JPH06101794A - Fluid pressure pulsation absorbing device - Google Patents

Abstract

PURPOSE:To provide a fluid pressure pulsation absorbing device which possesses the high reducing effect for the pressure pulsation and durability for a long period. CONSTITUTION:A fluid pressure pulsation absorbing device is equipped with an inlet pipe 12, outlet pipe 13, conduit part 11 which is made of rigid body and equipped with the fluid flow area larger than that of the inlet pipe 12 and the outlet pipe 13, a plurality of perforated plate 15 which are successively installed, keeping an interval, along the flow direction of the fluid 10 in the conduit part 11 and each of which has a number of through holes 15a, and a connecting pipe 17 whose fluid passing area installed between the terminal part 11c of the conduit part 11 and the outlet pipe 13 is gradually drawn to the fluid passing area of the outlet pipe 13 toward the downstream side of the fluid 10. Accordingly, the swirl in the fluid 10 as the main cause of the pressure pulsation is drastically reduced by the facts that the fluid 10 forms a laminar flow or the like because of the fluid passing area in the wide conduit part 11 or the fluid 10 is allowed to pass through a flow passage having a regulated narrow area in the passing in a through hole 15a having a small diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure pulsation absorber which is used by being inserted into a piping system such as a cooling device for cooling an object to be cooled which circulates a fluid to generate heat.

[0002]

2. Description of the Related Art A device for transferring or circulating a fluid such as a liquid or a gas through a pipe is often used. In such a device, a pump device for pumping a fluid generates pressure by an impeller having a finite number of blades, and a turbulent flow generated at a bent portion of a pipe causes pulsation in the fluid pressure. . In order to prevent this pressure pulsation from interfering with the function of the pipe or the device connected to the pipe, it is common to install a fluid pressure pulsation absorber at an appropriate position of the pipe to reduce the pressure pulsation. . As an example of such a piping system, FIG. 3 shows a piping system diagram of a cooling device that circulates a liquid to cool a cooled object that generates heat. In FIG. 3, 33 is a pump device having a finite number of impellers, 34 is a fluid pressure pulsation absorber, 35 is a heat exchanger, 36 is an object to be cooled, 37 is a liquid storage tank, and 38 is piping. FIG. 4 is a graph showing an example of the measurement result of the liquid pressure at the liquid outlet 33a of the pump device 33 in FIG. Approximately 0.1 due to finite number of impeller blades or turbulent flow generated at curved parts of piping.
There is a pressure pulsation of kg / cm ² .

FIG. 5 is a side sectional view of a conventional fluid pressure pulsation absorber used to reduce such pressure pulsations. A conventional fluid pressure pulsation absorber will be described with reference to FIG. In FIG. 5, 1
Is a metal first tubular body having a flow path for allowing the fluid 10 to flow therethrough and having a plurality of holes 2 on the wall surface and connecting screws 1a and 1b at both ends. Reference numeral 39 is a second tubular body that forms the pulsation absorbing space 4 communicating with the plurality of holes 2 of the first tubular body 1 with the first tubular body 1, and is made of rubber or the like. Made from body material. When the fluid 10 having the pressure pulsation flows through the inside of the first tubular body 1, a part 10 a of the fluid 10 flows into the pulsation absorbing space 4 through the hole 2, so that the second tubular body 39 enters the second tubular body 39. Pressure pulsations are transmitted. Since the second tubular body 39 is made of an elastic material, it increases its diameter when the pressure of the pressure pulsation rises, thereby increasing the volume of the pulsation absorbing space 4 to reduce the pressure rise, and when the pressure falls, the diameter thereof increases. The pressure drop is reduced by decreasing the volume of the pulsation absorbing space 4. That is, the pressure pulsation is reduced by the so-called absorption effect. Further, a part 10 a of the fluid that has passed through the hole 2 is a part 10 b of the fluid 10 that flows in the center of the first tubular body 1.
Since it passes through a longer path, the phase of the pressure pulsation of the part 10a of the fluid lags the phase of the pressure pulsation of the part 10b of the fluid 10. As a result, the pressure pulsations at the position where the part 10a of the fluid 10 and the part 10b of the fluid 10 merge together cancel each other out. That is, the pressure pulsation is also reduced by the so-called interference effect.

[0004]

In the fluid pressure pulsation absorber according to the above-mentioned prior art, the second cylindrical body which is the pulsation absorption chamber forming the pulsation absorption space between the second cylindrical body and the first cylindrical body is provided. Since it is made of elastic material such as rubber, which has low mechanical strength, the elastic material should be thick in order to have withstand pressure (5-10 kG / cm ² ) against the working pressure of the fluid at the normal usage level. Therefore, there is a problem that the required absorption effect cannot be provided, and the long-term durability is deteriorated due to deterioration of rubber and the like.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide a fluid pressure pulsation absorber having a high effect of reducing pressure pulsation and having long-term durability. It is in.

[0006]

In the present invention, the above-mentioned objects are as follows: 1) An inlet pipe through which a fluid flows and an outlet pipe through which a fluid flows out are provided at both ends of the inlet pipe and the fluid contained in the outlet pipe and the outlet pipe, respectively. A straight tubular rigid pipe section having a fluid flow area larger than the flow area and a large number of through holes are formed to allow the fluid to flow into the fluid flow path of the fluid path section. A plurality of perforated plates which are sequentially mounted at intervals along the direction, and 2) in the means described in the above item 1, the fluid flow area of the connecting portion between the pipe line portion and the outlet pipe. Is configured so as to be narrowed to the downstream side of the fluid to the fluid flow area of the outlet pipe, and 3) in the means described in the above 1, the end of the pipe line portion to which the outlet pipe is connected. A porous plate is attached to the section, and 4) the above 1 In the means described in the items 1 to 3, the pipe line portion, the inlet pipe, and the outlet pipe are all cylindrical, and the outer diameter of the perforated plate is the same as the inner diameter of the pipe line portion. To be achieved.

[0007]

In the present invention, for example, a cylindrical inlet pipe through which a fluid flows in and a cylindrical outlet pipe through which a fluid flows out are provided at both ends thereof, respectively. Also has a wide fluid flow area, for example, a cylindrical rigid pipe section and a large number of through holes are formed in the fluid passage of the pipe section along the direction in which the fluid flows. By providing a plurality of perforated plates having the same outer diameter as the inner diameter of the pipe line portion, which are sequentially mounted, the fluid containing vortices, which is the main cause of pressure pulsation, flows from the inlet pipe. When the fluid flows in, the flow velocity of the fluid is first reduced by the fluid flow area of the wide pipe section, so that the fluid becomes a laminar flow region or a flow close to it and flows through the pipe section. Contained in the flowing fluid It is rapidly attenuated in accordance with the downstream. Further, the vortex thus attenuated is forcibly suppressed by allowing the fluid to pass through the flow path regulated to have a small area when flowing through the through hole formed in the perforated plate.
By combining the low flow velocity with the flow through the perforated plate, the vortex in the fluid is significantly damped by the relatively short length of the conduit. When flowing into the through hole of the perforated plate or flowing out from the through hole of the perforated plate, a new vortex is not generated in the fluid due to the low flow velocity of the fluid.

Further, in the fluid pressure pulsation absorber having the above-mentioned structure, the fluid flow area of the connecting portion between the pipe line portion and the outlet pipe is made to reach the fluid flow area of the outlet pipe as the downstream side of the fluid flows. By gradually squeezing the fluid,
When flowing from a pipe section having a wide fluid flow area into an outlet pipe having a narrow fluid flow area and a fluid pipe connected to the outlet pipe, a new vortex is not generated in the fluid because the flow velocity changes gently. Absent.

Further, in the fluid pressure pulsation absorber having the above-mentioned structure, the perforated plate is attached to the end portion of the conduit portion to which the outlet pipe is connected, so that the fluid has a wide fluid flow area. When flowing into the outlet pipe having a narrow fluid flow area and the fluid piping connected to it from the pipe line part,
Since the fluid flows out to the outlet pipe while being regulated by the through hole having a small area formed in the perforated plate, no new vortex is generated in the fluid.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. Embodiment 1; FIG. 1 is a side sectional view of a fluid pressure pulsation absorber according to an embodiment corresponding to claims 1, 2 and 4 of the present invention, (a) is a side sectional view, and (b) is AA of FIG. 1a. FIG. In FIG. 1, the same parts as those of the conventional fluid pressure pulsation absorber shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 1, reference numeral 11 denotes a cylindrical pipe portion having a flow passage for allowing the fluid 10 to flow therethrough, and a metal inlet pipe 12 is provided on the side where the fluid 10 flows.
Metal outlet pipes 13 are attached to the sides where the fluid 10 flows out. The pipe passage portion 11 has a straight pipe-like pipe passage portion main body 11a having a fluid passage area sufficiently wider than the fluid passage area for the fluid 10 of the inlet pipe 12 and the outlet pipe 13 to pass through, and A flange 11b for mounting the inlet pipe 12 is attached by welding to the side of the passage body 11a on which the fluid 10 flows. Inlet pipe 1
2 is a cylindrical inlet pipe body 12 having the same diameter as the pipe 38.
a and by being attached to the inlet pipe body 12a by welding,
A flange 12b for mounting the inlet pipe 12 on the flange 11b and a flange 12c for mounting the inlet pipe 12 on the pipe 38 by welding to the inlet pipe main body 12a, and the outlet pipe 13 is constituted by the pipe 38. And a cylindrical outlet pipe body 13a having the same diameter as the outlet pipe body 13a
And a flange 13b for attaching the outlet pipe 13 to the pipe 38 by welding.

Reference numeral 17 denotes a cylindrical connecting pipe made of metal for connecting the terminal portion 11c of the pipe passage portion 11 and the outlet pipe main body 13a of the outlet pipe 13, and the end portion on the pipe passage portion 11 side is The outer diameter is the same as the inner diameter of the conduit body 11a, and the end on the outlet pipe 13 side is the same diameter as the outlet body 13a.
The inner diameter thereof is continuously and gradually reduced from the end on the side of 1 toward the end on the side of the outlet pipe 13, and the end on the side of the pipeline 11 is the terminal portion 11c of the pipeline 11. Further, the end portion on the outlet pipe 13 side is attached to the outlet pipe main body 13a by welding.

Reference numeral 15 is a disk-shaped metal perforated plate having an outer diameter equal to the inner diameter of the conduit body 11a,
A large number of small-diameter through holes 15a are provided. Perforated plate 15
Are alternately arranged with the cylindrical metal spacing pipe 16 having an outer diameter equal to the inner diameter of the conduit body 11a.
1a, and is sequentially mounted in the passage of the fluid 10 in the pipe line portion 11 along the direction in which the fluid 10 flows, at intervals according to the lengthwise dimension of the spacing pipe 16. Perforated plate 15
After being mounted on the conduit body 11a, the flange 11b and the flange 12b are integrally fastened together by a fastening structure such as a bolt with a hermetically sealed structure.

Since the present invention has the above-mentioned structure, the fluid 10 containing the vortex which is the main cause of the pressure pulsation is the inlet pipe 12.
Assuming that the fluid 10 has flowed in from, the fluid 10 first flows through the fluid passage portion of the pipe line portion 11 having a large fluid passage area, and the flow velocity is "the fluid passage area of the pipe 38" /
It is significantly reduced by the "fluid flow area of the conduit portion 11". As a result, the flow state of the fluid 10 becomes a laminar flow region or a flow close to it and flows through the inside of the pipe line portion 11. Therefore, the vortex contained in the flowing-in fluid 10 is generated. It is rapidly attenuated as it flows through. The damping of the vortices also reduces the pressure fluctuations of the fluid 10. Further, the vortex thus attenuated and weakened in vortex flow is caused when the fluid 10 flows through the small-diameter through hole 15a formed in the perforated plate 15 and passes through the flow passage restricted to a small area. With the rectification effect, it is suppressed even further. In this way, by combining the low flow velocity and the flow in the small-diameter through hole 15a, the vortex in the fluid 10 is significantly attenuated by the pipe path portion 11 having a relatively short length.

When flowing into the through hole 15a of the perforated plate 15 or flowing out from the through hole 15a of the perforated plate 15, a new vortex is not generated in the fluid 10 because the flow velocity of the fluid 10 is slow. . The fluid 10 in which the vortex is significantly attenuated and the pressure fluctuation is reduced flows out from the outlet pipe 13 to the pipe 38 having a small fluid flow area. The pipe line main body 11a and the outlet pipe 13 are connected to each other by the connecting pipe 17 The flow velocity of the fluid 10 between the pipe portion 11 and the outlet pipe 13 changes gently, so that a new vortex is prevented from being generated in the fluid 10.

Further, since the material of each part constituting the fluid pressure pulsation absorber is a metal which is a rigid body, it has sufficiently high long-term durability. Embodiment 2; FIG. 2 shows a fluid pressure pulsation absorber according to an embodiment corresponding to claims 1, 3 and 4 of the present invention, (a) is a side sectional view, (b) is BB of FIG. 2a. FIG. 2, the same parts as those of the fluid pressure pulsation absorber corresponding to claims 1, 2 and 4 of the present invention shown in FIG. 1 and the conventional fluid pressure pulsation absorber shown in FIG. Attached
The description is omitted.

In FIG. 2, reference numeral 18 is a conduit main body 11a.
Is an end plate made of metal having an outer diameter that is the same as the inner diameter of the outlet pipe body 13a and an inner diameter that is the same as the inner diameter of the outlet pipe body 13a. Are attached to the outlet pipe body 13a by welding.
The perforated plate 15 is mounted adjacent to the end plate 18. Since the present invention has the above-mentioned configuration, the combination of the conduit portion 1 and the perforated plate 15 is similar to the case of the above-described first embodiment.
The vortices in the fluid 10 are greatly dampened. Further, the fluid 10 in which the vortex is greatly damped and the pressure fluctuation is reduced is
Although it flows out from the pipe 3 to the pipe 38 having a small fluid flow area, the conduit body 11a and the outlet pipe 13 are connected by the end plate 18, and the perforated plate 15 is arranged adjacent to the end plate 18. Therefore, the fluid 10 flowing out from the pipe line portion 11 has a larger area than the total area of the fluid flow areas by the through holes 15a immediately after passing through the through holes 15a in the inner diameter portion of the outlet pipe body 13a. It will flow through the outlet pipe 13. As a result, the fluid 10 is regulated as a laminar flow state in the through hole 15a, and subsequently flows through the outlet pipe 13 having a slower flow velocity.
A new vortex is prevented from being generated inside.

In the description of Embodiments 1 and 2 above,
The material of each component constituting the fluid pressure pulsation absorber is assumed to be all metal, but the material is not limited to this, and may be, for example, a hard synthetic resin, or the like.
Different materials may be mixed. In short, any material can be used as long as it has long-term durability. Further, in connection with this, although each component of the fluid pressure pulsation absorber except for the perforated plate 15 and the interval pipe 16 is attached by welding, the present invention is not limited to this, and depending on the material used,
For example, it may be attached by adhesion.

Further, in the description of the first and second embodiments up to now, the perforated plate 15 is sandwiched between the spacing tubes 16,
It is assumed that the predetermined interval is maintained. According to this method, the perforated plate 15 can be replaced at any time with one having a hole diameter suitable for the conditions such as the flow velocity of the fluid 10 of the device to which the fluid pressure pulsation absorber is mounted. It is possible to have an advantage that the effect of reducing the pressure fluctuation provided can be effectively exhibited. However, the present invention is not limited to this. For example, if the usage conditions of the fluid pressure pulsation absorber are determined, a perforated plate 15 having a corresponding structure is used, and the perforated plate 15 is welded at predetermined intervals.
It may be fixed to the conduit portion 11 by an appropriate construction method such as adhesion. Further, in connection with this, the flange 11b and the flange 12b are integrally fastened by a fastening structure such as a bolt by a hermetically sealed structure.
When 5 is fixed to the conduit portion 11, the flange 11b and the flange 12b may be fixed to each other by an appropriate method such as welding or bonding.

Furthermore, in the above description of the first and second embodiments, the components such as the pipe line portion 11 and the perforated plate 15 which constitute the fluid pressure pulsation absorber are cylindrical or disc-shaped. The shape is not limited to this, and may be, for example, a rectangular tube shape or a rectangular shape.

[0021]

According to the present invention, an inlet pipe for letting in a fluid and an outlet pipe for letting out a fluid are provided at both ends of the inlet pipe, respectively, and the fluid is wider than the area of the inlet pipe and the outlet pipe through which the fluid flows. A rigid pipe section having a flow area and a large number of through-holes are bored, and are sequentially mounted in the fluid passage of the fluid in the pipe section at intervals along the fluid flow direction. For example, if a fluid containing vortices, which is the main cause of pressure pulsation, flows in from the inlet pipe by configuring with a plurality of perforated plates that have the same outer diameter as the inner diameter of the pipeline, First, since the flow velocity is reduced due to the large fluid flow area of the pipeline, the fluid becomes a laminar flow region or a flow close to it and flows through the pipeline. The vortex included in the vortex rapidly increases in the downstream direction. It is attenuated. Further, the vortex thus attenuated is forcibly suppressed by allowing the fluid to pass through the flow path regulated to have a small area when flowing through the through hole formed in the perforated plate. By combining the low flow velocity with the flow through the perforated plate, the vortex in the fluid is significantly damped by the relatively short length of the conduit. When flowing into the through hole of the perforated plate or flowing out from the through hole of the perforated plate, a new vortex is not generated in the fluid due to the low flow velocity of the fluid.

Further, in the fluid pressure pulsation absorber having the above structure, the fluid flow area of the connecting portion between the pipeline and the outlet pipe is gradually increased to the fluid flow area of the outlet pipe on the downstream side of the fluid. The fluid can be narrowed from the pipe line part with a wide fluid flow area by adopting a structure in which the perforated plate is attached to the end part of the pipe line part to which the outlet pipe is connected. The flow velocity changes slowly when it flows into the inlet pipe and the fluid pipe connected to it, or the outlet pipe remains in a state where the fluid is regulated by the through-hole with a small area formed in the perforated plate. New vortices are prevented from forming in the fluid due to the outflow to the.

By comprehensively providing the above, it is possible to significantly reduce the pressure pulsation in the liquid, and it is possible to realize the long-term durability because the pressure pulsation can be reduced by the rigid component parts. The effect is also possible.

[Brief description of drawings]

1 is a side sectional view of a fluid pressure pulsation absorber according to an embodiment corresponding to claims 1, 2, and 4 of the present invention, FIG.
(B) is a sectional view taken along line AA of FIG. 1a.

FIG. 2 (a) is a side sectional view of a fluid pressure pulsation absorber according to an embodiment corresponding to claims 1, 3, and 4 of the present invention,
2B is a sectional view taken along line BB of FIG. 2A.

[Fig. 3] Piping system diagram of cooling device

FIG. 4 is a graph showing an example of the measurement result of the liquid pressure in FIG.

FIG. 5 is a side sectional view of a conventional fluid pressure pulsation absorber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fluid 11 Pipe line part 11c Terminal part 12 Inlet pipe 13 Outlet pipe 15 Perforated plate 15a Through hole 17 Connection pipe

Claims (4)

[Claims] 1. An inlet pipe through which a fluid flows in and an outlet pipe through which a fluid flows out are provided at both ends thereof, and have a fluid flow area larger than the area through which the fluid flows in the inlet pipe and the outlet pipe. A straight tubular rigid pipe line portion and a large number of through holes are bored, and they are sequentially mounted in the flow passage of the fluid of the pipe line portion at intervals along the direction in which the fluid flows. A fluid pressure pulsation absorber comprising a plurality of perforated plates. 2. The fluid pressure pulsation absorber according to claim 1, wherein the fluid passage area of the connecting portion between the pipeline and the outlet pipe is on the downstream side of the fluid up to the fluid passage area of the outlet pipe. A fluid pressure pulsation absorber characterized by being throttled according to. 3. The fluid pressure pulsation absorber according to claim 1, wherein a perforated plate is attached to a terminal portion of a conduit portion to which the outlet pipe is connected. 4. The fluid pressure pulsation absorber according to claim 1, wherein each of the pipe line portion, the inlet pipe and the outlet pipe has a cylindrical shape, and the outer diameter of the perforated plate is the inner diameter of the pipe line portion. A fluid pressure pulsation absorber having the same dimensions.