JP2004154448A - Automatic fire extinguishing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic fire extinguishing system which is suitable for extinguishing a fire of cable connecting sections or the like installed in utility tunnels. <P>SOLUTION: The automatic fire extinguishing system for extinguishing the fire of the cable connecting section 11 or the like in the utility tunnel with use of suitable fire extinguishing agents, is provided with a fire detection sensor which is composed of smoke detecting sensors 13 and infrared flame detecting sensors 14 thereby detecting the fire when detecting both the smoke and the flame, spray nozzles 15 for spraying extinguishing agent which are predisposed toward fire breakout supposed positions such as cable connecting section 11 laid in the utility tunnels to spray the extinguishing agents to the fire breakout supposed positions, and extinguishing agent spray devices 18 for feeding the extinguishing agents to injecting nozzles 15 through actuations of the fire detecting sensor. According to the present invention, owing to pre-specification of extinguishing objects, the fire in the utility tunnels can securely and immediately be extinguished even with a little amount of extinguishing agents. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic fire extinguisher suitable for extinguishing a fire such as a cable connection portion laid in a cave.
[0002]
[Prior art]
A large number of electric cables and pipes are laid in the cave, and if an electric fire is caused by the cable in the cave, a ground fault may be caused to cause a catastrophic disaster. In particular, it is considered that a fire from a high-voltage cable connection is likely to occur.
[0003]
For this reason, an automatic fire extinguishing device that operates unattended is installed around the cable connection to take initial fire extinguishing measures. As a conventional automatic fire extinguishing system, a fire extinguishing system is used in which the entire manhole containing the cable connection is filled with a fire-extinguishing solution containing a large amount of water, or the cable connection is covered with a fire-resistant cloth. In the event of a fire, a fire extinguisher is released into the fire-resistant cloth (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-5-177008 [0005]
[Problems to be solved by the invention]
By the way, the conventional techniques as described above have the following problems to be solved.
Extinguishing a fire by filling the entire manhole with fire-extinguishing liquid is extremely large-scale, requiring not only a large amount of fire-extinguishing liquid but also a secondary disaster, and a great deal of time and cost for post-processing. There are difficulties.
In addition, when the cable connection is covered with a fire-resistant cloth and the fire extinguishing agent is released into the fire-resistant cloth in the event of a fire, the cable connection is always covered with a fire-resistant cloth. It is considered difficult to perform other maintenance.
On the other hand, the inside of the cave where the cable is laid is a hot and humid space due to easy generation of fog and heat generation of the cable, and the environmental condition is extremely poor such as dew condensation. Therefore, when a thermal sensor or a normal smoke detector is used as a sensor installed to detect a cable fire, the perception of the fire is unstable.
[0006]
The present invention has been made by paying attention to the above points, and an automatic fire extinguishing device capable of surely and quickly extinguishing a fire in a cave with a small amount of extinguishing agent by previously specifying a fire extinguishing target in the cave. It is intended to provide.
[0007]
[Means for Solving the Problems]
The present invention employs the following configuration to solve the above points.
<Configuration 1>
An automatic fire extinguishing device that extinguishes a fire in a cave, a fire detection sensor that is installed in a predetermined place in the cave in advance and detects a fire when it detects flame and smoke, and an estimated fire occurrence location in the cave in advance And a fire extinguishing agent spraying device for spraying a fire extinguishing agent to the expected fire occurrence location, and a fire extinguishing agent spraying device for supplying a fire extinguishing agent to the spray nozzle by operation of the fire detection sensor. And automatic fire extinguisher.
[0008]
<Configuration 2>
An automatic fire extinguishing device that extinguishes a fire at a cable connection in a cave, which is installed in a predetermined place in the cave in advance and detects a fire when detecting flame and smoke generated from the cable connection. A sensor, an injection nozzle arranged toward the cable connection portion, for injecting a fire extinguishing agent to the cable connection portion, and a fire extinguishing agent injection device for supplying a fire extinguishing agent to the injection nozzle. Automatic fire extinguisher.
[0009]
<Configuration 3>
An automatic fire extinguishing device that extinguishes a fire in a cable connection section provided in multiple stages in a vertical direction in a cave, and is installed in a predetermined place in a cave in advance and detects flame and smoke generated from the cable connection section. A fire detection sensor that detects a fire when the fire has occurred, an injection nozzle that is previously arranged above the uppermost cable connection portion and injects a fire extinguishing agent to the uppermost cable connection portion, An automatic fire extinguisher comprising:
[0010]
<Configuration 4>
4. The automatic fire extinguisher according to any one of the constitutions 1 to 3, wherein the fire detection sensor has a light source and a light receiving element installed with a light shielding plate interposed therebetween, and emits light of the light source irregularly reflected by smoke entering the inside. An automatic flame detection sensor comprising: a smoke detection sensor for detecting smoke by detecting a light receiving element; and an infrared flame detection sensor for detecting a flame by detecting a reverse current flowing in proportion to the amount of light when light strikes. Fire extinguisher.
[0011]
<Configuration 5>
In the automatic fire extinguisher according to any one of the constitutions 1 to 3, the extinguishing agent is a mixture of a chemical solution based on a fluorine-based surfactant and water, and the compounding ratio of the chemical solution to the water is 8 to 10. An automatic fire extinguisher characterized by being 12%.
[0012]
<Configuration 6>
In the automatic fire extinguisher according to any one of the constitutions 1 to 5, the fire extinguishing agent injection device is configured such that the fire extinguishing agent is constantly stored under atmospheric pressure, and the fire detection sensor operates to activate the fire extinguishing agent. An automatic fire extinguishing device, comprising: an injection pressurizing device that starts a pressurizing operation on the fire extinguishing agent and pressure-feeds the extinguishing agent to the injection nozzle.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described using specific examples.
FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view along line AA in FIG. 1, FIG. 3 is a front view along line BB, and FIG. It is sectional drawing which follows a line.
[0014]
FIGS. 1 to 4 show a situation in which the automatic fire extinguisher according to the present invention is disposed in a plurality of cable connecting portions 11 provided in multiple stages in a vertical direction in a tunnel manhole portion 10.
In these figures, a plurality of smoke sensors 13, infrared flame sensors 14, and injection nozzles 15 are arranged above the ceiling 12 of the manhole section 10, that is, above the uppermost cable connection section 11.
[0015]
The infrared flame detection sensor 14 detects a flame by detecting a reverse current flowing in proportion to the amount of light when light strikes a chip disposed on the sensor main body, and is disposed above the center of the cable connection portion 11. I have. When the infrared flame detection sensor 14 operates, it is automatically reset after a lapse of a predetermined time.
[0016]
The smoke sensor 13 has a structure in which a light source and a light-receiving element are installed with a light-shielding plate interposed therebetween, so that light does not normally hit the light-receiving part. The sensor detects smoke by detecting at the above, and is disposed above both end sides of the cable connection portion 11. When the smoke detection sensor 13 operates, it is automatically reset after a lapse of a predetermined time.
[0017]
The smoke sensor 13 and the infrared flame sensor 14 are equipped with a special heater around the sensor body so that they function properly even in a cave under bad conditions. It is made to evaporate and disappear before entering. Also, the structures of the smoke sensor 13 and the infrared flame sensor are themselves drip-proof so as to withstand use in a high-humidity environment.
[0018]
When both the infrared flame detection sensor 14 and the smoke detection sensor 13 are operating, it functions as a fire detection sensor for detecting a fire. That is, a signal of a fire occurrence is transmitted from the infrared flame detection sensor 14 and the smoke detection sensor 13 to a remote control panel (not shown). This fire signal may be transmitted by any known means, whether wireless or wired.
[0019]
The injection nozzle 15 is arranged toward the uppermost cable connection portion 11, and is connected via a pipe 17 to a fire extinguishing agent injection device 18 arranged at a corner in the manhole portion 10.
As the injection nozzle 15, a single-hole type nozzle having a single hole for delivering a fire extinguishing agent and having a deflector for maintaining the angle of spread of the injection, or a so-called multi-hole type nozzle having 6 to 8 holes is used. Although used, it is desirable that a constant flow rate of fire extinguisher can be discharged from time to time, and that the angle of spread of the fire extinguishing agent covers the entire cable joint connection.
[0020]
The fire extinguisher spray device 18 starts pressurizing the fire extinguisher in the tank by operating a fire detection sensor and a tank that always stores the fire extinguisher under atmospheric pressure, and sends the fire extinguisher to the injection nozzle 15 by compressed gas. And an injection pressurizing device (gas generator) for feeding under pressure.
If the fire extinguishing agent is always stored under atmospheric pressure and is sent by a gas generator in the event of a fire in response to a drive signal from a sensor, safety at all times is ensured and the quality of the fire extinguishing agent can be maintained over a long period of time. There are advantages to be retained.
[0021]
As a fire extinguisher tank, a 30-liter stainless steel container is used, and a gas generator is inserted into the container from the upper central portion of the stainless steel container and fixed with screws. The gas generator is connected to the control panel by a starting electrical connector and a two-wire dedicated cable. The gas generator is provided with a small hole which is normally closed with a seal, and discharges gas from the hole when an electric signal for starting is received. The extinguishing agent in the tank is fed to the injection nozzle 15 by the pressure of this gas.
In the case of a tank that does not use a gas generator, even a 30-liter container can fill 25 liters of fire extinguisher, and the remaining 5 liters are spaces for compressed air for pressurization or compressed nitrogen. Therefore, even a 30 liter tank can contain only 25 liters of fire extinguisher. Further, there is a disadvantage that the discharge pressure is high in the early stage of the operation, and the pressure drops in the latter half. On the other hand, in the tank of this embodiment, 29.5 liters of fire extinguishing agent can be filled in a 30 liter container. The remaining 0.5 liter space is pressurized by the gas emitted by the gas generator, and the gas generator continues to be pressurized while the fire extinguishing agent is gradually released to the outside, so that stable discharging is performed until all the fire extinguishing agent is released. Pressure is maintained.
[0022]
The fire extinguishing agent is a mixture of a chemical based on a fluorine-based surfactant and water, and the mixing ratio of the chemical to water is 8 to 12%, preferably 10%.
The Fire Fighting Law stipulates the use of surfactants for foam digestion. According to the certification standards of the Fire Services Certification Association, the mixing ratio of chemicals and water is two types, 3% and 6%. Three percent are commonly used for parking and other fire fighting, and six percent are commonly used for fire fighting in oil tanks. On the other hand, in the present invention, the compounding ratio of the chemical is 8 to 12%, preferably 10%. Thereby, as will be described later, the adhesion to the fire extinguishing target, the release status, and the fire extinguishing effect are excellent.
A fire extinguisher using a chemical solution based on a fluorine-based surfactant has a characteristic change that is stable over a long period of time, has excellent wettability and permeability, and has a three-dimensional structure such as the cable connection portion 11. The fire extinguishing ability to combusted matter is high, and further, there is an advantage that the surface of the foam quickly spreads to the combustion surface by the action of the surfactant to extinguish the fire.
[0023]
The automatic fire extinguisher installed as described above operates as follows. That is, when a fire occurs by igniting from any of the cable connection portions 11 in the cave, the infrared flame sensor 14 first operates, and then the smoke sensor 13 operates. When both sensors operate, it is detected that a fire has occurred, and this is input to the control panel as a fire signal. This input signal is sent to the fire extinguishing agent injection device 18 to operate the same, and the fire extinguishing agent is ejected from the injection nozzle 15 through the pipe 17. In the drawing, reference numeral 20 indicates the diffusion range of the fire extinguishing agent ejected from the ejection nozzle 15.
[0024]
When only one of the infrared flame detection sensor 14 and the smoke detection sensor 13 operates, it is regarded as a malfunction and the operation of the operated sensor is automatically reset after a lapse of a predetermined time.
When the fire detection sensor detects a fire in the cave, it is desirable that the control panel also performs normal fire notification to inside and outside the cave.
[0025]
In order to extinguish a fire in the cable connecting portions 11 provided in multiple stages in the vertical direction in the cave, the injection nozzle 15 is previously arranged above the uppermost cable connecting portion 11, and the uppermost cable connecting portion is disposed. The following effects can be expected by injecting a fire extinguisher into 11. In other words, when a fire extinguishing agent is sprayed on the upper portion of the uppermost cable connection portion 11 in the event of a fire, the fire extinguishing agent flows along the side surface from the upper surface of the cable connection portion 11 and flows downward, and the upper surface of the cable connection portion 11 directly below. And falls down along the side from the upper surface of the cable connection portion. In this way, the fire extinguishing agent covers the outer surface of the lower cable connection portion 11 one after another. Therefore, by properly selecting the viscosity of the fire extinguishing agent, it is possible to extinguish the fire steadily.
[0026]
<test>
A test was performed on the sensor detection ability and the fire extinguishing ability of the automatic fire extinguisher of the present invention under the following conditions. Hereinafter, description will be made with reference to FIGS.
[0027]
Test equipment;
1. Model size of simulated sinus manhole 21 (1) Size Length 5,400mm, Width 2,700mm, Height 3,210mm
(2) The specification temporary frame closed the back and ceiling with plywood and a thin steel plate, and installed side walls on three sides. It can be opened and closed at any time with a disaster prevention sheet.
2. Model of the simulated 275 kv cable connection part 22 (1) Size Length 2,000 mm
(2) Specifications As shown in FIG. 5, three cable connecting portions 22 were vertically arranged in three stages, simulated by a steel plate cylindrical winding, and the surface was wound by an insulating tape.
3. Simulated cable connection part receiving shelf model (1) Size length 5400mm, height 300mm
(2) Specifications As shown in FIG. 5, the smoke detection sensor 13 and the infrared flame detection sensor 14 were installed on the cable connection part 22 assuming a fire-extinguishing obstacle.
Using the above equipment, heptane (flammable liquid) is used in three places (A1, A2, A3, B1, B2, B3, C1, C2, C3) of each of the three cable connection parts 22 for a total of nine places. Then, ignition was performed sequentially, and a test was performed at each location.
[0028]
Test results;
1. Sensor detection test (1) Smoke detection test Since the flame state and smoke generation state could not be generated stably (smoke does not generate enough even in the early stage of ignition), the relationship between the fire position and the detection time Could not be found, but smoke was detected with good sensitivity in all tests.
The reaction time from ignition was about 1-2 minutes.
[0029]
(2) Infrared flame sensing test Due to the characteristic of infrared light that it is difficult to reflect, there is a large difference in the reaction time between the position where it can be directly viewed from the sensor and the position where it cannot be seen.
As a whole, the reaction time differs depending on the distance and the viewing angle from the sensor. However, when the flame became sufficiently large, it was detected with almost no time difference.
In addition, when the detection was performed with an ignition lighter, it was confirmed that no detection was detected at any position. However, it is designed so that it does not react to the degree of the flame of the ignition lighter in the specification of the fire detection sensor.
[0030]
-The reaction time from the firing at the position 1 (A1, B1, C1) on the wall side was about 3-43 seconds (15 seconds on average).
-The reaction time from the ignition at the position 2 (A2, B2, C2) at 45 degrees below the wall side was about 3-34 seconds (average 22 seconds). However, in some cases, it was not detected during small-scale burning.
The reaction time from the ignition at the position 3 (A3, B3, C3) on the front was about 1 to 6 seconds (3 seconds on average).
[0031]
2. Fire extinguishing ability test In this test, it was confirmed that the fire extinguishing agent was extinguished during the injection, in other words, it was confirmed that the fire was completely extinguished, and the fire was not extinguished as it was after the extinguishing agent was injected.
Based on the results of the sensor detection test, a fire extinguishing test was performed at a position (A2, B2, C2) where the reaction speed of the sensor was the slowest, that is, a position negative from the sensor and the extinguishing agent injection nozzle.
FIG. 6 shows the test results.
[0032]
The fire extinguishing agent was prepared by mixing a chemical solution based on a fluorine-based surfactant and water, and used the one in which the mixing ratio of the chemical solution to water (chemical compounding ratio) was initially set to 6%. However, it was found that the fire extinguishing agent having a chemical compounding ratio of 6% could not extinguish the fire during the jetting of the fire extinguishing agent. The reason for this is that there are many places where the cable connection part to be extinguished is shaded, and the cable connection parts of each phase interfere with each other, and the fire extinguishing agent does not directly reach the combustion part by injection.
[0033]
Therefore, the same test was carried out with a fire extinguishing agent having a chemical compounding ratio of 10%, with the aim of increasing the viscosity of the fire extinguishing agent to increase the amount of foam generated and to cover the cable connection portion with foam.
As a result, it was confirmed that the fire could be stably extinguished at the burning part. In addition, the place where the fire was extinguished was burned directly with a burner, but it was confirmed that reignition did not occur.
It should be noted that even a fire extinguisher having a chemical solution mixing ratio of 8 to 12% is considered to be effective.
[0034]
The above test confirmed that fire extinguishing on one side of the manhole was possible with 30 liters of fire extinguishing agent. Therefore, even though the automatic fire extinguishing system of the present invention always has a 60-liter (two 30-liter containers) extinguishing agent for both sides of the manhole, the existing extinguishing equipment used about 600 liters of the extinguishing agent. It is possible to reduce the size by about 1/10 compared to
[0035]
Although the above description has been directed to the occurrence of a fire from a cable connection in a cave, the present invention is not limited to this. If there is a place where a fire can be assumed in advance in the cave, the fire detection sensor and the injection nozzle 15 may be arranged with the place as a target. In the above description, a case where the cable connection portions are provided in multiple stages in the vertical direction is described as a representative example, but the present invention is also applicable to a case where a plurality of cable connection portions are arranged in the horizontal direction.
In addition, in the present invention, since the high-viscosity extinguishing agent goes around between the cable connecting portions, a sufficient fire extinguishing power can be obtained only by injecting the extinguishing agent from above the cable connecting portion. However, in order to more quickly and surely extinguish the fire, an injection nozzle 15 may be added to the side of the cable connection portion so that the fire extinguishing agent is injected from above and from the side simultaneously. .
[0036]
【The invention's effect】
According to the automatic fire extinguisher of the present invention, the fire extinguisher is provided with a fire detection sensor that detects a fire when detecting flame and smoke, an injection nozzle that injects a fire extinguishing agent, and a fire extinguisher injection device that supplies a fire extinguisher to the injection nozzle. By arranging the injection nozzles in advance toward the expected fire location in the cave, it is possible to reliably detect fire even in a cave under adverse conditions of high temperature and humidity. Since the fire extinguishing target in the road is specified in advance, it is possible to surely and quickly extinguish the fire in the cave with a relatively small amount of fire extinguishing agent.
[Brief description of the drawings]
FIG. 1 is a plan view showing one embodiment of an automatic fire extinguisher according to the present invention.
FIG. 2 is a front view taken along the line AA of FIG.
FIG. 3 is a front view along the line BB.
FIG. 4 is a sectional view taken along line CC of FIG. 1;
FIGS. 5A and 5B are diagrams showing equipment for functional testing of the automatic fire extinguishing apparatus of the present invention, wherein FIG. 5A is a front view and FIG. 5B is a side view.
FIG. 6 is a diagram showing a result of a function test of the automatic fire extinguisher according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Cave manhole part 11 Cable connection part 12 Ceiling 13 Smoke detection sensor 14 Infrared flame detection sensor 15 Injection nozzle 17 Piping 18 Fire extinguishing agent injection device

Claims (6)

An automatic fire extinguisher for extinguishing a fire in a cave,
A fire detection sensor that is installed in advance in a predetermined place in the cave and detects a fire when detecting flame and smoke,
An injection nozzle which is arranged in advance toward a fire occurrence supposed point in the cave and injects a fire extinguisher to the fire occurrence supposed point,
An automatic fire extinguishing system, comprising: a fire extinguishing agent injection device that supplies a fire extinguishing agent to the injection nozzle by operation of the fire detection sensor. An automatic fire extinguisher for extinguishing a fire at a cable connection in a cave,
A fire detection sensor that is installed in a predetermined place in the cave in advance and detects a fire when detecting flame and smoke generated from the cable connection part,
An injection nozzle that is arranged toward the cable connection portion and injects a fire extinguishing agent against the cable connection portion,
An automatic fire extinguishing device, comprising: a fire extinguishing agent injection device that supplies a fire extinguishing agent to the injection nozzle. An automatic fire extinguisher that extinguishes a fire at a cable connection portion provided in multiple stages in a vertical direction in a cave,
A fire detection sensor that is installed in a predetermined place in the cave in advance and detects a fire when detecting flame and smoke generated from the cable connection part,
An injection nozzle that is arranged in advance before the uppermost cable connection portion and injects a fire extinguisher against the uppermost cable connection portion,
An automatic fire extinguishing device, comprising: a fire extinguishing agent injection device that supplies a fire extinguishing agent to the injection nozzle. The automatic fire extinguisher according to any one of claims 1 to 3,
The fire detection sensor, a light source and a light-receiving element are provided with a light-shielding plate interposed therebetween, and a smoke detection sensor that detects the light by detecting the light of the light source diffusely reflected on the smoke that has entered the interior and the light-receiving element, An automatic fire extinguishing device, comprising: an infrared flame detection sensor that detects a reverse current flowing in proportion to the amount of light when the light is applied to detect a flame. The automatic fire extinguisher according to any one of claims 1 to 3,
The automatic fire extinguisher wherein the extinguishing agent is a mixture of a chemical solution based on a fluorine-based surfactant and water, and a compounding ratio of the chemical solution to the water is 8 to 12%. The automatic fire extinguisher according to any one of claims 1 to 5,
The fire-extinguishing agent injection device always starts the pressurizing operation on the fire-extinguishing agent in the tank by the operation of the tank that stores the fire-extinguishing agent under atmospheric pressure and the fire detection sensor, and discharges the fire-extinguishing agent. An automatic fire extinguishing device, comprising: an injection pressurizing device that feeds pressure to an injection nozzle.

Images