Water ingress detection module

Abstract

The purpose of the present invention is to provide a water ingress module that achieves an improvement in maintainability and an increase in the number of detectable water ingress locations. A water ingress detection module 25 according to the present invention comprises: a container 25a; an introduction part 25b for dripping a liquid outside the container 25a into the container 25a from an upper portion of the container 25a; and a vibrator 25c for transmitting vibrations generated due to contact with the liquid dripped from the introduction part 25b to a detection member. The water ingress module according to the present invention is configured such that an optical fiber is not subjected to bending but is subjected to vibrations, and an optical tester detects the location of the vibrations.

Description

Water Ingress Detection Module

[0001] The present disclosure relates to a water ingress detection module for detecting water ingress in structures such as manholes.

[0002] FIG. 1 is a diagram for explaining a related water ingress detection system. The water ingress detection system is composed of an optical tester 10 and a water ingress detection module 20, and has a function of detecting water ingress in the manhole 5. The water ingress detection module 20 is installed in the optical fiber 50 in each manhole 5. The optical tester 10 is an OTDR (Optical Time Domain Reflectometer) that measures the optical loss in the longitudinal direction of the optical fiber by injecting test light into the optical fiber and receiving the backscattered light propagating in the opposite direction to the incident direction. The water ingress detection module 20 includes an expander 21 that swells due to moisture inside, and has a function of applying a bending γ to the optical fiber 50 with the swollen expander 21 when the manhole 5 is flooded.

[0003] As shown in the test result display of FIG. 1, the optical tester 10 can detect the bending loss due to the bending γ from the received level of the backscattered light, and can grasp that water ingress has occurred in the manhole 5 existing at position B from the distance.

[0004] "Identification Technology of Outdoor Optical Wiring Equipment for Advanced Optical Equipment Operation", NTT Technical Journal 2009.11

[0005] In the water ingress detection system of FIG. 1, the expander 21 included in the water ingress detection module 20 cannot be reused, and it takes costs and man-hours for replacement work and the like, and there are problems in maintainability. Further, since the water ingress detection system of FIG. 1 detects water ingress by the bending loss of the optical fiber, there is a limit to the received level of the backscattered light received by the optical tester 10, and the number of flooded manholes that can be detected simultaneously is limited. That is, the water ingress detection system of FIG. 1 also has a problem that it is difficult to increase the detectable number.

[0006] An object of the present invention is to provide a water ingress module that can improve maintainability and increase the number of detectable water ingress locations in order to solve the above problems.

[0007] To achieve the above objective, the immersion module according to the present invention is configured to apply vibration to the optical fiber rather than bending it, and an optical tester detects the location of the vibration.

[0008] Specifically, the immersion module according to the present invention comprises: a container; an introduction section for dripping liquid from outside the container into the container from the top of the container; and a vibrator that transmits vibrations generated by the liquid dripped from the introduction section to a sensing member.

[0009] Initially, when the manhole is flooded, no water enters the container. However, when the water level rises to the inlet at the top of the flood module, water enters the container through the inlet and drips into it. The dripping water falls onto a transducer, causing it to vibrate, and this vibration is transmitted to the optical fiber, which is the sensing element. It is preferable to use a Distributed Acoustic Sensing (DAS) optical tester capable of measuring the time variation of vibration along the longitudinal direction of the optical fiber to detect this vibration. The vibration continues until the transducer inside the container is submerged. The inlet is a component located at the top of the container and has an inverted cone shape with a hole at the bottom through which liquid passes. For example, the inlet is a funnel.

[0010] Furthermore, the immersion module according to the present invention may be configured to include a container and an introduction unit that drips liquid from outside the container into the container from the top of the container and vibrates a sensing member with the dripped liquid.

[0011] Alternatively, instead of using a transducer, the system could be configured so that water dripped into the container directly falls onto the optical fiber, which acts as the detection element. The dripping water itself can cause vibrations in the optical fiber, which can then be detected by the DAS (Digital Absorbing Sensor). The vibrations will continue until the optical fiber inside the container is submerged in water.

[0012] This flood-proof module is reusable because it does not contain an expanding agent. In other words, this flood-proof module solves the maintenance problem. Furthermore, because this flood-proof module applies vibration rather than bending to the optical fiber at the flooded area, the attenuation of the light intensity of backscattered light is small, and the number of flooded areas that can be detected can be increased.

[0013] Therefore, the present invention can provide a flood module that can improve maintainability and increase the number of detectable flooded areas.

[0014] The flooding module according to the present invention preferably further comprises a check valve located at the bottom of the container for discharging the liquid accumulated in the container. When the flooding is resolved, the water inside the container can be easily drained through the check valve.

[0015] The container of the flood-proof module according to the present invention preferably has a ventilation opening that allows air to enter and exit between the inside and outside. Allowing air to enter and exit the container facilitates the dripping of water during flooding and the drainage of water when flooding is resolved.

[0016] Furthermore, the above inventions can be combined as much as possible.

[0017] This invention provides a flood module that can improve maintainability and increase the number of detectable flooded areas.

[0018] This is a diagram illustrating a related flood detection system. This is a diagram illustrating a flood detection system equipped with a flood detection module according to the present invention. This is a diagram illustrating a flood detection system equipped with a flood detection module according to the present invention. This is a diagram illustrating a flood detection system equipped with a flood detection module according to the present invention. This is a diagram illustrating a flood detection system equipped with a flood detection module according to the present invention.

[0019] Embodiments of the present invention will be described with reference to the attached drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to these embodiments. In this specification and in the drawings, components with the same reference numerals refer to the same components.

[0020] (Embodiment 1) Figure 2 is a diagram illustrating the flood detection system of this embodiment. This flood detection system consists of a vibration-type flood detection module 25, an optical tester 10, a computer 11, a storage device 12, a network 14, and a user terminal 13. The flood detection module 25 is a device that is placed in a structure such as a manhole and applies vibration to the optical fiber 50 when the structure is flooded. The optical tester 10 is a device that detects vibration of the optical fiber 50, and a DAS is preferred. The computer 11 includes a processor and memory connected to the processor. The processor is an electronic device composed of logic circuits that respond to and execute instructions. The memory is a tangible storage medium readable by a computer in which a computer program is encoded. One of the components of the memory is the program. The computer 11 outputs the result of executing the program stored in the memory to the user terminal 13. The network 14 is a data communication network. Communication is performed via the network using electronic signals and optical signals. This flood detection system includes a user terminal 13 that is operated by a user and connected to a computer 11 via a network 14. The optical tester 10, computer 11, storage device 12, network 14, and user terminal 13 are based on known technologies.

[0021] (Embodiment 2) Figure 3 is a diagram illustrating a flood detection system equipped with a flood detection module 25 of this embodiment. The flood detection module 25 comprises a container 25a, an introduction section 25b that drips liquid from outside the container 25a into the container 25a from the top of the container 25a, and a vibrator 25c that transmits vibrations generated by the liquid dripped from the introduction section 25b to a detection member. The introduction section 25b is, for example, a funnel. The liquid is, for example, water that has flowed into the manhole 5. The detection member is an optical fiber 50.

[0022] This flood detection system has the functions of "generating vibrations in the optical fiber when water dripping from the inlet hits a transducer" and "measuring vibrations in the longitudinal direction of the optical fiber."

[0023] The function of "generating vibrations in the optical fiber by having water dripped from the inlet hit the transducer" is as follows: Initially, when the manhole 5 is flooded, the inside of the container 25a of the flood detection module 25 remains filled with air. Subsequently, when the water level in the manhole 5 rises to the top of the flood detection module 25, the water enters from the inlet 25b installed at the top of the container 25a and begins to drip inside the container 25a. The dripped water droplets w hit the transducer 25c inside the container 25a, causing the transducer 25c to vibrate. This vibration is transmitted to the optical fiber 50. This vibration continues until the transducer 25c inside the container 25a is submerged in water. In other words, the function of "generating vibrations in the optical fiber by having water dripped from the inlet hit the transducer" enables flood detection using vibrations different from conventional methods.

[0024] The "vibration measurement in the longitudinal direction of the optical fiber" function can be implemented using DAS. Since vibration occurs in the portion of the optical fiber 50 that passes through the flooded manhole 5, the measurement results of the optical tester 10 allow for confirmation of the change in vibration amplitude at distance B relative to other locations, as shown in the test result display in Figure 3. In other words, the worker can recognize from the test result display that flooding has occurred in the manhole 5 at distance B.

[0025] Furthermore, the flood detection module 25 is located at the bottom of the container 25a and preferably includes a backflow prevention valve 25d for draining the liquid accumulated in the container 25a. When the flooding is resolved, the water inside the container can be easily drained through the backflow prevention valve 25d. Draining the water from inside the container makes it possible to reuse the flood detection module 25.

[0026] (Embodiment 3) Figure 4 is a diagram illustrating a flood detection system equipped with the flood detection module 25 of this embodiment. The flood detection module 25 comprises a container 25a and an introduction section 25b that drips liquid from outside the container 25a into the container 25a from the top of the container 25a and vibrates a detection member with the dripped liquid.

[0027] The water ingress detection module 25 differs from the water ingress detection module 25 in Figure 3 in that the water droplets dripped from the introduction section 25b directly hit the optical fiber 50 instead of the transducer, causing the optical fiber 50 to vibrate. In other words, in this embodiment, the function of "generating vibration in the optical fiber by having water dripped from the introduction section hit the optical fiber" enables water ingress detection using vibration, which is different from conventional methods.

[0028] The function of "vibration measurement in the longitudinal direction of the optical fiber" and the backflow prevention valve 25d are the same as in Embodiment 1.

[0029] (Embodiment 4) Figure 5 is a diagram illustrating a flood detection system equipped with the flood detection module 25 of this embodiment. The flood detection module 25 of this embodiment is the same as the flood detection module 25 described in Embodiment 2 or 3, characterized in that the container 25a has a ventilation opening 25e that allows air to enter and exit between the inside and outside. By providing a ventilation opening 25e on the side of the container 25a that releases the air inside the container 25a to the outside, water droplets W can be smoothly dripped from the introduction part 25b, the optical fiber 50 can be continuously vibrated, and it becomes easier to detect flooding of the manhole 5.

[0030] Figure 5 shows a structure in which the flood detection module 25 described in Embodiment 2 is equipped with a ventilation opening 25e, but the flood detection module 25 described in Embodiment 3 may also be equipped with a ventilation opening 25e.

[0031] (Effects of the Invention) The present invention determines whether water has entered the optical fiber by generating vibrations in the optical fiber with a dripped water droplet and detecting these vibrations with a DAS. In other words, the above-described water ingress detection module 25 has the function of generating vibrations in the detection member (optical fiber 50) by dripping water droplets into a sealed space (container 25a) when the water level in the external space rises, and applying the water droplets to the vibrator attached to the detection member (optical fiber 50) or directly to the detection member (optical fiber 50).

[0032] This invention makes it possible to reuse the flood detection module. Furthermore, the number of flooded manholes can be measured simultaneously at multiple locations, as long as they are within the measurable distance of the optical tester.

[0033] Although this specification describes a flood detection module installed in a manhole, the flood detection module of the present invention is not limited to manholes and can be installed in any type of closure that is susceptible to flooding.

[0034] 5: Manhole 10: Optical tester 11: Computer 12: Storage device 13: User terminal 14: Network 15: Display unit 20: Flood detection module 21: Expanding agent 25: Flood detection module 25a: Container 25b: Inlet 25c: Transducer 25d: Backflow prevention valve 25e: Ventilation opening 50: Optical fiber

Claims

1. A water ingress detection module comprising: a container; an introduction section for dripping liquid from the outside of the container into the inside of the container from the top of the container; and a vibrator that transmits vibrations generated by the liquid dripped from the introduction section to a detection member.

2. A water ingress detection module comprising: a container; and an introduction unit that drips liquid from outside the container into the container from the top of the container and vibrates a detection member with the dripped liquid.

3. The flood detection module according to claim 1 or 2, further comprising a backflow prevention valve located at the bottom of the container for discharging the liquid accumulated in the container.

4. The immersion detection module according to claim 1 or 2, characterized in that the container has a ventilation opening for the exchange of air between the inside and outside.

Images