JPH08278433A - Method for laying optical sensor fiber cable - Google Patents

Abstract

PURPOSE: To provide a method for laying an optical sensor fiber cable having a protective effect without impairing the temp. measuring performance of the optical sensor fiber cable and without degrading the laying efficiency of the optical sensor fiber cable. CONSTITUTION: A tube 1 is provided with a slit 3 at one point in a longitudinal direction over the entire length. A lead-in line 4 is fused to the front end 2a of the optical sensor fiber cable 2. The tube 1 is formed of a soft material imparting less friction to the coating material of the optical sensor fiber cable 2. The lead-in line 4 is put into the tube 1 from the slit 3 and the optical sensor fiber cable 2 is withdrawn into the tube 1 by pulling the lead-in line 4, by which the optical sensor fiber cable 2 is inserted into the tube 1 when the optical sensor fiber cable 2 is inserted into the tube. The tube 1 in the measuring part of the optical sensor fiber cable 2 is thereafter removed and temp. measurement is executed in the removed part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to plant component equipment such as tanks, pipes and valves in industrial facilities such as power plants such as nuclear power and thermal power plants and chemical plants, or an optical fiber temperature distribution measuring device for measuring the area ambient temperature. The present invention relates to a method of laying an optical sensor fiber cable.

[0002]

2. Description of the Related Art A conventional optical cable laying method is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-316004, which is an assembly of plastic hollow pipes having a lead-in wire built into a planned route of laying in advance. Is installed, and then the optical fiber cable is inserted into each hollow pipe. Such a method of laying an optical fiber cable has been performed for an optical fiber for communication or data transmission.

As another laying method, there is a laying method using an existing structural material. This method is disclosed, for example, in JP-A-57-141597,
Install a pipe, conduit or cable tray in the remaining space of the beam of the steel structure inside the nuclear power plant containment vessel, pass an optical fiber cable through the pipe or conduit, or place an optical fiber cable on the cable tray. It is to put it.

On the other hand, there is known an optical fiber temperature distribution measuring device utilizing the temperature dependence of backscattered light such as Raman scattered light. Since this type of optical fiber temperature distribution measuring device can measure the temperature distribution in the length direction of the optical fiber cable, the optical fiber cable itself may be used as a temperature sensor. That is, the optical fiber temperature distribution measuring device utilizes the fact that the light intensity of backscattered light such as Raman scattered light or Rayleigh scattered light generated when pulsed light is incident on the optical fiber has temperature dependence, Since it is a temperature sensor itself, it is possible to measure the temperature distribution in the cable longitudinal direction. As the optical fiber, various single mode and multimode fibers are used. The coating of the optical fiber cable changes depending on the environment of the measurement location, but PVC coating or polyimide coating is used.

[0005]

By the way, when such an optical sensor fiber cable is installed by the conventional laying method as described above, for example, when the optical sensor fiber cable is inserted into a pipe such as a conduit or a plastic pipe as in the former case. In addition, although the optical sensor fiber cable has an excellent protective effect, the space between the optical sensor fiber cable and the tube wall and the tube wall block outside air, and the temperature measurement performance is deteriorated. On the other hand, if the tray is installed instead of the tube like the latter, the cable can be protected without deteriorating the temperature measurement performance, but since the tray has a larger occupied area than the tube, the optical sensor fiber When laying a cable, the laying efficiency becomes worse than that of a pipe. Moreover, if the optical sensor fiber cable is simply placed on the tray, the optical sensor fiber cable may be damaged from the opened upper portion.

The present invention has been made in view of the above-mentioned circumstances of the prior art, and an object thereof is to efficiently install an optical sensor fiber cable without impairing the temperature measurement performance of the optical sensor fiber cable. Another object of the present invention is to provide a method of laying an optical sensor fiber cable that can be used.
Another object of the present invention is to provide a method of laying an optical sensor fiber cable which is excellent in protection and is not damaged by others.

[0007]

Among the above objects, regarding the temperature measurement performance and the installation efficiency, after inserting the optical sensor fiber cable into a flexible tube, the tube of the temperature measurement portion is removed and the cable is exposed. To be achieved. For protection, fix the optical sensor fiber cable to the mountain steel with wedge-shaped slits on one side of the web at appropriate intervals, or fix the optical sensor fiber cable of the beam of the existing structural material to the remaining space that can be protected. It is achieved by doing.

[0008] Specifically, in order to achieve the above object, the first means is a method of laying an optical sensor fiber cable at a desired place in a facility, in which a slit is provided in the longitudinal direction. It is characterized in that the flexible tube is installed in advance in a desired laying route and then the optical fiber cable is inserted into the tube.

The second means is the first means, in which the optical sensor fiber cable is inserted into the tube by binding a lead wire to one end of the optical sensor fiber cable and connecting the lead wire to the slit. Is inserted into the tube, and then the pull-in wire is pulled to pull the optical sensor fiber cable into the tube.

The third means is the same as the first means, except that the optical sensor fiber cable is inserted through the tube, and then the tube of the measuring portion is moved from the outer peripheral portion of the optical sensor fiber cable by the optical sensor fiber cable. It is characterized by being removed.

The fourth means is characterized in that, in the third means, the portion of the tube which remains without being removed from the outer peripheral portion of the optical sensor fiber cable is fixed by gripping the outer peripheral portion of the tube with a metal fitting. I am trying.

Further, the fifth means is characterized in that, in the fourth means, the metal fitting is fixed by attaching it to a mountain steel having wedge-shaped slits formed on one side of the web at appropriate intervals.

Further, the sixth means is characterized in that, in the fourth means, the metal fitting is fixed by mounting it in the remaining space of the beam of the existing structural material.

[0014]

The flexible tube to be laid in advance can improve the insertion performance and the layability by selecting a material having a small friction coefficient with the outer cover of the optical sensor fiber cable. In addition, by forming a slit in the length direction of the tube, it is possible to easily remove the tube that does not need the temperature measurement unit. The remaining tube becomes a buffer layer when fixing the cable, and it is possible to prevent excessive external force from being applied to the cable.

The mountain steel in which wedge-shaped slits are formed on one side of the web at appropriate intervals has a small cross-sectional area at the place where the slits are formed, so that the web can be easily plastically deformed by hand, and the optical sensor fiber Support and protection can be provided according to the bent portion of the cable. Alternatively, it can be achieved by fixing the optical sensor fiber cable of the beam of the existing structural material to the remaining space that can be protected.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

1A and 1B are views showing a method of laying an optical sensor fiber cable according to an embodiment of the present invention. FIG. 1A is a perspective view of a main part and FIG. 1B is a sectional view taken along the line AA. is there. FIG.
In the above, the tube 1 is provided with one slit 3 in the longitudinal direction over the entire length thereof, and by opening the slit 3, an object can be put into the tube 1. On the other hand, the optical sensor fiber cable 2 has a lead-in wire 4 bound to the tip 2a. The tube 1 is made of a flexible material (for example, a synthetic resin such as a vinyl chloride admixture) that has little friction with the covering material of the optical sensor fiber cable 2. If the tube 1 and the optical sensor fiber cable 2 are configured in this way, when inserting the optical sensor fiber cable 2 into the tube 1, first insert the lead-in wire 4 into the tube 1 from the slit 3 and pull the lead-in wire 4. Pull the optical sensor fiber cable 2 into the tube 1 and
Is inserted into the tube 1. Therefore, it is not necessary to pass the optical sensor fiber cable 2 through the tube 1 in advance. Therefore, when laying in the facility, first,
The tube is routed along the laying point, and the optical sensor fiber cable 2 is inserted as described above.

After inserting the optical sensor fiber cable 2, the tube 1 other than the fixed portion of the optical sensor fiber cable 2 is removed as shown in FIG. The reason for removing is that the measuring performance of the temperature measuring portion is not deteriorated, but upon removing, the tube 1 is opened from the slit 3 portion, and the tube at that portion is cut and removed. The tube 1 left without being removed is sandwiched between the grip 5 and the optical sensor fiber cable 2 as a cushioning material as shown in the sectional view of FIG. In this figure, the tube 1 is wound around the optical sensor fiber cable 2 in multiple layers, and is clamped from above with the grip fitting 5. This is because the inner diameter of the tube is formed relatively larger than the outer diameter of the optical sensor fiber cable 2 so that the frictional force does not become large when the optical sensor fiber cable 2 is pulled in, as shown in FIG. 1B. Thus, the smaller the inner diameter, the smaller the number of turns. The grip fitting is not limited to the structure shown in FIG. 3, and various clamps can be used. In addition, in FIG. 2, the tube 1 at a portion other than the portion gripped by the grip fitting 5 is shown.
Although the tube 1 has been removed, at the time of laying, the tube 1 is removed only at the portion necessary for temperature measurement, and the other portion is left covered with the tube 1. This enables accurate temperature measurement.

FIG. 4 shows the structure of the angle steel 7 for protecting and fixing the optical sensor fiber cable 2. FIG. 4A is a perspective view, and FIG. 4B is a sectional view taken along line BB of FIG.
The angle steel 7 has wedge-shaped slits 8 formed on one side of the web 7a at appropriate intervals. The interval between the wedge-shaped slits 8 and the depth of the wedge-shaped slits 8 are appropriately selected, and the wedge-shaped slits 8 are bent to plastically deform to obtain an arbitrary curvature. As can be seen from FIG. 4 (b), the grip 5 is fixed to the web 7 b having no wedge-shaped slit 8 by bolts 6. The bolt 6 may be a screw or a screw. By doing so, the optical sensor fiber cable 2 is covered with the angle steel 7, so that the optical sensor fiber cable 2 is effectively protected from the outside.

The shape of the wedge-shaped slit 8 is shown in FIG. That is, the slit is shaped like a wedge, and when the mountain steel 7 is bent inwardly with respect to the wedge-shaped slit 8 as shown in FIG. 4 (a), the wedge-shaped webs are prevented from hitting each other. The angle θ of the slit 8 is selected.
Further, the tip of the wedge-shaped slit 8 may be rounded so that stress is not concentrated. The cutting depth L'of the slit 8 is
It depends on the degree of bending of the angle steel 7. Usually, it may be about 1/2 of the width L of the web.

FIG. 6 shows an example in which the optical sensor fiber cable 2 is laid in the remaining space of the H steel which is an existing steel frame structure.
FIG. 6A is a sectional view of H steel, and FIG. 6B is a side view thereof. As can be seen from FIG. 6, the optical sensor fiber cable gripping fixture 5 is sandwiched and fixed to the H steel 9 web by the holding bolt 11 for the H fixture 9 of the fixing fixture 10. The installation interval of the fixing metal fittings 10 can be arbitrarily determined according to the situation. By doing so, the H steel 9 can be easily installed without the need for drilling a fixing bolt hole. Further, since the optical sensor fiber cable 2 is extremely thin and lightweight, it can be fixed by an adhesive tape or the like instead of the grip fitting 5. Needless to say, not only the H steel 9 but also an existing steel material having a space portion capable of protecting the optical sensor fiber cable 2 can be installed and used.

[0022]

As described above, the present invention has the following effects.

That is, according to the invention of claim 1,
A flexible tube with a slit in the length direction is installed in advance in a desired installation route, and then the optical sensor fiber cable is inserted into the tube, so the man-hours associated with installation can be reduced, and the efficiency is high. The optical sensor fiber cable can be installed.

According to the second aspect of the present invention, the lead-in wire is bound to one end of the optical sensor fiber cable, the lead-in wire is inserted into the tube through the slit, and then the lead-in wire is pulled to form the optical sensor fiber cable. Since the optical sensor fiber cable is drawn into the tube, the optical sensor fiber cable can be mounted after the routing, and the optical sensor fiber cable can be efficiently laid.

According to the third aspect of the present invention, after the optical sensor fiber cable is inserted into the tube, the tube of the measuring portion is removed from the outer peripheral portion of the optical sensor fiber cable by the optical sensor fiber cable. Can be set accurately and efficiently.

According to the fourth aspect of the invention, since the portion of the tube which remains without being removed from the outer peripheral portion of the optical sensor fiber cable is gripped and fixed from the outer periphery of the tube by the metal fitting, the light can be easily and efficiently provided. The sensor fiber cable can be attached.

According to the invention as set forth in claim 5, since the fixing metal fittings are attached to the mountain steel in which wedge-shaped slits are formed in the web on one side at appropriate intervals, the mounting can be performed easily and the optical sensor can be formed by the mountain steel. The fiber cable can be surely protected.

According to the sixth aspect of the present invention, since the fixing metal fitting is attached to the remaining space of the beam of the existing structural material, the beam can surely protect the optical sensor fiber cable.

[Brief description of drawings]

FIG. 1 is a diagram showing a method of laying an optical sensor fiber cable according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which an unnecessary portion of the tube of the optical sensor fiber cable in the example is removed.

FIG. 3 is a cross-sectional view showing a state in which an optical sensor fiber cable is fixed by a holding metal fitting in the embodiment.

FIG. 4 is a diagram showing an example in which angle steel is laid and used as a protection member for an optical sensor fiber cable.

FIG. 5 is a plan view showing a state of slits of angle steel according to the example.

FIG. 6 is a diagram showing an example in which an optical sensor fiber cable is laid using the remaining space of H steel.

[Explanation of symbols]

 1 Tube 2 Optical Sensor Fiber Cable 2a Tip of Optical Sensor Fiber Cable 3 Slit 4 Lead-in Wire 5 Grip Metal Fitting 6 Bolt 7 Angle Steel 7a, 7b Web 8 Wedge Slit 9 H Steel 10 Fixing Metal Fitting 11 Holding Bolt

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shigeo Otake 3-2-2, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Engineering Service Co., Ltd.

Claims (6)

[Claims] 1. A method of laying an optical sensor fiber cable for laying an optical sensor fiber cable at a desired location in a facility, wherein a flexible tube having a slit in a length direction is previously installed at a desired laying route, and thereafter, An optical sensor fiber cable laying method, wherein an optical fiber cable is inserted into the tube. 2. The optical sensor fiber cable is inserted into the tube by binding a lead-in wire to one end of the optical sensor fiber cable, inserting the lead-in wire into the tube through the slit, and then inserting the lead-in wire. The optical sensor fiber cable laying method according to claim 1, wherein the optical sensor fiber cable is pulled by pulling the optical sensor fiber cable into the tube. 3. The optical sensor fiber cable is inserted through the tube, and then the tube of the measurement portion is removed from the outer peripheral portion of the optical sensor fiber cable by the optical sensor fiber cable. Optical sensor fiber cable laying method. 4. The optical sensor fiber cable according to claim 3, wherein a portion of the tube, which is left without being removed from the outer peripheral portion of the optical sensor fiber cable, is gripped and fixed from the outer periphery of the tube by a metal fitting. How to lay. 5. The optical sensor fiber cable laying according to claim 4, wherein the fixing is performed by attaching the metal fittings to a mountain steel having wedge-shaped slits formed on one side of the web at appropriate intervals. Method. 6. The optical sensor fiber cable laying method according to claim 4, wherein the fixing is performed by attaching the metal fitting to the remaining space of the beam of the existing structural material.