JP2009295025A - Fire decision device and fire alarm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire decision device and a fire alarm that effectively determines a fire especially with improved accuracy. <P>SOLUTION: The fire decision device includes a smoke sensor 4, a CO sensor 3, a calculation means 2 of calculating a smoke density gradient Gs, a smoke density difference maximum value ¾d¾max, and a CO density gradient Gco, and an elapsed time measuring means 2 of measuring an elapsed time Ts until smoke density reaches first set smoke density and second set smoke density, and determines a fire on the basis of the smoke density gradient Gs, the smoke density difference maximum value ¾d¾max, the elapsed time Ts, and the CO density gradient Gco. Further, when the CO density is higher than CO alarm density after the decision is made that no fire has occurred, the decision is made again that a fire has occurred. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fire / non-fire discrimination device and a fire alarm using the fire / non-fire discrimination device.

  Conventional fire alarms include, for example, a thermal sensor that detects temperature rise, a smoke sensor that detects smoke, a flame sensor that detects flame, and a CO sensor that detects carbon monoxide (CO) concentration. There are a single type having a sensor and a composite type having these sensors combined. A ministerial ordinance that establishes technical standards for residential fire alarms and automatic fire alarm equipment for houses stipulates having smoke sensors.

  A smoke fire alarm with a smoke sensor reacts to dust accumulation and cigarette smoke in the living room, and reacts to smoke and water vapor generated during cooking in the kitchen. May occur. For this reason, smoke fire alarms have not been approved for use in the kitchen. However, in recent years, it has become mandatory to install fire alarms in single-family homes, and smoke-based fire alarms have been adopted in the technical standards, and smoke-type fire alarms can be used in the kitchen. It is becoming increasingly important.

  In addition, from an experiment simulating a house fire, there is a fire in which the toxic CO concentration rises before the amount of smoke increases, such as futon kun burning with sleeping cigarettes. Sometimes, in the worst case, there is a risk that the CO concentration or carbon monoxide hemoglobin (COHb) will reach a dangerous area before the smoke fire alarm is given, and will be delayed.

  On the other hand, an international standardization organization (ISO) has proposed an alarm device that detects CO generated together with smoke at the time of a fire and issues an alarm when the CO concentration exceeds a threshold value. The threshold value of CO concentration is determined based on the experiment of EN standard fire test standard TF3, and the threshold value is as low as 50 ppm. However, since the CO concentration generated from the combustion equipment (stove, fan heater, etc.) used on a daily basis can be higher than 50 ppm, such a low CO concentration threshold is used to operate the combustion equipment. May react and give a false alarm.

  As described above, with conventional fire alarms, even if a physical quantity such as smoke that exceeds the threshold is detected, is it due to a fire, or is it due to a non-fire caused by cooking or use of a combustor? It was not possible to make a judgment, and a false alarm was generated or a fire could not be detected early.

In order to solve the above problems, as a conventional fire alarm device, as a method for discriminating between fire and non-fire, 1) a method of changing an operation level according to smoke rising time and comparing it with a threshold (for example, Patent Document 1) 2) A method for setting a fire area and a non-fire area and selecting which area from smoke and CO concentration (for example, refer to Patent Document 2), 3) of smoke and CO concentration A method of determining a fire based on a change rate (for example, see Patent Document 3) has been proposed.
JP 2006-146738 A JP 2006-146843 A JP 2006-277138 A

  In the case of a fire, depending on the type and amount of combustibles, smoke may be emitted gradually or suddenly from a certain point. In the former case, it is possible to distinguish between fire and non-fire by the above-described conventional method, but it is not clear whether the latter case can be effectively distinguished.

  Accordingly, in view of the above-described problems, the present invention can effectively distinguish between a real fire and a non-fire, and in particular, a fire / non-fire discrimination device and a fire / non-fire discrimination device that improve the accuracy of fire discrimination. The purpose is to provide a used fire alarm.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a fire / non-fire discrimination device for discriminating between a fire and a non-fire, a smoke sensor for detecting a smoke concentration, and a CO sensor for detecting a CO concentration. And the smoke density detected at each predetermined detection timing by the smoke sensor continuously fluctuates between the first set smoke density and the second set smoke density set higher than the first set smoke density. And calculating a slope of the linear expression approximated linearly as a smoke density slope Gs based on the plurality of smoke density measured data, and calculating the smoke density measured data and the smoke density value represented by the primary expression. A maximum value of the difference is calculated as a smoke density difference maximum value | d | max, and a linear expression approximated linearly based on a plurality of measured CO concentration data detected at the same time as the measured data of the smoke density Cs. Is the CO concentration gradient Gco Calculating means for emitting, smoke density gradient determining means for determining whether or not the smoke concentration gradient Gs is less than a preset smoke concentration gradient threshold, and the smoke density difference maximum value | d | max A smoke density difference judging means for judging whether or not the smoke density difference threshold value is less than a preset smoke density difference threshold, and a process until the smoke density reaches the second set smoke density from the first set smoke density Elapsed time measuring means for measuring time Ts; elapsed time determining means for determining whether or not the elapsed time Ts measured by the elapsed time measuring means exceeds a preset elapsed time threshold; CO concentration gradient determining means for determining whether or not the CO concentration gradient Gco exceeds a preset CO concentration gradient threshold value, and whether the CO concentration detected by the CO sensor is equal to or higher than the CO alarm concentration Determine whether or not Fire determination means for determining a fire according to a combination of determination results of the O concentration determination means, the smoke concentration gradient determination means, the smoke concentration difference determination means, the elapsed time determination means, and the CO concentration gradient determination means; If the determination results of the smoke concentration gradient determining means, the smoke concentration difference determining means, the elapsed time determining means and the CO concentration gradient determining means do not correspond to the combination for determining the fire, a non-fire A non-fire determining means for determining the non-fire when the non-fire determining means determines that the CO concentration is equal to or higher than the CO alarm concentration after the CO concentration determining means determines that the non-fire is detected. What is determined as non-fire by the determination means is characterized as re-identifying as fire.

  The invention according to claim 2 made to solve the above-mentioned problem is a fire alarm using the fire / non-fire discrimination device according to claim 1, wherein the fire / non-fire discrimination device discriminates a fire. The smoke concentration is determined by the first fire determination means for determining whether or not the smoke concentration exceeds a predetermined first fire determination smoke threshold, and the first fire determination means. And a notification means for notifying a fire alarm when it is determined that the first fire determination smoke threshold is exceeded.

  The invention according to claim 3, which has been made to solve the above problem, sets a predetermined delay time in the fire alarm device according to claim 2 when it is determined that the fire / non-fire discrimination device is non-fire. And a second fire judgment in which the smoke concentration is set higher than the first fire judgment smoke threshold over the predetermined delay time set by the delay time setting means. And a second fire determination means for determining whether or not the smoke threshold value is exceeded. The notification means further includes a second fire determination means for determining whether the smoke density is the second fire determination smoke. When it is determined that the threshold value is exceeded, a fire alarm is notified.

  According to the first aspect of the present invention, since fire / non-fire is discriminated based on the smoke density gradient Gs, the smoke density difference maximum value | d | max, the elapsed time Ts, and the CO density gradient Gco, it is particularly preferable to use fire and cooking. It is possible to effectively distinguish non-fire due to. In addition, when it is determined that the CO concentration is equal to or higher than the CO alarm concentration after it is determined as non-fire, since it is determined again as a fire, it is possible to improve the accuracy of fire determination such as smoldering fire.

  According to the invention described in claim 2, when a fire / non-fire discrimination device determines that a fire has occurred, a fire alarm is notified when the smoke concentration exceeds the first fire determination smoke threshold. Can be detected at an early stage and reliably notified, especially false alarms caused by cooking can be reduced, and a fire alarm particularly suitable for use in a kitchen or the like can be realized.

  According to the third aspect of the present invention, when it is determined that the fire / non-fire determination device is non-fire, the smoke density is more than the first fire determination smoke threshold over the set predetermined delay time. Since the fire alarm is notified when the second fire determination smoke threshold value set higher in advance is exceeded, it is possible to particularly reduce false alarms due to cooking.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a fire alarm using a fire / non-fire discrimination device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a fire alarm using a fire / non-fire discrimination device according to an embodiment of the present invention. The fire alarm 1 includes a microcomputer (hereinafter referred to as a microcomputer) 2, a CO sensor 3, a smoke sensor 4, an alarm output unit 5, an external output unit 6, and a storage unit 7.

  The microcomputer 2 includes a CPU 2a, a ROM 2b, and a RAM 2c, and the CPU 2a executes various processes including control according to the present embodiment in accordance with a control program stored in the ROM 2b. The RAM 2c appropriately stores data, programs, and the like necessary for the CPU 2a to execute various processes.

  The CO sensor 3 detects the CO concentration in the air and outputs a sensor output corresponding to the CO concentration. The CO sensor 3 may be any sensor that can detect the CO concentration. For example, a catalytic combustion type, an electrochemical type, an NDIR type, or the like is used.

  The smoke sensor 4 detects the amount of smoke in the air and outputs a sensor output corresponding to the amount of smoke. There are various types of smoke sensors. In this embodiment, as the smoke sensor 4, a photoelectric type including a light emitting element and a light receiving element that receives irregularly reflected light from smoke particles is used.

  The alarm output unit 5 is for outputting a fire alarm under the control of the microcomputer 2, such as a sound output circuit such as a buzzer or a speech processor that emits an alarm sound or an alarm voice message, or a display output circuit such as an LED or LCD that displays an alarm. Etc. are configured. The external output unit 6 includes a communication circuit that transmits an alarm signal output from the microcomputer 2 to an external system, a security center, or the like.

  The memory | storage part 7 is a non-volatile memory means comprised by EEPROM (Electrically Erasable and Programmable ROM) etc., for example. The storage unit 7 stores a first set smoke density, a second set smoke density, an elapsed time threshold value, a smoke density gradient threshold value, and a CO concentration gradient preset for use in the determination process described later. A threshold value, a smoke concentration difference threshold value, a first fire determination smoke threshold value, a second fire determination threshold value, and a CO alarm concentration value are stored.

  Next, operation | movement of the fire alarm 1 which has the above-mentioned structure is demonstrated. In the present invention, in order to solve the above-described problems, the cooking test and the fire test shown in FIGS. 2 and 3 are performed, and a fire / non-fire discrimination method is obtained based on the test results.

  FIG. 2 shows the cooking test results. In FIG. 2, as cooking test items, the types and conditions of the objects are “Sanma 1 animal_GT + R (1)”, “Sanma 1 animal_R (2)”, “Sanma 1 animal_R (3)”, “Meat “Vegetable_GT + R (1)”, “Meat vegetable_GT + R (2)”, “Meat vegetable_GT + R (3)”, “Meat_Ventilation-free (1)”, “Meat_Ventilation-free (2)” and “Meat_Ventilation-free” (3) ”, the smoke density gradient Gs between Csth1 (% / m) <smoke density Cs <Csth2 (% / m) (smoke density Cs is set lower than the fire judgment smoke threshold The first set smoke density Csth1 (for example, 2.5)% / m and the second set smoke density Csth2 (for example, 6)% that is set lower than the fire determination smoke threshold and higher than the first set smoke density. / Smoke density gradient in smoke density change characteristics during continuous fluctuations between / m) and | ( Measured value)-(primary formula) | maximum value of smoke density difference | d | max and elapsed time Ts between Csth1 <Cs <Csth2 (elapsed time during which smoke density Cs continuously varies between Csth1 and Csth2) Time) and the CO concentration gradient Gco between Csth1 <Cs <Csth2 (in the CO concentration change characteristic while the smoke concentration Cs continuously varies between the first set smoke concentration Csth1 and the second set smoke concentration Csth2) CO concentration gradient).

  Here, for example, in “One Sanma_GT + R (1)”, one Sanma is a test that uses a fish grilling net to burn Sanma and generate smoke. GT is a display when the ventilation fan directly above the gas table is operated, and R is a ventilation fan installed on the ceiling. (1) indicates that the number of tests is the first. “Meat vegetable_GT + R” is a product in which pork belly is fried to some extent in a frying pan, vegetables are added, smoke is generated, and ventilation fans GT and R are operated. “Meat_No ventilation” means that when the pork loin is baked in a frying pan and smoke is generated, the ventilation fan is not activated.

  FIG. 3 shows the fire test results. In FIG. 3, as the fire test items, smoke density gradient Gs and maximum smoke density difference | d for sinter, stove duvet (100% cotton), stove duvet (50% cotton poly), tempura and urethane | Max, elapsed time Ts, and CO concentration gradient Gco.

  For example, “Kun-yaki (1)” represents the first test in which a fire that caused a smoldering fire was generated by sandwiching a heater serving as a fire source between 100% cotton futon and heating at 450 ° C. for 17 minutes. ing. "Stove futon (100% cotton)" is a situation where a 100% cotton futon is placed in contact with a heater so as to face a reflective electric stove with a 1kW reflector, and the stove is ignited to generate a fire. Tested. “Stove duvet (50% cotton poly)” is the same test as a stove duvet (100% cotton) on a 50% cotton 50% polyester duvet. “Tempura” is made by putting salad oil in a pan and continuously heating it with a gas stove to ignite it. “Urethane” is a product that ignites nude urethane with a lighter or the like to cause a fire.

  The fire test was conducted in a fire test room simulating the residence of a general house, and the cooking test was conducted in a cooking test room simulating a kitchen of a general house.

  FIG. 4 is a diagram schematically showing a cooking test room simulating a kitchen of a general house. As shown in FIG. 4, in a room in which a gas table GR is arranged at one corner of a room, a large ventilation fan GT is arranged on the upper wall, and a small ventilation fan R is arranged on the ceiling, the gas table GR is used and The cooking test was performed with the ventilation fans GT and R not being driven. Then, CO concentration and smoke concentration data were collected for the case where measurement was performed with the fire alarm 1 arranged on the wall facing the wall with the door D, that is, the right wall of the gas table GR.

  FIG. 5 is a diagram schematically showing a fire test chamber. As shown in FIG. 5, with the fire alarm 1 placed on the top of the wall facing the wall with the sliding door HD and the vent V and the fire source placed near the center of the floor, the CO concentration and smoke concentration Data was collected.

The calculation method of the smoke density gradient Gs and the smoke density difference maximum value | d | max in FIGS. 2 and 3 is as follows. For example, consider a case where the smoke density Cs generated by fire or cooking changes as shown in FIG. 6 while increasing from Csth1 to Csth2. In FIG. 6, the smoke sensors 4 measure the measurement times t0, t2, t3,. . . , Tn are measured data of smoke density Cs detected at Cs0, Cs1, Cs2, Cs3,. . . , Csn. The trapezoidal area formed by the smoke density Cs0 at time t0 and the smoke density Cs1 at time t1 (time integrated value of the smoke density Cs) is A1, and is formed by the smoke density Cs1 at time t1 and the smoke density Cs2 at time t2. The area of the trapezoidal part is A2, and the area of the trapezoidal part formed in the same manner is A3,. . . . , An, and the area of each trapezoidal part is obtained. Finally, the total area (time integrated value of smoke density Cs from time t0 to tn) S, which is the sum of all trapezoidal parts from time t0 to time tn, is as follows: Ask.
S = ΣAn (1)

Next, the smoke density Cs0 at the time t0 and the area of the rectangular portion formed between the times t0 and tn (a constant portion of the integrated value of the smoke density Cs from the time t0 to tn) Ss are obtained as follows.
Ss = Cs0 × (tn−t0) (2)

Next, the area Ss of the rectangular portion is subtracted from the total area S, and an upper area (a variation portion of the integrated value of the smoke density Cs from time t0 to tn) St obtained by removing the rectangular portion from the trapezoidal portion is obtained.
St = S−Ss (3)

Next, assuming a triangle having an area comparable to the obtained St between times t0 and tn, and assuming that the height is h, it can be expressed by the following equation.
St = {(tn−t0) × h} / 2 (4)

Next, the height h is obtained from the above equation (4).
h = 2St / (tn-t0) (5)

Next, when the obtained height h is divided by (tn−t0), the smoke concentration gradient Gs (% / m / sec) is obtained as follows as the average gradient of the smoke concentration Cs from the time t0 to the time tn. .
Gs = h / (tn−t0) = 2St / (tn−t0) ² (6)

As described above, the smoke density gradient Gs can be obtained. Then, when the change in the smoke density Cs during the time t from the time t0 to the time tn is expressed in the form of the primary expression y = ax + b, the following has the smoke density gradient Gs (= a) obtained as described above. The linear expression can be approximated by a linear expression.
Cs = {2St / (tn−t0) ² } t + b (7)
Here, t is time and b is an intercept.

  And the measured data Cs0, Cs1, Cs2, Cs3,. . . , Csn and the smoke density value represented by the linear expression approximated by the above-mentioned linear approximation, the maximum value is calculated as the smoke density difference maximum value | d | max.

  The CO concentration gradient Gco can also be obtained in the same manner as the method for calculating the smoke concentration gradient Gs described above based on the CO concentration during the time t0 to tn, but the description thereof is omitted here.

  FIG. 7 shows, as an example, (a) a graph representing the measured value of the smoke concentration Cs and the linear expression obtained as described above from the measured value in the case of the cooking test “one samurai_GT + R”, and (b ) It is a graph showing the density difference between the measured value and the primary expression. In the graph of FIG. 7A, the linear expression is represented by Cs = 0.01t−2.106. From the graph of FIG. 7B, the maximum value of | (actual value) − (primary expression) | It can be seen that d | max is 1.438.

  From the experimental results shown in FIGS. 2 and 3, the parameters for fire / non-fire determination are set to Gs <so that the object of the fire test is determined to be fire and the object of the cooking test is determined to be non-fire. th1 (th1 is an optimum value by verification with an actual machine, for example, in a range of 0.15 to 0.18), | d | max <th2 (th2 is an optimum value by verification with an actual machine, For example, it is in the range of 1.4 to 1.7.), Ts> th3 (th3 is an optimum value by verification with an actual machine, for example, in the range of 20 to 50 seconds) and Gco> th4 ( th1 is an optimum value obtained by verification with an actual machine, and is set in a range of 0.4 to 0.6, for example.

Combining the parameters set as described above, the following judgment conditions are used to distinguish between fire and non-fire and whether the fire is a smoldering fire or a general fire other than a smoldering fire. I did it.
Discrimination condition A. If Gs <th1 and Gco> th4, it is determined that the fire is fired.
Discrimination condition B. If Gs <th1 and | d | max <th2 and Ts> th3, it is determined as a smoldering fire.
Discrimination condition C.I. If | d | max <th2 and Gco> th4, it is determined as a general fire.
Discrimination condition D. If Gs <th1 and | d | max <th2, it is determined as a general fire.
Discrimination condition E.E. If none of the above applies, it is determined as non-fire.
The priority order of each condition is A>B>C>D> E.

  FIG. 8 is a diagram showing a fire / non-fire discrimination pattern based on the discrimination conditions described above. In this fire / non-fire discrimination pattern, th1, th2, th3, and th4 are set as a smoke concentration gradient threshold value, a smoke concentration difference threshold value, an elapsed time threshold value, and a CO concentration gradient threshold value, respectively. Stored in the unit 7.

  As a result of the determination based on the above-mentioned fire / non-fire determination conditions, when it is determined that the fire is detected, the alarm delay time is set to 0 second and the smoke concentration Cs is increased to 8% / m, for example. Announce a fire alarm. A general fire determination smoke threshold is 10% / m. In the present invention, the fire detection sensitivity is increased by setting a smoke concentration lower than that as the fire determination smoke threshold.

  On the other hand, if it is determined as non-fire as a result of the determination based on the above-mentioned fire / non-fire determination condition, the alarm delay time is set to 45 seconds, for example, and the fire determination smoke threshold is set to 10% as a general value. / M, and fire alarm is notified 45 seconds after smoke density Cs rises to 10% / m. However, if the smoke density Cs becomes less than 10% / m before 4 seconds elapse, the 45-second count by the timer is reset and the 45-second count is started again.

  Next, refer to the flowcharts shown in FIGS. 9 to 12 for the detailed operation of the fire detection process of the fire alarm executed by the control of the CPU 2a of the microcomputer 2 based on the setting of the fire / non-fire discrimination condition as described above. While explaining.

  In FIG. 10, the CPU 2a first reads the sensor outputs of the CO sensor 3 and the smoke sensor 4 at every predetermined detection timing (for example, every second) after turning on the power (step S1), and then reads the read CO sensor. Based on the sensor outputs of 3 and smoke sensor 4, a conversion calculation process for obtaining CO concentration Cco and smoke concentration Cs is performed (step S2).

  Next, the CPU 2a determines whether or not the obtained smoke density Cs exceeds a preset first set smoke density Csth1 (step S3). If the smoke density Cs does not exceed Csth1 (N in Step S3), then the process returns to Step S3, and if it exceeds (Y in Step S3), then the elapsed time Ts until the smoke density Cs reaches Csth2 from Csth1 Is started (step S4: elapsed time measuring means). The reason why the first set smoke density Csth1 is set to 2.5% is that the output fluctuation error of the smoke sensor 4 is estimated to be about 1% / m, for example, and an unnecessary fire / This is to prevent the non-fire discrimination logic from operating. In addition, the reason why the second set smoke density is 6% is that the appraisal standard is “do not ring for 5 minutes at 5% / m”, and the fire determination threshold value in the fire determination described later is 7 to 7 This is for setting in a range of 10% / m.

  Next, the CPU 2a stores the obtained smoke density Cs, CO density Cco, and Ts count value in the storage unit 7 (step S5). Next, the CPU 2a reads the sensor outputs of the CO sensor 3 and the smoke sensor 4 at every predetermined detection timing (step S6), and then, based on the read sensor outputs of the CO sensor 3 and the smoke sensor 4, the CO concentration Conversion calculation processing for obtaining Cco and smoke density Cs is performed (step S7).

  Next, the CPU 2a determines whether or not the smoke density Cs exceeds a preset second smoke density Csth2 (step S8). If the smoke density Cs does not exceed Csth2 (N in step S8), then the process returns to step S5.

  If the smoke density Cs exceeds Csth2 (Y in step S8), the CPU 2a then calculates the smoke density gradient Gs, the smoke density difference maximum value | d | max, and the CO density gradient Gco (step S9: Calculation means). The smoke density gradient Gs and the smoke density difference maximum value | d | max are calculated, for example, when the smoke density Cs converted from the sensor output from the smoke sensor 4 measured every second is continuously between Csth1 and Csth2. It is calculated by the above-described calculation method based on actually measured data of a plurality of smoke concentrations Cs that fluctuate periodically. The slope Gco of the CO concentration Cco is calculated by, for example, a plurality of smokes in which the smoke concentration Cs converted by the sensor output from the smoke sensor 4 measured every second continuously varies between Csth1 and Csth2. The calculation is based on the actual measurement data of the concentration Cs and the actual measurement data of the CO concentration Cco detected at the same time. When the actual measurement data is equal to or lower than Csth1, the calculation is canceled, and from the time when Csth1 is exceeded, the measurement data of a plurality of smoke concentrations Cs that continuously vary between Csth1 and Csth2 is again used. Is calculated.

  Next, the CPU 2a sets all of the Gs_flag, | d | max_flag, Ts_flag, and Gco flag to “0” and stores them in the storage unit 7 (step S10).

  Next, the CPU 2a determines whether or not the smoke density gradient Gs is less than a preset smoke density gradient threshold th1 (step S11: smoke density gradient determination means). If the smoke density gradient Gs is less than th1 (Y in step S11), then the CPU 2a rewrites the Gs_flag stored in the storage unit 7 from “0” to “1” (step S12), and then step S13. Proceed to If the smoke density gradient Gs is not less than th1 (N in step S11), the process proceeds to step S13.

  In step S13 (smoke density difference determination means), the CPU 2a determines whether or not | d | max is less than a preset smoke density difference threshold th2. If | d | max is less than th2 (Y in step S13), then the CPU 2a rewrites the | d | max_flag stored in the storage unit 7 from “0” to “1” (step S14). Next, the process proceeds to step S15. If | d | max is not less than th2 (N in step S13), the process directly proceeds to step S15.

  In step S15 (elapsed time determination means), the CPU 2a determines whether or not the elapsed time Ts exceeds a preset elapsed time threshold th3. If the elapsed time Ts exceeds th3 (Y in step S15), the CPU 2a then rewrites the Ts_flag stored in the storage unit 7 from “0” to “1” (step S16), and then step S17. Proceed to If Ts does not exceed th3 (N in Step S15), the process proceeds to Step S17 as it is.

  In step S17 (CO concentration gradient determination means), the CPU 2a determines whether or not the CO concentration gradient Gco exceeds a preset CO concentration gradient threshold th4. If the CO concentration gradient Gco exceeds th4 (Y in step S17), the CPU 2a then rewrites the Gco_flag stored in the storage unit 7 from “0” to “1” (step S18), and then step Proceed to S19. If Gco does not exceed th4 (N in step S17), the process directly proceeds to step S19.

  Next, the CPU 2a determines whether or not the Gs_flag stored in the storage unit 7 is “1” and the Gco_flag is “1” (step S19). If the Gs_flag is “1” and the Gco_flag is “1” (Y in step S19), the CPU 2a then determines that the fire type is smoldering fire based on the fire / non-fire determination pattern shown in FIG. (Step S20), and then proceeds to the fire determination process of Step S30.

  If the Gs_flag is not “1” and the Gco_flag is not “1” (N in step S19), then the CPU 2a indicates that the Gs_flag is “1”, the | d | max_flag is “1”, and the Ts_flag is “1”. "Is determined (step S21). If the Gs_flag is “1”, the | d | max_flag is “1”, and the Ts_flag is “1” (Y in step S21), then the CPU 2a performs the fire / non-fire determination pattern shown in FIG. Then, the fire type is determined to be a smoldering fire (step S22), and then the process proceeds to the fire determination process of step S30.

  If the Gs_flag is not “1” and the | d | max_flag is “1” and the Ts_flag is not “1” (N in Step S21), then the CPU 2a determines that the | d | max_flag is “1” and the Gco_flag. Is determined to be “1” (step S23). If the | d | max_flag is “1” and the Gco_flag is “1” (Y in step S23), then the CPU 2a sets the fire type to general fire based on the fire / non-fire discrimination pattern shown in FIG. (Step S24), and then proceeds to the fire determination process of step S30.

  If the | d | max_flag is not “1” and the Gco_flag is “1” (N in step S241), then the CPU 2a determines whether the Gs_flag is “1” and the | d | max_flag is “1”. Is determined (step S25). If the Gs_flag is “1” and the | d | max_flag is “1” (Y in step S25), then the CPU 2a sets the fire type to general fire based on the fire / non-fire discrimination pattern shown in FIG. (Step S26), and then the process proceeds to a fire determination process in step S30.

  If the Gs_flag is not "1" and the | d | max_flag is not "1" (N in step S25), then the CPU 2a sets the fire type to non-fire based on the fire / non-fire discrimination pattern shown in FIG. (Step S27).

  If it is determined in step S27 that there is no fire, then the CPU 2a determines whether or not the CO concentration is equal to or higher than the CO alarm concentration (for example, 300 ppm) (step S28). If the CO concentration is equal to or higher than the CO alarm concentration (Y in step S28), then the CPU 2a re-determines the fire type as smoldering (step S29), and then proceeds to the fire determination process in step S30. If the CO concentration is not equal to or higher than the CO alarm concentration (N in step S28), the process proceeds to the non-fire determination process in step S31.

  If it is determined in step S28 that the CO concentration is equal to or higher than the CO alarm concentration, the reason for re-determining that the non-fire is determined as a smoldering fire is as follows.

  That is, among those determined as non-fire, any of the parameters such as Gs, | d | max, Ts, Gco, etc. indicates non-fire depending on various conditions even though a fire has actually occurred. In some cases, this tendency is often judged as non-fire, especially in the case of a smoldering fire. For example, as the smoke concentration Cs increases from Csth1 to Csth2 by many smoldering fire tests, the increase in the CO concentration is very slow, and any of the parameters Gs, | d | max, Ts, Gco Is known to be a non-fire value. It has also been found that the CO concentration when the smoke concentration becomes Csth2 or more is higher than the CO alarm concentration in all the numerous smoldering fire tests.

  On the other hand, in the CO alarm device that detects the CO alarm by detecting the CO concentration, the JIA test regulation 6.2 “Incomplete combustion gas detection part reliably and promptly detects the generated carbon monoxide. "In the case of a smoldering fire, when the smoke concentration becomes Csth2 or more, the CO alarm is already set to CO. It is considered that an alarm has been issued.

  Therefore, even if it is determined in step S27 that there is no fire, if it is determined in step S28 that the CO concentration is greater than or equal to the CO alarm concentration, a fire such as a smoldering fire may have occurred. For this reason, it is determined again as a smoldering fire in step S29, and the process proceeds to the fire determination process in step S30.

  As described above, the CPU 2a determines fire / non-fire according to the fire / non-fire determination pattern of FIG. 8, and selects the fire determination process of step S30 or the non-fire determination process of step S31 according to the determination result.

  Next, in the fire determination process in step S30, as shown in the flowchart of FIG. 11, the CPU 2a first sets a delay time T = 0 seconds (step S301), and then the smoke density Cs is set in advance. It is determined whether or not a set first fire determination smoke threshold value is exceeded, for example, 8% / m (set lower than a general 10% / m) (step S302).

  If the smoke density Cs exceeds the first fire determination smoke threshold value (Y in step S302), the CPU 2a then issues an alarm notifying the occurrence of a fire (step S303). That is, the CPU 2a generates an alarm signal and outputs the alarm signal to the alarm output unit 5. The alarm output unit 5 issues an alarm by sounding an alarm sound or displaying an alarm display. Moreover, the external output part 6 sends out the message | telegram etc. for alert | reporting a fire outbreak to an external system, a security center, etc. as needed.

  Next, the CPU 2a determines whether or not the smoke density Cs is below the first fire determination smoke threshold (step S304). If the smoke density Cs is not lower than the first fire determination smoke threshold value (N in step S304), the process returns to step S303, and the alarm is continued. If the smoke density Cs is below the first fire determination smoke threshold (Y in step S304), the CPU 2a then cancels the fire alarm (step S305), and then returns to step S301.

  On the other hand, if the smoke concentration Cs does not exceed the first fire determination smoke threshold value in step S302 (N in step S302), the CPU 2a then determines whether or not the smoke concentration Cs is less than Csth1. (Step S306). If the smoke density Cs is not lower than Csth1 (N in step S306), then the process returns to step S302. If the smoke density Cs is lower than Csth1 (Y in step S306), then the process returns to step S3 in FIG.

  Thus, in the fire determination process of step S30, it is determined whether or not the smoke density Cs exceeds the first fire determination smoke threshold at the delay time T = 0 seconds, and if it exceeds, a fire alarm is issued. .

  Next, in the non-fire determination process of step S31, as shown in the flowchart of FIG. 12, the CPU 2a first sets the delay time T = 45 seconds and starts counting the delay time counting timer t ( Step S311). Next, the CPU 2a determines whether or not the smoke density Cs exceeds a preset second fire determination smoke threshold of 10% / m (set to a general value) (step S312).

  If the smoke density Cs exceeds the second fire determination smoke threshold (Y in step S312), the CPU 2a then determines whether or not the timer count t has reached T = 45 seconds or more ( Step S313). If the timer count t is not T = 45 seconds or more (N in step S313), the process returns to step S312. If the timer count t is equal to or greater than T = 45 seconds (Y in step S313), the CPU 2a then issues an alarm notifying the occurrence of a fire (step S314). That is, the CPU 2a generates an alarm signal and outputs the alarm signal to the alarm output unit 5. The alarm output unit 5 issues an alarm by sounding an alarm sound or displaying an alarm display. Moreover, the external output part 6 sends out the message | telegram etc. for alert | reporting a fire outbreak to an external system, a security center, etc. as needed.

  Next, the CPU 2a determines whether or not the smoke density Cs falls below the second fire determination smoke threshold (step S315). If the smoke density Cs is not lower than the second fire determination smoke threshold value (N in step S315), the process returns to step S314, and the alarm is continued. If the smoke density Cs is below the second fire determination smoke threshold (Y in step S315), the CPU 2a then cancels the fire alarm (step S316), and then returns to step S311.

  On the other hand, if the smoke density Cs does not exceed the second fire determination smoke threshold value in Step S312, the CPU 2a resets the timer count t (Step 317). Then, it is determined whether or not the smoke density Cs is lower than Csth1 (step S318). If the smoke density Cs is not lower than Csth1 (N in Step S318), then the process returns to Step S312. If the smoke density Cs is lower than Csth1 (Y in Step S318), then the process returns to Step S3 in FIG.

  In this way, in the non-fire determination process of step S31, the delay time T = 45 seconds is set, and the smoke density Cs must exceed the second fire determination smoke threshold before the delay time T = 45 seconds. If this is the case, it will be judged as non-fire and a fire alarm will not be issued. However, if the smoke density Cs exceeds the second fire determination smoke threshold before the delay time T = 45 seconds, it is determined that the fire is not a non-fire but a fire alarm is issued. That is, even when it is determined that there is no fire in step S27 of FIG. 10 and the process proceeds to the non-fire determination process (FIG. 12) of step S31, the smoke concentration Cs is long for the second fire determination as in the set delay time. If it exceeds the smoke threshold, it is judged as a real fire and a fire alarm is issued. Therefore, not only false alarms during non-fire based on generation of temporary CO and smoke such as cigarettes, but also false alarms during non-fire based on CO and smoke generated during cooking are reduced. become.

  As is clear from the above description, in the flowcharts of FIGS. 9 and 10, step S4 corresponds to the elapsed time measuring means in the claims, step S9 corresponds to the calculating means in the claims, and step S11 corresponds to the claims. Corresponding to the smoke concentration gradient determining means, step S13 corresponds to the smoke density difference determining means in the claims, step S15 corresponds to the elapsed time determining means in the claims, and steps S20, 22, 24, and 26 in the claims. Corresponding to the fire determination means, step S27 corresponds to the non-fire determination means in the claims, and step S28 is processing corresponding to the CO concentration determination means in the claims. In the flowchart of FIG. 11, step S302 corresponds to the first fire determination means in the claims, and step S303 corresponds to the notification means in the claims. In FIG. 12, step S311 corresponds to the delay time setting means in the claims, step S312 corresponds to the second fire determination means in the claims, and step S314 corresponds to the notification means in the claims. ing.

  As described above, according to the present invention, it is possible to effectively distinguish between a fire and a non-fire according to the degree of increase in the smoke concentration, reliably notify the fire, and particularly reduce false alarms due to cooking. it can. In addition, when it is determined that the CO concentration is equal to or higher than the CO alarm concentration after it is determined as non-fire, since it is determined again as a fire, it is possible to improve the accuracy of fire determination such as smoldering fire.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and application are possible.

  For example, if it is determined in step S28 in FIG. 10 that the CO concentration is equal to or higher than the CO alarm concentration and the process proceeds to the fire determination process in step S30, the first in steps S302 and S304 in FIG. The fire determination smoke threshold may be switched to a lower value (for example, 7% / m) to make it easier to generate a fire alarm.

  In the above-described embodiment, the case where the present invention is applied to a fire alarm device has been described. However, the present invention is not limited to this, and the present invention can also be applied to a combined alarm device having both functions of a CO alarm device and a fire alarm device.

It is a block diagram which shows the structure of the fire alarm using the fire / non-fire discrimination apparatus which concerns on embodiment of this invention. It is a figure which shows a cooking test result. It is a figure which shows a fire test result. It is a figure which shows roughly the cooking test room which imitated the kitchen of the general house. It is a figure which shows a fire test chamber schematically. It is a figure for demonstrating the calculation method of smoke density inclination Gs and smoke density difference maximum value | d | max. (A) is an example of a graph representing the measured value of the smoke concentration and the primary expression obtained as described above from the measured value, and (b) is an example of a graph representing the density difference between the measured value and the primary expression. FIG. It is a figure which shows a fire / non-fire discrimination pattern. It is a flowchart which shows the detailed operation | movement of the fire detection process of the fire alarm device of FIG. It is a flowchart which shows the detailed operation | movement of the fire detection process of the fire alarm device of FIG. It is a flowchart which shows the detailed operation | movement of the fire detection process of the fire alarm device of FIG. It is a flowchart which shows the detailed operation | movement of the fire detection process of the fire alarm device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fire alarm device 2 Microcomputer 2a CPU (Calculation means, smoke concentration inclination determination means, CO concentration inclination determination means, CO concentration determination means, elapsed time measurement means, elapsed time determination means, fire determination means, non-fire determination means, first Part of the fire determination means, second fire determination means, delay time setting means, and notification means)
3 CO sensor 4 Smoke sensor 5 Alarm output part (part of the notification means)
7 Memory part

Claims (3)

A fire / non-fire discrimination device that distinguishes between fire and non-fire,
A smoke sensor for detecting smoke concentration;
A CO sensor for detecting the CO concentration;
A plurality of smoke concentrations continuously detected between a first set smoke concentration and a second set smoke concentration set higher than the first set smoke concentration at a predetermined detection timing by the smoke sensor. Is calculated as a smoke concentration gradient Gs based on a linear approximation of the smoke concentration gradient Gs, and the difference between the smoke concentration measurement data and the smoke concentration value represented by the primary equation is calculated. The maximum value is calculated as the smoke density difference maximum value | d | max, and the slope of the linear expression approximated linearly based on the measured data of a plurality of CO concentrations detected at the same time as the measured data of the smoke density Cs. Calculating means for calculating the CO concentration gradient Gco;
A smoke concentration gradient determining means for determining whether the smoke concentration gradient Gs is less than a preset smoke concentration gradient threshold;
Smoke density difference determining means for determining whether or not the smoke density difference maximum value | d | max is less than a preset smoke density difference threshold value;
An elapsed time measuring means for measuring an elapsed time Ts until the smoke density reaches the second set smoke density from the first set smoke density;
Elapsed time determining means for determining whether or not the elapsed time Ts measured by the elapsed time measuring means exceeds a preset elapsed time threshold;
CO concentration gradient determination means for determining whether or not the CO concentration gradient Gco exceeds a preset CO concentration gradient threshold;
CO concentration determination means for determining whether or not the CO concentration detected by the CO sensor is equal to or higher than a CO alarm concentration;
A fire discriminating means for discriminating a fire according to a combination of determination results of the smoke concentration gradient determining means, the smoke concentration difference determining means, the elapsed time determining means and the CO concentration gradient determining means;
When the determination results of the smoke concentration gradient determination unit, the smoke concentration difference determination unit, the elapsed time determination unit, and the CO concentration gradient determination unit do not correspond to the combination for determining the fire, a non-fire And non-fire discrimination means
After determining that the non-fire is determined by the non-fire determining means and then determining that the CO concentration is higher than the CO alarm concentration by the CO concentration determining means, the non-fire determining means determines that the non-fire is detected. Fire / non-fire discrimination device characterized by re-identifying A fire alarm using the fire / non-fire discrimination device according to claim 1,
First fire determination means for determining whether or not the smoke concentration exceeds a predetermined first fire determination smoke threshold when the fire / non-fire determination device determines that a fire has occurred;
Informing means for informing a fire alarm when the first fire judging means judges that the smoke concentration exceeds the first fire judging smoke threshold value;
A fire alarm device comprising: In the fire alarm according to claim 2,
A delay time setting means for setting a predetermined delay time when it is determined as a non-fire by the fire / non-fire determination device;
Whether the smoke density exceeded a second fire determination smoke threshold set in advance higher than the first fire determination smoke threshold over the predetermined delay time set by the delay time setting means And a second fire determination means for determining whether or not
The notification means further notifies a fire alarm when the second fire determination means determines that the smoke concentration exceeds the second fire determination smoke threshold value. .

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