JP7788836B2 - Fire Surveillance System - Google Patents

Description

The present invention relates to a fire extinguishing monitoring system that monitors the status of a fire extinguishing agent.

A fire extinguishing device is known that sprays a fire extinguishing agent onto heat-generating points in cables, including cables or electric wires, installed in a cable tray (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2018-89156

In facilities such as power plants, cable trays are installed over lengths of several kilometers. If the fire extinguishing devices described in Patent Document 1 were installed on the cable trays, a huge number of fire extinguishing devices, numbering in the thousands, would be required along the direction in which the cables are laid. If workers were to visually monitor whether the extinguishing agent in the fire extinguishing devices described in Patent Document 1 was in a normal state, this could increase the burden on the workers.

The present invention aims to provide a fire extinguishing monitoring system that can reduce the burden of monitoring the status of the extinguishing agent in a fire extinguishing device installed in a cable tray.

One aspect of the present invention is a fire extinguishing monitoring system comprising: a fire extinguishing tube having a container in which pressurized fire extinguishing agent is sealed and whose outer casing melts when heated to release the fire extinguishing agent; a sensor for detecting the release of the fire extinguishing agent; a cable tray in which cables are laid and in which multiple fire extinguishing tubes are installed along the laying direction of the cables; a heat-resistant sheet covering the cables and multiple fire extinguishing tubes in the cable tray; a monitoring device that alerts to abnormalities occurring in the fire extinguishing tubes based on changes in detection values of the multiple sensors ; and a loop circuit that connects the multiple sensors in series , wherein the sensors are configured to switch between an on state and an off state based on changes in pressure inside the container, and the monitoring device transmits detection signals to the loop circuit at predetermined times and detects abnormalities occurring in at least one of the fire extinguishing tubes based on whether or not the detection signal is received and generates an alarm .

This invention enables real-time monitoring of abnormalities occurring in a cable tray equipped with a fire extinguishing tube that automatically releases fire extinguishing agent, and detects and reports abnormalities occurring in the fire extinguishing tube, thereby reducing the burden on workers in terms of monitoring.

Furthermore, the sensor of the present invention may be configured to switch between an ON state and an OFF state based on changes in pressure within the container, and may include a loop circuit that connects multiple sensors in series. The monitoring device may transmit a detection signal to the loop circuit at a predetermined timing, and based on whether or not the detection signal is received, may detect an abnormality occurring in at least one of the fire extinguishing tubes and generate an alarm.

According to the present invention, by providing a loop circuit that detects the on/off state of the sensor, wiring length can be reduced and device configuration can be simplified compared to methods that monitor each individual sensor.

Furthermore, the sensor of the present invention may change to an OFF state based on the release of the extinguishing agent, and the loop circuit may change to an open state based on the OFF state of at least one of the sensors, and the monitoring device may detect an abnormality occurring in at least one of the fire extinguishing tubes when the detection signal cannot be received based on the open state.

According to the present invention, the off state of the sensor can be detected based on a loop circuit, simplifying the device configuration.

Furthermore, when the loop circuit is in the open state, the monitoring device of the present invention may transmit the detection signal from at least one of the first electrode and the second electrode connected to the loop circuit, receive a reflected signal of the detection signal, and calculate the installation position of the fire extinguishing tube when the sensor is in the off state based on the transmission time of the detection signal and the reception time of the reflected signal.

According to this invention, even if the loop circuit is open, the location of the fire extinguishing tube where an abnormality has occurred can be estimated by receiving a reflected signal of the detection signal, thereby reducing the monitoring burden on workers.

The present invention may also include a plurality of imaging units provided in each area where a predetermined number of fire extinguishing tubes are installed, capturing images of the state of the cable trays, and the monitoring device may display images captured by the imaging units capturing images of the area including the installation locations.

According to the present invention, the imaging unit captures an image of the area including the location of the fire extinguishing tube where an abnormality has occurred, making it possible to monitor the condition of the cable tray in real time.

Furthermore, the fire extinguishing tube of the present invention may be equipped with an indicator that changes based on changes in pressure inside the container, and the indicator may be installed exposed from the heat-resistant sheet in a position where an operator can visually detect any abnormalities occurring in the fire extinguishing tube.

According to the present invention, the indicator is installed in the cable tray so that it is exposed outside the heat-resistant sheet, allowing workers to visually detect any abnormalities in the fire extinguishing tube.

Furthermore, the fire extinguishing tube may be fixed to the cable tray via a fixing member, and the fixing member that fixes the sensor and the indicator side may be configured to suppress heat transfer from the cable tray to the fire extinguishing tube.

This invention reduces the risk of sensor and indicator failure by suppressing the heat transferred from the cable tray to the fire extinguishing tube when heat is generated in the cables.

Furthermore, the sensor of the present invention may be installed exposed from the heat-resistant sheet to prevent malfunction when heat is generated.

According to the present invention, the sensor is positioned so that it is exposed from the heat-resistant sheet, thereby preventing the sensor from failing due to the effects of temperature rise within the cable storage space inside the heat-resistant sheet.

This invention reduces the burden of monitoring the status of the extinguishing agent in a fire extinguishing device installed in a cable tray.

FIG. 2 is a plan view showing the schematic configuration of a cable tray that is the object of monitoring by the fire extinguishing monitoring system. FIG. 2 is a side view of the cable tray. FIG. 10 is a diagram illustrating an example of the configuration of an indicator. 1 is a block diagram showing the configuration of a fire extinguishing monitoring system. FIG. 1 is a block diagram showing the configuration of a fire extinguishing monitoring system in a state in which an abnormality is detected. FIG. 10 is a diagram showing an example of a notification image displayed on a display unit.

The following describes a fire extinguishing monitoring system according to an embodiment of the present invention, with reference to the drawings.

As shown in Figures 1 and 2, the fire extinguishing monitoring system 1 includes a cable tray C, which is the object of on-site monitoring, and a monitoring device 10 that detects abnormalities in the cable tray C. The cable tray C is a support structure for installing cables K, such as multiple power lines and multiple communication lines, in power facilities such as nuclear power plants. The cable tray C is formed, for example, from a plate-shaped metal material. The cable tray C includes, for example, a pair of side plates C1 and C2 arranged opposite each other. The side plates C1 and C2 are formed in the shape of rectangular strips. The longitudinal direction of the side plates C1 and C2 is aligned along the laying direction of the cables K (x-axis direction). The lateral direction of the side plates C1 and C2 is aligned upright along the vertical direction (z-axis direction).

The bottoms of a pair of side panels C1, C2 are connected by multiple cross beams C3. The cross beams C3 are formed in a rectangular plate shape. The longitudinal direction of the cross beams C3 is aligned perpendicular to the longitudinal direction of the side panels C1, C2 (y-axis direction). The short side of the cross beams C3 is aligned along the laying direction of the cables K (x-axis direction). As a result, the upper surfaces of the multiple cross beams C3 serve as resting surfaces for the cables K, on which the cables K are placed. Multiple fire extinguishing tubes F are installed above the cables K in the laying direction of the cables K. The spacing between adjacent fire extinguishing tubes F is, for example, -20 cm to +20 cm. Adjacent fire extinguishing tubes F are arranged, for example, with a partial overlap. The spacing and arrangement method of adjacent fire extinguishing tubes F are not limited to the example shown and may be changed as appropriate depending on the type of fire extinguishing tube F and the type of cable tray C to be installed. The fire extinguishing tube F, for example, comprises a tubular container F1. Container F1 has a storage space for storing fire extinguishing agent. Container F1 is made of, for example, a resin material.

A sensor F2 that detects the release of extinguishing agent is provided at one end of the container F1, closing the opening. The sensor F2 is, for example, a pressure sensor that detects the pressure in the storage space inside the container F1. An indicator F3 (see Figure 3) that changes its display based on changes in pressure inside the container is provided at the other end of the container F1, closing the opening. The indicator F3, for example, displays the pressure level inside the container F1 as a meter. The storage space inside the container F1 is filled with pressurized extinguishing agent. When the outside of the container F1 is heated, the outer shell melts, and extinguishing agent is released from the melted point based on the internal pressure of the storage space.

The fire extinguishing tube F is bent, for example, into a U-shape. The bent side of the U-shaped portion of the fire extinguishing tube F is fixed, for example, to the inner wall surface C1A of the side plate C1 via a pair of fixing members B1. The fixing members B1 are formed, for example, from a metal material. The fixing members B1 are formed so that when heat is generated in the cables K, the heat from the side plate C1 is conducted to the container F1, making it easier for the container F1 to melt. One and the other ends of the fire extinguishing tube F are placed on the top of the side plate C2. The sensor F2 and the indicator F3 are arranged to protrude outward from the side plate C2.

The sensor F2 and indicator F3 are fixed to the upper surface C2B of the side plate C2 by a fixing member B2. The fixing member B2, which fixes the sensor F2 and indicator F3, is made of, for example, a resin material. The fixing member B2 is designed to reduce the heat transfer from the side plate C2 to the sensor F2 and indicator F3 when the cables K generate heat. The fixing member B2 may be made of a metal material. In this case, the container F1 may be fixed to the fixing member B2 via an insulating material between them to reduce the heat transfer from the side plate C2 to the sensor F2 and indicator F3. In other words, the fixing member B2 is designed to reduce the heat transfer from the cable tray C to the fire extinguishing tube F. This reduces the heat transfer from the cable tray C to the fire extinguishing tube F when the cables K generate heat, reducing the risk of failure of the sensor F2 and indicator F3.

The cable tray C is covered with a heat-resistant sheet T. The heat-resistant sheet T is made of a flame-retardant film material. The cable tray C is wrapped with the heat-resistant sheet T to form a storage space for cables K. The heat-resistant sheet T has a slit T1 at the position of the sensor F2 and indicator F3, allowing the sensor F2 and indicator F3 to protrude from the slit T1 into the external space outside the storage space. In other words, the sensor F2 is installed exposed from the heat-resistant sheet T to prevent malfunction and to prevent exposure to heat within the storage space when heat is generated. The indicator F3 is installed exposed from the heat-resistant sheet T in a position where the operation of the fire extinguishing tube F can be visually detected by an operator.

The multiple sensors F2 are electrically connected to a monitoring device 10 that reports the operation of the fire extinguishing tube based on changes in the detection values of the multiple sensors F2. The cable tray C extends over several kilometers, and several thousand sensors F2 are installed. Therefore, if the detection value of each sensor F2 were to be detected individually, the amount of wiring would be enormous. Therefore, the multiple sensors F2 are connected in series to form a loop circuit R. The multiple sensors F2 are electrically connected to the monitoring device 10 via the loop circuit R. The loop circuit R has, for example, a first electrode R1 and a second electrode R2, and is connected to the monitoring device 10.

As shown in FIG. 4, the fire extinguishing monitoring system 1 may monitor n cable trays C at n sites (n is a natural number) using the monitoring device 10. Site n may be set not only for different locations, but also for each unit of cable tray C. In the loop circuit R, each sensor F2 is configured to switch between an ON state and an OFF state based on changes in pressure within the container. The monitoring device 10, for example, transmits a detection signal to the loop circuit R at a predetermined timing, and detects the operation of at least one fire extinguishing tube F based on whether or not the detection signal is received, and generates an alarm. The fire extinguishing monitoring system 1 may also include multiple imaging units 20 that capture images of the cable tray status. For example, an imaging unit 20 is provided for each area where a predetermined number of fire extinguishing tubes F are installed. The monitoring device 10 displays images captured by the imaging unit 20, which captures images of the area including the installation location.

The monitoring device 10 is configured, for example, by an information processing terminal device such as a personal computer. The monitoring device 10 includes, for example, a detection unit 11 that detects a break in the loop circuit R. The detection unit 11 generates, for example, a detection signal and transmits it to the loop circuit R. The detection unit 11 receives the detection signal that returns from the loop circuit R. The detection signal is formed, for example, into a pulse signal having a predetermined frequency. The detection unit 11 includes, for example, a bandpass filter, and removes noise having various frequency components based on the induced current generated in the loop circuit R due to the influence of the cables K before receiving the detection signal. The detection unit 11 outputs the received detection signal to the calculation unit 12. The calculation unit 12 controls the detection unit 11 to generate the detection signal and determine a break in the loop circuit R based on the received detection signal.

As shown in FIG. 5, if sensor F2 is configured to change to an OFF state when extinguishing agent is released, loop circuit R changes to an open state when at least one sensor F2 is OFF. In addition, the OFF state of sensor F2 is also detected when an abnormality such as a malfunction of sensor F2 or a drop in pressure inside the fire extinguishing tube F due to deterioration occurs. When the calculation unit 12 cannot receive a detection signal due to the open state of loop circuit R, it detects an abnormality such as the operation of at least one fire extinguishing tube or a malfunction of sensor F2, and determines that heat has been generated in cables K or an abnormality has occurred in sensor F2.

When the loop circuit R is in an open state, the calculation unit 12 estimates the position of the sensor F2, which is in an off state. The calculation unit 12 executes a predetermined position estimation program stored in the memory unit 14. For example, when the loop circuit R is in an open state, the calculation unit 12 transmits a detection signal from at least one of the first electrode R1 and the second electrode R2 connected to the loop circuit R. The detection signal is reflected in the loop circuit R at the position of the sensor F2, which is in an off state, and flows back as a reflected signal. The calculation unit 12 receives the reflected signal of the detection signal, calculates the distance of the sensor F2, which is in an off state, based on the transmission time of the detection signal and the reception time of the reflected signal, and estimates the position of the sensor F2, which is in an off state, i.e., the position of the fire extinguishing tube F, based on the calculation result.

The calculation unit 12 identifies the site m (m is a natural number less than or equal to n) containing the fire extinguishing tube F where the abnormality occurred, and causes the imaging unit 20, which images the area including the position of the fire extinguishing tube F, to capture an image of the cable tray C at the site m. The calculation unit 12 causes the display unit 13 to display an alert image indicating that an abnormality has occurred. The calculation unit 12 also causes the display unit 13 to display the image captured by the imaging unit 20. The worker can compare the alert image displayed on the display unit 13 with the image captured by the imaging unit 20, monitor changes in the surrounding conditions of the cable tray C, and determine whether the fire extinguishing tube F has been activated based on heat generation, or whether the abnormality is due to a cause such as a malfunction of the sensor F2.

As shown in FIG. 6, the display unit 13 displays a notification image H that notifies of an abnormality in sensor F2. The notification image H displays, for example, a message H1 notifying of an abnormality in sensor F2 and an image H2 captured by the imaging unit 20 that captures the position of sensor F2. The display unit 13 is configured with a display device such as a liquid crystal display or an organic EL display. The calculation unit 12 may also transmit the notification image H to a mobile terminal device such as a smartphone or tablet terminal carried by a worker performing monitoring work at the site.

Based on the alarm image H displayed on the mobile terminal device, the worker goes to the abnormal location on site and checks whether there is an abnormality with the cable tray C. The worker checks the display of the indicator F3 exposed from the cable tray C. If the worker confirms an abnormality, he or she peels off the heat-resistant sheet T from the relevant area and checks the condition of the cables K. Based on the condition of the cables K, the worker considers replacing or repairing the cables K. If the fire extinguishing tube F was operating, the worker replaces the fire extinguishing tube F. After returning to the original state, the worker covers the cable tray C with the heat-resistant sheet T. If the worker finds no visible abnormalities with the cable tray C or fire extinguishing tube F and discovers a malfunction of the sensor F2, he or she replaces the fire extinguishing tube F.

As described above, the fire extinguishing monitoring system 1 can automatically detect abnormalities, such as the operation or failure of the fire extinguishing tube F, that have occurred in the cable tray C. The fire extinguishing monitoring system 1 is provided with a loop circuit R, which reduces the amount of wiring connected to multiple sensors F2 and simplifies the device configuration. When the loop circuit R is open, the fire extinguishing monitoring system 1 inputs a detection signal to the loop circuit R and estimates the position of the abnormal sensor F2 based on the detection of the reflected signal. The fire extinguishing monitoring system 1 can capture an image of the position of the abnormal sensor F2 using the imaging unit 20 and display the captured image. The fire extinguishing monitoring system 1 automatically estimates the position of the abnormal fire extinguishing tube F, thereby reducing the burden on workers who would otherwise have to visually monitor the long-distance cable tray C.

The above-mentioned calculation unit 12 is realized, for example, by a processor such as a CPU executing a program (software) stored in the storage unit 14. Each step of the calculation process in the calculation unit 12 is performed by executing a program installed in the monitoring device 10. Furthermore, some or all of the functions of these components may be realized by hardware (including circuitry) such as an LSI, ASIC, FPGA, or GPU, or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device such as an HDD or flash memory, or may be stored on a removable storage medium such as a DVD or CD-ROM and installed by inserting the storage medium into a drive.

Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are within the scope and spirit of the invention, as well as the scope of the invention and its equivalents as set forth in the claims. For example, while the fire extinguishing monitoring system 1 has been illustrated as detecting the off state of sensor F2, this is not limited thereto and the system may be configured to detect the on state of sensor F2. While the indicator F3 is illustrated as a meter display, this is not limited thereto and the system may be configured to illuminate an illuminant such as an LED to indicate an abnormality. The calculation unit 12 may be configured to detect an abnormality based on a change in the image of indicator F3 in the image captured by the imaging unit 20.

1 Fire extinguishing monitoring system 10 Monitoring device 11 Detection unit 12 Calculation unit 13 Display unit 14 Memory unit 20 Imaging units B1, B2 Fixing member C Cable tray F Fire extinguishing tube F1 Container F2 Sensor F3 Indicator H Notification image H1 Message H2 Captured image K Cables R Loop circuit R1 First electrode R2 Second electrode T Heat-resistant sheet

Claims (7)

a fire extinguishing tube having a container in which a pressurized fire extinguishing agent is sealed and whose outer shell melts when heated to release the fire extinguishing agent, and a sensor for detecting the release of the fire extinguishing agent;
a cable tray in which cables are laid and in which a plurality of the fire extinguishing tubes are installed along the laying direction of the cables;
a heat-resistant sheet covering the cables and the plurality of fire extinguishing tubes in the cable tray;
a monitoring device that notifies an abnormality occurring in the fire extinguishing tube based on changes in the detection values of the plurality of sensors;
a loop circuit that connects the plurality of sensors in series ,
the sensor is configured to switch between an on state and an off state based on a change in pressure within the container;
A fire extinguishing monitoring system in which the monitoring device transmits a detection signal to the loop circuit at a predetermined timing, detects an abnormality occurring in at least one of the fire extinguishing tubes based on whether or not the detection signal is received, and generates an alarm . the sensor changes to an OFF state upon release of the extinguishing agent;
the loop circuit changes to an open state based on the OFF state of at least one of the sensors;
The monitoring device detects an abnormality occurring in at least one of the fire extinguishing tubes when the detection signal cannot be received based on the open state.
The fire extinguishing monitoring system according to claim 1 . When the loop circuit is in the open state, the monitoring device transmits the detection signal from at least one of the first electrode and the second electrode connected to the loop circuit, receives a reflected signal of the detection signal, and calculates the installation position of the fire extinguishing tube when the sensor is in the off state based on the transmission time of the detection signal and the reception time of the reflected signal.
The fire extinguishing monitoring system according to claim 2 . a plurality of imaging units provided for each area where a predetermined number of the fire extinguishing tubes are installed, for imaging the state of the cable tray;
the monitoring device displays an image captured by the imaging unit that captures an image of the area including the installation position.
The fire extinguishing monitoring system according to claim 3 . the fire extinguishing tube includes an indicator that changes based on changes in pressure within the vessel;
The indicator is installed exposed from the heat-resistant sheet at a position where an abnormality occurring in the fire extinguishing tube can be visually detected by an operator.
A fire extinguishing monitoring system according to any one of claims 1 to 4 . The fire extinguishing tube is fixed to the cable tray via a fixing member,
The fixing member for fixing the sensor and the indicator side is configured to suppress heat transfer from the cable tray to the fire extinguishing tube.
The fire extinguishing monitoring system according to claim 5 . The sensor is installed exposed from the heat-resistant sheet so as to prevent malfunction when heat is generated.
A fire extinguishing monitoring system according to any one of claims 1 to 6 .