Inspection method for cable tray

Abstract

To detect leakage of a fire-extinguishing agent in a cable tray.SOLUTION: An inspection method for a cable tray fire-extinguishing facility comprises: a cable tray that holds a cable; a sensing tube that is provided in the cable tray and melted by heat of a fire, and has a fire-extinguishing agent inside; an open type injection nozzle that is provided in the cable tray and discharges the fire-extinguishing agent; a covering member that covers the cable tray; and a pipe capable of supplying the fire-extinguishing agent to the injection nozzle. The method includes the steps of: sucking the fire-extinguishing agent in the cable tray through the pipe and the injection nozzle; and analyzing the sucked fire-extinguishing agent to detect leakage of the fire-extinguishing agent.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for inspecting a cable tray. [Background technology]

[0002] A conventional cable tray is disclosed, for example, in JP 2022-48318 A (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-48318 Summary of the Invention [Problem to be solved by the invention]

[0004] With conventional cable trays, it is difficult to detect leaks of fire extinguishing agent. [Means for solving the problem]

[0005] The inspection method for cable tray is as follows: a cable tray for holding the cables; A sensing tube having a fire extinguishing agent therein, the sensing tube being provided in the cable tray and melting due to heat of a fire; An open-type injection nozzle provided in the cable tray for discharging a fire extinguishing agent; A covering member for covering the cable tray; A method for inspecting a cable tray fire extinguishing system comprising: sucking gas from within the cable tray through the piping and the injection nozzle; and analyzing the aspirated gas to detect leakage of the extinguishing agent.

[0006] In the cable tray inspection method including the above steps, the fire extinguishing agent in the cable tray can be sucked by using a conventional open-type injection nozzle and piping, so that the fire extinguishing agent in the cable tray can be analyzed and the leakage of the fire extinguishing agent can be inspected without disassembling the cable tray.

[0007] Preferably, the step of detecting leakage of the extinguishing agent includes irradiating the aspirated gas with laser light and detecting leakage of the extinguishing agent based on a Raman scattering wavelength having a peak characteristic specific to the extinguishing agent.

[0008] In this case, the peak of the Raman scattering wavelength is sufficiently large to reliably detect the leakage of the extinguishing agent. Note that the extinguishing agent can be detected not only by resonance Raman scattering light but also by simple Raman scattering depending on the concentration.

[0009] Preferably, the extinguishing agent comprises CF3CF2C(O)CF(CF3)2. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a cable tray fire extinguishing system 60 according to a first embodiment. [Diagram 2] 1 is a front view of a container support 20 according to a first embodiment. [Diagram 3] 4A to 4C are diagrams illustrating an inspection method for a cable tray fire extinguishing system 60 according to the first embodiment. [Figure 4] 1 is a schematic diagram showing a process of gas analysis using an optical gas sensor 101. FIG. [Diagram 5] 1 is a graph showing the characteristics of a fire extinguishing agent (FK-5-1-12), and a graph showing a resonance Raman spectrum. [Figure 6] FIG. 11 shows a method and apparatus for measuring extinguishing agent leakage using a remote sensing device 201 according to a second embodiment. [Figure 7] FIG. 11 is a diagram showing a method and apparatus for measuring leakage of extinguishing agent from a multi-stage cable tray 31 using a remote measurement device 201 according to a second embodiment. [Figure 8] FIG. 11 is a block diagram showing a configuration of a remote measurement device 201 according to a second embodiment. [Figure 9] FIG. 3 is a diagram of an apparatus 300 for measuring a resonance Raman spectrum using a tunable laser beam. [Figure 10] This is resonance Raman spectrum data obtained when sample 1 is irradiated with laser light 311 having a wavelength of 210 nm and an energy of 1 mJ. [Figure 11] This is resonance Raman spectrum data obtained when sample 2 is irradiated with laser light 311 having a wavelength of 210 nm and an energy of 1 mJ. [Figure 12] This is resonance Raman spectrum data obtained when sample 1 is irradiated with laser light 311 having a wavelength of 266 nm and an energy of 3 mJ. [Figure 13] This is resonance Raman spectrum data obtained when sample 2 is irradiated with laser light 311 having a wavelength of 266 nm and an energy of 3 mJ. [Figure 14] FIG. 4 is a diagram of an apparatus 400 for measuring a resonance Raman spectrum using laser light in an open system. [Figure 15] 1 is a graph showing the relationship between the distance from the measuring device 400 and the signal strength in an open system. [Figure 16] This is resonance Raman spectrum data obtained when extinguishing agent gas (FK-5-1-12) was irradiated with laser light with a wavelength of 210 nm. [Figure 17] This is resonance Raman spectrum data obtained when a fire extinguishing agent (FK-5-1-12) gas is irradiated with a laser beam with a wavelength of 225 nm. [Figure 18] This is resonance Raman spectrum data obtained when a fire extinguishing agent (FK-5-1-12) gas is irradiated with a laser beam with a wavelength of 250 nm. [Figure 19] This is resonance Raman spectrum data obtained when a fire extinguishing agent (FK-5-1-12) gas is irradiated with a laser beam with a wavelength of 266 nm. [Figure 20]This is resonance Raman spectrum data obtained when extinguishing agent gas (FK-5-1-12) was irradiated with laser light with a wavelength of 278 nm. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment will be described with reference to the drawings. The same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0012] (Embodiment 1) Fig. 1 is a schematic diagram of a cable tray fire extinguishing system 60 according to embodiment 1. As shown in Fig. 1, in the cable tray fire extinguishing system 60 according to embodiment 1, a container valve 19 is attached to the upper part of a fire extinguishing agent storage container 1. The fire extinguishing agent storage container 1 is supported by a container support body 15.

[0013] Connected to the container valve 19 are a copper pipe 25 for discharging the extinguishant, a sensing tube 24, a pressure switch 4 for the sensing tube, and a pressure switch 3 for the storage container. The pressure switch 4 for the sensing tube is not limited to being directly connected to the container valve 19, and may be connected to the middle of the sensing tube 24 (near the pressure gauge). The pressure switch 4 for the sensing tube and the pressure switch 3 for the storage container do not have to be connected to the container valve 19.

[0014] The inside of the sensing tube 24 is constantly pressurized. The sensing tube 24 extends into the cable tray 31. The cable tray 31 is installed in a factory, a building, a power plant, etc. The cable tray 31 is cylindrical, and a cable is installed inside it. The cable tray 31 is covered with a flame-retardant sheet 32 ​​as a covering member. The flame-retardant sheet 32 ​​is fixed to the cable tray 31 by a fixing band 33. A stainless steel band is wrapped around the cable tray 31 in the same position as the fixing band 33, preventing the flame-retardant sheet 32 ​​from sagging into the cable tray 31.

[0015] A sensing tube 24 is provided in the cable tray 31. The sensing tube 24 may or may not be in contact with the cable. A copper pipe 25 for discharging a fire extinguishing agent is provided in the cable tray 31. An open-type injection nozzle 34 for discharging a fire extinguishing agent is attached to the copper pipe 25 for discharging a fire extinguishing agent.

[0016] In the extinguishing agent storage container 1, for example, a halogenated extinguishing agent, FK-5-1-12, is enclosed as an extinguishing agent. This agent is pressurized by nitrogen in the extinguishing agent storage container 1. This nitrogen is supplied to the sensing tube 24 via the sensing tube pressure switch 4. When supplying nitrogen into the sensing tube 24 during installation, if nitrogen is introduced from the extinguishing agent storage container 1, the amount of nitrogen in the extinguishing agent storage container 1 will decrease, so nitrogen may be filled into the sensing tube 24 from outside the extinguishing agent storage container 1.

[0017] When the heat of the fire causes the sensing tube 24 to melt, the pressure inside the sensing tube 24 drops.

[0018] When the pressure in the sensing tube 24 drops, the container valve 19 operates and the extinguishing agent (FK-5-1-12) is discharged from the extinguishing agent discharge nozzle 34 in the cable tray 31 through the extinguishing agent discharge copper pipe 25.

[0019] When the pressure inside the sensing tube 24 drops, the sensing tube pressure switch 4 is activated and a signal is sent out.

[0020] When the pressure inside the extinguishant storage container 1 drops, the storage container pressure switch 3 is activated and a notification signal is sent.

[0021] The cable tray 31 is often installed near the ceiling of the building, and because it is located at a high altitude, it cannot be inspected without preparing scaffolding, making the inspection work very labor-intensive.

[0022] The inside of the cable tray 31 is an enclosed space, and a flame-retardant sheet 32 ​​is wrapped around it to prevent the spread of fire and to contain the fire extinguishing agent (FK-5-1-12) within the cable tray 31, so it is not possible to visually check inside the cable tray 31.

[0023] FIG. 2 is a front view of container support 20 according to the first embodiment.

[0024] The container support body 15 is mainly made of steel square pipes and angle bars. The container support body 15 is made by welding steel materials. It has sufficient strength to hold multiple fire extinguishant storage containers 1.

[0025] The extinguishant storage container 1, which is constituted by a cylinder, stores a liquid extinguishant such as FK-5-1-12. In this embodiment, three extinguishant storage containers 1 are provided in parallel, but more or less extinguishant storage containers 1 may be provided.

[0026] The container valve 19 of the extinguishant storage container 1 is connected to the copper pipe connection joint 6 by a flexible tube 2. As a result, the extinguishant in the extinguishant storage container 1 is supplied to the copper pipe connection joint 6 via the flexible tube 2.

[0027] The pressure inside the fire extinguishing agent storage container 1 is constantly monitored, and if the pressure drops, the storage container pressure switch 3 is activated and a signal is sent to a monitoring room or the like.

[0028] The pressure inside the sensing tube 24 is constantly monitored, and a drop in this pressure activates the sensing tube pressure switch 4, which issues a notification signal. The notification signal is then transmitted to a monitoring room or the like.

[0029] Based on these communication signals, a monitoring room or the like can recognize that a fire has occurred.

[0030] The container fixing metal fitting 5 engages with the container support body 15 to hold the fire extinguishant storage container 1. A screw thread is provided on the outer peripheral surface of the end of the container fixing metal fitting 5, and the container fixing metal fitting 5 can be fixed to the container support body 15 by screwing a nut onto the screw thread.

[0031] The copper pipe connection joint 6 is attached to the container support body 15. The copper pipe connection joint 6 is interposed between the flexible tube 2 and the extinguishing agent discharge copper pipe 25 and is airtightly connected to them. The extinguishing agent flows inside the copper pipe connection joint 6.

[0032] A sensing tube 24 is connected to the sensing tube filling joint 11. Nitrogen is supplied to the sensing tube filling joint 11 from the fire extinguishing agent storage container 1. The sensing tube filling joint 11 is attached to the container support body 15.

[0033] Fig. 3 is a diagram showing a method for inspecting the cable tray fire extinguishing system 60 according to the first embodiment. As shown in Fig. 3, during inspection, a flexible pipe 103 is connected to the extinguishing agent discharging copper pipe 25. An optical gas sensor 101 and a suction pump 102 are connected to the flexible pipe 103. By driving the suction pump 102, gas in the cable tray 31 is sucked through the extinguishing agent discharging copper pipe 25 and the open-type extinguishing agent discharging jet nozzle 34.

[0034] If extinguishing agent leaks from the sensing tube 24 into the cable tray 31, the leaked extinguishing agent is sucked in through the extinguishing agent discharge nozzle 34 and reaches the optical gas sensor 101 serving as an analyzer.

[0035] 4 is a schematic diagram showing the process of gas analysis by the optical gas sensor 101. For example, a measurement visualization device described in JP 2013-167497 A can be used as the optical gas sensor 101. The optical gas sensor 101 measures whether CF3CF2C(O)CF(CF3)2 (FK-5-1-12: NOVEC (registered trademark) 1230) contained in the fire extinguishing agent is contained in the sucked gas.

[0036] The optical gas sensor 101 is an optical gas sensor using a Raman scattering method. As shown in Fig. 4, the optical gas sensor 101 includes a gas detection unit 110, and an incident side optical fiber 120 and a receiving side optical fiber 130 connected to the gas detection unit 110.

[0037] One end of the incident optical fiber 120 is connected to a light source such as a monochromatic light source, a laser, or a high-intensity LED, and guides the light from the light source to the gas detection unit 110 as shown by the arrow 182. One end of the receiving optical fiber 130 is connected to a photodetector such as a photomultiplier tube, an avalanche photodiode, a phototransistor, or a CCD, and guides the Raman scattered light generated in the gas detection unit 110 to the photodetector as shown by the arrow 183. An ADC (analog-digital conversion circuit), a computer, or the like is connected to the photodetector. Then, the type and concentration of the gas present in the gas detection unit 110 can be calculated from the detection signal of the photodetector by a known method. For example, an interference filter is inserted between the receiving optical fiber 130 and the photodetector, and the concentration of the gas to be measured can be measured by selecting the Raman scattered light corresponding to the gas to be measured by the interference filter. The type of gas present in the gas detection unit 110 can be identified by replacing the interference filter.

[0038] The gas detection unit 110 is a part that is directly exposed to the gas to be measured, and corresponds to a so-called probe that is fixed to a location (measurement position) where the gas is to be measured, such as inside a pipe. Note that the gas detection unit 110, the light source, and the photodetector are connected by the incident side optical fiber 120 and the receiving side optical fiber 130, so that only the gas detection unit 110 is fixed to the measurement position, and other devices such as the light source and the photodetector can be installed at locations away from the measurement position.

[0039] The gas detection unit 110 is composed of a small optical bench 111, an incident side microlens 112, and a receiving side microlens 113. The small optical bench 111 is a flat plate member having dimensions of several mm to several tens of mm square.

[0040] A ferrule 121 is fixed to the tip of the incident side optical fiber 120. A ferrule 131 is fixed to the tip of the receiving side optical fiber 130. On the compact optical bench 111, a micromirror 118 is integrally formed.

[0041] The Raman scattering phenomenon is a phenomenon in which, when light is irradiated onto a substance such as a gas, the wavelength of some of the scattered light changes due to the molecular vibration or rotation of the substance. Such scattered light is called Raman scattered light. It is also known that the wavelength of Raman scattered light differs for each molecular species (gas species in gases, bonded molecular species in liquids), and there is a correlation between the gas concentration and the intensity of Raman scattered light. Therefore, the gas species can be identified from the Raman scattered light wavelength, and the gas concentration can be identified from the Raman scattered light intensity. It is also known that when the laser wavelength matches the resonant excitation wavelength specific to the substance, the resonance effect generates Raman scattered light (hereinafter sometimes referred to as "resonant Raman scattered light") that is significantly more intense than normal Raman scattered light.

[0042] The gas detection unit 110 in this embodiment is configured with a Raman scattering optical system in which laser light emitted from the tip of the incident side optical fiber 120 is incident on the gas to be measured, and Raman scattered light emitted by the interaction between the laser light and the gas to be measured is incident on the tip of the receiving side optical fiber 130.

[0043] An example of parameters for measuring the extinguishing gas is shown below. In the Raman scattering optical system configured in the gas detection unit 110 of the optical gas sensor 101 used in the test, the angle α between the optical axis of the incident side optical fiber 120 and the normal to the reflecting surface of the micromirror 118 is 8.6°, the angle β between the optical axis of the incident side optical fiber 120 and the optical axis of the light receiving side optical fiber 130 is 151.9°, the distance between the incident side microlens 112 and the micromirror 118 on the optical axis of the incident side optical fiber 120 is 20.0 mm, and the distance between the light receiving side microlens 113 and the optical axis of the incident side optical fiber 120 on the optical axis of the light receiving side optical fiber 130 is 9.55 mm. In addition, a second harmonic laser light of an Nd:YAG laser (Explorer manufactured by Spectra Physics) with an oscillation wavelength of 532 nm was used as a light source connected to the incident side optical fiber 120, and a photomultiplier tube (R3896 manufactured by Hamamatsu Photonics KK) was used as a photodetector connected to the light receiving side optical fiber 130. Then, gas was introduced into the gas detection unit 110 from the flexible pipe 103, and the signal intensity obtained by the photodetector was measured.

[0044] In this embodiment, the extinguishing gas is analyzed using Raman scattered light from the extinguishing gas that is the irradiated object, but the extinguishing gas may be analyzed by other methods, for example, ultraviolet absorption spectroscopy.

[0045] Furthermore, although an example has been given in which CF3CF2C(O)CF(CF3)2 constituting FK-5-1-12 (product name: Novec (registered trademark) 1230) contained in the gas is analyzed, other gases, for example, halon gas, may also be analyzed.

[0046] In the analysis method configured as described above, the gas in the cable tray 31 is sucked in via the open-type extinguishing agent discharge jet nozzle 34 and the extinguishing agent discharge copper pipe 25, and the gas is analyzed to detect the extinguishing agent leak, so that the extinguishing agent leak in the cable tray 31 can be detected with high accuracy by making the most of the existing equipment. Therefore, it becomes possible to inspect the extinguishing agent leak in the cable tray 31 while minimizing the addition of new equipment.

[0047] (Embodiment 2) Fig. 5 is a graph showing the characteristics of the extinguishing agent (FK-5-1-12) and a graph showing the resonance Raman spectrum. Fig. 6 is a diagram showing a method and apparatus for measuring leakage of an extinguishing agent using a remote measurement device 201 according to a second embodiment.

[0048] In the second embodiment, the resonance Raman spectrum of the extinguishing agent is used to measure the concentration of the extinguishing agent present at a distance, and to measure leakage of the extinguishing agent from piping, tubes, and the like.

[0049] As shown in Figure 5, ultraviolet light with a wavelength of 266 nm is used as the incident light for the extinguishing agent. Taking into consideration the results of preliminary experiments and the versatility of the laser device, 266 nm was selected from the resonance wavelength range.

[0050] As shown in Figure 5, the areas indicated by A1 to A3 show the peaks of the resonance Raman spectrum of the fire extinguishing agent gas. Among these, the peak A1 with the highest light intensity is 754.6 cm -1 When converted to wavelength, 271.4 nm was adopted as the observation wavelength.

[0051] As shown in FIG. 6, the worker 152 holds a handheld remote measurement device 201. The remote measurement device 201 identifies the presence of extinguishing agent (FK-5-1-12). Specifically, it identifies the type of substance and locates its location by capturing Raman scattered light (FIG. 5) generated from the extinguishing agent. By scanning with a laser beam, it is possible to capture the spatial distribution of the target gas in three dimensions. This makes it possible to detect extinguishing agent leaking from the joint of the sensing tube 24 outside the cable tray 31 or from a gap in the fire prevention sheet of the cable tray 31, and to locate the location of the leak.

[0052] The worker 152 holds a handheld remote measurement device 201. A laser beam is emitted from the remote measurement device 201 in the direction indicated by an arrow 202. The laser beam emitted from the remote measurement device 201 is irradiated onto the metal duct 151 for fixing the sensing tube 24, the sensing tube 24 in the portion where the metal duct 151 is not present, and the cable tray 31. The remote measurement device 201 receives the generated Raman scattered light (resonance Raman spectrum: FIG. 5), and can identify whether or not a fire extinguishing agent is leaking in the irradiated portion based on the information on the received light.

[0053] In the remote measurement device 201 according to the second embodiment, unlike the first embodiment, it is not necessary to move the extinguishing agent in the cable tray 31 to the vicinity of the remote measurement device 201. Therefore, it is possible to detect leakage of the extinguishing agent in a place that is difficult to access.

[0054] Fig. 7 is a diagram showing a method and device for measuring leakage of extinguishing agent from multiple stages of cable trays 31 using remote measurement device 201 according to the second embodiment. As shown in Fig. 7, when cable trays 31 are provided and stacked in multiple stages, remote measurement device 201 is attached to extension device 155 that extends upward from the ground. In this way, remote measurement device 201 is brought close to cable tray 31 of the stage to be measured. As a result, remote measurement device 201 can be brought close to the gaps between each cable tray 31, making it possible to measure leakage of extinguishing agent from cable tray 31 of each stage.

[0055] Fig. 8 is a block diagram showing the configuration of a remote measurement device 201 according to the embodiment 2. As shown in Fig. 8, the remote measurement device 201 according to this embodiment includes a laser device 210, a telescope 220, a spectroscopic optical system 230, a photodetector 240, total reflection mirrors 251 and 252, and a processor 260. This device has a configuration similar to that described in Japanese Patent No. 7231971.

[0056] The laser device 210 has an oscillator 211 which is a laser light source. The laser device 210 can be configured to include a harmonic generator 212 as necessary, as in this embodiment, and to convert the laser light oscillated by the oscillator 211 into a harmonic (for example, the fifth harmonic) and emit it to the outside. The emitted laser light is emitted into the irradiated space 270 via total reflection mirrors 251 and 252.

[0057] The type of the laser device 210 is not particularly limited, but a solid-state laser is preferable. A typical solid-state laser is configured to excite a laser medium arranged in an optical resonator (for example, two reflecting mirrors) by applying optical energy from an excitation light source (for example, a flash lamp). The laser medium is solid, and for example, a solid-state laser having a laser medium made of a crystalline material obtained by doping Nd, Yb, or the like on a glass or ceramic such as ytterbium aluminum garnet (YAG) called a laser crystal can be used. A more preferable embodiment of the laser is a semiconductor pumped solid-state laser (DPSS-L) that uses laser light output from a semiconductor laser as excitation light, and is capable of short pulse oscillation of 3 ns or less (preferably 2 ns or less, more preferably 1 ns or less), whereas the pulse width of a solid-state laser is about 5 to 10 ns. For example, the microchip type DPSS-L of this embodiment has a semiconductor laser, a collimating lens, a laser crystal with an HR coat, a saturable absorber, an output mirror, and an SHG crystal, and is a device that significantly reduces the size of a solid-state laser while ensuring a constant output for the solid-state laser. Examples of microchip type DPSS-L laser crystals include Nd:YAG, Nd:YLF, Nd:glass, Nd:YVO4, Yb:YAG, and Nd:GVO.

[0058] In the microchip type DPSS-L (microchip laser), the oscillation wavelength of the semiconductor laser is set to a band that efficiently acts on the laser crystal, making it possible to achieve high-efficiency excitation despite its compact size. In addition, the laser crystal used is extremely small, about a few millimeters in size, and a reflective coating (HR coat) is applied to one end of the laser crystal, allowing the laser crystal alone to function as a resonator mirror. In addition, a crystal called a saturable absorber, which becomes transparent when a certain amount of energy is accumulated, is used to function as a Q-switch. In the microchip type DPSS-L, these crystals and optical elements are monolithically integrated to achieve miniaturization and robustness.

[0059] In this way, by using a microchip laser, which is an ultra-compact pulse laser, as the oscillator 211 of the laser device 210, it is possible to reduce the size of the laser device 210 or the entire remote measurement device 201 and to increase the robustness. In addition, as a microchip laser, there is also a laser integrated with the harmonic generator 212, such as a microchip laser that emits the fifth harmonic of Nd:YAG.

[0060] In this embodiment, the laser device 210 irradiates the irradiated space with pulsed laser light to excite the extinguishing agent and generate resonance Raman scattering light caused by the extinguishing agent. By irradiating the laser light in pulses, the distance between the light detection device 240 and the extinguishing agent can be obtained from the time of laser light irradiation and the time of detection of the resonance Raman scattering light.

[0061] In addition, when the laser device is to identify multiple substances, it is necessary to have a mechanism that can switch and irradiate excitation wavelengths appropriate for each substance. However, since the remote measurement device 201 of this embodiment is used to measure extinguishing agents, the laser device 210 can be configured to irradiate only laser light with a single excitation wavelength of 266 nm.

[0062] Laser light emitted from laser device 210 in the direction indicated by arrow 202 is reflected by total reflection mirrors 251 and 252 and irradiated into irradiated space 270. Raman scattered light or resonant Raman scattered light from irradiated space 270 proceeds in the direction indicated by arrow 203 and reaches telescope 220.

[0063] The telescope 220 is composed of a plurality of optical systems, and collects the Raman scattered light and the resonance Raman scattered light incident from the irradiated space 270. In this embodiment, the deep ultraviolet laser light emitted from the laser device 210 collides with the fire extinguishing agent in the irradiated space 270, generating the Raman scattered light and the resonance Raman scattered light. A part of the Raman scattered light and the resonance Raman scattered light generated in the irradiated space 270 enters the telescope 220 together with the visible light. In addition, it is preferable to use a deep ultraviolet telescope that collects the ultraviolet light around the wavelength of 271.4 nm for the telescope 220 in order to receive the resonance Raman scattered light caused by the fire extinguishing agent and to exclude other light components as much as possible. In addition, in such a deep ultraviolet telescope, it is preferable that all the optical systems collect the deep ultraviolet light with high efficiency, and it is preferable that they are reflective in terms of efficiency and aberration.

[0064] The spectroscopic optical system 230 is a spectrometer or a combination of a long-pass filter and a band-pass filter, and separates light in the wavelength range of 271.4 nm, which includes resonance Raman scattering light caused by the fire extinguishing agent, from the light that has passed through the telescope 220. In the spectroscopic optical system 230, by separating only the deep ultraviolet wavelength of 271.4 nm, the influence of background light can be reduced.

[0065] The photodetector 240 is an ICCD detector, a photomultiplier tube, an APD (avalanche photodiode), or the like, which receives light in the 271.4 nm wavelength region dispersed by the spectroscopic optical system 230, and detects a received light signal with an intensity corresponding to the intensity of the received light. The photodetector 240 is preferably provided with a gate that opens and closes the light reception in synchronization with the irradiation pulse of the laser light, and is configured to receive only the light during the time period when the resonance Raman scattered light is emitted (the time period when the laser light is applied) by the opening and closing operation of the gate.

[0066] The processing device 260 calculates the distance from the remote measurement device 201 to the extinguishing agent from the return time of the Raman scattered light or the resonance Raman scattered light. The remote measurement device 201 also has a scanning device capable of changing the direction of irradiation of the laser light (the direction of the laser device 210) and the direction of reception of the light by the light detection device 240 (the direction of the light detection device 240), and can measure the spatial distribution of the extinguishing agent by scanning the light emitted from the laser device 210 in the vertical / horizontal or horizontal / tilt directions within the irradiated space 270 based on a control command from the processing device 260. The remote measurement device 201 can measure the three-dimensional distribution of the extinguishing agent within a range of a radius of 15 meters from the remote measurement device 201, for example, by detecting the resonance Raman scattered light caused by the extinguishing agent while gradually changing the angle of the direction of irradiation of the laser light and the direction of reception of the resonance Raman scattered light.

[0067] Since the irradiated space 270, which is an open space, contains a large amount of atmospheric components such as oxygen, nitrogen, and water vapor, even when a laser beam with an excitation wavelength for exciting the extinguishing agent is irradiated into the irradiated space in which the extinguishing agent exists, Raman scattered light due to the atmospheric components is also generated and is received by the light detection device 240. However, since the Raman shift of the Raman scattered light due to the atmospheric components does not overlap with the Raman shift of the resonant Raman scattered light due to the extinguishing agent, the light detection device 240 can detect the received light signal of the resonant Raman scattered light due to the extinguishing agent even in the atmosphere without being interfered with by the Raman scattered light due to the atmospheric components. For example, when a 266 nm laser beam is irradiated, the Raman shift of the Raman scattered light due to oxygen is 1556 cm -1 The Raman shift of the nitrogen-induced Raman scattering is 2331 cm -1 The Raman shift of the Raman scattering light caused by water vapor is 3652 cm -1 The Raman shift of the resonance Raman scattering light caused by the fire extinguishing agent has the highest light intensity of 754.6 cm -1 By detecting the received light signal at (271.4 nm, A1 in Figure 5), it is possible to separate the extinguishing agent from atmospheric components and detect the extinguishing agent even in the atmosphere.

[0068] In particular, the light detection device 240 detects a wavelength of 2000 cm where the signal strength of the received light signal is particularly large. -1 The signal intensity at the following Raman shift is detected. In this embodiment, -1 The received signal was detected at the Raman shift of

[0069] (Resonance Raman spectrum at wavelengths of 210 nm and 266 nm in a closed system) 9 is a diagram of a measurement apparatus 300 for a resonance Raman spectrum using a wavelength-tunable laser beam. In the measurement apparatus 300, a laser beam 311 is emitted from a tunable laser source 301. The laser beam 311 is reflected by a mirror 302. The laser beam 311 passes through a gas cell 306. A fire extinguishing gas is sealed in the gas cell 306. Resonance Raman scattered light 312 is emitted from the fire extinguishing gas. The resonance Raman scattered light 312 passes through a long-pass filter 305 and a convex lens 304, and enters a high-sensitivity spectrometer 303.

[0070] The resonance Raman spectrum data when samples 1 and 2 using FK-5-1-12 gas were sealed in a gas cell and the wavelength of laser light 311 was 210 nm with 1 mJ of energy and the wavelength was 266 nm with 3 mJ of energy are shown in Figs. 10 to 13. In Figures 10 to 13, the peaks indicated by A11 to A15 and A21 to A23 are due to FK-5-1-12 (note that the number of detectable peaks varies depending on the influence of the signal-to-noise ratio, etc.). Therefore, it was found that FK-5-1-12 could be detected. In other words, it was confirmed that in the process of detecting leakage of the extinguishing agent FK-5-1-12, it is possible to detect leakage of the extinguishing agent by irradiating it with laser light and receiving the resonance Raman scattering wavelength with the peak characteristics specific to the extinguishing agent.

[0071] (Resonance Raman spectrum in an open system) 14 is a diagram of a measurement device 400 for a resonance Raman spectrum using laser light in an open system. In an open space, an FK-5-1-12 gas emission system 406 was installed 7 meters away from a measurement device 400, which is a remote measurement device for a fire extinguishing agent (FK-5-1-12). FK-5-1-12 was released into the atmosphere from the emission system 406. A valve and a Teflon (registered trademark) tube were connected to a bottle 407 containing liquid FK-5-1-12, and the design was such that FK-5-1-12 vaporized at room temperature would be released into the atmosphere.

[0072] A laser beam 411 of 266 nm and pulse energy of 1 mJ was emitted from a laser device 404 of the remote measurement device in the direction indicated by the arrow, reflected by a total reflection mirror 405, and irradiated to a measurement point (irradiated space) of an emission system 406. In addition to irradiating the laser beam, a telescope 403 collected resonance Raman scattered light 412 incident from the irradiated space, and a photodetector 401 received resonance Raman scattered light caused by FK-5-1-12 and Raman scattered light caused by the atmosphere incident from the irradiated space. From among them, a received light signal of resonance Raman scattered light caused by FK-5-1-12 was detected, and the signal intensity of the received light signal was measured.

[0073] In order to detect the resonant Raman scattering light caused by FK-5-1-12, the measuring device 400 is equipped with a filter 402 having an edge filter that passes light with a wavelength of 266 nm or more, and a bandpass filter that extracts the resonant Raman scattering light of FK-5-1-12 with a center wavelength of 271.4 nm and a full width at half maximum of 10 nm. The measured time data was averaged 750 times to calculate the results. One measurement takes about 1 second.

[0074] Measurement conditions: Distance: 7 m, Liquid FK-5-1-12 vaporized at room temperature, Number of averaging: 750, Observation wavelength: 271.4 nm (Raman shift = 754.6 cm -1 ) From Figure 15, the presence of gas FK-5-1-12 was detected at a distance of 7 m.

[0075] (Raman shifts for various excitation wavelengths in a closed system) Using the apparatus shown in FIG. 9, the Raman shift of the fire extinguishing gas FK-5-1-12 was investigated at excitation wavelengths of 210 nm, 225 nm, 250 nm, 266 nm, and 278 nm. As a result, the Raman shift was 760.4 cm at each wavelength. -1 , 1250.6cm -1 and 1780.7 cm -1 The Raman shift of was confirmed. Detailed resonance Raman spectrum data is shown in Figures 16 to 20. The peaks indicated by "A" in Figures 16 to 20 are derived from FK-5-1-12. The nitrogen Raman light intensity is normalized to 1000 counts.

[0076] This enabled the detection of the fire extinguishing gas FK-5-1-12 at various excitation wavelengths.

[0077] According to the present disclosure, 2000 cm -1 Less than or equal to 1800 cm -1 The Raman shift of -1 The received light signals can be detected at the following Raman shifts (resonance Raman scattering wavelengths).

[0078] Appendix 1 A remote measurement device for a fire extinguishing agent that measures a fire extinguishing agent present in an irradiated space, A laser device that emits laser light into the irradiated space to cause the extinguishing agent to generate resonance Raman scattering light; a light detection device that receives resonance Raman scattered light caused by the fire extinguishing agent from the irradiated space; a processing device that controls the operation of the laser device and the light detection device and detects the extinguishing agent present in the irradiated space based on a signal from the light detection device; The photodetector is 2000 cm -1 A remote measurement device for extinguishing agents that detects received light signals at the following Raman shifts:

[0079] Appendix 2 The laser device irradiates the laser light into the irradiation space, which is an open space; The extinguishing agent remote measurement device according to claim 1, wherein the processing device detects resonant Raman scattered light caused by the extinguishing agent and incident from the irradiated space which is an open space.

[0080] Appendix 3 The laser device comprises an oscillator that emits laser light of a specific wavelength, and a harmonic generator that converts the specific wavelength into a harmonic with which the extinguishing agent resonates.

[0081] Appendix 4 The oscillator is a microchip laser that emits laser light of a single excitation wavelength into an irradiated space, 4. The fire extinguishing agent remote metering device of claim 3, wherein the harmonic generator is a single harmonic generator.

[0082] Appendix 5 The remote measurement device for a fire extinguishing agent according to claim 3, wherein the oscillator is a microchip laser that emits laser light having a pulse width of 3 ns or less into an irradiated space.

[0083] Appendix 6 The light detection device also receives Raman scattered light caused by the fire extinguishing agent from the irradiated space, The extinguishing agent remote measurement device described in Appendix 1, wherein the treatment device measures the concentration of the extinguishing agent based on the resonance Raman scattered light caused by the extinguishing agent when the concentration of the extinguishing agent present in the irradiated space is less than a predetermined value, and measures the concentration of the extinguishing agent based on the Raman scattered light caused by the extinguishing agent when the concentration is equal to or greater than the predetermined value.

[0084] Appendix 7 The photodetector is 760.4 cm -1 A remote measurement device for a fire extinguishing agent according to any one of claims 1 to 6, which detects a received light signal at a Raman shift of

[0085] Appendix 8 A method for remotely measuring a fire extinguishing agent present in an irradiated space, comprising: A step of emitting laser light from a laser device into the irradiated space, the laser light causing the extinguishing agent to generate resonance Raman scattering light; The photodetector detects the amount of fire extinguishing agent that is emitted from the irradiated space within 2000 cm -1 detecting the fire extinguishing agent by receiving resonance Raman scattered light at a Raman shift of and detecting a fire extinguishing agent present in the irradiated space at a concentration of 100 ppm or less based on a signal from the optical detection device.

[0086] Appendix 9 The extinguishing agent comprises CF3CF2C(O)CF(CF3)2.

[0087] Appendix 10 The wavelength of the laser light is 210 nm or more and 278 nm or less.

[0088] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments, and it is intended to include the equivalent meaning of the claims and all modifications within the scope of the claims. [Explanation of symbols]

[0089] 1 Extinguishing agent storage container, 2 Flexible tube, 3 Pressure switch for storage container, 4 Pressure switch for sensing tube, 5 Container fixing bracket, 6 Copper pipe connection joint, 11 Sensing tube filling joint, 15 Container support body, 19 Container valve, 20 Container support, 24 Sensing tube, 25 Copper pipe for discharging extinguishing agent, 31 Cable tray, 32 Flame retardant sheet, 33 Fixing band, 34 Extinguishing agent injection nozzle, 60 Cable tray fire extinguishing equipment, 101 Optical gas sensor, 102, suction pump, 103, flexible piping, 110, gas detector, 111, small optical bench, 112, incident microlens, 113, receiving microlens, 118, micromirror, 120, incident optical fiber, 121, 131, ferrule, 130, receiving optical fiber, 151, metal duct, 152, worker, 155, extension device, 201, remote measurement device, 210, laser device, 211, oscillator, 212, harmonic generator, 220, telescope, 230, spectroscopic optical system, 240, photodetector, 251, 252 Total reflection mirror, 260 processing device, 270 irradiated space, 300 measuring device, 301 tunable laser light source, 302 mirror, 303 high-sensitivity spectrometer, 304 convex lens, 305 long-pass filter, 306 gas cell, 311 laser light, 312 resonant Raman scattered light, 400 measuring device, 401 photodetector, 402 filter, 403 telescope, 404 laser device, 405 total reflection mirror, 406 emission system, 407 bottle, 411 laser light, 412 resonant Raman scattered light.

Claims

1. a cable tray for holding the cables; A sensing tube having a fire extinguishing agent therein, the sensing tube being provided in the cable tray and melting due to heat of a fire; An open-type injection nozzle provided in the cable tray for discharging a fire extinguishing agent; A covering member for covering the cable tray; A method for inspecting a cable tray fire extinguishing system comprising: sucking gas from within the cable tray through the piping and the injection nozzle; and analyzing the aspirated gas to detect leakage of extinguishing agent.

2. 2. The cable tray inspection method according to claim 1, wherein the step of detecting a leak of the extinguishing agent includes irradiating the aspirated gas with laser light to detect a leak of the extinguishing agent based on a Raman scattering wavelength having a peak characteristic specific to the extinguishing agent.

3. The extinguishing agent is CF ３ CF ２ C(O)CF(CF ３ ) ２ 3. The method for inspecting a cable tray according to claim 1 or 2, comprising:

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