JPS62445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a method and apparatus for detecting a leakage point in a fluid transport path for transporting oil or the like.

Conventionally, in oil transmission pipelines, etc., electric cables whose dielectric constant changes due to oil are installed along the pipelines, and this is used as an oil leak detection line to detect changes in impedance that occur in the electric cables due to oil leaks. There are devices that monitor the end of the cable to detect oil leaks, and spring structures that use the weight of oil leaks collected in the oil sump to push down a spring-loaded rod to close electrical contacts for indicating oil leaks. In some cases, oil leaks are detected by placing a detector at each detection point in the longitudinal direction of the pipeline, but in the former case, it is necessary to increase the amount of change so that changes in cable impedance can be identified. Because it is difficult,
This must be detected by converting it into pulses, and even if the detection signal is converted into pulses in this way, the pulses will not travel far enough due to losses caused by the electric cables and external noise added to it. However, by providing such means in a long oil pipeline, it has not been possible to satisfactorily detect oil leaks.

In addition, in the latter case, expensive detectors must be installed at each of the many detection points set in the long pipeline, which requires a large number of parts and a lot of work to install them. This resulted in uneconomical equipment requirements.

In order to solve the above-mentioned problems, the present invention uses a plurality of flexible optical transmission bodies such as optical fibers or optical cables made of a plurality of optical fibers arranged in parallel to prevent leakage of fluid transport channels. The purpose of this paper is to realize a location detection method and device.

The method and apparatus of the present invention will be explained below with reference to the illustrated embodiments.

FIG. 1 shows a first embodiment of the method of the present invention. In this embodiment, a long fluid transport channel 3 having a transport start end 1 and a transport end 2 is divided into a plurality of detection zones in the longitudinal direction. 4 ₁ , 4 ₂ , 4 ₃ ...4n- ₂ ,
4n- ₁ , 4n, and the fluid transport path 3
Optical transmission bodies 5 ₁ , 5 ₂ , 5 ₃ , etc. consisting of optical fibers or optical cables are arranged along the longitudinal direction of
_-2,5n - _1,5n are attached.

In this case, a light transmitter 6 is provided at both ends of each optical transmission body.
₁ , 6 ₂ , 6 ₃ ... 6n- ₂ , 6n- ₁ , 6n,
and receivers 7 ₁ , 7 ₂ , 7 ₃ ... 7n- ₂ , 7
n- ₁ , 7n are attached, and the above-mentioned optical transmission bodies 5 ₁ to 5 between each light transmitter and light receiver
Interference receiving parts 8 ₁ , 8 _{2 ,} 8 ₃ . . . 8 n- 2 , 8 n- ₁ , 8 n where optical transmission is obstructed by leaked fluid are shown in n.
is formed by a separation space, and these interference receiving parts ₈₁ to 8n are connected to each detection section 4 described above.
One each is arranged from ₁ to 4n.

When the present invention consists of the above embodiment, light is passed from each light transmitter 6 ₁ to 6n to each optical transmission body 5 ₁ to 5n toward the light receivers 7 ₁ to 7n, and this is transmitted at the light receiving end side. During such monitoring, if fluid leaks, for example, in the detection section ₄₁ of the fluid transport path 3, the leaked fluid will enter the interference receiving section ₈₁ in that section. and optical transmission body 5
The light does not reach the light receiver ₇₁ of _{No. 1} , and it is revealed that there is a leak in the detection section ₄₁ of the fluid transport path 3 due to this light-blocking state.

Of course, even if fluid leaks in the other detection sections ₄₂ to 4n, the location of the leak can be determined in the same manner as described above.

Next, a second embodiment of the method of the present invention will be explained with reference to FIG. 2. In this embodiment, each optical transmission body 5 ₁
5n is folded back into a U-shape, the light transmitters 6 ₁ to 6n and the light receivers 7 ₁ to 7 ₂ are arranged on one end side of the fluid transport path 3, and the U-shaped portion of each optical transmission body 5 ₁ to 5n is arranged. Interference receiving sections 8 ₁ to 8n, which are formed in the same manner as described above, are arranged in each of the detection sections 4 ₁ to 4n, respectively.

In the case of this embodiment as well, _the respective optical transmission bodies _{5 1}
By passing light through .about.5n, leakage points in the fluid transport path 3 can be detected as in the previous embodiment.

Next, a third embodiment of the present invention will be explained with reference to FIG. 3. In this embodiment, each detection section 4 ₁ to 4
The state of fluid leakage at point n can be detected using different optical signals for each detection section.In this case, in the longitudinal direction of the fluid transport path 3, there are multiple flexible The optical transmission bodies 5 ₁ to 5 ₄ are disposed, and in each detection section 4 ₁ to 4 n, interference receiving parts 8 a , 8 b , 8 c , 8 of the optical transmission bodies 5 ₁ to 5 ₄ are arranged.
d, 8e, 8f, 8g, 8h, and 8i are arranged as shown in the figure, and a single light transmitter 6 is attached to the light transmitting end of each optical transmitter ₅₁ to ₅₄ , and a single light transmitter 6 is attached to the light receiving end side of each optical transmitter 51 to 54. is equipped with a light receiver 7, a logic circuit 9, and a display 10 that operates based on the light receiver 7.

In this embodiment, assuming that there is no leakage in each of the detection sections 4 ₁ to 4n, the light receiver 7 has "0000".
A normal signal is now input, and this is the logic circuit 9.
If there is leakage in the detection section ₄₁ , the interference receiver 8a is shielded and a leakage signal of "1000" is displayed on the display _10. ,4 ₃ ...4n leakage,
The interference receivers in each section are blocked, and the signals are "0100", "0010"..."0101", "1010", "1001"
Accordingly, depending on the type of this signal appearing at the light receiving end, it is possible to determine whether or not there is a leak in the fluid transport path 3, and if there is a leak, the location of the leak can be determined. You will be able to tell where it is. At this time, the number of sections that can be detected is 2 ⁿ -1 for the number of codes n.

The above description relates to a method of detecting a leakage point in the fluid transport path 3, but when this is specifically implemented, the means shown in FIG. 4 and subsequent figures are adopted.

First, referring to FIG. 4 and FIG.
In the lower part of the space 11, that is, in the longitudinal direction below the fluid transport path 3, the optical transmission bodies 5 _{1 to 5} in FIGS. 5n, or the optical transmission bodies _{51 to 54} in FIG. In order to correspond to each of the above-mentioned embodiments, the interference receivers 8 _{and 1} shown in FIGS. 1 and 2, respectively.
.about.8n, or the interference receivers 8a to 8i shown in FIG. 3 are arranged.

In this case, the detection sections 4 ₁ to 4n are adjacent to each other in the longitudinal direction of the fluid transport path 3;
Since there is a possibility that leakage fluid generated within a certain detection section may intrude into the detection sections on both sides thereof, a partition member 13 may be provided at the boundary of each of the detection sections 4 ₁ to 4 n in order to prevent this. be.

Furthermore, the optical transmission bodies 5 ₁ to 5n used here are
As briefly explained above, it is a multi-core optical cable made of an optical fiber (single-core cable) or an aggregate of optical fibers, and the interference receiving part ₈₁ of the optical transmission body ₅₁ is located in the above-mentioned separation space. In the case where the interference receiving part ₈₁ is formed in such a manner, as _shown in _FIG . A sleeve 15 having a through hole 14 may be attached to the interference receiving portion ₈₁ so that the interference can be collected.

Of course, similar means are provided in each of the interference receiving units of the other optical transmission bodies 5 ₂ to 5n.

Further, each of the optical transmission bodies 5 ₁ to 5n may be housed in a protective tube 18 as shown in FIG. 7, or embedded in a tape-shaped resin protective layer 19 as shown in FIG. As shown in Fig. 9, the adhesive member 20 may cause the fluid to collect, so when these reinforcing means are provided, openings should be provided at predetermined locations in each protection member so that the leakage fluid can sufficiently spread to each interference receiving part. Communicating parts such as sections, cuts, and spaces are now provided.

Furthermore, as another means for protecting each optical transmission body, as shown in _FIG .
The part where the interference receiving part is located is covered with a covering member 21 that is breathable and liquid permeable, such as a mesh metal, and the other parts are covered with a covering member 22 that is not breathable or liquid permeable, such as synthetic resin. Sometimes.

Note that when each of the optical transmission bodies 5 ₁ to 5n is housed in the protection tube 18 as shown in FIG. Therefore, in order to prevent this, as shown in FIG. 11, the protective cylinder 18 is filled with a mixture 23 that has a fluid blocking effect, except for the areas where each interference receiving part is located, or this mixture is 23 may be filled with a member that significantly impedes fluid circulation, such as sponge-like rubber, plastic, felt, or other fibrous material.

In addition, the communication part of the protection tube 18 in FIG.
In this FIG. 11, reference numeral 24 indicates.

Since the present invention is as described above, the following characteristic effects can be obtained.

In other words, since this is a method and device for detecting leakage points in fluid transport channels mainly using flexible optical transmission bodies such as optical fibers and optical cables, it is possible to detect leakage points in locations where the space between the light transmitter and the light receiver cannot be seen through. In addition, compared to electrical detection methods, it is possible to realize highly sensitive detection with almost no external influences such as noise and immediate response to leakage. Since the transmission state is simply interrupted or the amount of light is attenuated, there is no possibility of malfunctions occurring.

Furthermore, the interference receiving part of the optical transmission body may be a separated space into which leaked fluid can freely enter, and therefore the optical transmission body itself does not need to be made of a special material that can be dissolved by the fluid, and a special detection element is not required. In this respect, there is no increase in the number of parts or complication of the structure, and the optical transmission body itself is small in diameter and lightweight, so even if it were to be made into a concrete device. In addition, since the device does not require a large-scale equipment and is economical, and the interference receiving section is constituted by a separation space, the object to be detected can be either a liquid or a gas, and is versatile.

Furthermore, even in the case of ensuring leakage detection at the interference receiver, that is, light blocking and attenuation of light intensity, the various means shown in the embodiments can sufficiently increase accuracy and provide satisfactory reliability in terms of performance. Moreover, since the main component is an optical transmission medium that does not change over time, high performance can be maintained for a long time.

[Brief explanation of the drawing]

1 to 3 are schematic explanatory diagrams showing various embodiments of the method and apparatus of the present invention, FIG. 4 is an explanatory diagram for embodying the same apparatus, and FIGS. 5 to 11 are schematic illustrations of the same apparatus. It is a partial explanatory view showing various embodiments when embodying. 3...Fluid transport path, ₄₁ to 4n...Detection section,
5 ₁ to 5n... optical transmission body, 8 ₁ to 8n and 8a
~8i... interference receiving section, 11... space section, 12...
Mantle, 13... Partition member, 14... Through hole, 15...
...Sleeve, 18...Protective tube, 19...Protective layer,
20... Adhesive member, 21, 22... Covering member, 2
3...Admixture, 24...Communication part.

Claims (1)

[Scope of Claims] 1. A plurality of flexible optical transmission bodies arranged in parallel are each provided with an interference reception portion formed by a separation space through which leakage fluid can freely enter, and each of the optical transmission bodies is At least one of the interference receiving parts is arranged in each of a plurality of detection sections set in the longitudinal direction below the outer periphery of the fluid transport path, and each of the optical transmission bodies has a distance from its light transmitting end to its light receiving end. The optical transmission disturbance state of the optical transmission body, where the light is blocked or the amount of light is attenuated due to fluid leaking in any of the above detection sections entering the interference receiving section in that section, is detected at the light receiving end side of the optical transmission body. A method for detecting a leak point in a fluid transport path, characterized in that the leak point in the fluid transport path is detected by displaying the information. 2. As a means of displaying the optical transmission disturbance state of each optical transmission body in each detection section on its light receiving end side, the light blocking or light intensity attenuation state appearing on the light receiving end side and the state without this are indicated by separate optical signals. A method for detecting a leakage point in a fluid transport path according to claim 1, wherein the leakage point is taken out. 3 A space is provided on the outer periphery of the fluid transport path, and a mantle is provided, and a plurality of detection sections are provided to divide the inside of the space in the longitudinal direction, and a plurality of flexible detection sections arranged in parallel with each other are provided. Each of the optical transmission bodies is provided with an interference receiving section formed by a separation space into which leakage fluid can freely enter, and at least one interference receiving section among the interference receiving sections of the plurality of optical transmission bodies is provided below each of the detection sections. A leakage point detection device for a fluid transport path, characterized in that each of the leakage point detection devices are arranged. 4. The leak point detection device for a fluid export path according to claim 3, wherein a sleeve having a through hole is attached to the interference receiving portion of the optical transmission body formed by the space. 5. The outer periphery of the interference receiving part of the optical transmitter is covered with a covering member that is breathable or liquid-permeable, and the other outer periphery of the optical transmitter is covered with a covering member that is non-air permeable or liquid-impermeable. A leakage point detection device for a fluid transport path according to claim 3, characterized in that: 6. A leakage point in a fluid transport path according to claim 3, characterized in that the outer periphery of the optical transmission body is covered with a protective member, and the protective member is provided with a communicating part that communicates with the interference receiving part. Detection device. 7. The leak point detection device for a fluid transport path according to claim 3, characterized in that a partition member is provided at the boundary of each detection section provided on the longitudinal outer periphery of the fluid transport path. 8. The outer periphery of the optical transmission body is covered with a cylindrical protection member, and the protection member is filled with a member that blocks or obstructs the flow of fluid except for the interference receiving part of the optical transmission body. A leak point detection device for a fluid transport path according to claim 6.