JPH11232565A - Method and device for detecting fire within closed conduit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sensitively detect the occurrence of a fire and a fire occurring point without regard to environment at an early stage when the fire occurs within a closed counduit by detecting the occurrence of a fire from wind velocity at respective parts such as the neighborhood of a ceiling, that of a middle part, that of a floor. SOLUTION: At three levels of housing shelves 7a to 7c, a (neighborhood of the ceiling) measuring instrument 11a, a (neighborhood of the middle part) measuring instrument 11b and a (neighborhood of the floor) measuring instrument 11c respectively consisting of an anemometer 9 measuring the wind velocity of an air flow and an anemoscope 10 measuring the wind direction of the air flow are respectively arranged at places A to D arranged nearly at regular intervals in the length direction of the inside of the closed conduit. These measuring instruments are respectively connected to a signal processor 12, which processes the wind velocity and wind direction signals of the air flows of the respective parts of respective places to transmit to an arithmetic controller 13. When the controller 13 recognizes a fire occurrence pattern, a warning device 14 is operated to output warning and a monitoring panel 17 displays the wind velocity and wind direction signals of the air flows of the respective parts of the respective places on a display screen 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting a fire in a closed space (hereinafter referred to as "underdrain") in which electric cables and communication cables are laid.

[0002]

2. Description of the Related Art For example, in a factory, a large number of high-voltage electric cables and communication cables for supplying electricity to many facilities are laid. In general, these cables are often concentrated and housed in a culvert having an inspection port and a cable outlet from the viewpoint of protection and ensuring safety.

[0003] The culvert is usually disposed underground, on the ceiling or under the floor, but when laid in a factory where high heat is generated, the cable is exposed to a high heat environment in addition to the electric resistance heat of the cable. The sheath of the cable may be degraded or damaged by being bitten by a rat, causing a spark due to a short circuit, igniting the cable sheath and developing into a fire. Conventionally, measures have been taken to prevent such a phenomenon from occurring, but it is difficult to completely eliminate fire anxiety.

[0004] Therefore, conventionally, in the event that a fire occurs due to the ignition of the cable coating, a fire detection method for detecting the fire early is as follows: (1) A heat sensing device is arranged in a culvert to reduce the temperature caused by the fire. A method of detecting the occurrence of a fire by detecting the rise of the fire. (2) A method of locating a smoke detector in a culvert and detecting the occurrence of a fire by detecting smoke caused by a fire in the culvert. It has been known.

[0005] However, in the case of the method (1), the inside of the culvert under a high temperature environment is considerably high even in a normal case, and it is necessary to detect a subtle temperature rise immediately after the occurrence of a fire with high sensitivity. Is difficult, the detection accuracy is low, and the fire cannot be reliably detected unless the fire spreads to some extent.
In the case of the method (2), in a culvert under an environment containing dust and the like, there is considerable dust and the like even in a normal case, and it is difficult to detect subtle smoke immediately after a fire with high sensitivity. Therefore, there is a problem that the detection accuracy is low, and the detection cannot be reliably performed unless the fire spreads to some extent.

[0006]

SUMMARY OF THE INVENTION The present invention provides a fire detection method and a fire detection method capable of detecting a fire occurrence and a fire occurrence point with high sensitivity without being influenced by the environment at an early stage when a fire occurs in a culvert. An apparatus is provided.

[0007]

Means for Solving the Problems A first invention of the present invention is:
At one or more locations along the length of the culvert, measure the wind speed at each location near the ceiling, near the middle, and near the floor at each location, and detect the occurrence of fire in the culvert based on the wind speed at each location at each location. This is a method for detecting a fire in a culvert. The second invention measures the wind direction of each part near the ceiling and floor at each location at one or more locations in the length direction of the culvert, and generates a fire in the culvert from the wind direction of each part at each location. A method for detecting a fire in a culvert, comprising: According to a third aspect of the present invention, at one or a plurality of locations in the length direction of the culvert, the wind speed of each part near the ceiling, the middle, and the floor of each part, and the wind velocity of each part near the ceiling and the floor near each part This is a method for detecting a fire in a culvert based on measuring a wind direction and detecting the occurrence of a fire in the culvert and its occurrence point based on the wind speed of each part.

The invention according to a fourth aspect of the present invention is that the vicinity of the ceiling, the vicinity of the middle of each of one or a plurality of locations in the length direction in the culvert,
Anemometers installed at each part near the floor, a signal processing device that processes wind speed signals from each anemometer, wind speed patterns of each part at each location at the time of a preset fire, and actual signals from the signal processing device An arithmetic and control unit for comparing and calculating the wind speed pattern of each part of each part, an alarm device, and a monitoring panel having an alarm lamp and a display screen for displaying the wind speed. is there. A fifth invention is directed to a wind vane installed at each location near a ceiling or a floor at one or more locations in a longitudinal direction in a culvert, and a signal processing device for processing a wind direction signal from each wind vane. And an arithmetic and control unit for comparing and calculating a preset wind direction pattern of each part at each point at the time of fire occurrence and a wind direction pattern of each part of each actual part from the signal processing device, an alarm device, and an alarm lamp. A fire detecting device in a culvert, comprising a monitoring panel having a display screen for displaying a wind direction. The sixth invention is
An anemometer installed near the ceiling, near the middle, and near the floor at one or more locations along the length of the culvert, and an anemometer installed near the ceiling and near the floor at each location And a signal processing device for processing a wind speed signal and a wind direction signal from each anemometer and each anemometer, and a wind speed and a wind direction pattern of each part of each place at the time of a preset fire and actual actual data from the signal processing device. An arithmetic and control unit for comparing and calculating the wind speed and the wind direction pattern of each part of the place, an alarm device,
A fire detector in a culvert comprising a monitoring panel having an alarm lamp and a display screen for displaying wind speed and direction.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when a fire occurs in a culvert, the occurrence of the fire can be detected at an early stage with high accuracy by measuring the wind speed and direction of the airflow generated by the fire. It is. The wind speed and direction of this air flow change relatively sensitively in the event of a fire, and are not affected by the environment as in the conventional method, so that the detection accuracy is extremely good.

The present inventors have proposed the above-mentioned conventional (1) and (2)
In the case of the detection method described above, based on the recognition that it is difficult to detect the fire only after the spread of the fire and that early measures are not taken, we examined fire detection methods that can replace these conventional detection methods. Through various experiments and analyses, in the case of a relatively small enclosed space such as a culvert, if a fire occurs, the air currents centered on oxygen and carbon dioxide gas over a fairly wide range centering on the fire origin They came to find that they move sensitively. The present invention has been completed as a result of repeated experiments and analyzes based on this finding.

According to the analysis of the present inventors, for example, FIG.
In a culvert 2 having two openings 1a and 1b in the longitudinal direction as shown in FIG. 2, in a normal case, an extremely weak airflow in one direction is changed from one opening 1a having a large pressure to the other opening 1b having a small pressure. 3 results. Although the absolute value of the wind speed 5 of this air flow 3 is small, it is large near the middle b, near the ceiling a and near the floor c.
Has a small distribution.

However, when a fire occurs, the airflow 3
Changes direction. For example, as shown in FIG.
If a fire 4 occurs between the two openings 1a and 1b,
On both sides of the point where the fire 4 occurred, the direction of the airflow changed with the middle part b as the boundary, and the area near the ceiling a
Air flow 3a exiting through one opening 1a, 1b through
a, 3b, the airflow 3b entering the fire point through the floor c near the floor
Occurs. That is, the airflow 3a near the ceiling a is the opening 1
Since the air flow near the floor a is directed toward the fire occurrence point, the air flow direction is opposite at the respective portions on both sides of the fire occurrence point.

Further, as shown in FIG.
In the case of only b, the direction of the airflow changes on both sides of the center of the point where the fire 4 occurs, as in the case of FIG. However, since there is no opening on one side of the fire occurrence point, an airflow 3c from the fire occurrence point to the fire occurrence point through the vicinity a of the ceiling and the vicinity c of the floor is generated, and an opening is formed on the other side of the fire occurrence point. 1b
There is an opening 1b through the vicinity of the ceiling a from the fire occurrence point
3a, and an airflow 3b entering the fire occurrence point from the opening 1b through the vicinity c of the floor. The above changes in airflow are
It has been confirmed that it occurs earlier than temperature rise or smoking.

Thus, by measuring the wind speed and direction of the air flow in the culvert 2, the occurrence of a fire in the culvert 2 can be detected, and the approximate fire occurrence point can be known. When a fire occurs in the culvert 2, the airflow characteristically changes at three locations near the ceiling a, near the middle b, and near the floor c in the culvert. FIG.
Is a mathematical expression showing changes in the wind speed and direction of the airflow in the normal state and in the state where a fire has occurred in each part of the culvert 2 near the ceiling a, near the middle b, and near the floor c.

(1) Normal case [Change in wind speed of air flow] As shown in FIG. 3 (a), the wind speed distribution 5 of the air flow in the culvert 2 is large near the middle (b), and near the ceiling (a) and the floor. It becomes smaller near (c). The average wind speed of each part is defined as Va (near the ceiling), Vb (near the middle), V
If c (near the floor), it can be expressed by (Va + Vc) / 2 <Vb (1).

[Change in Airflow Wind Direction] As shown in FIG. 3A, the airflow direction is the same in the vicinity of the middle (b), near the ceiling (a), and near the floor (c). Va wind direction = Vb wind direction = Vc wind direction (2)

(2) In the case of a fire (fire occurrence on the left side) [Change in wind speed of air flow] As shown in FIG. 3 (b), the wind speed distribution 5 of the air flow is near the ceiling (a) and near the floor (c). Large
It becomes smaller near the middle (b). Assuming that the average wind speed of each part is Va (near the ceiling), Vb (near the middle), and Vc (near the floor), (Va + Vc) / 2> Vb (3) Can be represented by

[Changes in Airflow Wind Direction] As shown in FIG. 3B, the airflow direction is rightward near the ceiling (a) and leftward near the floor (c). Va wind direction = right direction, Vc wind direction = left direction (4) In this case, the point of occurrence of fire 4 is on the left side of the measurement position.

(3) In the event of a fire (fire occurrence on the right side) [Change in wind speed of air flow] As shown in FIG. 3 (c), the wind speed distribution 5 of the air flow is near the ceiling (a) and near the floor (c). It is large and small near the middle (b). Average wind speed of each part is Va (near the ceiling), Vb (near the middle), Vc (near the floor)
Then, (Va + Vc) / 2> Vb (5)

[Changes in Airflow Wind Direction] As shown in FIG. 3C, the airflow direction is leftward near the ceiling (a) and rightward near the floor (c). Va wind direction = leftward, Vc wind direction = rightward ... (6) In this case, the point of occurrence of fire 4 is on the right side of the measurement position.

From the above, the occurrence of a fire can be detected by measuring the wind speed of the airflow in each of the vicinity of the ceiling, the vicinity of the middle, and the vicinity of the floor at substantially the same location in the length direction of the culvert. Further, the occurrence of the fire and the approximate point of the occurrence of the fire can be detected by measuring the wind direction of the airflow in each of the vicinity of the ceiling and the floor near the same location in the length direction of the culvert.

Furthermore, if both the wind speed measurement and the wind direction measurement are performed, the occurrence of a fire and the point where the fire occurred can be detected more reliably. However, culverts are often set up for quite long distances, and when the wind speed and direction are measured at only one location in the length direction of the culvert, when the distance from the fire origin is long, the When the culvert is installed over a long distance, the measurement of the wind speed and wind direction should be performed by measuring the culvert. Is preferably performed at a plurality of locations arranged at intervals of, for example, 50 m to 100 m in the length direction.

As a method of detecting the occurrence of a fire or a fire occurrence point from the wind speed or wind direction at each part of each place, for example, a pattern of the wind speed or wind direction of the airflow at each part at each place at the time of fire occurrence is set in advance. In addition, there is a method of using a monitoring panel that, when the wind speed or the wind direction of the airflow that satisfies this pattern, generates a fire alarm and blinks an indicator lamp at a measurement point near the fire point at the same time.

For example, at one measurement point, the wind speed and wind direction pattern described in (2) above is obtained, and at the other measurement point, (3)
If the wind speed and wind direction pattern becomes as follows, it indicates that the fire occurrence point is located between these two measurement points. Therefore, by flashing the display lamps of these two measurement points on the monitoring panel, It can be detected that there is between these two measurement points.

According to the fire detection method of the present invention configured as described above, it is possible to accurately detect the occurrence and point of occurrence of a fire earlier than the conventional fire detection method, and to take safety measures including fire extinguishing and equipment maintenance measures. Etc. can be taken at an early stage.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an example of a fire detecting device embodying the present invention shown in FIGS. This example
This is a case where a culvert for laying an underground electric cable between an electric facility and a manufacturing facility is a fire detection target.

In FIG. 4, reference numeral 2 denotes a culvert, which has a plurality of cable outlets 1a and 1b at an upper part and a plurality of inspection ports 6 which can be opened and closed at a side portion. There are three stages of cable storage shelves 7a, 7b, 7c extending to the storage shelves.
Is housed.

The three levels of storage shelves 7a, 7b, 7c
A measuring device 11a (near the ceiling) comprising an anemometer 9 for measuring the wind speed of the airflow and an anemometer 10 for measuring the wind direction of the airflow;
(Near the middle) Measuring device 11b, (Near the floor) Measuring device 11
c are arranged at substantially equal intervals in the length direction of the culvert 2
D is provided at each of the four positions.

Each of these measuring devices is connected to a signal processing device 12, which processes a wind speed and a wind direction signal of an airflow from each part at each location and sends the processed signals to an arithmetic and control unit 13. Send. In this arithmetic and control unit, various wind speeds and wind direction patterns based on the expressions (1) to (6) are set in advance, and the arithmetic and control unit uses the set pattern and each part (A to D). And a pattern based on a wind speed and a wind direction signal of the airflow from each of the parts a, b, and c.

The arithmetic and control unit includes an alarm device 14 for issuing an alarm for a fire occurrence, an alarm lamp 15 for each location (A to D), and a wind speed for each location (a, b, c) for each location. A monitoring panel 17 (see also FIG. 6) provided with a display screen 16 for displaying the wind direction is connected, and when the arithmetic and control unit 13 recognizes a fire occurrence pattern, the alarm unit 14 is activated to issue an alarm. At the same time, the monitor panel 17 displays the wind speed and direction of the airflow at each location on the display screen 16, and at the same time, an alarm lamp 15 at each location where the occurrence of a fire is detected.
Flashes.

Therefore, when the occurrence of a fire is detected, it can be known by the alarm device 14 issuing an alarm and by the flashing of the alarm lamp 15 of the monitor panel 17,
At the same time, the approximate point where the fire occurred can be known from the blinking point of the alarm lamp 15. ADVANTAGE OF THE INVENTION The fire detection method of this invention can detect an outbreak of a fire early and accurately, even if it is in an environment of high temperature, a lot of dust, etc., without being influenced by these environments.

Note that the present invention is not limited to this example. For example, in this example, the culvert 2 has a rectangular cross section and is provided with openings such as the cable outlet 2 and the inspection port 3, but the shape is not limited to a rectangle, but may be a square or a circle. Is also good. A new opening may be provided, but this is not essential. Further, the airflow anemometer 9 and the airflow anemometer 10 are provided in parallel, but a measuring device having both an anemometer function and an anemometer function may be used.

In this example, the anemometer 9 and the anemometer 10
And the measurement information from the anemometer 9 and the anemometer 10 is used together, but the measurement information from either the anemometer 9 or the anemometer 10 may be used, or the anemometer 9 and the anemometer Even if only one of the total 10 is arranged, it is possible to detect the occurrence of a fire or the occurrence of a fire and the point where the fire occurred.

Processing of wind speed and wind direction information, arithmetic control, alarm,
Regarding the configuration of the fire detection device of the present invention, such as a fire occurrence detection system such as display, and the arrangement position of the measurement device,
Depending on the construction conditions of the culvert and the cable conditions to be accommodated,
Changes are made within the scope satisfying the above claims.

[0035]

According to the present invention, when a fire occurs in a culvert, the occurrence of the fire can be detected at an early stage with high accuracy by measuring the wind speed and direction of the air flow that changes due to the fire. it can. The wind speed and direction of this air flow change relatively sensitively in the event of a fire,
Since there is no influence of the environment such as temperature and dust as in the conventional method, the detection accuracy is extremely good.

[Brief description of the drawings]

FIG. 1 is a conceptual side sectional view showing the direction and wind speed distribution of an airflow in a culvert in a normal state obtained by an experiment.

FIG. 2 (a) is a schematic side sectional view showing the direction and wind speed distribution of the air flow in a culvert at the time of a fire obtained in an experiment,
(B) is a side sectional conceptual diagram showing the direction of the airflow in the culvert and the wind speed distribution in another example (when the opening position is different) at the time of fire occurrence obtained in the experiment.

FIG. 3 is a conceptual explanatory diagram showing an example of a method of determining the direction of the air flow and the wind speed distribution in a culvert in a normal state and when a fire occurs, which is used in the fire detection method according to the present invention.

FIG. 4 is a conceptual explanatory side sectional view showing an example of equipment arrangement for implementing the present invention.

FIG. 5 is a sectional view of the culvert in FIG. 4;

FIG. 6 is an enlarged view of the monitoring panel in FIG.

[Explanation of symbols]

 1a-1b Cable outlet (opening) 2 Underdrain 3, 3a, 3b, 3c Air flow 4 Fire 5 Wind speed distribution 6 Inspection port 7a, 7b, 7c Storage shelf 8 Electric cable 9 Anemometer 10 Anemometer 11a, 11b, 11c Measuring device Reference Signs List 12 signal processing device 13 arithmetic and control device 14 alarm device 15 alarm lamp 16 display screen 17 monitoring panel

Claims (6)

[Claims] At one or more locations in the length direction of the culvert, the wind speed of each portion near the ceiling, near the middle, and near the floor at each location is measured, and a fire in the culvert is measured based on the wind speed at each location at each location. A method for detecting a fire in a culvert, characterized by detecting occurrence. 2. At one or more locations in the longitudinal direction of the culvert, the wind direction of each part near the ceiling and floor is measured at each location, and the occurrence of fire in the culvert is determined based on the wind direction at each location at each location. A method for detecting a fire in a culvert, comprising detecting a point at which the fire occurs. 3. At one or more locations in the longitudinal direction of the culvert, the wind speed at each location near the ceiling, near the middle, and the floor at each location, and the wind direction at each location near the ceiling and the floor at each location. A method for detecting a fire in a culvert based on the following formula: 4. An anemometer installed at each location near the ceiling, near the middle, and near the floor at one or more locations in the length direction of the culvert, and a signal for processing an anemometer signal from each anemometer A processing device, an arithmetic and control unit for comparing and calculating a preset wind speed pattern of each part at each location at the time of fire occurrence and a wind speed pattern of each part of each actual location from the signal processing device, an alarm device, and an alarm A fire detector in a culvert, comprising a monitoring panel having a lamp and a display screen for displaying wind speed. 5. An anemoscope installed at each location near the ceiling or floor at one or more locations in the length direction of the culvert, and a signal processing device for processing a wind direction signal from each anemometer. An arithmetic control unit for comparing and calculating a preset wind direction pattern of each part at the time of a fire occurrence and a wind direction pattern of each part of the actual place from the signal processing device, an alarm device, an alarm lamp, and a wind direction A fire detection device in a culvert, comprising a monitoring panel having a display screen for displaying a fire. 6. An anemometer installed at each location near the ceiling, near the middle, and near the floor at one or more locations in the length direction of the culvert, and each location near the ceiling and near the floor at each location An anemometer installed in the system, a signal processing device for processing the wind speed signal and the wind direction signal from each anemometer and each anemometer, and a preset wind speed and wind direction pattern and signal processing device for each part at each time of fire occurrence An arithmetic and control unit for comparing and calculating the wind speed and wind direction pattern of each part of the actual part from
A fire detector in a culvert comprising an alarm device, an alarm lamp, and a monitoring panel having a display screen for displaying wind speed and direction.