KR20110107259A - Fire alert apparatus using for fiber optics and fire alerting method using it - Google Patents

Abstract

The present invention relates to a fire detection apparatus using an optical fiber and a fire detection method using the same. The present invention relates to a fire detection apparatus using an optical fiber for detecting a fire by installing an optical fiber cable in an area such as a tunnel, an underground roadway, an underground cavity. And an optical fiber deformer installed at a plurality of places of the optical fiber cable to bend or cut the optical fiber cable in the event of a fire, a light irradiator for irradiating pulsed laser light to the optical fiber deformer, and light irradiated by the light irradiator to scatter from the optical fiber cable An optical analyzer that receives backscattered light reflected backwards, converts and amplifies an electrical signal, and analyzes an output signal of the optical analyzer to determine whether a fire occurs and a location of a signal processor and a signal processor that determine a fire location And a display unit for displaying a fire occurrence position. Provided is a fire detection apparatus using an optical fiber comprising a.

Description

Fire detection apparatus using optical fiber and fire detection method using same {FIRE ALERT APPARATUS USING FOR FIBER OPTICS AND FIRE ALERTING METHOD USING IT}

The present invention relates to a fire detection apparatus using an optical fiber and a fire detection method using the same, and more particularly, the real-time location of the fire occurs over a protective area having a relatively wide linear section such as a tunnel or underground cavity using the optical fiber and the optical fiber deformer. The present invention relates to a fire detection apparatus using an optical fiber and a fire detection method using the same.

Due to the complex living conditions of modern society, common living facilities, plant production facilities, and dangerous facilities are inevitably distributed in specific areas, and living facilities such as electric power, communication, gas, district heating, and water supply and drainage facilities There is a trend to be installed in a batch. In addition, the road tunnel, which is a structure similar to the underground common ward, is rapidly increasing in construction to solve the problem of reducing logistics cost and protecting nature according to the geological structure of Korea.

As these structures store and handle various kinds of dangerous goods and are very important social facilities, it is an environmental feature that can be expected to spread enormous amounts of damage to the whole society in the event of a disaster. Due to the excessive retention of moisture and dust, various air flow changes, and most of all, inaccessibility of the site, it was difficult to expect the efficiency of maintenance work.

In order to solve this problem, a fire monitoring system has been designed using an electric or electronic heat sensor or a smoke sensor for fire monitoring of a structure such as a building or a tunnel. However, since these sensors do not have a wide detection range, a large number of sensors need to be installed for monitoring a large area such as a tunnel, and wireless or wired communication must be connected to each sensor. In addition, there is a problem that the installation cost is required, and the sensor installed in this way is a place where the environment of the cavity or the road tunnel is high in moisture and dust. .

To save maintenance and replacement costs, the Raman OTDR system has been proposed to accurately measure the location of fire and the temperature at that point. The Raman OTDR system calculates the distance of the backscattered light after the laser pulse is incident, calculates the distance of the spot where the laser pulse is reflected, and detects the location of the fire. Using the Raman effect, Stokes light and anti- Stokes is a system that measures temperature as an intensity ratio of light. Although the Raman OTDR system has the advantage of being accurate, the equipment for measuring the temperature using the Raman effect is expensive and practically difficult to install in the industry, and the data analysis time of tens of seconds to several minutes is required for the temperature measurement. There was a problem that could not be applied to a fire that requires a response.

The present invention is to solve the problems of the Raman OTDR system as described above, it is possible to detect the temperature rise in real time, and can be measured with a low-cost measurement equipment without the need for wired and wireless communication device for each sensor and installation cost An object of the present invention is to provide a fire detection apparatus using an inexpensive optical fiber and a fire detection method using the same.

The object of the present invention is to install a fiber optic cable in an area such as a tunnel, underground driveway, underground co-operation, fire detection device using an optical fiber, which is installed in a plurality of places of the optical fiber cable bending the optical fiber cable when a fire occurs. Or an optical fiber deformer for cutting and deforming, a light irradiator for irradiating pulsed laser light to the optical fiber deformer, and light emitted by the light irradiator is scattered from the optical fiber cable to receive backscattered light that is reflected back and converts the electrical signal. And an optical analyzer to amplify the optical analyzer and a signal processor to determine whether a fire occurs and a location of a fire by analyzing an output signal of the optical analyzer, and a display unit to display a fire and a location of a fire. Can be achieved by means of a fire detection device .

Still another object of the present invention is to provide a fire detection method using an optical fiber for detecting a fire by installing an optical fiber cable in an area such as a tunnel, an underground roadway, an underground cavity, a first step of deforming an optical fiber cable at a fire occurrence point, A second step of injecting the pulsed laser light into the optical fiber cable, a third step of receiving the backscattered light scattered and conveyed back to the incident direction, and amplifying the received backscattered light by converting the electrical signal By analyzing the amplification signal of the fourth step and the fourth step to determine whether the fire occurs and the location of the fire occurs, it can also be achieved by a fire detection method using an optical fiber comprising a fifth step of displaying this.

The fire detection apparatus using the optical fiber and the fire detection method using the optical fiber according to the present invention cause a sudden bending of the optical fiber by using a shape memory alloy that restores to its original shape in the event of a fire, and the amount of analysis data is relatively small by measuring it with a general OTDR. This has the advantage of accurately detecting the location of the fire in real time.

In addition, in the present invention, by using the optical fiber compared to the conventional fire detection device using an electrical or electronic sensor device, the measurement equipment is very low cost, real-time fire detection is possible and can reduce the cost required to install a communication line with the sensor In other words, it is possible to install fire detection in a relatively large area using a single fiber.

1 is a block diagram of a fire detection apparatus using an optical fiber of an embodiment according to the present invention.
Figure 2 is an example of the optical fiber deformer used in the fire detection apparatus of an embodiment according to the present invention.
Figure 3 is an example of the optical fiber deformer used in the fire detection apparatus of an embodiment according to the present invention.
Figure 4 is an example of the optical fiber deformer used in the fire detection apparatus of an embodiment according to the present invention.
Figure 5 is an example of the optical fiber deformer used in the fire detection apparatus of an embodiment according to the present invention.
Figure 6 is an example of the optical fiber deformer used in the fire detection apparatus of an embodiment according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the advantages, features and preferred embodiments of the present invention.

1 is a block diagram of a fire detection apparatus using an optical fiber of an embodiment according to the present invention. The fire detection apparatus using the optical fiber is a light irradiation unit 100 for irradiating pulsed laser light to the optical fiber cable 600, the optical fiber modifier 500 is installed, the laser light irradiated to the optical fiber cable 600 and the irradiated light scattering And a light circulator 200 for separating backscattered light returned in different directions, a light analyzer 300 for detecting a backscattered light, and an amplifier for amplifying a detection signal, and outputting the light from the light analyzer 300. It is composed of a signal processor for determining the location of the fire by processing the signal to be displayed and a display unit for displaying it. In addition, an optical switch for selectively selecting the plurality of optical fiber cables 600 may be further provided.

The light irradiation unit 100 is composed of a power supply unit, a pulse generator and a laser diode module, the power supply unit is a device for supplying the power required for each unit, the pulse generator is a pulse current of the drive current for driving the laser diode module It is a device for generating. The pulse waveform of the current component is used as an input signal to drive the laser diode to convert the pulse diode into high-speed pulse light, and then transmit the pulsed light through the optical fiber cable 600.

The laser pulse irradiated from the light irradiation unit 100 is transmitted through the optical fiber cable 600, and the back scattered light generated from the optical fiber travels in the opposite direction to the incident light and returns back to the light irradiation unit 100. Therefore, in order to measure the backscattered light, a part that is separated in another direction so as not to return to the incident direction is required. Such a part is an optical circulator 200.

The backscattered light output from the optical circulator 200 is input to the optical analyzer 300. The optical analyzer is composed of a detector for converting the incident backscattered light into an electrical signal capable of signal processing, and an amplifier for sensing and amplifying the input. It converts the backscattered light into an electrical signal and amplifies it. Since 98% or more of the back scattered light is composed of Rayleigh scattered light, a Rayleigh light filter may be selected and imposed between the detector and the light circulator 200.

The signal processor 300 controls a digital signal processor (DSP) board OTDR board using a computer and acquires data. DSP-enabled OTDR boards include pulse generators, laser diodes, photodiodes, optical circulators, and data acquisition. The computer communicates with the DSP-based OTDR board using RS232 to control the components. Signal processing of the OTDR, including control of the OTDR sensor system and acquisition of data from the system, is performed by a particular signal processing program. The signal processing program calculates the time at which the scattered light returns over a certain intensity after the laser pulse is incident, using the principle of the Optical Time Domain Reflectometer (OTDR), and calculates the location of the fire by calculating the distance between the spot where the laser pulse is reflected and whether there is a fire. Can be detected.

Fire information obtained through this method, that is, whether or not a fire has occurred in the protective area and the location of fire occurrence, is displayed on the display unit.

In the fire detection apparatus using the optical fiber according to the present invention, when a fire occurs in a protective area, a plurality of optical fiber modifiers 500 are formed at bending places in the optical fiber cable 600 installed at a corresponding position. The optical fiber deformer 500 is a device that generates deformation by cutting or bending the fixed optical fiber cable 600 when the ambient temperature is above a predetermined temperature.

2 is an example of an optical fiber modifier 500 according to an embodiment of the present invention. The optical fiber deformer 500 of FIG. 2 is an example implemented using the shape memory alloy 520 which is restored to its original state to be shrunk when more than 50 heat is applied thereto. The shape memory alloy 520 in the case is expanded in its original state to fix one end to the first fixing part 510, and the other end to be fixed to the optical fiber cable 600 using an adhesive or the like. At room temperature, the shape memory alloy 520 is maintained in an expanded state as shown in FIG. 2 (a). When a fire occurs, the shape memory alloy 520 is heated with 50 or more heat, as shown in FIG. 2 (b). As shown, the shape memory alloy 520 is contracted to its original state. The optical fiber cable 600 attached to the contracted shape memory alloy 520 has a large bending as shown in FIG. 2 (b), and this bending is based on the principle detected by the OTDR system.

In the present invention, a high temperature shape memory alloy is used. When the spring or plate is formed of the high temperature shape memory alloy, when the spring or plate is pulled or bent at a room temperature of 30 or less, the spring is stretched, and the plate is bent, which is a dryer. When heated to 50 or more using the back and the like to return to the original shape.

After a strain is applied below a certain temperature (temperature Ms at which a low-temperature phase is generated, 30 in the above example), and then heated to a predetermined temperature (temperature Af at which the high-temperature phase is completely produced, 50 in the example), the shape is returned to the shape before deformation. The memory effect is called the shape memory alloy.

The shape memory alloy can be formed of various materials such as Ni-Ti, Cu, Fe, etc. The most representative Ni-Ti-based alloy has a very poor machinability, but is mainly used for easy hot working such as pressing and rolling. .

In the case of the embodiment of Figure 2, even if the fire is extinguished and the temperature is lowered to room temperature, the optical fiber modifier 500 should be replaced because it is not deformed. An example in which recycling is possible even after the temperature drops normally after extinguishing a fire will be described with reference to FIG. 3.

3 is an example of an optical fiber modifier 500 according to an embodiment of the present invention. The optical fiber deformer 500 of FIG. 3 is an example implemented using a shape memory alloy 520 and a general metal 590 which are restored to their original state to be shrunk when heat of 50 ° C. or more is applied thereto. The shape memory alloy 520 in the case is expanded in its original state to fix one end to the first fixing part 510, and the other end to be fixed to the optical fiber cable 600 using an adhesive or the like. As shown in FIG. 3, one end is fixed to the second fixing part 580, and the other end is fixed to the optical fiber cable 600 using an adhesive or the like.

At room temperature, as shown in FIG. 3A, the shape memory alloy 520 is maintained in an expanded state, and the general metal elastic body 590 is maintained in a state where elasticity is not applied. 50 or more heat is applied to the 520 and the shape memory alloy 520 shrinks to its original state, as shown in FIG. 3 (b), and the general metal elastic body 590 is deformed to a stretched state. The optical fiber cable 600 attached to the contracted shape memory alloy 520 has a large bending as shown in FIG. 3 (b), and this bending is based on the principle detected by the OTDR system. Then, when the fire is extinguished, and the temperature is lowered to the normal temperature, the stretched general elastic metal 590 is contracted to restore the state as shown in FIG. 3 (a), so that the optical fiber deformer 500 can be recycled. .

4 is an example of an optical fiber modifier 500 according to an embodiment of the present invention. 4 illustrates an optical fiber deformer for cutting an optical fiber cable when a fire occurs. When the heat is applied to the inside of the cylinder 530, the material expands in volume 540, and the upper part is provided with a sealing stopper 550 which rises to the upper part as expansion, and the cutter 560 is mounted on the sealing stopper 550. Installed. Representative examples of the cutter 560 may be a sharp metallic blade. Normally, while maintaining a state as shown in FIG. 3 (a) and a fire occurs, the sealing stopper 550 rises as shown in FIG. 3 (b), and thus the cutter 560 installed on the upper portion rises. While cutting the optical fiber cable 600. Therefore, the OTDR detects backscattered light due to cutting and detects a fire occurrence position and fire occurrence.

Representative examples of the material 540 in which the volume is expanded when heat is applied are shown in Table 1, and mercury is the most favorable but harmful substance, and acetone is the next most suitable material.

Material name Mercury ether Acetone Chromoform Carbon tetrachloride Methanol benzene Bromine ethanol Thermal expansion coefficient (mm / K) 61 1.51 14.3 12.7 12.2 12.0 11.5 11.2 11.0 Breaking point (℃) 356 34 56.5 61.2 77 64.7 80.1 59 78

In the example of FIG. 4, the optical fiber cable 600 has been described as being cut, but when a metal rod or the like is installed instead of the cutter 560 installed on the sealing plug 550, the bending may be caused to the optical fiber cable 600. Of course. When the optical fiber cable 600 is cut when a fire occurs, the optical fiber cable 600 is disconnected from the inlet 555 through which the optical fiber cable 600 is drawn and the outlet 565 through which the optical fiber cable 600 is drawn. It is good to fix with an adhesive or the like.

The fire detection method using the fire detection apparatus of FIG. 1 presented in the present invention is a fire detection method using an optical fiber for detecting a fire by installing an optical fiber cable in an area such as a tunnel, an underground road, an underground common pit, and an optical fiber at a fire occurrence point. A first step of bending or cutting deformation of the cable, a second step of injecting pulsed laser light into the optical fiber cable, a third step of receiving backscattered light scattered and conveyed back in the incident direction; By analyzing the amplified signals of the fourth and fourth stages of converting the received backscattered light by electrical signals and amplifying the signals, the presence or absence of the fire and the location of the fire can be determined and displayed by the fifth step. .

5 is an example of an optical fiber modifier used in a fire detection apparatus of an embodiment according to the present invention. 2 to 4, since the optical fiber deformer is expensive to use the shape memory alloy, there are some difficulties in the actual industrial application. 5 and 6 propose an optical fiber deformer that can be implemented at a relatively low price instead of the shape memory alloy.

In FIG. 5, an optical fiber deformer is implemented using a glass tube and a general metal spring containing a thermal expansion material therein. Figure 5 (a) is the installation state of the optical fiber modifier before the fire occurs, Figure 5 (b) shows the deformation state of the optical fiber deformer when a fire occurs. The case 70 is fixed using the case fixing screw 71 to pass the optical fiber cable 60 through the internal through passage 73. The optical fiber cable 60 is supported by using a glass tube 75 containing a thermal expansion material 77 on one side in a direction perpendicular to the passage through which the optical fiber cable 60 passes. On the opposite side, a spring 87 is made of ordinary metal and is compressed to support the optical fiber cable 60 to maintain a straight state. That is, the glass tube 75 supports the compressive force of the spring 87 to maintain the flat state without the bending of the optical fiber cable 60.

One end of the glass tube 75 filled with the thermal expansion material 77 is fixed to the case 70 through the third fixing part 79, and the other end is connected to the optical fiber cable 60 through the cable first support 81. Function to support. In this case, the thermal expansion material 77 should be filled in the sealed state inside the glass tube 75, and may be sealed using the third fixing part 79 and the first cable supporter 81, or the third fixing part 79. And a separate stopper other than the cable first support 81 may also be provided and sealed. Similarly, one end of the general metal compression spring 87 is fixed to the case 70 through the fourth fixing part 83, and the other end is interposed between the optical fiber cable 60 through the cable second support 85. The balance of the force with the cable first support 81 to be placed on. The fire detection time can be easily set according to the type of thermal expansion material 77 filled in the glass tube 75, and of course, it can be implemented by changing the color to visually check this. For example, a glass tube ruptured between 38 ° C. and 68 ° C. is red, and a glass tube ruptured between 66 ° C. and 93 ° C. is green.

Before the fire occurs, the state as shown in FIG. When a fire occurs, deformation as shown in FIG. 5 (b) occurs. That is, the ambient temperature increases, and the volume of the thermal expansion material filled in the glass tube 75 increases due to the elevated temperature, thereby destroying the glass tube 75. As a result, the spring 87 in the compressed state is relaxed, and the optical fiber cable 60 is bent by the relaxed spring 87. Therefore, the OTDR detects the backscattered light due to the bending and detects the fire occurrence position and fire occurrence.

6 is an example of an optical fiber modifier used in a fire detection apparatus of an embodiment according to the present invention. In FIG. 6, bimetals 93 and 95 are formed of general metal materials having different thermal expansion coefficients, protrusions 97 are formed on the bimetal, and the protrusions 97 deform the optical fiber cable 60 in the event of a fire. The optical fiber modifier was implemented using. 6 (a) is a state of installation of the optical fiber deformer before a fire occurs, Figure 6 (b) shows a deformation state of the optical fiber deformer when a fire occurs.

The case 70 is fixed using the case fixing screw 71 to pass the optical fiber cable 60 between the inner through passages 73. At the lower end of the passage 73 through which the optical fiber cable 60 passes, a bimetal made of two metals 93 and 95 having different thermal expansion coefficients is fixed to the case 70 by the fifth fixing portion 91, and among the two metals, In the metal 93 having a relatively low coefficient of thermal expansion, a protrusion 97 protruding outward is formed. In addition, the optical fiber cable 60 is interposed therebetween, and when the bimetal is bent, a receiving space 99 is formed to accommodate the protrusion 97 in a portion opposite to the protrusion 97.

The state as shown in Fig. 6 (a) is maintained before the fire occurs. If a fire occurs, it is deformed as shown in Fig. 6 (b). That is, the ambient temperature rises, and the bimetals 93 and 95 are bent to the upper side in the drawing by the elevated temperature, whereby the protrusion 97 is also bent upward. The bent protrusion 97 causes the optical fiber cable 60 to be bent. Therefore, the OTDR detects the backscattered light due to the bending and detects the fire occurrence position and fire occurrence. In the embodiment shown in FIG. 6, the location of the bimetal and the receiving space 99 is just one embodiment, and may be any position opposite to each other with the optical fiber cable 60 interposed therebetween. As a result, the optical fiber cable 60 may be positioned above, and the accommodation space 99 may be located below.

While the preferred embodiments of the present invention have been described using specific terms, such descriptions are for illustrative purposes only, and it is understood that various changes and modifications may be made without departing from the spirit and scope of the following claims. Should be done.

100: light irradiation unit 200: optical circulator
300: optical analyzer 500: optical fiber strainer
510: first fixing portion 520: shape memory alloy
530: cylinder 540: thermal expansion material
550: sealing plug 555: inlet
560: cutting machine 565: outlet
580: second fixing portion 590: a general metal elastic body
600: fiber optic cable

Claims (11)

In the fire detection device using the optical fiber to detect the fire by installing the optical fiber cable in the tunnel, underground driveway, underground common ward, etc.
An optical fiber deformer installed at a plurality of places of the optical fiber cable to bend or cut the optical fiber cable in case of fire;
A light irradiation unit for irradiating pulsed laser light to the optical fiber modifier;
An optical analyzer for receiving the backscattered light scattered from the optical fiber cable and reflected back by the light irradiator and converting and amplifying the electrical signal;
A signal processor for analyzing the output signal of the optical analyzer to determine whether a fire has occurred and a location of the fire;
Fire detection device using the optical fiber, characterized in that it comprises a display unit for displaying the presence or absence of fire and the location of the fire of the signal processing unit.
The method of claim 1,
The optical fiber deformer is a fire detection apparatus using an optical fiber, characterized in that it comprises at least one selected from the shape memory alloy, bimetal, and thermal expansion material.
3. The method according to claim 1 or 2,
The optical fiber modifier includes a case having an inlet and an outlet through which the optical fiber cable is introduced and drawn out, and one end of which is fixed to the first fixing part of the case, and the other end of which is a shape memory alloy fixed to the optical fiber cable. Fire detection device using an optical fiber, characterized in that.
The method of claim 3,
The optical fiber deformer is a fire detection device using an optical fiber, characterized in that one end is fixed to the second fixing portion of the case, the other end comprises a spring made of a common metal fixed to the optical fiber cable.
The method of claim 2,
The shape memory alloy is a fire detection device using an optical fiber, characterized in that made of one metal selected from Ni-Ti, Cu, and Fe-based.
3. The method according to claim 1 or 2,
The optical fiber deformer includes a case having an inlet and an outlet through which the optical fiber cable is drawn in and drawn out, and a sealing stopper installed inside the case and accommodating a thermal expansion material therein, and an upper portion of the optical fiber cable rising upward according to the expansion of the thermal expansion material. Fire detecting device using an optical fiber, characterized in that it comprises a cylinder provided, and a cutter installed above the sealing stopper.
3. The method according to claim 1 or 2,
The optical fiber deformer has a case having an inlet and an outlet through which the optical fiber cable is drawn in and drawn out, and one end is fixed to a third fixing part of the case and the other end has a thermal expansion material therein configured to support the optical fiber cable. Filled glass tube, and one end is fixed to the fourth fixing portion of the case and the other end includes a spring installed in a compressed state while balancing the strength and the other end of the glass tube with the optical fiber cable therebetween. Fire detection device using optical fiber.
The method of claim 7, wherein
The other end of the glass tube is further provided with a cable first support for supporting the cable, the first support and the fire detection device using the optical fiber, characterized in that the optical fiber cable abuts.
The method according to claim 6 or 7,
The thermal expansion material is a fire detection device using an optical fiber, characterized in that one of the material selected from mercury, ether, acetone, chloroform, carbon tetrachloride, methanol, benzene, bromine water and ethanol.
3. The method according to claim 1 or 2,
The optical fiber deformer includes a case having an inlet and an outlet through which the optical fiber cable is drawn in and drawn out, a first end of which is fixed to a fifth fixing part of the case, and the other end of which is formed of a free end, and a metal forming the bimetal. And a projection portion formed on a metal having a low coefficient of thermal expansion, and an accommodation space for accommodating the projection at a position at which the projection is bent when a fire occurs with the optical fiber cable interposed therebetween. .
In the fire detection method using the optical fiber to detect the fire by installing the optical fiber cable in the tunnel, underground driveway, underground common area, etc.,
A first step of bending or cutting the optical fiber cable at the fire occurrence point;
A second step of injecting pulsed laser light into the optical fiber cable;
A third step of receiving the back-scattered light which is scattered by the incident pulse-raised light and is conveyed in the incident direction again;
A fourth step of amplifying the received backscattered light by converting an electrical signal;
A fire detection method using an optical fiber comprising a fifth step of analyzing the amplification signal of the fourth step to determine the presence or absence of the fire and the location of the fire, and to display it.

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