JP2017049799A - Fire detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To substantially match the timing to issue a dirt previous notice alarm as a whole by automatically changing a dirt previous notice threshold in accordance with a progress situation of a dirt degree at a side of a fire detector without requiring operation or processing on a fire prevention reception board.SOLUTION: A fire detector 16 in a tunnel comprises: fire detection parts 16a and 16b for detecting a fire via translucent windows 36; and a test light source 42, a dirt light-receiving part 44 and an amplification part 46 as a dirt detection part for the translucent window. In the case when a dirt level exceeds a predetermined dirt threshold, a control part 32 transmits a dirt alarm signal to a fire prevention reception board. In the case when the dirt level exceeds a predetermined dirt previous notice threshold smaller than the dirt threshold and is smaller than the dirt threshold, the control part transmits a dirt previous notice alarm signal to the fire prevention reception board. A dirt prediction part 48 detects a change of the detected dirt level and predicts a dirt level at a scheduled time point such as preset cleaning timing based on the change of the dirt level. A threshold change part 50 changes the dirt previous notice threshold in accordance with the dirt level that is predicted by the dirt prediction part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fire detector that is connected to a signal line drawn from a disaster prevention receiving board and monitors a fire in a tunnel.

  Conventionally, in order to protect people and vehicles from fire accidents that occur in tunnels for exclusive use of automobile roads, fire detectors that monitor fires have been installed and connected to signal lines drawn from disaster prevention reception boards. ing.

  The fire detector has detection areas in both the left and right directions, and, for example, at intervals of 25 m or 50 m so that detection areas with adjacent fire detectors overlap each other along the longitudinal direction of the tunnel. Arranged continuously at intervals.

  In addition, the fire detector monitors the radiation from the fire flame generated in the tunnel through the translucent window, such as infrared rays, and monitors the contamination of the translucent window to maintain the flame monitoring function. doing. The contamination of the translucent window is monitored by periodically receiving test light from a test light source provided in the detector, entering the translucent window via the detection area side space outside the detector, and receiving it with a light receiving element. The light reception level at that time is compared with that at the time of initial non-fouling, for example, to obtain a dimming rate indicating the degree of contamination, and when the dimming rate exceeds a predetermined contamination threshold, a contamination warning is output. Further, a lower notice dirt threshold value is set for the dirt threshold value, and a dirt notice warning is issued when the light reduction rate exceeds the dirt notice threshold value.

  In addition, the fire detectors installed in the tunnel increase the contamination of the translucent windows over time due to adhesion of fouling substances floating in the environment, so the translucent windows must be cleaned at regular intervals. It is carried out.

  However, the degree of contamination of the translucent window varies depending on the location of the fire detector and the direction of the wind, and the extent of contamination that progresses during a certain period until cleaning is performed. Depending on the right and left of the translucent window provided in the vessel. The detector has a sensitivity compensation function so that the fire monitoring operation can be continued until the contamination warning is output even if the contamination warning is output. Here, for example, when a certain detector outputs a warning contamination warning, the time until the detector reaches the contamination warning level is not constant depending on the installation location. Similarly, the period until the warning notice warning is output may differ greatly for each detector. For this reason, there was a case where unnecessary temporary cleaning was performed for the fire detector having a small degree of stain progress of the translucent window.

  In order to solve such problems, when the warning notice of a certain fire detector is issued earlier than the other fire detectors, the threshold value for the notice of dirt is higher than before by an input operation to the disaster prevention receiver. Change the value so that the dirt warning warning is issued slowly, and when the dirt spreads to the fire detectors installed in the tunnel as a whole, the warning warning is issued so that cleaning is performed efficiently. A system has been proposed (Patent Document 1).

JP 2000-315285 A

  However, in changing the contamination warning threshold in such a conventional tunnel disaster prevention system, the degree of contamination detected by all fire detectors in the disaster prevention reception panel is collected, and the contamination warning threshold is individually set for each fire detector. It is necessary to set and change the contamination warning threshold value of a specific fire detector as necessary. Since the contamination warning threshold value for each fire detector is stored and managed, the control processing is complicated and changes are required. There is also a problem that takes time.

  In addition, when a dirt notice threshold is set on the fire detector side and a dirt notice warning is judged, for example, the change of the dirt notice threshold is instructed by specifying the address of a specific fire detector in the disaster prevention receiver. It is necessary to send a command, and similarly, it is necessary to manage the situation of the dirt alarm threshold set for each fire detector on the disaster prevention reception board side, and there is a problem that it takes time and effort to operate it .

  The present invention automatically changes the dirt notice threshold according to the progress of the degree of dirt on the fire detector side and does not require any operation or processing at the disaster prevention reception board, and a dirt notice warning is issued as a whole. The purpose is to provide a fire detector that can be installed in a tunnel that can be arranged in almost the same time.

(Fire detector)
The present invention
A transmission unit connected to a signal line to the disaster prevention receiver,
A fire detection unit for detecting radiation from the fire through the translucent window;
A dirt detector for detecting a dirt level indicating the degree of dirt on the translucent window;
When the dirt level detected by the dirt detector exceeds a predetermined dirt threshold, a dirt alarm part that transmits a dirt alarm signal to the disaster prevention receiver,
When the dirt level detected by the dirt detector exceeds a predetermined dirt notice threshold smaller than the dirt threshold and less than the dirt threshold, a dirt notice warning section that transmits a dirt notice warning signal to the disaster prevention receiving board;
In a fire detector with
A stain prediction unit that detects a change in the stain level detected by the stain detection unit for each predetermined prediction cycle, and predicts a stain level at a preset time point based on the change in the stain level;
A threshold value changing unit for changing the dirt notice threshold value according to the dirt level predicted by the dirt prediction unit;
Is provided.

(Dirt level prediction)
Here, the dirt prediction unit Tc is the scheduled period up to the scheduled time, Ts is the dirt prediction period, D is the dirt level detected in the dirt prediction period Ts, ΔD is the dirt level change rate of the dirt prediction period Ts, and the number of dirt predictions Is n times, the estimated dirt level De at the scheduled scheduled cleaning is De = D + ΔD (Tc−n · Ts)
Calculate as

(Upper limit of dirt notice threshold)
Further, the threshold value changing unit sets an upper limit threshold value of the dirt notice threshold value, and changes the dirt notice threshold value to the upper threshold value when the dirt level predicted by the dirt prediction unit exceeds a predetermined upper limit threshold value.

(Dimming rate)
In addition, the dirt detector
A test light source unit that periodically irradiates the translucent window with test light via an external space;
A test light receiving unit that receives the test light incident through the translucent window and outputs a test light reception signal;
Using the level of the test light reception signal when the dirt monitoring is started or restarted as a reference, the dimming rate relative to the reference is detected as the dirt level every time the test light reception signal is obtained from the test light receiving unit.

(Basic effect)
The present invention relates to a transmission unit connected to a signal line drawn from a disaster prevention receiver, a fire detection unit for detecting radiation from a fire through a translucent window, and a stain indicating the degree of contamination of the translucent window. The contamination detection unit that detects the level, the contamination detection unit that transmits a contamination alarm signal to the disaster prevention receiver when the contamination level detected by the contamination detection unit exceeds a predetermined contamination threshold, and the contamination detected by the contamination detection unit In a fire detector provided with a dirt notice warning unit for sending a dirt notice warning signal to a disaster prevention receiving panel when the level exceeds a predetermined dirt notice threshold smaller than the dirt threshold and less than the dirt threshold, a predetermined prediction is made. A change in the dirt level detected by the dirt detection unit is detected for each cycle, and a dirt prediction unit that predicts a dirt level at a preset scheduled time based on the change in the dirt level, and a dirt level predicted by the dirt prediction unit Dirty notice according to Since the threshold value changing unit for changing the value is provided, the dirt level at the scheduled cycle arrival time (scheduled date) such as the cleaning time is predicted according to the degree of dirt of the translucent window, for example, the expected dirt level is obtained. By changing the dirt notice threshold in this way, even if the progress of the degree of dirt on the translucent window provided in the fire detector installed in the system is different, the period until the next scheduled scheduled maintenance For example, local early occurrence of a dirt warning in the system can be suppressed, and unnecessary response to the dirt warning warning can be reduced. For this reason, it becomes possible to appropriately perform the cleaning work in response to the dirt notice warning.

  In addition, the change of the dirt notice threshold is automatically performed on the fire detector side, so it is not necessary to change the dirt notice threshold on the disaster prevention reception board or to instruct the fire detector to change the process and processing. It is possible to reduce the processing burden on the panel side and the burden on the management side.

(Effect by predicting the dirt level)
In addition, the dirt prediction unit Tc is the scheduled period up to the scheduled time, Ts is the dirt prediction period, D is the dirt level detected at the dirt prediction period Ts, ΔD is the dirt level change rate of the dirt prediction period Ts, and In the case of n times, the predicted dirt level De at the scheduled scheduled cleaning is De = D + ΔD (Tc−n · Ts).
As a result, it is possible to change the dirt notice threshold by obtaining the dirt level at the scheduled cycle arrival, such as the regular cleaning time, by linear prediction based on the actual dirt level change. Therefore, even if the dirt level changes nonlinearly, the dirt level at the time of regular cleaning can be predicted more accurately and changed to an appropriate dirt notice threshold.

(Effect of upper limit of dirt notice threshold)
In addition, the threshold changing unit sets the upper limit threshold of the dirt notice threshold, and when the dirt level predicted by the dirt prediction unit exceeds the upper threshold, the dirt notice threshold is changed to the upper threshold. When the degree of dirt is high, it is possible to prevent the dirt notice threshold value from being changed to a higher value than necessary.

(Effects due to dimming rate)
In addition, the dirt detection unit includes a test light source unit that periodically irradiates the translucent window with test light from the outside, and a test light receiving unit that receives the test light incident through the translucent window and outputs a test light reception signal. Level when the test light receiving signal is obtained from the test light receiving unit, with reference to the level of the test light receiving signal when the monitor and the dirt monitoring are started or restarted, that is, when the transparent window is not dirty. As a result, the attenuation level of the test light reception signal is detected as the dimming rate. It is possible to appropriately perform the process of predicting the dirt level on the scheduled date.

Explanatory diagram showing an overview of the tunnel disaster prevention system Block diagram showing the outline of the functional configuration of the disaster prevention reception board Block diagram showing outline of functional configuration of fire detector Explanatory drawing showing the appearance of the fire detector Time chart showing change of dirt notice threshold based on dirt prediction Flow chart showing dirt threshold change control by fire detector

[Outline of tunnel disaster prevention system]
FIG. 1 is an explanatory diagram showing an outline of a so-called R-type transmission disaster prevention system to which a fire detector of the present invention is applied. As shown in FIG. 1, an upstream tunnel 1a and a downstream tunnel 1b are constructed as tunnels for an automobile road.

  Fire detectors 16 are installed, for example, at intervals of 25 meters along the walls in the tunnel longitudinal direction inside the upstream tunnel 1a and the downstream tunnel 1b. The fire detector 16 includes two sets of fire detectors, so that the fire detector 16 has detection areas in both the upward and downward directions in the longitudinal direction of the tunnel, and is adjacent to the fire detectors disposed along the longitudinal direction of the tunnel. It arrange | positions continuously so that a detection area may mutually overlap, and a fire is detected by observing the radiation from the flame by the fire which occurred in the detection area, for example, infrared rays.

  The fire detector 16 is connected to the fire detector 16 by connecting the power and transmission lines 12a and 12b to the upstream tunnel 1a and the downstream tunnel 1b from the disaster prevention receiving board 10, and the fire detector 16 has a unique address for each line. It is set.

[Disaster prevention reception board]
FIG. 2 is a block diagram showing an outline of the functional configuration of the disaster prevention reception board. As shown in FIG. 2, the disaster prevention receiving board 10 includes a control unit 18, and the control unit 18 is a function realized by executing a program, for example, and includes a CPU, a memory, various input / output ports and the like as hardware. Use computer circuit etc.

  For the control unit 18, transmission units 20a and 20b are provided, and a plurality of fire detectors 16 installed in the upstream tunnel 1a and the downstream tunnel 1b are connected to the transmission lines 12a and 12b drawn from the transmission units 20a and 20b, respectively. doing.

  Further, an alarm unit 22 having a speaker, an alarm indicator lamp, etc., a control unit 18, a display unit 24 having a liquid crystal display, a printer, etc., an operation unit 26 having various switches, etc., an IG child communicating with an external monitoring facility A modem 28 for connecting station equipment is provided, and an IO unit 30 to which ventilation equipment, alarm display board equipment, radio rebroadcast equipment, camera monitoring equipment, lighting equipment, and fire pump equipment are connected is provided.

  The control unit 18 of the disaster prevention receiving board 10 repeatedly transmits a call message including a polling command instructing the transmission units 20a and 20b and sequentially specifying the addresses of the fire detector 16, and the fire detector 16 sets the self-address. When a matching call message is received, a response message indicating its own detection state including a fire, a dirt alarm, and a dirt notice alarm is returned.

  The control unit 18 of the disaster prevention receiving board 10 outputs a fire alarm when a fire is detected by receiving a response message from the fire detector 16 and performs interlocking control of other facilities via the IO unit 30 to detect a contamination alarm or a contamination. If a warning warning is detected, the address of the fire detector 16 is specified, and a corresponding dirt warning or dirt warning warning is output.

[Fire detector]
FIG. 3 is a block diagram showing an outline of the functional configuration of the fire detector, and FIG. 4 is an explanatory diagram showing the appearance of the fire detector.

  As shown in FIG. 3, the fire detector 16 includes two sets of fire detection units 16a and 16b. As representatively shown by the fire detection unit 16a, the sensor units 38a and 38b, and amplifications corresponding to each of them. The processing units 40a and 40b, the control unit 32, and the transmission unit 34 are provided. A translucent window 36 provided on the detector cover is disposed in front of the sensor units 38a and 38b, and light energy from an external detection area is incident on the sensor units 38a and 38b via the translucent window 36. doing.

  Further, in order to monitor the contamination of the translucent window 36, a contamination detection unit including a test light source unit 42, a contamination light receiving unit 44, and an amplification unit 46 is provided.

  Here, as shown in FIG. 4, the fire detector 16 is provided with two sets of translucent windows 36 in the sensor housing portion 54 provided at the top of the housing 52, and each of the translucent windows 36 is provided with each of them. The sensor parts of the fire detection parts 16a and 16b shown in FIG. 3 are arranged. In addition, two sets of light-transmitting windows for test light sources 56 containing individual test light sources 42 are provided in positions near the light-transmitting window 36 where the sensor unit can be seen.

  Referring to FIG. 3 again, the fire detection unit 16b has the same configuration as the fire detection unit 16a, but the control unit 32 is provided as a unit common to both, for example, a CPU, memory, various input / output ports as hardware, etc. Use a computer circuit equipped with

The fire detector 16a monitors the fire by, for example, two-wavelength flame detection. The sensor unit 38a selects from the optical energy incident through the translucent window 36, 4.4 to 4.5 μm radiation, which is a resonance emission band of CO ₂ specific to flame, by an optical wavelength bandpass filter. The light is transmitted (passed), the energy of the radiation is detected by the light receiving sensor and subjected to photoelectric conversion, and then subjected to predetermined processing such as amplification by the amplification processing unit 40a to obtain a light receiving signal corresponding to the amount of energy to the control unit 32. Output.

  The sensor unit 38b selectively transmits (passes) radiant energy of 5 to 6 μm from the light energy incident through the translucent window 36 by the optical wavelength bandpass filter, and the energy of the radiation is received by the light receiving sensor. After detection and photoelectric conversion, the amplification processing unit 40b performs predetermined processing such as amplification, and outputs the received light signal corresponding to the amount of energy to the control unit 32.

  The control unit 32 determines the presence or absence of flame by taking the relative ratio of the received light signal levels output from the amplification processing units 40a and 40b and comparing it with a predetermined threshold value. Then, the transmission unit 34 is instructed to set fire detection information in a response message to the call message that matches the self-address, and control to transmit to the disaster prevention receiving board 10.

  The stain detection unit composed of the test light source unit 42, the stain light receiving unit 44, and the amplification unit 46 turns on the test light source 42 at a predetermined cycle, for example, once a day, according to an instruction from the control unit 32, and emits test light. The test light is incident on the dirt light receiving unit 44 through the translucent window 36, and the test light is converted into an electric signal by the light receiving sensor provided in the dirt light receiving unit 44, amplified by the amplifying unit 46, and stained in the control unit 32. A detection signal is output.

  The control unit 32 has a function as a contamination alarm unit, and when the contamination level based on the contamination detection signal from the amplification unit 46 exceeds a predetermined contamination threshold, a call message that matches the self-address via the transmission unit 34. Control is performed to set the dirt alarm information in the response message to and send it to the disaster prevention receiving board 10.

  Further, the control unit 32 has a function as a dirt notice warning unit, and when the dirt level based on the dirt detection signal from the amplification unit 46 exceeds a predetermined dirt notice threshold value which is smaller than the dirt threshold value, the control unit 32 is connected via the transmission unit 34. Then, control is performed to set the dirt notice warning information in the response message to the call message that matches the self address and to transmit it to the disaster prevention receiving board 10.

Here, the control unit 32 obtains the light attenuation rate of the translucent window 36 indicating the degree of contamination based on the contamination detection signal from the amplification unit 46, and uses this light attenuation rate as the contamination level to determine the contamination warning warning and the contamination alarm determination processing. I do. The calculation of the light reduction rate of the translucent window 36 by the control unit 32 is based on the level of the dirt detection signal at the start of fire monitoring when the translucent window 36 is not soiled or at the end of cleaning of the translucent window 36 as the reference level Er. Each time a dirt detection signal of detection level E is obtained from the amplifying unit 46, the light attenuation rate D is set to D = 1− (E / Er)
Calculate as

  The light attenuation rate D calculated in this way is a value that increases in proportion to the increase in the degree of contamination of the translucent window 36. In the following description, the light attenuation rate D will be described as the contamination level D.

[Change control of threshold value for fire detector contamination]
The control unit 32 of the fire detector 16 shown in FIG. 3 is further provided with functions of a dirt prediction unit 48 and a threshold value changing unit 50.

  The dirt prediction unit 48 detects the change rate ΔD of the dirt level D based on the dirt detection signal of the amplification unit 46 every predetermined prediction cycle Ts, and based on the change rate ΔD of the dirt level, a predetermined periodic cleaning is performed. The dirt level De at the scheduled time (scheduled date) is predicted. Further, the threshold value changing unit 50 changes the dirt notice threshold value Dth according to the dirt level De predicted by the dirt prediction unit 48.

  FIG. 5 is a time chart showing the change of the dirt notice threshold based on the dirt prediction. In FIG. 5, the horizontal axis represents the number of days, the vertical axis represents the dirt level D, and the monitoring start date when the light-transmitting window 36 is free of dirt is defined as the first day, and a scheduled period corresponding to a regular cleaning period as a guideline. Tc is set to 180 days corresponding to 6 months, and the scheduled scheduled cleaning date is set to the 180th day from the monitoring start date. In addition, Ts = 30 days is set as the prediction cycle Ts, and the predicted number n until the scheduled scheduled cleaning date of the 180th day is n = 6. Note that the regular cleaning cycle Tc and the prediction cycle Ts are examples, and an appropriate number of days, a period, or the number of times can be set as necessary.

  In the example of FIG. 5, assuming a change in the straight line 60 based on an empirical change in the degree of dirt, the dirt level on the scheduled cleaning day 180 days after the assumption of the straight line 60 is initially set as the dirt notice threshold Dth. ing.

  Therefore, when the dirt level changes along the transition assumed by the straight line 60, the dirt level D reaches the dirt notice threshold Dth on the scheduled scheduled cleaning date, and a dirt notice alarm can be issued. The change varies depending on the installation location of the fire detector 16 and the like, and it cannot be said that the dirt level D necessarily reaches the dirt notice threshold Dth on the scheduled scheduled cleaning date.

  Therefore, in the present embodiment, the dirt notice threshold value Dth is changed by predicting the dirt level De on the scheduled scheduled cleaning date every prediction cycle Ts.

  For example, as shown in FIG. 5, if the dirt level on the 30th day after the first prediction cycle Ts has passed is a dirt level D1 exceeding the dirt level assumed by the straight line 60, the dirt level D = 0 and 30 on the start date. The dirt level De1 of the scheduled scheduled cleaning date 150 days later (180th day) is predicted by an extension of the straight line 62 connecting the day dirt level D1, and the predicted dirt level De1 is set as a new dirt notice threshold Dth1. . That is, the initially set dirt notice threshold Dth is changed to the dirt notice threshold Dth1 based on the dirt prediction.

  Subsequently, assuming that the dirt level on the 60th day when the next prediction cycle Ts has passed is a dirt level D2 that exceeds the dirt level assumed on the straight line 60, a straight line 64 connecting the previous dirt level D1 and the current dirt level D2. The dirt level De2 is obtained 120 days after the extension line (180th day), and the estimated dirt level De2 is set as a new dirt notice threshold Dth2. That is, the previously set dirt notice threshold value Dth1 is changed to the dirt notice threshold value Dth2 based on the new dirt prediction.

  Similarly, every time the prediction cycle Ts = 30 days elapses, the control for predicting the dirt level on the scheduled scheduled cleaning date and changing the dirt notice threshold value is repeated.

In order to realize the dirt prediction shown in FIG. 5, the dirt prediction unit 48 of the present embodiment has a scheduled period corresponding to a regular cleaning cycle as a guide, Tc, a dirt prediction period Ts, and a dirt prediction count n times ( When the contamination level detected at time (n · Ts) is D, and the contamination level change rate at time (n · Ts) is ΔD, the estimated contamination level De at the scheduled scheduled cleaning is calculated by the following equation.
De = D + ΔD (Tc−n · Ts) (Formula 1)
Here, the contamination level change rate ΔD of the contamination prediction period Ts is _expressed as follows: ΔD = (D _n −D _n−1 ) / Ts (formula 2) _where D _n−1 is the previous contamination level and D _{n is} the current contamination level. )
Given in.

  FIG. 5 shows an example in which the dirt level exceeds the assumed straight line 60. However, when the dirt notice threshold based on the predicted dirt level is equal to or higher than the upper limit threshold, an upper limit threshold is set. Further, when the notice threshold calculated based on the predicted dirt level is less than or equal to the initial Dth, Dth (initial threshold = lower threshold) is set.

  This is repeated after the 180th day, which is the scheduled scheduled cleaning date. At this time, the next 180 days is set as the scheduled cycle Tc, and the predicted number n is also reset. The dirt level De is not reset.

  According to the present embodiment, the degree of contamination of the fire detector 16 installed in the tunnel varies depending on the installation location, the wind direction, etc., but a warning contamination warning is output by changing the contamination warning threshold based on the prediction of the contamination level. The time is relatively uniform, and unnecessary cleaning work is reduced, making it easier to plan work.

  Further, the threshold value changing unit 50 sets the upper limit threshold value (Dth) max of the dirt notice threshold value Dth as described above, and when the dirt level predicted by the dirt prediction unit 48 is equal to or higher than the upper limit threshold value (Dth) max, The dirt notice threshold is fixed to the upper limit threshold (Dth) max. The upper limit threshold value (Dth) max for the dirt notice is set to a value that does not exceed the dirt threshold value for judging the dirt alarm. Thereby, even when the degree of dirt progress of the translucent window 36 is fast, it is possible to prevent the dirt notice threshold value from being unnecessarily changed to a high value. For this reason, the dirt notice warning is always issued before the dirt alarm.

  FIG. 6 is a flowchart showing the contamination threshold value change control by the fire detector. As shown in FIG. 6, the control unit 32 of the fire detector 16 sets a regular cleaning cycle (scheduled cycle) Tc, a predicted contamination cycle Ts, a predicted number n = 0, and a predicted number upper limit in step S1. The setting of the periodic cleaning cycle Tc and the predicted contamination cycle Ts can be performed by, for example, transmitting a batch setting message from the disaster prevention receiving board 10 to all the fire detectors 16. Accordingly, it is possible to arbitrarily change the regular cleaning cycle Tc and the dirt prediction cycle Ts.

  Then, if the control part 32 discriminate | determines the monitoring start by step S2 by the monitoring start message from the disaster prevention receiving board 10, etc., a fire monitoring operation | movement will be started and it will progress to step S3. In step S3, when it is determined that the predicted dirt timing has been reached due to the elapse of the predicted period Tc, the process proceeds to step S4, where the number of times of prediction n is increased by 1. Then, the process proceeds to step S5 and the predicted dirt period (n Ts) The dirt change rate ΔD at the time point is calculated, and then the dirt level De on the scheduled scheduled cleaning date is predicted by (Formula 1) in step S6.

  Subsequently, the process proceeds to step S7, and when it is determined that the predicted dirt level De is less than the upper threshold (Dth) max, the dirt notice threshold Dth currently set to the dirt level predicted in step S8 is changed. On the other hand, if it is determined in step S7 that the predicted dirt level De is equal to or higher than the upper limit threshold (Dth) max, the dirt notice threshold Dth currently set in step S9 is changed to the upper limit threshold (Dth) max.

  Subsequently, the processing from step S3 is repeated until the upper limit of the number of predictions n is determined in step S10, and when the upper limit of the number of predictions n is reached, the number of predictions n is reset to n = 0 in step S11. The processing from S3 is similarly continued.

  In addition, when cleaning is performed by regular maintenance or the like, the disaster prevention reception panel 10 instructs resumption by a predetermined command. Therefore, when the fire detector 16 detects reception of a resumption instruction command, the process starts from step S1. Resume processing.

[Modification of the present invention]
(Change of dirt notice threshold by dirt prediction)
The change of the dirt notice threshold by the dirt prediction is obtained by linear approximation based on the change rate of the dirt level according to (Equation 1), but as another embodiment, the dirt level assumed for the dirt level for each prediction cycle is as follows. If the value is higher than, the dirt notice threshold value is increased by a predetermined value, and if it is below the assumed dirt level, the dirt notice threshold value may be decreased by a predetermined value.

(Change of dirt notice threshold)
In the above-described embodiment, the dirt level predicted on the scheduled cleaning date based on the change rate of the dirt level is changed to the new dirt notice threshold, but the dirt level that is lower than the predicted dirt level by a predetermined value is set to the dirt notice threshold. You may change to By changing to a dirt notice threshold value lower than the predicted dirt level in this way, it becomes possible to issue a dirt notice warning before the scheduled scheduled cleaning date.

(Fire detector)
In the above embodiment, a two-wavelength type fire detector is taken as an example, but other methods may be used. For example, in addition to the above-described two wavelengths, the resonance emission band of CO ₂ is in the 4.4 to 4.5 μm band. On the other hand, radiation energy in a wavelength band on the short wavelength side, for example, in the vicinity of 3.8 μm, is detected by a method similar to the two-wavelength method, and the presence or absence of flame is determined by the relative ratio of each received light signal in these three wavelength bands. A wavelength flame detector may be used.

(Other)
The present invention includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

DESCRIPTION OF SYMBOLS 1a: Uplink tunnel 1b: Downlink tunnel 10: Disaster prevention receiving board 12a, 12b: Transmission line 16: Fire detector 16a, 16b: Fire detection part 18, 32: Control part 20a, 20b, 34: Transmission part 36: Transparent Optical windows 38a, 38b: Sensor units 40a, 40b: Amplification processing unit 42: Test light source unit 44: Dirt light receiving unit 46: Amplification unit 48: Dirt prediction unit 50: Threshold change unit

Claims (4)

A transmission unit connected to a signal line to the disaster prevention receiver,
A fire detection unit for detecting radiation from the fire through the translucent window;
A dirt detecting unit for detecting a dirt level indicating a degree of dirt of the translucent window;
When the contamination level detected by the contamination detection unit exceeds a predetermined contamination threshold, a contamination alarm unit that transmits a contamination alarm signal to the disaster prevention receiver,
When the dirt level detected by the dirt detector exceeds a predetermined dirt notice threshold smaller than the dirt threshold and less than the dirt threshold, a dirt notice warning part transmits a dirt notice warning signal to the disaster prevention receiving board;
In a fire detector with
A stain prediction unit that detects a change in the stain level detected by the stain detection unit for each predetermined prediction cycle, and predicts a stain level at a preset time point based on the change in the stain level;
A threshold changing unit for changing the dirt notice threshold according to the dirt level predicted by the dirt predicting unit;
A fire detector characterized by the provision of
2. The fire detector according to claim 1, wherein the contamination predicting unit is configured such that a predetermined cycle up to the scheduled time is Tc, a contamination prediction cycle is Ts, a contamination level detected by the contamination prediction cycle Ts is D, and a contamination prediction cycle Ts. When the dirt level change rate is ΔD and the estimated number of times of dirt is n, the predicted dirt level De at the scheduled scheduled cleaning is De = D + ΔD (Tc−n · Ts).
Fire detector characterized by calculating as:
2. The fire detector according to claim 1, wherein the threshold value changing unit sets an upper limit threshold value of the dirt notice threshold value, and the dirt notice value when the dirt level predicted by the dirt predicting unit exceeds the upper limit threshold value. A fire detector, wherein a threshold value is changed to the upper threshold value.
The fire detector according to claim 1, wherein
The dirt detector
A test light source unit that periodically irradiates the translucent window with test light via an external space;
A test light receiving unit that receives the test light incident through the translucent window and outputs a test light reception signal;
A light attenuation rate with respect to the reference is detected as the contamination level every time a test light reception signal is obtained from the inspection light receiving unit with reference to the level of the test light reception signal when the contamination monitoring is started or restarted. And fire detector.

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