JP2011052816A - Method and device for evading resonance in valve attaching pipe, and valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for evading easily pipe resonance even when the pipe resonance occurs, using a volume of a valve cavity part in a valve box, and a valve device. <P>SOLUTION: This device or the like includes a gate valve 2 having the valve box 4 with a pair of openings, a valve stem 6 attached with a valve element 8, and positioned in an inside of the valve box 4, and the valve cavity part in the valve box 4, and a valve attaching pipe attached with the gate valve, and a valve cavity inner volume regulating member 14 capable of changing the volume of a cavity part 10 inside is inserted or stored into the inside of the cavity part 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resonance avoidance method and apparatus for valve mounting piping, and a valve apparatus.

  In plants and the like, for example, pipes through which fluids such as water, oil, steam, and air circulate are frequently used. Such a pipe through which fluid flows (hereinafter referred to as fluid pipe) is provided with a valve for stopping the flow of the fluid in the fluid pipe or adjusting the flow rate.

An example of the valve is a gate valve. A conventional gate valve will be described with reference to FIG.
FIG. 5 is a block diagram showing the configuration of a conventional gate valve.
In FIG. 5, the gate valve 2 mainly includes a valve box 4, a valve stem 6, and a valve body 8.

The valve box 4 has a box shape as a whole, and has two openings (a first opening 42 and a second opening 44). The first opening 42 and the second opening 44 are each connected to a fluid pipe through which a fluid flows.
The valve rod 6 is provided in the valve box 4 so as to be movable up and down, and is configured to move up and down by operating a handle (not shown) attached to the valve rod 6.
The valve body 8 is attached to the tip of the valve stem 6 and moves up and down as the valve stem 6 moves up and down. The valve body 8 is often configured in a tapered shape that tapers from the upper part to the lower part, which is also shown in the drawing.

  In the gate valve shown in FIG. 5, the valve rod 6 and the valve body 8 are raised in the state of FIG. 5, and the valve body 8 is at a position away from the first opening 42 and the second opening 44. The first opening 42 and the second opening 44 are opened and in a valve-open state.

When the valve stem 6 and the valve body 8 are lowered from the state of FIG. 5, the valve body 8 moves to a position corresponding to the first opening 42 and the second opening 44. When the valve body 8 moves to a position corresponding to the first opening 42 and the second opening 44, the first opening 42 and the second opening 44 are closed by the valve body 8 and are closed. .
That is, by moving the valve stem 6 up and down, the valve body 8 can be moved between a position corresponding to the first opening 42 and the second opening 44 and a position away from the first opening 42 and the second opening 44. The gate valve 2 is opened and closed by the movement.

  When the gate valve 2 as shown in FIG. 5 is attached to the fluid pipe, resonance occurs when the frequency due to the pulsation of the fluid flowing in the fluid pipe matches the natural frequency of the gate valve 2, Due to the occurrence of resonance, there is a problem that loosening of bolts in the fluid piping connection due to noise and vibration occurs.

  As a technique for dealing with pipe resonance, for example, Patent Document 1 discloses a frequency of cavity noise generated in a branch pipe by partitioning the branch pipe of the main pipe into a branch pipe of the main pipe to change the cross-sectional area of the branch pipe. A technique for preventing resonance by changing the frequency is disclosed.

Japanese Utility Model Publication No. 7-14297

  However, the technique disclosed in Patent Document 1 is a technique for preventing resonance that occurs in a branch pipe provided in the main pipe, and it is difficult to apply the technique to a valve.

Therefore, it is conceivable to determine the piping structure and valve specifications so that resonance does not easily occur in consideration of the fluid flow in advance. Occasionally, pipe resonance is difficult to avoid.
In addition, when it is understood that pipe resonance occurs despite the prior examination, the pipe and its peripheral equipment have already been completed, and the bent and branched parts of the pipe that are likely to be the source of pulsation are valved. In many cases, it is difficult to take measures such as moving away from the site, and it is difficult to respond afterwards.

  In addition, it is considered possible to suppress resonance by designing a structure where there is a possibility of resonance, such as a valve, in a part where fluid pulsation is expected to be severe. In addition to significantly reducing the degree of freedom, there are problems in terms of cost and occupied area for piping installation, such as an increase in the length of the piping.

In view of this, the inventor has focused on the valve cavity 10 formed between the valve box 4 and the valve stem 6 and the valve body 8 in the valve box 4 shown in FIG.
The volume of the valve cavity 10 is considered to affect the natural frequency of the gate valve 2. However, depending on the fluid piping to which the conventional gate valve 2 is attached, whether the fluid piping is gas or liquid, the flow velocity of the fluid, the gate valve 2 Since the state of the fluid passing through the gate valve varies greatly depending on the restriction on the upstream side, etc., as described above, the piping structure including the volume of the valve cavity 10 is not considered, so that resonance is unlikely to occur in consideration of the fluid flow in advance. Since it was difficult to determine the standard of the valve, it has not been attracting attention in the past.
Furthermore, the valve creator who creates the valve is usually different from the user who uses the valve, and it is realistic to create the volume of the valve cavity 10 in accordance with the usage form at the stage of creating the valve. Due to the fact that it is difficult, the volume of the valve cavity 10 has not been noticed.

  Accordingly, in view of the problems of the prior art, a pipe resonance method and apparatus, and a valve apparatus that can easily avoid pipe resonance even when pipe resonance occurs by utilizing the volume of the valve cavity in the valve box The purpose is to provide.

  In order to solve the above problems, in the present invention, there is provided a valve box having a pair of openings, a valve rod to which a valve body is attached and positioned in the valve box, and a hollow part in the valve box. A resonance avoidance method for the attached valve attachment pipe, wherein resonance of the valve attachment pipe is avoided by changing an internal volume of the hollow portion.

  The natural frequency of the valve changes by changing the internal volume of the cavity. Therefore, if the internal volume of the cavity is changed when resonance occurs, the natural frequency of the valve changes and resonance can be avoided.

  Further, as an apparatus invention for realizing the problem, a valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, a valve having a hollow portion in the valve box, and the valve And a valve-cavity volume adjusting member capable of changing the volume in the cavity portion is inserted or housed in the cavity portion.

  The natural frequency of the valve changes by changing the internal volume of the cavity. Therefore, if the internal volume of the cavity is changed when resonance occurs, the natural frequency of the valve changes and resonance can be avoided. The valve cavity volume adjusting member capable change the volume of the cavity, insertion or because storage is possible avoidance of resonance by the cavity, not only include the new device of the present invention, existing It is possible to implement the present invention with a simple modification in the valve.

  Moreover, as invention of the valve apparatus for implement | achieving a subject, the valve box which has a pair of opening, the valve rod to which a valve body is attached and is located in the said valve box, and the hollow part in the said valve box In the apparatus, the hollow portion can be exposed, and a mounting portion to which a volume adjusting member for adjusting the volume in the hollow portion can be attached to a facing surface in the hollow portion.

  Accordingly, when resonance occurs when the valve device is attached to a pipe and used, the cavity is exposed, and a volume adjusting member is attached to the attachment in the cavity, so that the content of the cavity is obtained. The product changes and the natural frequency of the valve changes, thus avoiding resonance.

  Further, in a valve device having a valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, and a cavity part in the valve box, a volume for adjusting the volume of the cavity part The adjustment member is housed in the cavity.

Thereby, when resonance occurs when the valve device is attached to a pipe and used, the natural frequency of the valve is changed by adjusting the volume adjusting member to change the internal volume of the cavity, It is possible to avoid resonance.
The volume adjusting member may be configured so that part of the volume adjusting member reaches outside the valve box and the volume adjusting member can be adjusted from outside the valve box.

Further, in a valve device having a valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, and a cavity part in the valve box, the volume of the cavity part is changed. The partition part which can do is attached in the said cavity part, It is characterized by the above-mentioned.
Furthermore, the partition may have a shape that changes a boundary shape in the cavity as the volume of the cavity changes.

  By changing the boundary shape in the cavity, the effective volume applied to resonance in the cavity changes, so that resonance can be avoided by changing the boundary shape when resonance occurs.

  As described above, according to the present invention, a pipe resonance method and apparatus that can easily avoid pipe resonance even when pipe resonance occurs by using the volume of the valve cavity in the valve box, and a valve An apparatus can be provided.

FIG. 3 is a configuration diagram illustrating the periphery of a valve cavity of the gate valve according to the first embodiment. FIG. 6 is a configuration diagram illustrating the periphery of a valve cavity of a gate valve according to a second embodiment. It is an AA direction top view in FIG. FIG. 6 is a configuration diagram illustrating the periphery of a valve cavity of a gate valve according to a third embodiment. It is a block diagram which shows the structure of the conventional gate valve. It is a conceptual diagram of a Helmholtz resonator. FIGS. 7A and 7B are diagrams in which the gate valve is deformed to be regarded as a Helmholtz resonator, FIG. 7A is a diagram in which the valve box is deformed, and FIG. 7B is a diagram in which the valve body is deformed. It is the figure which combined the valve box deformation body and valve body deformation body in FIG. 7, and looked at the opening part from the bottom.

As described above, the inventors focused on the valve cavity 10 in FIG. 5 and studied a technique that can easily avoid pipe resonance even when pipe resonance occurs. The examination will be described with reference to FIG.
First, the calculation of the natural frequency of the valve cavity 10 was studied using a Helmholtz resonator.

First, the outline of the Helmholtz resonator will be described.
FIG. 6 is a conceptual diagram of a Helmholtz resonator.
In the Helmholtz resonator, a pipe (duct) having a length L and a cross-sectional area A is opened in a container 52 having an internal volume V.
It is known that the natural frequency f of the Helmholtz resonator is obtained by the equation (1).

但し、ｃは音速である。

Where c is the speed of sound.

Next, calculation of the natural frequency of the valve cavity 10 using a Helmholtz resonator will be described.
First, the gate valve 2 is divided into a valve box 4 and a valve body 8 and is considered to have the form shown in FIG. 7A and 7B are diagrams in which the gate valve is deformed so as to be regarded as a Helmholtz resonator, FIG. 7A is a diagram in which the valve box 4 is deformed, and FIG. 7B is a diagram in which the valve body 8 is deformed. In addition, the number in a figure represents the dimension and a unit is mm.

  In FIG. 7A, a valve box deformed body 4 ′ in which the valve box 4 is deformed corresponds to the container 52 in FIG. 6 and a valve cavity 46 ′ in which a portion including the valve cavity 10 in FIG. 6 includes an opening 48 ′ including a first opening 42 and a second opening 44.

Next, using FIG. 7A and FIG. 7B, the natural frequency f of the valve cavity 10 is obtained by the above-described equation (1). For that purpose, c, V, and A are necessary.
As for c, the gate valve 2 is assumed to be used for the steam fluid piping, and a sound velocity of 700 m / s in the steam was used.

V is the volume of the valve cavity 46 'minus the volume of the valve body 8'.
Here, the volume V ₁ of the valve cavity 46 ′ is
V ₁ = π / 4 × 260 (mm) ² × 260 (mm) = 0.0138 (m ³ )
The volume V _{2 of the} valve body 8 ′ is
V ₂ = π / 4 × 220 (mm) ² × 130 (mm) +98 (mm) × 80 (mm) × 190 (mm) = 0. 06443 (m ³ )
Therefore, the required volume V is
V = V ₁ −V ₂ = 0.0138−0.00643 = 0.00737 (m ² )

Regarding A, two ways were considered.
FIG. 8 is a view in which the valve box deformable body 4 ′ and the valve body deformable body 8 ′ in FIG. 7 are combined and the opening 48 ′ is viewed from below.
As a first way of thinking about A, A was obtained without considering the area where the valve body deforming body 8 ′ blocks the opening 48 ′.
When the A at this time is _{A 1,} the A 1 = 140 (mm) × 240 (mm) = 0.0336 (m 2).
As a second way of thinking about A, A was obtained in consideration of the area where the valve body deforming body 8 ′ blocks the opening 48 ′.
Assuming that A at this time is A ₂ , A ₂ = 140 (mm) × 240 (mm) −115 (mm) × 240 (mm) = 0.006 (m ² )
A ₁ and A ₂ are the maximum and minimum values that A can take.

（ｉｉ）Ａ＝Ａ_２＝０．００６（ｍ^２）であるとき、

となる。従って、弁空洞部１０の固有振動数ｆは、３８０〜５９０Ｈｚの範囲内であると計算できる。 Therefore, when the natural frequency f of the valve cavity 10 is obtained using the equation (1),
(I) When A = A ₁ = 0.0336 (m ² )

(Ii) When A = A ₂ = 0.006 (m ² ),

It becomes. Accordingly, the natural frequency f of the valve cavity 10 can be calculated to be in the range of 380 to 590 Hz.

In order to confirm the validity of the above calculation, when the gate valve deformed in the diagram shown in FIG. 7 is applied to a fluid pipe in which the fluid is steam, the measured natural frequency f of the valve cavity 10 is 420 Hz. It was.
Therefore, it can be said that the calculation for determining the natural frequency by deforming the gate valve 2 and considering it as a Helmholtz resonator is reasonable.

From the above examination, when the gate valve 2 is regarded as a Helmholtz resonator, in equation (1), c is constant depending on the fluid flowing through the pipe to which the valve is applied, and A is constant depending on the valve specification. It can be said that f changes in proportion to 1 / √V.
That is, in the gate valve 2, it was confirmed that the natural frequency changed when the volume of the cavity portion was changed.
Therefore, in the present invention, the natural frequency is changed by changing the volume of the valve cavity 10 to prevent resonance.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

FIG. 1 is a configuration diagram illustrating the periphery of the valve cavity of the gate valve according to the first embodiment.
In FIG. 1, the same reference numerals as those in FIG.
1, in addition to the gate valve having the conventional structure shown in FIG. 5, an attachment portion 12 and a volume adjusting member 14 attached to the attachment portion 12 are provided. The volume adjusting member 14 has a block shape.

The valve cavity 10 can be opened and exposed.
The attachment portion 12 is fixedly provided on a surface facing the valve cavity portion 10 in the valve box 4. The mounting portion 12 is fixedly provided on a surface facing the valve cavity 10 in the valve box 4, and does not move along with the movement of the valve rod 6 and the valve body 8, and further a volume adjusting member 14 described later Other shapes, sizes, positions, and the like are not particularly limited as long as they can be attached so as to be located in the valve cavity 10. Any number of attachment portions 12 may be provided as long as space and arrangement in the valve box 4 are possible. However, since the man-hour concerning the attachment / detachment work of the volume adjustment member 14 mentioned later will become large when there are too many numbers of the attaching parts 12, it is preferable to set it as about 1-3.

The volume adjusting member 14 is configured to be attachable to the attachment portion 12 so as to be positioned in the valve cavity portion 10. The volume adjusting member 14 is detachable from the mounting portion 12.
Further, a plurality of types of volume adjusting members 14 having different sizes are prepared, and one or a plurality of them are selected and attached to the attachment portion.

A procedure for avoiding resonance in the gate valve 2 having such a configuration will be described.
First, the gate valve 2 is attached to the necessary fluid piping with the volume adjusting member 14 removed, and the use of the gate valve 2 is started.
If resonance does not occur by circulating the fluid through the fluid pipe, the operation is continued as it is.

When resonance occurs by circulating a fluid through the fluid pipe, the flow of the fluid in the fluid pipe is stopped, the valve cavity portion 10 is opened, and the volume adjusting member 14 is attached to the attachment portion 12. By attaching the volume adjusting member 14, the volume of the valve cavity 10 changes and the natural frequency f also changes.
The size of the volume adjusting member 14 to be attached is determined by measuring the natural frequency at the time when resonance occurs, and deforming the gate valve 2 as shown in FIG. 7, and using the equation (1). The volume adjusting member 14 is selected so that the result of calculating the difference from the natural frequency of the actually measured value.

According to the first embodiment, if the mounting portion 12 is provided in the valve box 4, it is possible to change the volume of the valve cavity portion 10 simply by opening the valve cavity portion 10 and attaching the volume adjusting member 14. Become. Since the natural frequency of the valve cavity 10 is changed by changing the volume of the valve cavity 10, the natural frequency of the valve cavity 10 is changed by attaching the volume adjusting member 14 when resonance occurs. Resonance can be suppressed.
Moreover, since the natural frequency of the valve cavity 10 can be calculated by regarding the gate valve as a Helmholtz resonator as described above, the volume adjusting member 14 having an appropriate size is selected using the calculation. Can be attached.

  In this embodiment, the operation is started with the volume adjustment member 14 removed, and the volume adjustment member 14 is attached when resonance occurs. However, the operation is started with the volume adjustment member 14 attached. When resonance occurs, the volume adjusting member 14 may be removed or replaced with a volume dispensing member 14 having a different size.

FIG. 2 is a configuration diagram illustrating the periphery of the valve cavity of the gate valve according to the second embodiment. FIG. 3 is a plan view in the AA direction in FIG.
2 and 3, the same reference numerals as those in FIGS. 1 and 5 described above represent the same items, and the description thereof is omitted.
2 and 3, a volume adjusting device 16 is provided in addition to the gate valve having the conventional structure shown in FIG.

  The tip of the volume adjusting device 16 is located in the valve cavity 10, and the portion located in the valve cavity 10 has a block shape. The other end of the volume adjusting device 16 passes through the upper end of the valve box 4 and reaches the outside. The volume adjusting device 16 is configured to be movable up and down, and is configured to be fixed at an arbitrary position moved further up and down.

A procedure for avoiding resonance in the gate valve 2 having such a configuration will be described.
First, the gate valve 2 is attached to a necessary fluid pipe in a state where the volume adjusting device 16 is fixed at an arbitrary height position, and use of the gate valve 2 is started.
If resonance does not occur by circulating the fluid through the fluid pipe, the operation is continued as it is.

When resonance is generated by circulating a fluid through the fluid piping, the volume adjusting device 16 is moved up and down while the fluid circulation in the fluid piping is continued. By moving the volume adjusting device 16 up and down, the volume of the valve cavity 10 changes and the natural frequency f also changes.
Then, the volume adjusting device 16 is moved up and down to change the volume of the valve cavity 10, and the volume adjusting device 16 is fixed at a position where the resonance falls.

  According to the second embodiment, since the volume of the valve cavity 10 can be changed without opening the valve box 4, resonance can be suppressed without stopping the use of the gate valve 2. Resonance can be suppressed without shortening the operating time of a plant or the like that uses the valve 2. In addition, since the volume adjusting device 16 is simply moved up and down in order to suppress the resonance, the work related to the suppression of the resonance is very simple.

FIG. 4 is a configuration diagram illustrating the periphery of the valve cavity of the gate valve according to the third embodiment.
4, the same reference numerals as those in FIG. 5 already described represent the same items, and the description thereof is omitted.
4, in addition to the gate valve having the conventional structure shown in FIG. 5, a partition portion 18 is provided.

  The tip of the partition 18 is located in the valve cavity 10, and the portion located in the valve cavity 10 has a plate shape. The other end of the partition 18 passes through the upper end of the valve box 4 and reaches the outside. Moreover, the partition part 18 is comprised so that a vertical movement is possible, and it is comprised so that it can fix in the arbitrary positions moved up and down.

  In the gate valve 2 having such a configuration, by using the partition portion 18, the inside of the valve cavity portion 10 is partitioned, the position of the wall surface is changed, and the boundary shape in the valve cavity portion 10 is changed in a complicated manner. Can be suppressed.

  Further, in the same manner as the gate valve described with reference to FIGS. 2 and 3 in the second embodiment, the actual volume in the valve cavity 10 is also changed by moving the partition 18 up and down.

  As described above, in the first embodiment, the second embodiment, and the third embodiment, the gate valve has been described. However, the gate valve is not limited to the gate valve as long as the valve has a valve cavity portion, such as a globe valve and an angle valve. Can also be applied.

  By utilizing the volume of the valve cavity in the valve box, it can be used as a pipe resonance method and apparatus, and a valve apparatus that can easily avoid pipe resonance even when pipe resonance occurs.

2 Gate valve 4 Valve box 6 Valve rod 8 Valve body 10 Valve cavity portion 12 Mounting portion 14 Volume adjusting member 16 Volume adjusting device 18 Partitioning portion

Claims (6)

A resonance avoidance method for a valve mounting pipe having a valve box having a pair of openings, a valve rod attached with a valve body and positioned in the valve box, and having a valve having a cavity in the valve box. And
A resonance avoidance method for a valve mounting pipe, wherein resonance of the valve mounting pipe is avoided by changing an internal volume of the hollow portion. A valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, and a valve having a cavity in the valve box;
Resonance avoidance of the valve mounting pipe, comprising: a valve mounting pipe to which the valve is mounted; and a valve cavity volume adjusting member capable of changing a volume in the cavity section is inserted or housed in the cavity section. apparatus. In a valve device having a valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, and a cavity in the valve box,
The cavity can be exposed;
A valve device comprising a mounting portion to which a volume adjusting member for adjusting a volume in the hollow portion can be mounted on a surface facing the inside of the hollow portion. In a valve device having a valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, and a cavity in the valve box,
A valve device characterized in that a volume adjusting member for adjusting the volume of the cavity is housed in the cavity. In a valve device having a valve box having a pair of openings, a valve rod to which a valve body is attached and located in the valve box, and a cavity in the valve box,
A valve device characterized in that a partition portion capable of changing a volume of the hollow portion is attached in the hollow portion.   The valve device according to claim 5, wherein the partition portion has a shape that changes a boundary shape in the cavity portion with a change in volume of the cavity portion.

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