JP4795702B2 - Fire detection system in variable oxygen concentration space - Google Patents

Description

  The present invention is a fire detection system for detecting a fire in a target space, and in particular, a fire detection system for detecting a fire in an oxygen concentration variable space in which the oxygen concentration can be adjusted from a normal oxygen concentration to a low oxygen concentration. About.

  Conventionally, there has been proposed a fire sensor that detects various physical quantities in a target space, determines that a fire has occurred when the detected physical quantity exceeds a predetermined threshold value, and notifies that effect. Yes. For example, a light emitting means and a light receiving means are provided, and light scattered by smoke of light emitted by the light emitting means is received by the light receiving means, and a fire has occurred when the amount of received light exceeds a predetermined threshold There is a smoke sensor that determines and outputs a warning (for example, see Patent Document 1). Alternatively, a CO that includes a carbon monoxide (CO) detection element and determines that a fire has occurred when the amount of CO detected by the CO detection element exceeds a predetermined threshold value and outputs a notification. There exists a sensor (for example, refer patent document 2).

  Conventionally, there has been proposed a fire prevention system that can prevent a fire in this space by reducing the oxygen concentration in a space where humans do not enter and exit (see, for example, Patent Document 3). Such a conventional fire detection system in an oxygen concentration variable space includes, for example, an inert gas supply device that supplies an inert gas to the target space and an outside air supply device that supplies the outside air to the target space. It had been. When the human is absent, the target space is filled with an inert gas by using the inert gas supply device to make the target space an incombustible atmosphere. When the human is in the room, the external space is used to supply the target space. By supplying outside air, the target space was made to have an oxygen concentration that allows humans to survive. According to such a system, when an incombustible atmosphere is used, a fire can be prevented from occurring in the target space. When the oxygen concentration is such that humans can survive, there is no health problem even if a human enters the target space. There is an advantage that it does not occur.

JP-A-8-171686 JP 2001-216580 A JP 2003-102858 A

Here, the inventor of the present application shows that various physical states (for example, smoke and CO diffusion states in the target space) indicating the occurrence of a fire are low when the oxygen (O ₂ ) concentration in the target space is a normal oxygen concentration. It has been found that different properties (behaviors) are exhibited when the oxygen concentration is used. However, the installation position of the conventional fire sensor and the fire alarm conditions are determined on the assumption that the target space has a normal oxygen concentration. Various problems such as inability to detect could occur.

  For example, conventional smoke sensors and CO sensors have been arranged on the ceiling of the target space and in the vicinity thereof. This is because, when the target space has a normal oxygen concentration, when a fire breaks out, a high-temperature hot air flow rises, and smoke and CO rises relatively early in the vicinity of the ceiling with this hot air flow. This is because it is reasonable to install a smoke sensor or a CO sensor near the ceiling in order to detect CO early. In contrast, when the subject space has a low oxygen concentration, the inventor of the present application has an incomplete combustion state and does not cause a fire even if there is a fire source. It was found that it drifted slowly throughout the target space. Therefore, even if a smoke sensor or a CO sensor is arranged near the ceiling of the target space as in the past, there is a possibility that a fire cannot be detected early.

  Conventionally, only one of the smoke sensor and the CO sensor is arranged in the target space, or both of them are arranged independently from each other. This is because when the target space has a normal oxygen concentration, the amount of smoke and CO increases together with the occurrence of a fire, and the occurrence of a fire can be sensed by detecting either of them. In contrast, when the subject space has a low oxygen concentration, the inventor of the present application is incompletely combusted even if there is a fire source. We found that it increased rapidly. Therefore, even if only the smoke sensor is arranged, there is a possibility that a fire cannot be detected early.

  For these reasons, when the target space has a low oxygen concentration, a fire detection system different from the conventional one is required. In particular, the oxygen concentration variable space that can adjust the oxygen concentration from the normal oxygen concentration to the low oxygen concentration. However, it is not enough to provide only a fire detection system suitable for normal oxygen concentration or only a fire detection system suitable for low oxygen concentration, and fire detection that can exhibit suitable performance at any oxygen concentration It is necessary to build a system.

  The present invention has been made in view of the above, and in an oxygen concentration variable space in which the oxygen concentration can be adjusted from a normal oxygen concentration to a low oxygen concentration, it is possible to detect fire early and reliably, etc. An object is to provide a fire detection system in a variable space.

In order to solve the above-described problems and achieve the object, the fire detection system in the oxygen concentration variable space according to claim 1 is an oxygen concentration variable space in which the oxygen concentration can be adjusted from a normal oxygen concentration to a low oxygen concentration. A fire detection system for detecting a fire in an oxygen concentration variable space that prevents fire or prevents deterioration of stored items by adjusting the oxygen concentration to a low oxygen concentration when a fire does not occur. It includes a first detection position in space, and a second detection position is lower than the first detection position in the oxygen concentration variable space, and a sensor capable of detecting a fire in at least two positions of the sensor Is different from the first sensor for detecting a predetermined first physical quantity in the oxygen concentration variable space and the first physical quantity in the oxygen concentration variable space. And a second sensor for detecting a second physical quantity, wherein the first detection position is suitable for detecting the first physical quantity in the oxygen concentration variable space adjusted to the normal oxygen concentration. And the second detection position is a position suitable for detecting the second physical quantity in the oxygen concentration variable space adjusted to the low oxygen concentration, and the first sensor is The first detection position is arranged, and the second sensor is arranged at the second detection position .

The fire detection system in the oxygen concentration variable space according to claim 2 is the fire detection system in the oxygen concentration variable space according to claim 1, in which the first sensor emits smoke that is the first physical quantity. It is a smoke sensor for detecting, and the second sensor is a CO sensor for detecting CO which is the second physical quantity.

The fire detection system in the oxygen concentration variable space according to claim 3 is the fire detection system in the oxygen concentration variable space according to claim 1 or 2 , wherein the oxygen concentration in the oxygen concentration variable space is equal to the normal oxygen concentration. If adjusted, fire is detected using at least the first sensor, and if the oxygen concentration in the oxygen concentration variable space is adjusted to the low oxygen concentration, at least the second sensor is used. Control means for switching the sensor so as to detect a fire using the sensor is provided.

The fire detection system in the oxygen concentration variable space according to claim 4 is an oxygen concentration variable space in which the oxygen concentration can be adjusted from a normal oxygen concentration to a low oxygen concentration, and the oxygen concentration is reduced when no fire occurs. A fire detection system for detecting a fire in an oxygen concentration variable space for preventing fire or preventing deterioration of stored items by adjusting to a concentration, wherein the first detection position in the oxygen concentration variable space, and the oxygen concentration A sensor capable of detecting a fire at at least two positions of the second detection position that is lower than the first detection position in the variable space, and the sensor includes the first detection position and the second detection position. A moving means for moving the sensor to a detection position of the sensor, and based on the oxygen concentration in the oxygen concentration variable space, the sensor is either the first sensor or the second sensor. Meanwhile, by moving through the moving means, characterized by comprising a control means for changing the detected position of the fire in the sensor.

Moreover, the fire detection system in the oxygen concentration variable space according to claim 5 is the fire detection system in the oxygen concentration variable space according to any one of claims 1 to 4 , wherein the first detection position is the It is a position near the ceiling in the oxygen concentration variable space.

According to the fire detection system in the oxygen concentration variable space according to claim 1, the fire can be detected at at least two positions of the first detection position and the second detection position in the oxygen concentration variable space. Therefore, it is possible to perform fire detection in a form suitable for the physical phenomenon of the oxygen concentration variable space that changes, and early and reliable fire detection can be performed.
In particular, fire detection can be performed at a position suitable for the physical phenomenon of the oxygen concentration variable space that changes according to the oxygen concentration, and early and reliable fire detection can be performed. In addition, by disposing sensors at each of the two positions, a mechanism and control for moving one sensor to two positions are not required, so that the fire monitoring system can be configured simply and inexpensively. it can.

According to the fire detection system in the oxygen concentration variable space according to claim 2 , since the smoke sensor is provided above and the CO sensor is provided below the smoke sensor, the smoke sensor rises near the ceiling in a normal oxygen concentration environment. By detecting smoke with a smoke sensor and detecting CO drifting in the entire oxygen concentration variable space with a low oxygen concentration environment with a CO sensor, early and reliable fire detection can be performed in any acidity environment. . Further, since the CO sensor is disposed, it is possible to prevent a person from being adversely affected by inhaling CO, and it is possible to construct a fire detection system considering safety other than fire.

According to the fire detection system in the oxygen concentration variable space according to claim 3 , the sensor used for fire detection can be automatically switched based on the oxygen concentration in the oxygen concentration variable space. Fire detection can be performed at a position suitable for the physical phenomenon of the changing oxygen concentration variable space, and early and reliable fire detection can be performed.

According to the fire detection system in the oxygen concentration variable space according to claim 4 , fire detection can be performed at a position suitable for a physical phenomenon of the oxygen concentration variable space that changes in accordance with the oxygen concentration, and an early and reliable fire is achieved. Sensing can be performed. Further, since one sensor is moved to two positions, it is not necessary to arrange sensors at each of the two positions, and the fire monitoring system can be configured simply and inexpensively by reducing the number of sensors. .

According to the fire detection system in the oxygen concentration variable space according to claim 5 , the fire is detected at a position near the ceiling in the oxygen concentration variable space when the oxygen concentration is equal to or higher than the predetermined oxygen concentration. It is possible to detect smoke and CO rising quickly.

  Hereinafter, an embodiment of a fire detection system in an oxygen concentration variable space according to the present invention will be described in detail with reference to the accompanying drawings. First, [I] the basic concept of the present invention will be described, then [II] each embodiment of the present invention will be described, and [III] Finally, a modification to the embodiment of the present invention will be described.

[I] Basic concept of the present invention First, the basic concept of the present invention will be described. The present invention relates to a fire detection system for detecting a fire that occurs in an oxygen concentration variable space in which the oxygen concentration can be adjusted from a normal oxygen concentration to a low oxygen concentration.

  Here, the target space is basically arbitrary, but for example, data centers, museums, museums, cultural property storage facilities, valuables warehouses, etc. where there is a strong demand for avoiding damage due to fire extinguishing in the event of a fire. Or a place where it is difficult to install a normal fire prevention facility such as an electric room of a super high-rise tower, or a facility that stores valuables that want to prevent deterioration by maintaining a low oxygen concentration.

  The low oxygen concentration is basically a concept including all oxygen concentrations lower than the oxygen concentration in the general atmosphere (about 21%, hereinafter referred to as “normal oxygen concentration”). This is the concentration at which the behavior of CO can be different from the normal oxygen concentration (concentration that can lead to fire by fire). In the following embodiment, an oxygen concentration of about 17% or less will be described as “low oxygen concentration”, but this specific threshold value can be arbitrarily changed.

In order to adjust the oxygen concentration in this way, in the present invention, various gases are introduced into the target space. Specifically, when reducing the oxygen concentration, an inert gas or a gas containing an inert gas at a high concentration is introduced. Here, the type of the inert gas is arbitrary, but in the following, an example using nitrogen gas will be described, and nitrogen gas or a gas containing nitrogen gas at a higher concentration than usual is referred to as “nitrogen gas”. Referred to as "enriched gas". In addition, when increasing the oxygen concentration, a gas containing outside air, oxygen, or oxygen at a higher concentration than usual, or a gas having an oxygen concentration higher than the oxygen concentration in the target space is introduced. Hereinafter, oxygen or a gas containing oxygen at a high concentration is referred to as “oxygen-enriched gas”.

  Here, one of the features of the present invention is that the sensors for detecting a fire are arranged at two or more positions in the target space. Here, as a form in which two or more positions are arranged, a form in which sensors are fixedly arranged in each of two positions (a form shown in the first embodiment described later) and a form in which one sensor is moved to two positions. (Form shown in Embodiment 2 described later). Then, the fire detection is performed at a position suitable for each oxygen concentration environment by switching the position of the sensor used for the fire detection between the case where the target space has a normal oxygen concentration and the case where the target space has a low oxygen concentration.

  Another feature of the present invention is that two types of sensors, a smoke sensor and a CO sensor, are provided as sensors for detecting a fire. Then, the type of sensor used for fire detection is switched between the case where the target space has a normal oxygen concentration and the case where the target space has a low oxygen concentration, so that the fire detection is performed with a type of sensor suitable for each oxygen concentration environment (described later). The form shown in Form 3).

[II] Embodiments of the Present Invention Each embodiment of the fire detection system in the oxygen concentration variable space according to the present invention will be described below. In each of these embodiments, after describing the overall configuration of the fire detection system and the like, fire detection processing performed by the fire detection system will be described.

[Embodiment 1]
First, Embodiment 1 according to the present invention will be described. In the first embodiment, sensors for detecting a fire are fixedly arranged at two positions in a target space.

(Configuration of fire detection system)
FIG. 1 is a diagram showing the overall configuration of the fire detection system according to the first embodiment. In FIG. 1, a target space 1 corresponds to the oxygen concentration variable space in the claims, and is configured as a closed space surrounded by wall surfaces in the upper, lower, left and right directions. In the target space 1, as shown in the figure, a smoke sensor 2, CO sensors 3 a to 3 d (collectively referred to as CO sensor 3 as necessary), and an O ₂ sensor 4 are arranged. In the vicinity, an oxygen concentration adjusting unit 5, an oxygen concentration control panel 6, and a fire monitoring panel 7 are arranged. These parts are electrically connected to each other as indicated by dotted lines in the figure.

  Among these, the smoke sensor 2 detects a fire based on the amount of smoke generated in the target space 1, and corresponds to the smoke sensor in the claims. Although the detection principle by the smoke sensor 2 is arbitrary, for example, a light emitting means and a light receiving means are provided, and the light emitted from the light emitting means is received by the light receiving means, and the amount of light received is predetermined. When the threshold value is exceeded, it is determined that a fire has occurred, and an alarm signal is output.

  Here, the smoke sensor 2 is installed at a position suitable for early detection of smoke in a normal oxygen concentration environment, specifically, on the ceiling 1a of the target space 1. FIG. 2 shows the temperature distribution of the target space 1 under normal oxygen concentration, and FIG. 3 shows the temperature distribution of the target space 1 under low oxygen concentration (the horizontal axis is the value after turning on the heater serving as a fire source). Elapsed time, vertical axis shows temperature change from initial value). As shown in FIG. 2, the temperature rises abruptly due to ignition under normal oxygen concentration, but the temperature rise is small because no ignition occurs under low oxygen concentration as shown in FIG. I understand that. That is, when the target space 1 has a normal oxygen concentration, when a fire occurs, a high-temperature hot air flow rises and smoke rises early in the vicinity of the ceiling 1a along with the hot air flow. The smoke sensor 2 is arranged on the ceiling 1a so that it can be detected. Hereinafter, the installation position of the smoke sensor 2 is referred to as a “first detection position”, and the height from the floor surface of the target space 1 to the installation position of the smoke sensor 2 (the position of the lower surface of the ceiling 1a) is referred to as the “first detection position”. 1 detection height (reference numeral H1) ".

  The CO sensor 3 detects a fire based on the amount of CO generated in the target space 1, and corresponds to the CO sensor in the claims. The CO sensor 3 includes a CO detection element. When the amount of CO detected by the CO detection element exceeds a predetermined threshold, it is determined that a fire has occurred. Here, the CO sensor 3 is installed at a suitable position for detecting CO early in a low oxygen concentration environment, specifically, at a position lower than the installation position of the smoke sensor 2. That is, when the target space 1 has a low oxygen concentration, as shown in FIG. 3, even if there is a fire source, an incomplete combustion state does not occur and a fire does not occur, and smoke and CO do not rise due to the hot air current. The CO sensor 3 is disposed at a position lower than the ceiling 1a so that the CO can be detected at an early stage. Hereinafter, the installation position of the CO sensor 3 is referred to as a “second detection position”, and the height from the floor surface of the target space 1 to the installation position of the CO sensor 3 (a position below the ceiling 1a) is referred to as “second detection position”. This is referred to as “height (reference H2)”.

  Here, it is preferable to determine the second detection position in consideration of an adverse effect on the person when CO is sucked by the person. That is, if a person inhales CO more than a certain amount, the life may be dangerous. Therefore, when CO is detected at the height where the person's head is located, and this detected amount reaches a predetermined amount that adversely affects the human body. It is preferable to issue an alarm or the like regardless of whether or not a fire has occurred. For this reason, in the first embodiment, the second detection height H2 of the CO sensor 3 is set to a height that matches the living area of the person, for example, about 1 to 2 m. Further, in order to easily and reliably install the CO sensor 3 at a height corresponding to the living area of the person in this way, the CO sensor 3a is configured as a wall-mounted type as in the conventional case, and the wall surface of the target space 1 In FIG. 2, the second detection height H2 is disposed. The CO sensor 3b is configured as a card type, and the CO sensor 3c is configured as a cellular phone integrated type and is carried by a person.

  The second detection position is preferably determined in consideration of the position of an object that can be a CO source. That is, in a low oxygen concentration environment, even if there is a fire source, a hot air current is not generated and it is difficult to go up to the ceiling 1a, and CO drifts in the entire target space 1. For this reason, it is difficult to detect CO in the vicinity of the ceiling 1a, and it is possible that the detection becomes more difficult as the distance from the CO source increases even at a position below the ceiling 1a. Therefore, it is preferable to arrange the CO sensor 3 in the vicinity of an object (for example, combustible material) that can be a CO source. For this reason, the CO sensor 3 d is configured as a movable desktop type and is disposed on a desk disposed in the target space 1.

  The card-type CO sensor 3b, the cellular phone-integrated CO sensor 3c, and the desktop CO sensor 3d are configured to include a wireless transmission unit (not shown) in addition to the configuration of a known general CO sensor. Yes. When a fire is detected, a notification signal indicating that fact is wirelessly transmitted to the fire monitoring panel 7 via the wireless transmission unit. In addition, since such a wireless transmission part can utilize the structure used for the well-known wireless fire detector, the specific description is abbreviate | omitted.

The O ₂ sensor 4 is an oxygen concentration measuring unit for measuring the oxygen concentration in the target space 1. The installation position of the O ₂ sensor 4 is arbitrary, but is installed on the wall surface of the target space 1 in the first embodiment.

  Next, the oxygen concentration adjusting unit 5 is an oxygen concentration adjusting means for adjusting the oxygen concentration of the target space 1 from the normal oxygen concentration to the low oxygen concentration. The oxygen concentration adjusting unit 5 is configured as a unit in which, for example, various devices for adjusting the oxygen concentration are accommodated in one housing. Specifically, a compressor for pumping outside air into the casing, and oxygen separation that separates oxygen and nitrogen from the outside air pumped by the compressor to generate nitrogen-enriched gas and oxygen-enriched gas A filter, an oxygen-enriched tank for storing the oxygen-enriched gas generated by the oxygen separation filter, and a nitrogen-enriched tank for storing the nitrogen-enriched gas generated by the oxygen separation filter Has been.

The oxygen concentration control panel 6 is oxygen concentration control means for controlling the oxygen concentration adjusting unit 5. The oxygen concentration control panel 6 controls the oxygen concentration adjusting unit 5 while referring to the oxygen concentration measured by the O ₂ sensor 4 to supply the target space 1 with oxygen-enriched gas or nitrogen-enriched gas. The oxygen concentration in the target space 1 is adjusted to a desired oxygen concentration.

  The fire monitoring panel 7 changes the fire detection position by switching the sensor used for fire detection to either the smoke sensor 2 or the CO sensor 3 based on the oxygen concentration in the target space 1. This corresponds to the control means in the claims. FIG. 4 is a block diagram functionally conceptually showing the electrical configuration of the fire monitoring panel 7. As shown in FIG. 4, the fire monitoring panel 7 includes an antenna 7a, a speaker 7b, a memory 7c, an external input / output terminal 7d, and a control unit 7e.

  Among these, the antenna 7a is a receiving means for receiving radio outputs from the card-type CO sensor 3b, the cellular phone-integrated CO sensor 3c, and the desktop CO-sensor 3d. The speaker 7b is a sound output means for generating a buzzer sound when a fire occurs. The memory 7c is storage means for storing various information necessary for processing of the fire monitoring panel 7, and particularly stores a threshold value indicating a boundary between the normal oxygen concentration and the low oxygen concentration. The external input / output terminal 7d is a group of terminals for performing input to the fire monitoring panel 7 and outputting from the fire monitoring panel 7. In the external input / output terminal 7d, the fire monitoring panel 7 is described above. In addition to the smoke sensor 2, the CO sensor 3, and the oxygen concentration control panel 6, the smoke sensor 2, the oxygen concentration control panel 6, and an external device to be linked are not electrically connected. The control unit 7e is a control unit that controls each unit of the fire monitoring panel 7, and includes, for example, a CPU (Central Processing Unit) that loads and executes a control program stored in the memory 7c. Yes.

(Fire detection processing)
Next, fire detection processing in the fire detection system configured as described above will be described. FIG. 5 is a flowchart of this fire detection process. As shown in FIG. 5, the control unit 7e of the fire monitoring panel 7 determines whether the oxygen concentration in the target space 1 is the normal oxygen concentration or the low oxygen concentration based on the output from the O ₂ sensor 4 ( Whether it is 17% or more) is monitored (step SA-1).

  When the oxygen concentration is normal (Yes in step SA-1), the control unit 7e emits light from the sensor arranged at the first detection height H1 (that is, the smoke sensor 2 in the first embodiment). It is monitored whether or not an information output has been performed (step SA-2). Then, when the alarm output is performed (step SA-2, Yes), the control unit 7e sounds an alarm sound to notify the fire, and performs an interlocked alarm output to a predetermined external device. The interlocking operation is performed at (Step SA-3). As described above, when the oxygen concentration is normal, fire detection can be performed using the smoke sensor 2 in the vicinity of the ceiling 1a. Therefore, early fire detection can be performed by detecting smoke rising in the vicinity of the ceiling 1a due to the hot air current. It can be carried out.

  On the other hand, when it is determined in Step SA-1 that the oxygen concentration in the target space 1 is a low oxygen concentration (No in Step SA-1), the control unit 7e is arranged at the second detection height H2. It is monitored whether or not a warning output is made from the sensor (that is, the CO sensor 3 in the first embodiment) (step SA-4). When the alarm output is performed (step SA-4, Yes), the control unit 7e sounds an alarm sound to notify the fire, and performs an interlocked alarm output to a predetermined external device. The interlocking operation is performed at (Step SA-3). Thus, when the oxygen concentration is low, fire detection can be performed using the CO sensor 3 below the vicinity of the ceiling 1a, so that CO drifting in the entire target space 1 is detected without rising to the vicinity of the ceiling 1a. By doing so, early fire detection can be performed.

(Modification of Embodiment 1)
Next, a modification of the first embodiment according to the present invention will be described. The fire detection system according to this modified example includes a heat sensor (heat sensor) at the first detection position, a smoke sensor and a CO sensor at the second detection position, and a smoke sensor at the first detection position. This is different from the first embodiment in which the CO sensor is arranged at the second detection position. However, about the structure substantially the same as Embodiment 1, the code | symbol same as used in Embodiment 1 is attached | subjected as needed, and the description is abbreviate | omitted.

(Configuration of fire detection system)
FIG. 6 is a diagram showing an overall configuration of a fire detection system according to this modification. In FIG. 6, the thermal sensor 8 is disposed at the first detection position H1, and the smoke sensor 2 and the CO sensors 3b to 3d are disposed at the second detection position H2.

  Among these, the thermal sensor 8 detects a fire based on the temperature of the target space 1, and corresponds to the sensor in the claims. Although the detection principle by the thermal sensor 8 is arbitrary, for example, a temperature detection element such as a thermistor is provided, and if the output of the temperature detection element exceeds a predetermined threshold, it is determined that a fire has occurred. Outputs an alarm signal.

(Fire detection processing)
Next, fire detection processing in the fire detection system configured as described above will be described. However, since this fire detection process can be performed similarly to the fire detection process of the first embodiment shown in FIG. 5, only the outline will be described. That is, the fire monitoring panel 7 monitors whether the oxygen concentration in the target space 1 is a normal oxygen concentration or a low oxygen concentration based on the output from the O ₂ sensor 4. Is the presence / absence of an alarm output from the thermal sensor 8 arranged at the first detection height H1, and at the time of low oxygen concentration, from the smoke sensor 2 and the CO sensors 3b to 3d arranged at the second detection height H2. If the alarm is output, the alarm is sounded to notify the fire, and the alarm is output to the specified external device. Let the action take place. According to this modification, particularly when the oxygen concentration is normal, the thermal sensor 8 detects a fire, so that the most popular thermal sensor as a fire sensor can be used as it is, and even in an existing building. A fire detection system with variable oxygen concentration space can be constructed easily and inexpensively. As the sensor arranged at the second detection height H2, only one of the smoke sensor 2 or the CO sensors 3b to 3d may be provided.

(Effect of Embodiment 1)
As described above, according to the first embodiment, the type and position of the sensor used for fire detection can be automatically changed according to the oxygen concentration in the target space 1, so that the target that changes according to the oxygen concentration Fire detection can be performed in a form suitable for the physical phenomenon in the space 1, and early and reliable fire detection can be performed. In addition, since a sensor is arranged at each of the two positions, a mechanism and control for moving one sensor to the two positions as in the second embodiment to be described later are unnecessary. Can be configured simply and inexpensively. In addition, since the CO sensor 3 is arranged in a person's living area, it is possible to prevent a person from being adversely affected by inhaling CO, and a fire detection system that considers safety other than fire can be constructed. Furthermore, when the thermal sensor 8 is arranged at the first detection height H1, the thermal sensor that is currently most popular as a fire sensor can be used as it is, and a fire detection system with a variable oxygen concentration space can be used even in an existing building. Easy and inexpensive to build.

[Embodiment 2]
Next, a second embodiment according to the present invention will be described. The fire detection system according to the second embodiment is different from the first embodiment in which two sensors are fixedly arranged in that one sensor is moved to two positions. However, about the structure substantially the same as Embodiment 1, the code | symbol same as used in Embodiment 1 is attached | subjected as needed, and the description is abbreviate | omitted.

(Configuration of fire detection system)
FIG. 7 is a diagram showing an overall configuration of the fire detection system according to the second embodiment. In FIG. 7, the target space 1 includes a smoke sensor 2, an O ₂ sensor 4, a lifting device 10, a projector screen 11, an oxygen concentration adjustment unit 5, an oxygen concentration control panel 6, and a fire monitoring panel 12. These parts are electrically connected as indicated by dotted lines in the figure.

  Among these, the lifting device 10 moves the smoke sensor 2 to two positions of the first detection height H1 and the second detection height H2, and corresponds to the moving means in the claims. Although the specific configuration of the lifting device 10 is arbitrary, for example, it is configured as a pneumatic actuator fixed to a wall surface in a direction along the vertical direction. By operating this actuator, the smoke sensor 2 is It is movable.

  The projector screen 11 is a projection roll screen for displaying an image projected from a projector device (not shown). FIG. 8 shows a perspective view of the projector screen 11. As shown in FIG. 8, the projector screen 11 includes a screen 11a constituting a projection surface of an image, and a winding mechanism 11b for winding or unwinding the screen 11a. Here, the smoke sensor 2 is fixed to the lower end of the screen 11a, and the smoke sensor 2 is moved up and down along with the screen 11a by winding or unwinding the screen 11a by the winding mechanism 11b.

  That is, the projector screen 11 is used as a means for moving the smoke sensor 2 to two positions of the first detection height H1 and the second detection height H2 in addition to the function as a roll screen for normal projection. It corresponds to the moving means in the claims. Note that the specific configuration of the projector screen 11 can be configured in the same manner as a conventional auto-winding projector screen, and thus detailed description thereof is omitted.

  The fire monitoring panel 12 changes the fire detection position by switching the sensor used for fire detection to either the smoke sensor 2 or the CO sensor 3 based on the oxygen concentration in the target space 1. This corresponds to the control means in the claims. FIG. 9 is a block diagram functionally conceptually showing the electrical configuration of the fire monitoring panel 12. As shown in FIG. 9, the fire monitoring panel 12 includes a speaker 12a, a memory 12b, an external input / output terminal 12c, and a control unit 12d. These units exclude the control contents of the control unit 12b. The speaker 7b, the memory 7c, the external input / output terminal 7d, and the control unit 7e according to the first embodiment are configured in substantially the same manner.

(Fire detection processing)
Next, fire detection processing in the fire detection system configured as described above will be described. FIG. 10 is a flowchart of this fire detection process. As shown in FIG. 10, the control unit 12d of the fire monitoring panel 12 determines whether the oxygen concentration in the target space 1 is the normal oxygen concentration or the low oxygen concentration based on the output from the O ₂ sensor 4 ( Whether it is 17% or more) is monitored (step SB-1). And when it is normal oxygen concentration (step SB-1, Yes), the control part 12d judges whether the smoke sensor 2 is arrange | positioned in the upper position, ie, 1st detection height H1, (step). SB-2) If not arranged (step SB-2, No), a control signal is sent to the lifting device 10 to drive the actuator, and a control signal is sent to the winding mechanism 11b to wind the screen 11a. By taking it, the smoke sensor 2 is moved until it reaches the first detection height H1 (step SB-2 to step SB-3).

  And the control part 12d monitors whether the alert output was performed from this smoke sensor 2 (step SB-4), and when the alert output was performed (step SB-4, Yes), An alarm sound is sounded to notify the fire, and an interlocking operation is performed by outputting an interlocking alarm to a predetermined external device (step SB-5). In this way, when the oxygen concentration is normal, the smoke sensor 2 can be moved to the vicinity of the ceiling 1a to perform fire detection. Therefore, smoke rising in the vicinity of the ceiling 1a due to the hot air current is detected to detect early fire detection. It can be carried out.

  On the other hand, when it is determined in step SB-1 that the oxygen concentration in the target space 1 is a low oxygen concentration (No in step SB-1), the control unit 12d determines that the smoke sensor 2 is at the lower position, that is, the second position. Is determined (step SB-6), and if not (step SB-6, No), a control signal is sent to the lifting device 10 to drive the actuator. In addition, the smoke sensor 2 is moved to the second detection height H2 by sending a control signal to the winding mechanism 11b to unwind the screen 11a (steps SB-6 to SB-7).

  And the control part 12d monitors whether the alert output was performed from this smoke sensor 2 (step SB-4), and when the alert output was performed (step SB-4, Yes), An alarm sound is sounded to notify the fire, and an interlocking operation is performed by outputting an interlocking alarm to a predetermined external device (step SB-5). In this way, when the oxygen concentration is low, the smoke sensor 2 can be moved downward from the vicinity of the ceiling 1a to detect the fire, so that the smoke drifting in the entire target space 1 without rising to the vicinity of the ceiling 1a. Early fire detection can be performed by sensing.

(Effect of Embodiment 2)
As described above, according to the second embodiment, the sensor used for fire detection can be automatically moved and changed in accordance with the oxygen concentration in the target space 1, so that the position changes according to the oxygen concentration. Fire detection can be performed at a position suitable for the physical phenomenon of the target space 1 to be performed, and early and reliable fire detection can be performed. Further, since one sensor is moved to two positions, it is not necessary to arrange sensors at each of the two positions as in the first embodiment, and the fire monitoring system can be simplified and simplified by reducing the number of sensors. It can be configured at low cost.

[Embodiment 3]
Next, a third embodiment according to the present invention will be described. The fire detection system according to the third embodiment is arranged at a plurality of positions with different heights in that a plurality of types of sensors arranged at substantially the same height are switched according to the oxygen concentration of the target space 1. This is different from the first embodiment in which the sensor is switched according to the oxygen concentration in the target space 1. However, about the structure substantially the same as Embodiment 1, the code | symbol same as used in Embodiment 1 is attached | subjected as needed, and the description is abbreviate | omitted.

(Configuration of fire detection system)
FIG. 11 is a diagram showing an overall configuration of the fire detection system according to the third embodiment. In FIG. 11, the target space 1 includes a smoke sensor 2, a CO sensor 3 a, an O ₂ sensor 4, an oxygen concentration adjustment unit 5, an oxygen concentration control panel 6, and a fire monitoring panel 20. These parts are electrically connected as indicated by dotted lines in the figure.

  Among these, the smoke sensor 2 and the CO sensor 3a are set at substantially the same height, specifically, the lower surface of the ceiling 1a. The CO sensor 3a according to the third embodiment outputs a voltage signal corresponding to the detected CO concentration. In the third embodiment, smoke corresponds to the first physical quantity in the claims, and CO corresponds to the second physical quantity in the claims.

  The fire monitoring panel 20 changes the fire detection position by switching the sensor used for detecting the fire to either the smoke sensor 2 or the CO sensor 3 based on the oxygen concentration in the target space 1. This corresponds to the control means in the claims. FIG. 12 is a block diagram functionally conceptually showing the electrical configuration of the fire monitoring panel. As shown in FIG. 12, the fire monitoring panel 20 includes a speaker 20a, a memory 20b, an external input / output terminal 20c, and a control unit 20d. These units exclude the control content of the control unit 20d. The speaker 7b, the memory 7c, the external input / output terminal 7d, and the control unit 7e according to the first embodiment are configured in substantially the same manner.

  Here, the control unit 20d switches the sensor used for fire detection to the smoke sensor 2 under a normal oxygen concentration environment, and the sensor used for fire detection to the CO sensor 3 under a low oxygen concentration environment. FIG. 13 shows CO concentration change under normal oxygen concentration, and FIG. 14 shows CO gas concentration change under low oxygen concentration (the horizontal axis is the elapsed time since turning on the heater serving as a fire source, The vertical axis shows the concentration of CO gas). As shown in FIG. 13, the CO concentration gradually increases under the normal oxygen concentration, but as shown in FIG. 14, the CO concentration rapidly increases under the low oxygen concentration. For this reason, in the third embodiment, a fire is detected by the smoke sensor 2 under normal oxygen concentration as in the conventional case, and a fire is detected by the CO sensor 3 under low oxygen concentration.

(Fire detection processing)
Next, fire detection processing in the fire detection system configured as described above will be described. FIG. 15 is a flowchart of this fire detection process. As shown in FIG. 15, the control unit 20d of the fire monitoring panel 20 determines whether the oxygen concentration in the target space 1 is the normal oxygen concentration or the low oxygen concentration based on the output from the O ₂ sensor 4 ( Whether it is 17% or more) is monitored (step SC-1). And when it is normal oxygen concentration (step SC-1, Yes), the control part 20d monitors whether the alarm output was performed from the smoke sensor 2 (step SC-2), and an alarm output is performed. In the case of failure, a warning sound is sounded to notify the fire, and an interlocking operation is performed by outputting an interlocking alarm to a predetermined external device (step SC-3). In this way, fire detection can be performed based on the output of the smoke sensor 2 at the time of normal oxygen concentration, so that early fire detection can be performed by detecting smoke that increases in the initial stage of fire in a normal oxygen concentration environment. it can.

  On the other hand, when it is determined in step SC-1 that the oxygen concentration in the target space 1 is a low oxygen concentration (No in step SC-1), the control unit 20d, based on the output from the CO sensor 3a, It is monitored whether or not the CO concentration of 1 is equal to or higher than a predetermined CO concentration (for example, 150 ppm, hereinafter referred to as fire CO concentration) indicating the occurrence of a fire (step SC-4). (Step SC-4, Yes) An alarm sound is sounded to notify the fire, and an interlocking operation is performed by outputting an interlocking alarm to a predetermined external device (Step SC-3). If it is determined in step SC-4 that the concentration is not equal to or higher than the fire CO concentration (No in step SC-4), the control unit 20d has a predetermined concentration that is lower than the fire CO concentration but may cause danger to the human body. Whether or not the CO concentration (for example, 50 ppm, below, dangerous CO concentration) or more is monitored (step SC-5), and if it is the dangerous CO concentration or more, an alarm is sounded to notify the danger (step SC). -6). In this way, when the oxygen concentration is low, fire detection can be performed based on the output of the CO sensor 3, so that it is possible to detect early CO by detecting CO that increases in the early stage of fire in a low oxygen concentration environment. it can.

(Effect of Embodiment 3)
Thus, according to the third embodiment, the type of sensor used for fire detection can be automatically switched according to the oxygen concentration in the target space 1, so that the physical quantity that increases in the early stage of the fire according to the oxygen concentration Fire detection can be performed based on the above, and early and reliable fire detection can be performed. In addition, since a sensor is arranged at each of the two positions, a mechanism and control for moving one sensor to the two positions as in the above-described second embodiment are not required. Can be configured simply and inexpensively.

[III] Modifications to Each Embodiment Although the embodiments of the present invention have been described above, the specific configuration and method of the present invention are within the scope of the technical idea of each invention described in the claims. It can be arbitrarily modified and improved within. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above-described contents, and the present invention solves the problems not described above or has the effects not described above. There are also cases where only some of the described problems are solved or only some of the described effects are achieved. For example, even if a fire in the target space 1 cannot be completely detected, the problem of the present application is achieved as long as the fire can be detected slightly more quickly than the conventional fire detection system.

(Relationship between each embodiment)
Various features shown in the embodiments can be mixed with each other. For example, in the second embodiment, only the smoke sensor is used, but a CO sensor may be further used as in the first and third embodiments. Alternatively, in the first embodiment, only the smoke sensor may be provided at the first detection height and the second detection height, and switching may be performed based on the oxygen concentration in the target space 1. In addition, a smoke sensor or a CO sensor that is fixedly installed as in the first embodiment and a smoke sensor that is movably arranged as in the second embodiment may be used.

(About the type, number, and interlocking mode of fire sensors)
The type, number, or interlocking form of sensors for detecting a fire are not limited to those described above. For example, in the first embodiment, the smoke sensor is used at normal oxygen concentration, and the CO sensor is used at low oxygen concentration, but both the smoke sensor and the CO sensor are used at low oxygen concentration. When an output is issued, it is determined that there is a fire, or the fire determination may be performed by taking AND of both notification outputs. In addition, the specific form of the fire sensor is also arbitrary. For example, when there is no person or object at the second detection height, which is the height of the living area, a wide area can be obtained using a separate sensor. You may make it cover. The number of fire sensors is also arbitrary, and a plurality of sensors of the same type may be arranged. Also, when the CO sensor is portable, various forms can be taken, and for example, it may be incorporated in a personal computer, a fixed telephone, a private PHS terminal, or the like. In the first to third embodiments, the presence or absence of a fire is determined based on whether or not the detected smoke or CO is greater than or equal to a predetermined amount, but the detection amount per unit time (the slope of the detection amount) It may be determined that a fire has occurred when the amount exceeds a predetermined amount. A single sensor may be a composite sensor having a function of detecting both smoke and CO, or both heat and CO.

(About detection position)
In addition to the first detection position and the second detection position, another detection position may be set and the sensor may be arranged here. For example, the oxygen concentration may be divided into three or more levels, and a fire may be detected using sensors arranged at different positions according to each level.

(Fire sensor switching mode)
The fire sensor is switched based on the output from the O ₂ sensor 4, but the oxygen concentration in the target space 1 may be received from the oxygen concentration control panel 6 and based on this. Moreover, it is not necessarily limited to automatic, and the user may switch manually.

  As described above, the fire detection system in the oxygen concentration variable space according to the present invention is used for fire detection in the oxygen concentration variable space, and is particularly useful for early and reliable detection of a fire at any oxygen concentration. is there.

It is a figure which shows the whole structure of the fire detection system which concerns on Embodiment 1 of this invention. It is a figure which shows the temperature distribution of the object space under normal oxygen concentration. It is a figure which shows the temperature distribution of the object space under a low oxygen concentration. It is a block diagram which shows the electrical structure of a fire monitoring board functionally conceptually. 3 is a flowchart of fire detection processing according to Embodiment 1; It is a figure which shows the whole structure of the fire detection system which concerns on the modification of Embodiment 1. FIG. It is a figure which shows the whole structure of the fire detection system which concerns on Embodiment 2 of this invention. It is a perspective view of a projector screen. It is a block diagram which shows the electrical structure of a fire monitoring board functionally conceptually. 6 is a flowchart of fire detection processing according to the second embodiment. It is a figure which shows the whole structure of the fire detection system which concerns on Embodiment 3 of this invention. It is a block diagram which shows the electrical structure of a fire monitoring board functionally conceptually. It is a figure which shows the density | concentration change of CO under normal oxygen concentration. It is a figure which shows the density | concentration change of CO under a low oxygen concentration. 10 is a flowchart of fire detection processing according to the third embodiment.

Explanation of symbols

1 target space 1a ceiling 2 smoke sensor 3,3A～3d CO sensor 4 O ₂ sensor 5 oxygen concentration adjusting unit 6 oxygen concentration control panel 7,12,20 fire monitoring panel 7a antenna 7b, 12a, 20a speaker 7c, 12b, 20b Memory 7d, 12c, 20c External input / output terminal 7e, 12d, 20d Control unit 8 Thermal sensor 10 Lifting device 11 Projector screen 11a Screen 11b Winding mechanism

Claims (5)

Oxygen concentration variable space that can adjust the oxygen concentration from normal oxygen concentration to low oxygen concentration, variable in oxygen concentration to prevent fire or prevent deterioration of stored items by adjusting the oxygen concentration to low oxygen concentration when fire does not occur A fire detection system for detecting a fire in a space,
A first detection position in the oxygen concentration variable space, and a second detection position is lower than the first detection position in the oxygen concentration variable space of a sensor capable of detecting a fire in at least two positions Prepared,
The sensor includes a first sensor that detects a predetermined first physical quantity in the oxygen concentration variable space, and a second sensor that detects a second physical quantity different from the first physical quantity in the oxygen concentration variable space. And consists of
The first detection position is a position suitable for detecting the first physical quantity in the oxygen concentration variable space adjusted to the normal oxygen concentration,
The second detection position is a position suitable for detecting the second physical quantity in the oxygen concentration variable space adjusted to the low oxygen concentration,
Placing the first sensor at the first detection position;
The second sensor is disposed at the second detection position,
A fire detection system in a variable oxygen concentration space. The first sensor is a smoke sensor for detecting smoke that is the first physical quantity;
The second sensor is a CO sensor for detecting CO which is the second physical quantity;
The fire detection system in the oxygen concentration variable space according to claim 1. When the oxygen concentration in the oxygen concentration variable space is adjusted to the normal oxygen concentration, a fire is detected using at least the first sensor, and the oxygen concentration in the oxygen concentration variable space is set to the low oxygen concentration. A control means for switching the sensor so as to detect a fire using at least the second sensor.
The fire detection system in the oxygen concentration variable space according to claim 1 or 2. Oxygen concentration variable space that can adjust the oxygen concentration from normal oxygen concentration to low oxygen concentration, variable in oxygen concentration to prevent fire or prevent deterioration of stored items by adjusting the oxygen concentration to low oxygen concentration when fire does not occur A fire detection system for detecting a fire in a space,
A sensor capable of detecting a fire at at least two positions: a first detection position in the oxygen concentration variable space; and a second detection position that is lower than the first detection position in the oxygen concentration variable space. Prepared,
Moving means for moving the sensor to the first detection position and the second detection position;
Based on the oxygen concentration in the oxygen concentration variable space, the sensor is moved to one of the first sensor and the second sensor via the moving means, so that a fire detection position in the sensor is detected. Control means for changing
A fire detection system in a variable oxygen concentration space. The first detection position is a position near a ceiling in the oxygen concentration variable space;
The fire detection system in the oxygen concentration variable space according to any one of claims 1 to 4.

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