JPH06300179A - Pipe line structure - Google Patents

Abstract

PURPOSE:To prevent equipment from being in a redundant state, to reduce a cost, and to suppress the generation of vibration and noise in a reducer disposed in a stage right preceded by a pressure reducing valve. CONSTITUTION:Members 1 and 2 having a plurality of holes la and 2a formed such that the holes are formed in a protrusion shape in the direction of the flow of fluid and a hole diameter is increased from the center of a pipe toward a periphery are located downstream from a pressure reducing valve and at a stage right preceded by a reducer 3 and in the reducer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine bypass pipe having a throttle valve with a large pressure reduction ratio installed in a power plant, a blowdown pipe used in a petrochemical plant, or the like, which is caused by the influence of fluids. The present invention relates to a piping structure that prevents noise.

[0002]

2. Description of the Related Art In a pipe having a pressure reducing valve with a high throttle ratio, as shown in FIG. 3, the fluid flowing in a reducer 22 disposed immediately after the pressure reducing valve 21 becomes a sonic flow, and shock waves and vortices are generated. easy. Therefore, in the reducer 22 arranged immediately after the pressure reducing valve 21, strong vibration and noise are likely to occur due to the influence of shock waves and vortices. Vibration and noise generated in the reducer 22 are generally dealt with by reducing the pressure in multiple stages or by providing the reducer 22 for a long time.

[0003]

If the decompression is performed in multiple stages as described above, or if a long reducer is provided immediately after the decompression valve to cope with vibration and noise, it may lead to redundant equipment. Equipment costs are high.

[0004] Therefore, an object of the present invention is to provide a pipeline structure which prevents redundant equipment and suppresses vibration and noise generated in a reducer disposed immediately after a pressure reducing valve in low-cost equipment. That is.

[0005]

In order to achieve the above-mentioned object, the present invention provides a convex shape in the fluid flow direction immediately before the reducer and / or in the reducer downstream of the pressure reducing valve, and the center of the pipe is formed. That is, a member provided with a plurality of holes whose diameters change from the periphery to the periphery is increased.

[0006]

[Function] By providing a member having a plurality of holes whose diameter increases from the center of the pipe to the periphery of the pipe immediately before and / or within the reducer, the fluid that has passed through the pressure reducing valve and becomes a sonic flow is The flow is blocked and decelerated, the flow rate in the central part decreases and the flow rate in the peripheral part increases.

Furthermore, since the shape of the member is convex in the direction of the fluid flow, the fluid passing through the holes provided in the peripheral portion of the member becomes a flow conforming to the shape of the reducer, and the effect of the reducer is obtained. Increase.

[0008]

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing an embodiment of the conduit structure of the present invention, and FIG. 2 is a diagram showing another embodiment of the conduit structure of the present invention.

In FIG. 1, reference numerals 1 and 2 denote first and second reverse conical cylindrical perforated plates arranged immediately before the reducer 3 provided immediately after the pressure reducing valve and inside the reducer 3, respectively. Also, the second perforated plates 1 and 2 are attached perpendicularly to the inner wall of the reducer 3. And these first
Also, the second perforated plates 1 and 2 are provided with a large number of holes 1a which become larger from the central portion of the reducer 3 to the peripheral portion thereof.
And 2a are provided.

The pipe line structure of the present invention has the above-mentioned structure. The fluid passing through the pressure reducing valve (not shown) tries to pass through the reducer 3 as a sonic flow. Blocked. The first perforated plate 1 has holes 1 formed so as to become larger from the central portion to the peripheral portion.
Since a is provided, the flow rate of the fluid passing through the first perforated plate 1 is small in the central portion and increases in the peripheral portion.

Then, the fluid is blocked by the first perforated plate 1 to cause a loss and is decelerated. Since the hole 1a is formed so as to become larger from the central portion of the reducer 3 toward the peripheral portion, the loss in the central portion is the largest and the loss becomes smaller in the peripheral portion. Therefore, the deceleration of the fluid is small in the peripheral portion, and the deceleration is large in the central portion.

In addition, since the first perforated plate 1 is vertically attached to the inner wall of the reducer 3, the fluid passing through the holes 1a provided in the peripheral portion of the first perforated plate 1 is reduced. Smooth flow in the direction in which 3 expands.

Further, by providing the second perforated plate 2, the effect of decelerating the fluid and the effect of suppressing the generation of vortices are enhanced, and the flow rate distribution of the fluid flowing in the reducer 3 is made more uniform.
At this time, the state of the fluid flowing in the pipe flows as indicated by the arrow in FIG.

The fluid flowing through the central portion of the pipe is greatly decelerated and is no longer a sonic flow, so that the generation of shock waves is suppressed. Further, since the fluid also flows to the peripheral portion inside the pipe, the generation of vortices is suppressed.

Further, as shown in FIG. 2, the same effect can be obtained by providing the hemispherical porous plate 11 in the reducer 13 provided immediately after the pressure reducing valve. This perforated plate 1
1 is also similar to the first and second porous plates 1 and 2 described above,
A plurality of holes 11a are provided so that the hole diameter increases from the center to the periphery of the pipe.

[0016]

As described above, according to the present invention, it is possible to suppress the generation of shock waves and vortices with a simple structure. Therefore, vibration
It is possible to suppress the generation of noise, and to prevent equipment redundancy and cost increase. By the way, when the inventors of the present invention conducted an experiment with the pipe having the pipe line structure of the embodiment shown in FIG. 1, the vibration generated from 300 μm was reduced to 30 μm, and the noise generated from 90 to 100 dB was 5%. -10 dB
Fell.

[Brief description of drawings]

FIG. 1 is a diagram showing a conduit structure of the present invention.

FIG. 2 is a diagram showing another embodiment of the conduit structure of the present invention.

FIG. 3 is a diagram showing a state of a fluid flowing in an expansion pipe provided immediately after a pressure reducing valve.

[Explanation of symbols]

 1 First Perforated Plate 2 Second Perforated Plate 3 Reducer

Claims (1)

[Claims] 1. A plurality of holes having a convex shape in the direction of fluid flow and having a diameter that increases from the center to the periphery of the pipe are provided immediately before the reducer and / or in the reducer on the downstream side of the pressure reducing valve. A pipe structure characterized by interposing a member.