valve 5 that controls the flow rate of air flowing through the tank 7 to control the internal pressure of the reinforcement frame 1, and a support leg accelerometer (support member accelerometer) 8 that measures the acceleration of the tank support leg (tank support member) 4. And, based on the measurement results of the tank body accelerometer 81 that measures the acceleration of the tank body 23, the support leg accelerometer (support member accelerometer) 8, and the tank body accelerometer 81, the pressure control valve 5 and the pressurization device A control device 9 for controlling 6 is installed.

When the control device 9 determines that the vibration frequency of the earthquake causes an oval vibration mode, the control device 9 pressurizes the reinforcement frame 1 so as to increase the internal pressure, and when it determines that the oval vibration mode does not occur. , the pressure is reduced so that the internal pressure of the reinforcing frame 1 is reduced.

In other words, the reinforcement frame 1 is pressurized to increase the internal pressure when it is determined that the vibration frequency of the earthquake causes the oval vibration mode, and when it is determined that the oval vibration mode does not occur. , is depressurized such that the internal pressure is reduced.

This reduces the additional fluid mass for modes in which the liquid 10 oscillates. Furthermore, depending on whether the reinforcing frame 1 is pressurized or depressurized, the reinforcing frame 1 slides in the longitudinal direction of the tank body 23, and the degree of movement is adjusted, so that the damping effect can be adjusted. can.

Next, the horizontal cylindrical tank 2 having the reinforcing frame 1 described in Example 4 will be described.

FIG. 4 is a partial schematic diagram illustrating a horizontal cylindrical tank 2 having a reinforcing frame 1 described in Example 4. FIG.

The horizontal cylindrical tank 2 described in Example 4 has the same configuration as the horizontal cylindrical tank 2 shown in FIG. Therefore, detailed description is omitted.

A reinforcing frame (hollow pipe) 1 has a U bellows 11 in a part of the reinforcing frame 1 that extends and contracts in the longitudinal direction of the reinforcing frame 1 .

Furthermore, the reinforcing frame 1 is installed in a direction substantially parallel to the U bellows 11, and is installed on the operating guide 12 that reinforces the U bellows 11 and allows expansion and contraction of the U bellows 11 only in the longitudinal direction, and the reinforcing frame 1, An operation guide fixed support 13 that fixes one of the operation guides 12 to the front (rear) of the U bellows 11, and is installed on the reinforcing frame 1 so that the other of the operation guides 12 can be slid to the rear (front) of the U bellows 11. and an actuation guide slide post 14 that supports the .

That is, the reinforcing frame 1 is provided with a U bellows 11 having an operation guide 12 that allows expansion and contraction only in the axial direction. In addition, the operation guide 12 expands and contracts the U bellows 11 only in a direction substantially parallel to the reinforcing frame 1 to suppress meandering of the U bellows 11 .

In addition, the U bellows 11 is preferably installed at one point on 2 to 3 turns of the coil spring-shaped hollow pipe and installed at 10 to 20 degrees per turn (1/36 to 1/18 of one turn). .

In general, when pressurizing a hollow pipe, the axial stress of the hollow pipe generated by the internal pressure is half of the circumferential stress of the hollow pipe, and the pressurization of the hollow pipe is due to the axial stress of the hollow pipe, Limited. In addition, the hollow pipe with the U bellows 11 has a larger axial stress than the hollow pipe without the U bellows 11 .

Therefore, the hollow pipe in which the U bellows 11 is installed expands over its entire length due to pressurization more than the hollow pipe in which the U bellows 11 is not installed.

That is, in Example 3, by installing the U bellows 11, the outer diameter of the reinforcement frame 1 is increased, and the contact load on the inner wall surface of the tank body 23 from the inside to the outside is further increased. can be made

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments are specifically described in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

Also, part of the configuration of one embodiment can be replaced with part of the configuration of another embodiment. Also, the configuration of another embodiment can be added to the configuration of one embodiment. Also, a part of the configuration of each embodiment can be deleted, a part of another configuration can be added, and a part of another configuration can be substituted.

Reference Signs List 1 Reinforcing frame 10 Liquid 11 U bellows 12 Operation guide 13 Operation guide fixed support 14 Operation guide slide support 2 Horizontal cylindrical tank 22 Torus-type cylindrical tank 23 Tank body 3 Base 4 Tank support leg 5 Pressure control valve 6 Pressure device 7 Pipe 8 Support leg accelerometer 81 ... Tank body accelerometer 9 ... Control device

Claims (8)

A cylindrical tank body that is installed horizontally and stores liquid, a tank support member that fixes the tank body to the foundation, and a contact load that is installed inside the tank body and transmits a contact load to the inner wall surface of the tank body. and a reinforcing frame installed like a coil spring. A horizontal cylindrical tank according to claim 1,
A horizontal cylindrical tank, wherein the tank body is a torus-shaped tank body. A horizontal cylindrical tank according to claim 2,
A horizontal cylindrical tank, wherein the ends of the reinforcing frame are joined together. A horizontal cylindrical tank according to claim 1,
A horizontal cylindrical tank, wherein the reinforcing frame is composed of a hollow pipe. A horizontal cylindrical tank according to claim 4,
A pipe for circulating air that applies internal pressure to the hollow pipe, a pressurizing device for pressurizing the air circulating through the pipe, and a pressure that controls the flow rate of the air circulating through the pipe and controls the internal pressure of the hollow pipe. A horizontal cylindrical tank, comprising: a control valve. A horizontal cylindrical tank according to claim 5,
A support member accelerometer for measuring acceleration of the tank support member, a tank body accelerometer for measuring acceleration of the tank body, and the pressure measured by the support member accelerometer and the tank body accelerometer. A horizontal cylindrical tank, comprising a control valve and a control device for controlling the pressure device. A horizontal cylindrical tank according to claim 4,
A horizontal cylindrical tank, wherein the hollow pipe has a U bellows extending and contracting in the longitudinal direction of the hollow pipe. A horizontal cylindrical tank according to claim 7,
A horizontal cylindrical tank, wherein the hollow pipe reinforces the U bellows and has an operation guide that allows expansion and contraction of the U bellows only in the longitudinal direction.

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