JP4615295B2 - Combined fire alarm - Google Patents

Description

  The present invention relates to a composite fire alarm incorporating a smoke sensor and a CO sensor.

As this type of alarm device, there is one provided with a thermal sensor, a smoke sensor, a CO sensor and the like. This conventional alarm device determines that an initial fire has occurred when the amount of heat detected by the thermal sensor exceeds a threshold, and the amount of smoke detected by the smoke sensor exceeds the threshold even if the amount of heat is below the threshold. If it is determined that there is an initial fire in the same manner as described above, it is determined that there is no fire when the amount of heat and the amount of smoke are below the threshold values, respectively. When it is determined that the initial fire has occurred, it is determined whether the CO concentration detected by the CO sensor exceeds the first threshold, and when the CO concentration exceeds the first threshold, it is determined that a full-scale fire has occurred (for example, Patent Documents). 1).
Japanese Patent No. 3325526 (page 3, FIGS. 1 and 3)

The above-mentioned conventional alarm is judged to be a fire early in the case of smoldering fires such as wood and futon where smoke and CO are generated simultaneously, but it is also judged to be a fire even in the case of cigarettes and the like in which smoke and CO increase simultaneously. This could cause malfunction.
The present invention has been made to solve such a problem. In the case of a smoldering fire in which the smoke concentration and the CO concentration rise slowly, the fire is detected early, and smoke (including steam) and CO are detected. The purpose of the present invention is to provide a combined fire alarm that makes it difficult to operate when the concentration decreases in a short time.

The composite fire alarm according to the present invention measures the elapsed time until the smoke detection unit and the CO detection unit, and the output of the smoke detection unit or the output of the CO detection unit reaches the first level. Time measuring means, operation level setting means for setting an operation level at the time of sensing of the smoke sensing unit and the CO sensing unit according to the elapsed time, and an accumulation time setting for setting a first accumulation time that changes according to the elapsed time And the operation level is determined to be greater than or equal to a preset threshold value. If the operation level is equal to or greater than the threshold value, it is determined that a fire report has occurred when this state continues until the first accumulation time has elapsed . In a combined fire alarm equipped with a fire / non-fire discrimination means that judges that a non-fire report is made when the operation level becomes lower than the threshold before one accumulation time elapses, the data value is set in advance according to the elapsed time. The And a data selection means for selecting a data value from the elapsed time measured by the time measurement means, and the operation level setting means includes the data value (0.1 ≦ n ≦ 1) selected by the data selection means and CO sensing. The operation level at the time of sensing of the smoke sensing unit and the CO sensing unit is calculated by substituting the output (Y) of the unit and the output (X) of the smoke sensing unit into a preset arithmetic expression (X + Y * n).

  In the present invention, when the output of the smoke sensing unit or the output of the CO sensing unit reaches the first level, the elapsed time until reaching the second level is measured, and the smoke sensing unit and the CO sensing unit are measured according to the elapsed time. The operation level at the time of sensing is set, and it is determined whether the operation level is equal to or higher than a preset threshold value. When the operation level is equal to or higher than the threshold value, it is determined as a fire report. A firewood fire that stands up makes it possible to detect a fire at an early stage, and even if smoke or steam of cigarettes or the like is detected together with CO, it is difficult to operate, and misinformation in a non-fire report can be reduced.

FIG. 1 is a block diagram showing a schematic configuration of a composite fire alarm according to an embodiment of the present invention.
The combined fire alarm 1 of the present embodiment includes a time measuring unit 21, an accumulation time setting unit 22, a detection level setting unit 23, a data selection unit 24, a fire / non-fire determination unit 25, a first changing unit 26, a first 2 includes a microcomputer 2 having functions of a change unit 27 and a display management unit 28 of a display means, a smoke detection unit 3, a CO detection unit 4, an LED 5, and a speaker 6.

  For example, when the output (smoke density) of the smoke detection unit 3 reaches the first level (for example, 2.5% / m), the microcomputer 2 has elapsed time t until it reaches the second level (for example, 5% / m). Measure. Thereafter, it is determined through the flag S whether or not the operation level and the accumulation time T are set. When the flag S is “0”, a coefficient n value as a data value set in advance according to the elapsed time t is selected from the measured elapsed time t, and an accumulation time T that changes according to the elapsed time t. (First accumulation time), specifically, an accumulation time T (first accumulation time) obtained by subtracting the elapsed time t from a preset 45 seconds (first time), for example.

  When the output of the CO sensing unit 4 is lower than, for example, 10 ppm (third level), the coefficient n value selected from the elapsed time t is reset to, for example, 1/10 (predetermined data value) and calculated first. Instead of the accumulated time T, for example, the accumulated time T of 40 seconds (second accumulated time) is reset. Further, when the output of the CO sensing unit 4 is lower than 10 ppm (third level), for example, lower than 4 ppm (fourth level), and the elapsed time t is less than 10 seconds (second time) set in advance, for example, For example, an accumulation time T of 60 seconds (third accumulation time) is set instead of the set accumulation time T (40 seconds).

Thereafter, the operation level at the time of sensing by the smoke sensing unit 3 and the CO sensing unit 4 is set according to the elapsed time t. Specifically, the output of the CO sensing unit 4 is processed with the coefficient n value (or 1/10) previously selected or reset, and the smoke sensing unit 3 and the CO are determined from the value and the output of the smoke sensing unit 3. The operation level when sensing by the sensing unit 4 is set. That is, the operation level at the time of sensing of the smoke sensing unit 3 and the CO sensing unit 4 is set based on the following arithmetic expression.
X + Y * n
In this equation, X is the detection level of the smoke detection unit 3, Y is the CO concentration based on the detection level of the CO detection unit 4, and n is a coefficient set according to the elapsed time t as described above.

  Then, it is determined whether or not the set operation level is greater than or equal to a preset threshold value, for example, “62”. If the operation level is greater than or equal to the threshold value, it is determined that the state is a fire report when this state continues until the accumulation time elapses. If the operation level becomes lower than the threshold before the accumulation time T elapses, it is determined as non-fire information. When the fire report is determined, the LED 5 is turned on, for example, and the occurrence of the fire is notified by voice through the speaker 6.

Next, the operation of the combined fire alarm device of the present embodiment will be described based on the flowcharts shown in FIGS.
The microcomputer 2 reads the respective detection levels of the smoke detection unit 3 and the CO detection unit 4 (S1), and first, the smoke density based on the detection level of the smoke detection unit 3 is 2.5% / m or more set in advance. It is determined whether or not (S2). When the smoke density is less than 2.5% / m, the elapsed time t, the flag S, the operation time Td and the accumulation time T are set to “0” (S5), and again the detection level of the smoke detector 3 and Reading of the sensing level of the CO sensing unit 4 is started (S1). On the other hand, when the smoke density based on the detection of the smoke detector 3 reaches 2.5% / m, the measurement of the elapsed time t is started (S3), and whether the smoke density has increased to 5% / m. Is determined (S4). When the smoke density of the smoke detector 3 is less than 5% / m, the operation time Td is set to “0” (S6), and the process returns to S1. The operation time Td is a continuation time when an operation level described later is equal to or greater than a threshold value.

  This operation of S1-> S2-> S3-> S4-> S6 is repeated until the smoke density of the smoke detector 3 is 2.5% / m or more and 5% / m or more, and the elapsed time t is counted up. Continue measuring. If the smoke density of the smoke detector 3 decreases to less than 2.5% / m while repeating this operation, it is judged as a non-fire report, and the elapsed time t during measurement is “0”. And the flag S, operation time Td, and accumulation time T are set to “0” (S5). Further, when the smoke density of the smoke detector 3 is 5% / m or more, it is determined whether or not the flag S is “1” (S7). When the flag S is “1”, it is determined that the operation level and the accumulation time T are set as described above, and the process proceeds to S9. When the flag S is “0”, the operation level and It is determined that the accumulation time T is not set, and the coefficient n / accumulation time setting process shown in the flowchart of FIG. 3 is entered.

  First, the flag S is set to “1” (S81), and a coefficient n value is selected from the elapsed time t measured previously (S82). As shown in S82, when the elapsed time t is 5 seconds or less, the coefficient n value is 1/10, and when the elapsed time t exceeds 5 seconds and 10 seconds or less, the coefficient n value is 1/7. As the elapsed time t becomes longer, the coefficient n value becomes larger. Since the possibility of fire is low when the elapsed time t is short, the CO concentration detected by the CO sensing unit 4 is reduced by a coefficient n value so that the sensing level (X) of the smoke sensing unit 3 is almost the operating level. ing. This takes into account the phenomenon of cigarette smoke that disappears in the air in a short period of time, and steaming during cooking. In addition, when the elapsed time t is long, the possibility of fire is high, so the added value of the detection level (X) of the smoke detection unit 3 and the CO concentration (Y) based on the detection level of the CO detection unit 4 becomes the operation level. I am doing so. This is because the smoke concentration is low, but the phenomenon of smoldering fires such as futons which increase with the passage of time is taken into consideration.

  After selecting the coefficient n value, the accumulation time T is calculated by subtracting the elapsed time t from a preset 45 seconds (S83). When the elapsed time t is 40 seconds or longer, the possibility of fire is high, so the accumulation time T is 5 seconds. Thereafter, it is determined whether or not the CO concentration based on the sensing level of the CO sensing unit 4 read in S1 is lower than 10 ppm (S84). When the CO concentration is higher than 10 ppm, it is determined that there is a possibility of fire, this process is terminated, and the process proceeds to S9 (FIG. 2). Also, when the CO concentration is lower than 10 ppm, it is assumed that CO has occurred during cooking (meat, vegetables, grilled fish, baked bread, etc.), and the previously selected coefficient n value is reset to 1/10 which is set in advance. Then, the accumulation time T is reset to 40 seconds (S85). After resetting the coefficient n value and the accumulation time T, it is determined whether the CO concentration of the CO sensing unit 4 is lower than 4 ppm and whether the measured elapsed time t is 10 seconds or less (S86). When the CO concentration is lower than 4 ppm and the elapsed time t is 10 seconds or less, the accumulation time T is determined to be 40 seconds to 60 seconds by judging that it is caused by steam generated during boiling or cooking and CO contained in the steam. (S87), this process ends, and the process proceeds to S9 (FIG. 2).

  When the above process is completed, the smoke detection level (X) read in S1, the CO concentration (Y) based on the CO detection level, and the coefficient n value selected according to the elapsed time t are preset. An operation level is calculated by substituting (X + Y * n) (S9). The operating level calculated by this arithmetic expression is the operating level when the CO concentration is 0 ppm. After the operation level is calculated, it is determined whether or not it is equal to or higher than a preset threshold (for example, 62) (S10). Here, when the operation level is “62” or more, it is determined that the operation level is equal to or greater than the threshold value, and measurement by counting up the operation time Td of the smoke detection unit 3 and the CO detection unit 4 when the operation level is equal to or greater than the threshold value is started. (S11). Then, it is determined whether or not the operation time Td is equal to or longer than the accumulation time T set in the process of S8 (S12). When the operation time Td has not passed the accumulation time T, the process returns to S1 to repeat the series of operations described above. In this case, since the flag S is “1” in S7, the set coefficient n value and accumulation time T are retained, and the smoke detection level and CO concentration read when returning to S1 are calculated. The calculation of the operation level is repeated by substituting for X + Y * n.

  When S1 to S4 → S7 → S9 to S12 are repeatedly performed, if the calculated operation level is less than the threshold value “62”, it is determined as a non-fire phenomenon due to steam or tobacco smoke during cooking as described above. Then, the measured operation time Td is cleared to “0” (S15), and the process returns to S1. When the operation time Td measured in S11 is equal to or longer than the accumulation time T (S12), it is determined as a fire report, the LED 5 is turned on and a fire is displayed (S13), and the occurrence of the fire is notified by voice through the speaker 6 (S14). ), Return to S1.

Next, the experimental results by the combined fire alarm of this embodiment will be described with reference to FIG. Note that this alarm is installed on the ceiling.
In the case of futon firewood without ventilation as Experiment 1, the time from the start of the experiment when the smoke concentration reached 2.6% / m of 2.5% / m or more was 1760 seconds, and further 5% / m The above time of 5.2% / m was 1829 seconds. In this case, since the elapsed time t is 69 seconds (1829-1760) exceeding 40 seconds, the coefficient n value is set to 1, and the accumulation time T is 5 seconds because the elapsed time t is 69 seconds exceeding 40 seconds. Is set. At this time, the operation level is equal to or higher than the threshold, the operation time Td in that state is 5 seconds or more of the accumulation time T, the LED 5 is turned on in 1880 seconds from the start of the experiment, and a sound of a fire is emitted from the speaker. It was.

  In the case of futon firewood with ventilation as Experiment 2, the time from the start of the experiment when the smoke concentration reached 2.6% / m of 2.5% / m or more was 1812 seconds, and further 5% / m The time when the above was reached was 1914 seconds. In this case, since the elapsed time t is 102 seconds (1914-1812) exceeding 40 seconds, the coefficient n value is set to 1, and the accumulation time T is 5 seconds because the elapsed time t is 69 seconds exceeding 40 seconds. Is set. At this time, the operation level is equal to or higher than the threshold value, the operation time Td in that state is 5 seconds or more of the accumulation time T, and in 1940 seconds from the start of the experiment, the LED 5 is lit in the same manner as described above, and a fire is generated from the speaker Was emitted by voice.

  In the case of tobacco smoke as Experiment 3, the time from the start of the experiment when the smoke concentration reached 2.6% / m, which is 2.5% / m or more, was 423 seconds, and further became 5% / m or more. Was 429 seconds. In this case, the elapsed time t is 6 seconds (429-423), and from that 6 seconds, the coefficient n value is calculated to 1/7, and the accumulation time T is calculated to be 39 seconds (45-6), but the CO concentration is 10 ppm. Since the lower value is 0 ppm, the coefficient n value is reset to 0.1 (1/10) and the accumulation time T is reset to 40 seconds. At this time, the operation level was less than the threshold value, so the operation was not performed (non-fire report).

  In the case of cooking meat and fried vegetables as Experiment 4, the time from the start of the experiment when the smoke concentration reached 2.8% / m of 2.5% / m or more was 600 seconds, and further 5% / m The time at which the above 5.2% / m was reached was 672 seconds. In this case, since the elapsed time t is 72 seconds (672-600) exceeding 40 seconds, the coefficient n value is set to 1 and the accumulation time T is set to 5 seconds, but the CO concentration is 4 ppm or more and lower than 10 ppm. Since it is 7 ppm, the coefficient n value is reset to 0.1 (1/10), and the accumulation time T is reset to 40 seconds. At this time, the operation level was less than the threshold value, so the operation was not performed (non-fire report).

  When the smoke was generated by burning the meat as Experiment 5, the time from the start of the experiment when the smoke concentration reached 2.6% / m of 2.5% / m or more was 246 seconds, and further 5% The time when it became more than / m was 263 seconds. In this case, the elapsed time t is 17 seconds (263-246), the coefficient n value is calculated to be 1/5 from that 17 seconds, and the accumulation time T is calculated to be 28 seconds (45-17), but the CO concentration is 4 ppm. Since the lower 3 ppm, the coefficient n value is reset to 0.1 (1/10), and the accumulation time T is reset to 60 seconds. At this time, the operation level is equal to or higher than the threshold value, the operation time Td in that state is 60 seconds or more of the accumulation time T, the LED 5 is turned on in 446 seconds from the start of the experiment, and a sound of the occurrence of fire is emitted from the speaker. It was.

  When the fish was baked as Experiment 6, the time from the start of the experiment when the smoke concentration reached 2.7% / m of 2.5% / m or more was 507 seconds, and further 5% / m or more. Was 567 seconds. In this case, since the elapsed time t is 60 seconds (567-507), the coefficient n value is 1, and the accumulation time T is set to 5 seconds because the elapsed time t is 60 seconds exceeding 40 seconds. Since the CO concentration is 2 ppm lower than 4 ppm, the coefficient n value is reset to 0.1 (1/10), and the accumulation time T is reset to 60 seconds. At this time, the operation level was less than the threshold value, so the operation was not performed (non-fire report).

  In the case of smoke from a plurality of smokers as Experiment 7, the time from the start of the experiment when the smoke concentration reached 2.7% / m of 2.5% / m or more was 272 seconds, and further 5% / m The time when the above 5.9% / m was reached was 278 seconds. In this case, the elapsed time t is 6 seconds (278-272), and from that 6 seconds, the coefficient n value is calculated as 1/7, and the accumulation time T is calculated as 39 seconds (45-6). At this time, the operation level is equal to or higher than the threshold, the operation time Td in that state is 39 seconds or more of the accumulation time T, the LED 5 is lit 400 seconds from the start of the experiment, and a sound of fire is emitted from the speaker. It was.

  As described above, according to the present embodiment, when the smoke density of the smoke detector 3 reaches 2.5% / m, the elapsed time t until it reaches 5% / m is measured, and the flag S is set to “0”. ”, The coefficient n value set according to the elapsed time t is selected from the measured elapsed time t, the accumulation time T (45−t) that changes according to the elapsed time t is set, and When the concentration of the CO sensing unit 4 is lower than 10 ppm, the coefficient n value selected from the elapsed time t is reset to 1/10, for example, and the storage time T of 40 seconds is substituted for the previously set storage time T. In addition, when the concentration of the CO sensing unit 4 is lower than 4 ppm and the elapsed time t is 10 seconds or less, 60 seconds is set instead of the reset storage time T of 40 seconds, and thereafter Process the concentration of the CO sensing unit 4 with the coefficient n value selected or reset previously, and The operation level at the time of detection of the smoke detection unit 3 and the CO detection unit 4 is set from the detection level of the detection unit 3, and it is determined whether or not the set operation level is equal to or higher than the threshold “62”. In this case, when this state continues until the accumulation time T elapses, it is judged as a fire report, and when the operation level becomes lower than the threshold before the accumulation time T elapses, it is judged as a non-fire report. So, it is possible to detect fire early in slow fire and CO fired fires, and even if smoke or steam such as cigarettes is detected together with CO, it operates if each concentration decreases in a short time This reduces the number of false alarms in non-fire reports.

  In the above embodiment, the elapsed time t until the smoke density of the smoke detector 3 reaches 2.5% / m to 5% / m is measured. The elapsed time t between predetermined CO concentrations may be measured by reading the CO concentration of the unit 4. Further, when the operation level exceeds the threshold value, an LED flashing or a warning notice by voice may be issued.

It is a block diagram which shows schematic structure of the composite-type fire alarm which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the composite-type fire alarm of this Embodiment. It is a flowchart which shows operation | movement of a coefficient n and accumulation | storage time setting process. It is a data figure which shows the experimental result by the composite-type fire alarm of this Embodiment.

Explanation of symbols

1 Combined fire alarm, 2 Microcomputer, 21 hour measurement unit, 22 Accumulation time setting unit,
23 operation level setting unit, 24 data selection unit, 25 fire / non-fire discrimination unit, 26 first change unit, 27 second change unit, 28 display management unit, 3 smoke detection unit, 4 CO detection unit, 5 LED, 6 Speaker.

Claims (3)

A smoke detector and a CO detector ;
When the output or the output of the CO sensing portion of the smoke detection unit reaches a first level, and time measuring means for measuring the elapsed time to reach the second level,
An operation level setting means for setting an operation level at the time of sensing by the smoke sensing unit and the CO sensing unit according to the elapsed time;
Accumulation time setting means for setting a first accumulation time that changes according to the elapsed time;
It is determined whether or not the operation level is equal to or higher than a preset threshold value. When the operation level is equal to or higher than the threshold value, it is determined as a fire report when this state continues until the first accumulation time elapses . In a combined fire alarm equipped with a fire / non-fire discrimination means that judges that the fire level is lower than the threshold before 1 accumulation time elapses ,
A data value is set according to the elapsed time in advance, and includes a data selection means for selecting a data value from the elapsed time measured by the time measurement means,
The operation level setting means includes a data value (0.1 ≦ n ≦ 1) selected by the data selection means, an output (Y) of the CO sensing unit, and an output (X) of the smoke sensing unit. A combined fire alarm device, wherein the operation level at the time of sensing of the smoke sensing unit and the CO sensing unit is calculated by substituting into a preset arithmetic expression (X + Y * n) . First changing means for instructing a setting change when the output of the CO sensor is lower than a third level;
The operation level setting means, when receiving the setting change instruction, multiplies the output of the CO sensing unit by a predetermined data value,
The accumulation time setting means, when receiving an instruction of the setting change, the composite type fire alarm according to claim 1, wherein setting the second accumulation time in place of the first accumulation time. A second changing means for instructing a setting change of an accumulation time when the output of the CO sensor is less than a fourth level lower than the third level and the elapsed time is shorter than a predetermined time set in advance;
3. The combined fire alarm according to claim 2, wherein the storage time setting means sets a third storage time longer than the second storage time when receiving the setting change instruction.

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