JPH0448398A - Disaster preventing system - Google Patents

Abstract

PURPOSE:To decide the kind of fire in a tunnel at early stages and to perform extinction in accordance with the kind of fire at early stages by detecting the occurrence of the fire based on the smoke or gas density of detection data in time lapse fashion by each sensor, deciding the occurrence of the fire based on temperature data, and specifying a position where the fire occurs. CONSTITUTION:The occurrence of the fire is detected based on the smoke or gas density of the detection data in time lapse fashion by the sensors 1a, 1b,... 1n, and the occurrence of the fire is decided by the temperature data, and the position where the fire occurs can be specified. In other words, the occurrence of the fire is detected based on the smoke or gas density of the detection data in time lapse fashion by the sensors 1a, 1b,... 1n, and the occurrence of the fire is decided by the temperature data, and the position where the fire occurs is specified, and also, the kind of extinction facility is selected by the transient pattern of the detection data, and the extinction facility in the periphery of a specified position where the fire occurs is operated and controlled. Thereby, it is possible to obtain an accident prevention system capable of deciding the kind of fire in the tunnel at early stages, and of performing appropriate extinction in accordance with the kind of fire at early stages.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a disaster prevention system.

[Conventional technology]

In conventional fire alarm systems, a fire detector generally detects a change in a single physical quantity such as smoke or heat caused by a fire, and sends a fire signal to a receiver when the detected value exceeds a set threshold level. fire alarm.

In this on-off type fire alarm system, which generates a fire signal depending on whether or not the threshold level is exceeded, if a detected value exceeding the threshold level is obtained due to a cause other than a fire, it is determined that there is a fire. There was a problem in which false alarms (non-fire alarms) were issued.

In order to solve the problems with such on/off type fire alarm systems, it is necessary to comprehensively judge a fire from multiple sampling data obtained by sampling or data processing analog detection data of different physical quantities caused by a fire. Various analog fire alarm devices have been proposed that can accurately determine a fire at the initial stage of fire by performing predictive calculations using function approximation or the like. As an example of this type of device, for example, Japanese Patent Application Laid-Open No. 60-48596
Publication No.

[Problem to be solved by the invention]

The above conventional technology targets general fires in specific limited sections such as rooms in hotels and general residences, and targets tunnel-shaped structures such as tunnels, common ditches, cable pits, and railway tunnels (hereinafter referred to as tunnels). No consideration was given to detecting fires in cables, etc., and there were problems as described below.

(1) In order to quickly and accurately confirm the occurrence of a fire and pinpoint its location in a cave, it is necessary to place a large number of detectors with different detection principles at regular intervals throughout the section, that is, the entire tunnel. , the number of detection points and data processing capacity increase.

(2) When a fire occurs in a section such as a cave, heat, smoke, and generated gas propagate and diffuse at high speed due to hot air currents, so data processing from a large number of detectors and arithmetic processing for judgment are necessary. All fires start all at once, making it difficult to confirm the occurrence of a fire and specify its location, and the processing power of the calculation means is insufficient, which slows down the determination of a fire.

(3) This makes it difficult to operate fire extinguishing equipment only in the vicinity of the location where the fire occurred.

The present invention has been made in view of the above points, and an object of the present invention is to provide a disaster prevention system that can quickly determine the type of fire in a tunnel and can quickly extinguish the fire appropriately according to the type of fire. That is.

[Means to solve the problem]

The above object is achieved by detecting the occurrence of a fire based on smoke or gas concentration detected over time by each sensor, determining the occurrence of a fire based on temperature data, and specifying the location of the occurrence. Then, the occurrence of a fire is detected based on the amount of detection data or gas concentration detected over time by each sensor, the occurrence of a fire is determined based on the temperature data, the location of the occurrence is determined, and the type of fire extinguishing equipment is determined based on the transition pattern of the detected data. This is achieved by selecting the location where the fire occurred and operating and controlling fire extinguishing equipment around the identified location of the fire.

[Effect]

By providing the above-mentioned means, fire can be comprehensively judged, and accurate detection and location can be performed at the initial stage of fire.

〔Example〕

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 1-5.

In a disaster prevention system equipped with gas, smoke, and temperature sensors la, lb, .
- The occurrence of a fire is detected based on the smoke or gas concentration of the temporal aspect ratio data obtained by 1n, the occurrence of a fire is determined based on temperature data, and the location of the occurrence is specified. Then, the occurrence of a fire is detected based on the smoke or gas concentration detected over time by each sensor la, lb, ... 1n,
In addition to determining the occurrence of a fire based on temperature data and specifying the location of the fire, the type of fire extinguishing equipment is selected based on the transition pattern of the detected data, and the fire extinguishing equipment is operated and controlled around the identified location of the fire. did. By doing this, fires can be judged comprehensively, and it becomes possible to accurately detect and locate fires at the initial stage, and to determine the type of fire within the tunnel at an early stage. It is possible to obtain a disaster prevention system that enables appropriate extinguishing of fire according to the type of fire at an early stage.

That is, as shown in the flowchart of FIG. 1, prior to data sampling, the fire level and initial value such as the abnormality determination level based on the shape of the detection section are set.

Sampled gas concentration and smoke concentration data Gl
, Gz・=Gt, Gsz, Ggz, -Gst are described, and the abnormality determination level G th * Cs t is set at a value determined to be abnormal (not normal).
h, G1≧Gth...(
1) Cs+≧Cst h −
If there is even one piece of data that is determined to be (2), this data group is filtered by averaging processing or the like to create data from which temporal increases and noise have been removed.

Assuming that these are G t * and Cs books, respectively, they are further compared with the abnormality determination level after the fillet reticulation process, and each is determined to be abnormal according to the following.

G1 ≧Gth' - (3)
Cst'g≧C5th' °°1
4) If it is determined to be abnormal again here, the temperature data θl,
Sampling is also started for θ2...θ, and if the eight filtered data are at or above the determination level below, it is determined that there is a fire.

θ4 ≧θth'...(5
) If θ- is below the fire determination level, the data sampling, filtering, and data storage routines for smoke concentration, gas concentration, and temperature are continued in a state where it is determined to be at the abnormality determination level, and the temperature rise is monitored. If the temperature does not rise while this routine continues and the smoke or gas concentration is below the abnormality determination level, some kind of abnormality has occurred, so confirm the point where it occurred and then reset it. did. This can also be done automatically.

If a fire is determined based on temperature data, the location of the fire is identified from the location of the temperature rise, a fire alarm and location display is performed on the output terminal device, and data sampling, filtering, and data storage are performed until the temperature falls below the fire determination level. Continue the routine.

Fires are detected and identified in this way, and an optical fiber cable or coaxial cable of a distributed temperature sensor is used as the temperature sensor. Temperature detection using optical fiber cables is based on (1) the fact that the intensity of Rayleigh backscattered light changes depending on the temperature of the optical fiber cable; (2)
) A method using Raman backscattered light newly generated by pulsed light incident on an optical fiber cable is currently being put into practical use.

By using the optical fiber cable as a temperature sensor in this way, the temperature and temperature rise position can be detected from the reflection time and amount of reflection of the optical pulse, and it can also be used as a transmission path for the disaster prevention system according to the present invention.

In the case of a coaxial cable, it has the same functions and effects as an optical fiber cable, but the distributed constant circuit has a one-dimensional spatial coordinate X.
, the distribution constant per unit length is L
, R, C, G, then the distributed voltage v (x
, t) and the distributed current i (x, t) are given by the following transmission line equation, where V□i is the input terminal voltage and current of the distributed constant circuit.

Therefore, if an impedance mismatch occurs due to a partial temperature rise in the middle of the coaxial cable, the reflected wave and waveform (backward reflection) will change at the input end, so the temperature at the point where the mismatch occurs and the temperature at that point will change. can be detected,
Also, like optical fiber cables, it can be used as a transmission path for disaster prevention systems.

In this way, an optical fiber cable or a coaxial cable is used as a distributed temperature sensor to detect and identify a fire.The operation and control of the fire extinguishing equipment will be explained with reference to the flowchart shown in FIG.

The basic principle of giving priority to temperature data in determining fire remains the same, but as shown in Figure 2, temperature data θl, θ2...θ1 are added as sampling data, and gas concentration and smoke concentration data Gx , Gx.

-Gt, Cst+ Csz, -Cst as well as initially set abnormality determination levels Gth, C5th, θth
If there is at least one piece of data for which it is determined that Gi≧Gth Cst≧C5th θ1≧θ th, this data group is subjected to averaging processing or the like to be filtered data.

This is the same as the above-mentioned Figure 1, respectively.

Assuming that CSt is 01 zero, compare it again with the abnormality determination level as follows.

01 ≧Gth'Cst*≧Cgth' θj ≧θth' If it is determined to be abnormal again, if the data that was initially determined to be abnormal is (1) gas concentration or smoke concentration, it is a cable fire. Therefore, the rise in temperature data is monitored in the same way as in FIG. That is, the routine of data sampling, filtering, and data storage of gas concentration or smoke concentration is continued until the temperature data reaches the abnormality determination level.

Additionally, if the temperature data does not exceed the abnormality judgment level while the routine continues, and the gas concentration or smoke concentration falls below the abnormality judgment level, the reset state is entered after confirming the point where the abnormality has occurred.2 This is done automatically. It is also possible. (2
) If the first data determined to be abnormal is temperature, it is predicted that it is an oil fire or a flaming fire, and a fire is determined based on an algorithm that prioritizes temperature data, and the location of the fire is identified from the location of the temperature rise.

As mentioned above, from the rising pattern of sampling data, (1) smoke or gas concentration abnormality → temperature data If it is determined that a fire is occurring, the type of fire extinguishing equipment suitable for extinguishing a cable fire - for example, water spray Fire extinguishing equipment can be selected. In addition, (2) Temperature data abnormality → If it is determined that the temperature data is a fire, select the type of fire extinguishing equipment suitable for extinguishing oil fires - for example, foam fire extinguishing equipment,
You can choose.

After selecting the type of fire extinguishing equipment, in the vicinity of the identified fire outbreak location, open valves are set up in certain areas or fire extinguishing equipment with area selection valves is activated to effectively limit the damage and extinguishing agent release area. be able to.

As in the case of FIG. 1, the fire alarm and occurrence location are displayed on the output terminal device, and the data sampling, filtering, and data storage routines are continued until the fire level falls below the fire judgment level.

The disaster prevention system according to this embodiment is installed along the cable laying route in a tunnel, and can be effective in early detection and early response to cable fires and the like.

In other words, a tunnel is a long-distance tunnel-shaped structure,
Moreover, in many cases they are buried underground, making it difficult to accurately detect the occurrence of a fire and identify the location of the fire. Cables and electric wires laid in tunnels are coated with flammable materials, and are susceptible to (1) cable ignition due to internal causes such as ground faults, short circuits, and overcurrents, or (2) fire during construction. When a fire is caused by an external factor such as arson, the heat dissipation space in a tunnel-shaped structure is narrow and the fire spreads through the heat storage device, making it difficult to extinguish the fire due to the generation of a large amount of black smoke and toxic gas. The characteristic of this cable fire is that the group cable generates a large amount of heat. In other words, underground structures in tunnels have limited entrances, and once a fire has broken out, it is important to limit the ignition point and accurately grasp the gas-filled state in order to carry out appropriate firefighting operations. This is a major factor.

The disaster prevention system shown in Figure 3 is similar to Figures 1 and 2.
Relay units 2 each containing a built-in CPU having a determination function as shown in the figure are installed at regular blocks along the cable laying route in the tunnel.

As mentioned above, la, lb...1n are sensors (analog detectors) that detect changes in physical quantities in the surrounding environment over time during steady state and due to fire outbreak, and are used for initial detection of fire outbreak in the target area. A plurality of spot-type gas sensors (gas concentration detectors) 1a and smoke sensors (smoke concentration detectors) lb are installed at appropriate intervals according to the shape of the detection target, and a plurality of them are connected. The temperature sensor 1n is connected to each relay unit 2 for the purpose of detecting temperature and specifying the location of a fire using a distributed temperature sensor. These gas sensors la,
The smoke sensor 1b has a built-in A/D conversion section and a transmission circuit section in which a unique address is set.

The data detected by each sensor la, lb...1n is
The receivers 3a, 3b, . . . , 3n of the relay unit 2 collect data every predetermined time period τ seconds using a polling method, and output the data to the data processing section 4.

The data processing unit 4 inputs detection data GI, Csi, θ, from the receivers 3a, 3b, . . . , 3n to each sensor la.

It is divided into 1b...1n and output to the data memory part 5, and the activation level G set in the level setting section 6 is also output.
th, C5th, and θth.

If the detected data is above the abnormality judgment level, filtering is performed by averaging processing, etc., and the filtered data 01, Cs 1, θ, is further compared with the abnormality judgment level, and when it is above the set level. It is determined that there is an abnormality (not normal), and the calculation unit 7 starts determining the fire and calculating the location of the fire occurrence.

The calculation unit 7 reads the data that exceeds the abnormality determination level from the data memory part 5, calculates the distribution of gas concentration, smoke concentration, or temperature distribution based on this detected data, and determines the location of the fire in the determination unit 8. to determine the flow direction of smoke and gas, the direction of temperature change, etc.

In the data memory part 5, each sensor la, lb...1n
A predetermined number of detection data and filtering processing data are sequentially updated and stored for each address.

The results from the determination unit 8 are output to the alarm display unit 9, the fire occurrence position display unit 10, the smoke and gas flow display unit 11, and are displayed on an output terminal device such as a CRT screen installed in the site management room or the like. . Also, from the data processing unit 4 to the environmental data display unit 1
2 indicates a non-abnormal state.

Information from the first determination section 8 is transferred from the transmission circuit section 13 of the relay unit 2 to a central processing unit installed in a central operation control room or the like, and the data of each relay unit 2 is centrally monitored.

Data is transferred between this relay unit 2 and the field management office and central operation control room via a modem.

One embodiment using a telephone line is shown in FIG.

As is clear from the figure, spot-type smoke and gas sensors lax, lbz...lno are connected to the relay unit 2a (and the other relay units 2b...2n as well). And between the relay units 2a, 2b'' and 2n, a distributed temperature sensor lnz that also serves as a transmission line, for example, an optical fiber cable, is installed.Usually, the relay units 2a, 2b
...2n is installed outside the tunnel. Of course, the optical fiber cable as the distributed temperature sensor Inn is installed in the tunnel of the detection target area. Relay units 2a, 2b...2
A telephone line and a PBX (digital exchange) 15 are connected between the CPU 14 in the central operation control room, which is the receiver, and each is equipped with a modem (digital/analog type modulation W) and an NCU (electric automatic calling/receiving unit). 1) 16.17 was installed to perform alarms and data transmission. These data are stored in CPUs installed in several site management offices and a central operation control room that connects these offices.
4a and displayed on terminal devices such as CR-Ts and printers in 14.

FIG. 5 shows an embodiment of a disaster prevention system that selects and controls fire extinguishing equipment. A relay unit 2 connected to a spot-type smoke and gas sensor 1 placed in the detection target area and a distributed temperature sensor lnx that also serves as a transmission line is used to confirm the occurrence of a fire and the location of the fire, and to determine the rising pattern of sampling data. Determine the type of fire and use these judgment results as a control bag for fire extinguishing equipment! ! Send a call on 18.

The fire extinguishing equipment has a release valve 19 for each predetermined area, and has a nozzle 20 to cover this area.

When a fire signal is received and the type of fire is determined to be an oil fire, the main valve 22 of the foam stock solution tank 21 is opened, and the release valve 19 is opened to release the foam agent mixed with water in the mixer 23 to the area concerned. , through the nozzle 20. If the type of fire was determined to be a cable fire, the release valve for the area where the fire occurred or the area in the direction of the spread of the fire was opened and water spray was sprayed. In addition, powder fire extinguishing equipment is also available.

It can also be used in combination with gas fire extinguishing equipment, etc.

In this way, according to this embodiment, the occurrence of a fire before the temperature rises immediately after the fire is detected by the change in smoke or gas concentration spreading inside the tunnel, and the distributed temperature sensor is used to detect the occurrence of a fire. Since the fire extinguishing equipment is selected and activated by specifying the temperature detection position 2 of the part, the following effects can be achieved.

(1) Since fires are comprehensively determined based on detection data over time from multiple detectors with different detection principles, fires can be detected accurately at the initial stage, and false alarms (non-fire alarms) can be detected. occurrence can be reduced.

(2) By combining the detection data from the distributed temperature sensor, it is possible to not only identify the location of the fire outbreak, but also detect the location of the fire inside the tunnel-shaped structure. to reduce the number of detector points,
In addition, data processing can be facilitated.

(3) The nature of the fire can be determined from the rising pattern of detected data.

(4) By using a gas detector capable of detecting HCl or the like, cable fires in particular can be detected accurately and easily.

(5) By being able to accurately detect fires, it is possible to automate the linkage with fire extinguishing equipment, and it is also possible to identify the location and determine the nature of the fire, so it is possible to select the type of fire extinguishing equipment that is suitable for the nature of the fire. It can be activated in a limited area.

(6) By installing the disaster prevention system according to this example in a tunnel, it is possible to perform early detection of cable fires or oil fires in the tunnel, and appropriate fire extinguishing equipment is limited to the vicinity of the fire occurrence location. It can be activated.

Another embodiment of the invention is shown in FIG.

In this embodiment, a distributed temperature sensor lnz connecting relay units 2a, 2b, . . . , 2n is used as a pass line. By doing so, it becomes easier to install the system over a longer distance and over a wider area than in the case described above.

Spot-type smoke and gas sensors far and l are installed in the relay unit 2a (same for relay units 2b...2n).
bx...1nO are connected to the relay unit 2a as in the case of FIG. 4.

2b...2n are connected by the path line of the distributed temperature sensor lnz. And relay units 2a, 2b...2n
The communication control unit 24 multiplexes and transmits digital signals from the CPU 14b installed in a central operation control room, etc.
I sent it to .

In this embodiment, the relay unit 2a.

2b...2n performs data sampling and filtering of gas and smoke concentration, and when the level is abnormal, the CPU 14b
It is now possible to send out warnings and data.

The CPU 14b receives the received data and the distributed temperature sensor lnz.
After processing the data, determining the fire, identifying the location of the fire, and calculating the mushroom distribution of each data, the alarm and determination results are displayed on the terminal device.

〔Effect of the invention〕

As described above, the present invention enables early determination of the type of fire within a tunnel and appropriate extinguishing according to the type of fire. It is possible to obtain a disaster prevention system that enables appropriate extinguishing according to the type of fire.

[Brief explanation of the drawings] Fig. 1 is a flowchart of fire detection in one embodiment of the disaster prevention system of the present invention, Fig. 2 is a flowchart in conjunction with fire extinguishing equipment of the same embodiment, and Fig. 3 is the same. FIG. 4 is an explanatory diagram of a system using a telephone line according to an embodiment; FIG. 5 is an explanatory diagram showing a system configuration in conjunction with fire extinguishing equipment according to an embodiment; FIG. The figure is an explanatory diagram showing a system configuration when a pass line of another embodiment of the disaster prevention system of the present invention is used. 1a...Gas sensor, 1b...Smoke sensor, 1n...
・Temperature sensor, lnz...Distributed temperature sensor.

Claims (1)

[Claims] 1. In a disaster prevention system equipped with smoke, gas, and temperature sensors arranged at multiple points within a target section, fire detection is performed based on the smoke or gas concentration detected over time by each of the sensors. A disaster prevention system characterized by detecting the occurrence of a fire, determining the occurrence of a fire based on temperature data, and identifying the location of the fire. 2. The disaster prevention system according to claim 1, wherein the temperature sensor uses an optical fiber cable or a coaxial cable as a distributed temperature sensor, and is also used as a transmission path of the system. 3. The disaster prevention system according to claim 1, wherein the smoke, gas and temperature sensors are arranged inside a tunnel-shaped structure such as a tunnel or a common ditch. 4. The disaster prevention system according to claim 1 or 3, wherein the gas sensor is capable of detecting HCl. 5. In a disaster prevention system equipped with smoke, gas, and temperature sensors placed at multiple points within the target section, detecting the occurrence of a fire based on the smoke or gas concentration of the detection data over time by each of the sensors, Determine the occurrence of a fire based on temperature data, identify the location of the fire, select the type of fire extinguishing equipment based on the transition pattern of the detected data, and activate the fire extinguishing equipment around the identified location of the fire.・
A disaster prevention system characterized by being controlled. 6. The disaster prevention system according to claim 5, wherein if the temperature rise occurs later than the smoke or gas concentration rise in the transition pattern of the detection data, it is determined that there is a cable fire. 7. The disaster prevention system according to claim 5, wherein if the temperature rise occurs earlier than the smoke or gas concentration rise in the transition pattern of the detection data, it is determined that there is an oil fire. 8. The disaster prevention system according to claim 5, 6, or 7, wherein the disaster prevention system is configured to extinguish fires suitable for cable fires and oil fires.