JPS60157695A - Fire alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fire alarm system that detects humidity, smoke concentration, etc. caused by a fire using an analog sensor and determines a fire on the receiver side.

(Prior art) In recent years, in order to solve the problem of false alarms and delays in fire detection in so-called on-type fire alarm systems, in which fire detection was determined by setting a threshold value to a fire detector, the temperature or smoke concentration caused by a fire has been Detected by analog sensor and sent to receiver,
A so-called analog fire alarm device has been proposed in which a fire is determined based on analog data received on the receiver side.

By the way, in such an analog fire alarm system, the reliability of the analog data is extremely important because it is necessary to process the analog data from the sensor to determine whether there is a fire, but even if the sensor itself is reliable, Sensor installation conditions,
That is, if the height of the ceiling surface where the sensor is installed changes, it is expected that the analog data will differ even under the same fire conditions.

However, conventional devices do not take into account the height of the ceiling where the sensors are installed, causing problems with the reliability of fire judgment when multiple analog sensors are installed on ceilings of different heights. .

(Objective of the Invention) The present invention has been made in view of the above-mentioned problems of the conventional art. To provide a highly reliable fire alarm device that can perform fire judgment processing without receiving any damage.

(Structure of the Invention) In order to achieve this object, the inventors of the present application experimentally investigated the correlation between the height of the detection output and the height of the ceiling surface on which the analog fire sensor is installed. Based on this correlation, analog data or a threshold value for determining a fire is set in advance, and the data is corrected to that obtained at the reference height to determine a fire.

(Example) -3- FIG. 1 is a block diagram showing one embodiment of the present invention.

First, let me explain the structure along with its function: 1a and 1b.

...1n is an analog sensor that detects and outputs changes in physical phenomena caused by fire, such as temperature or smoke concentration, in an analog manner, and the detection outputs of the analog sensors 1a to 1n are connected to the reception 1fIN2 by signal lines. .

Note that the detection data of the analog sensors 1a to 10 is sent to the receiver 2.
It may also be sent in response to a time-sharing call from.

A sampling circuit 3 is provided in the receiver 2 to which the analog sensors 1a to 1n are connected by signal lines.
~1n analog detection signals are sequentially sampled at regular intervals and converted into digital signals by the A/D converter 4. The output of the A/D converter 4 is input to a correction calculation circuit 5, and analog sensors 1a to 1 set by a ceiling height setting circuit 6 are input.
Based on the installation height with respect to each ceiling surface of n, a correction calculation is performed to correct the detection data to the detection data when installed at a specified ceiling surface height, for example, 2.5 m.

The correction of the detection data by this correction calculation circuit 5 is performed by the second.
This is based on the correlation obtained from the experimentally obtained graph shown in Figure 3, which shows the change in sensor detection output when the height of the ceiling surface on which the analog sensor is installed is changed.

In other words, Figure 2 shows the relative value of the detection level when the output level is 1.0 when the smoke sensor is installed 2.5 m directly above the fire point, and the height of the smoke tip is changed. Figure 3 shows the changes based on experimental data, and Figure 3 shows the detection level when the temperature sensor is installed 2.5 m directly above the fire point.
It shows the change based on experimental data of the relative value of the detection level when the height of the ceiling surface is changed, and the relative value is y,
Assuming that the height of the ceiling surface is 11, in both cases of Figures 2 and 3, = 5 - y - αe'''1' (H - Ha) ... (1) However, α
is the coefficient HO that corrects the variation in the sensor output.It has been experimentally confirmed that the relationship of the relative output y to the height of the ceiling surface (t) can be obtained according to the index β given by the standard ^x2.5m>. Therefore, the correction calculation circuit 5 of FIG. 1 executes correction calculation of the detected data based on the correlation of equation (1).

This correction calculation is performed as follows, assuming that the actual detection data is Dr.
Based on the above equation (1), [)s-Dr/'W=Dr/(Xe""""=, (2
>, the correction data [)S can be entered.

Here, β on the right side of equation (2) is a constant obtained from the graph shown in Figure 2.3, and since the height H of the ceiling surface is known in advance for each analog sensor, Regarding the right side of equation (2), K=1/V=1/αe−ρ(
H-1°) (3), and the correction coefficient K can be determined for each analog sensor.

Therefore, in the correction calculation circuit 5 of FIG. 1, Ds =
Dr
The detection data obtained when the sensor is installed at a ceiling height of H-2.degree. 5 m, which gives a value of 1.0, is determined by a correction calculation.

Of course, the reference height of the ceiling surface that provides the relative output V=1.0 is not limited to H=2.5 m, and can be determined using an appropriate height as the reference.

Referring again to FIG. 1, the detection data corrected to the reference height of the ceiling surface by the correction calculation circuit 5 is provided to the fire judgment circuit 7, and a fire judgment is made based on the correction data. The fire judgment in this fire judgment circuit 7 is as follows:
For example, a process is executed in which the degree of risk is calculated based on the current detection data and a fire is determined. Here, the degree of danger is defined as the increase in temperature or smoke concentration due to the occurrence of a fire, and the time it will take for the environmental condition to reach a dangerous state for humans in the near future.

This degree of danger can be calculated using the difference method, which predicts the time it will take to reach a predetermined danger level based on the difference between the current detection data and the previous detection data, or the difference method, which calculates the time until a predetermined danger level is reached, or the change in temperature or smoke concentration due to a fire. There is a function approximation method that approximates a polynomial, calculates a constant of the polynomial from a plurality of current and past detection data, and calculates the time required to reach a predetermined danger level as a solution to the polynomial.

Once the degree of danger is calculated using the difference method or function approximation method, it is compared with a predetermined threshold of the degree of danger, and the shorter the time taken to reach the danger level, that is, the shorter the degree of danger, the higher the possibility of a fire. Therefore, when the calculated degree of danger falls below the threshold of the degree of danger, it is determined that there is a fire and output.

Furthermore, in addition to predicting and determining fires using the difference method or function approximation method, the corrected detection data is compared with a preset alarm level threshold, and when the detected data exceeds the threshold level, it is determined that there is a fire. You may also do so.

When a fire horn is obtained in the fire judgment that is applied to the fire judgment circuit 7, the fire output is given to the alarm display unit 8, and a fire alarm is displayed together with the district display indicating the area where the analog sensor is installed. That's what I do.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to the operation flow shown in FIG. 4.

First, the sampling circuit 3 of the receiver 112 receives analog detection data D from the analog sensors 1a to 1n at regular intervals.
I, D2. . . . Dn is sequentially sampled in block a, and the sampling data is converted into digital data by the A/D converter 4 and provided to the correction calculation circuit 5.

On the other hand, each analog sensor 9 is installed in the ceiling height setting circuit 6.
- The installation height for every 18 to 1n is set in advance, and using the installation height of the analog sensor corresponding to each detection data, block b executes the correction calculation based on the above formula (5), The correction data calculated in block b is given to the fire judgment circuit 7, and the judgment block C calculates the degree of danger and the threshold value of the degree of danger obtained by predictive calculation based on the difference method or function approximation method. Fire is determined by comparing or comparing the correction data with a preset alarm level threshold, and when the degree of danger is below the danger threshold, it is determined that there is a fire and a fire alarm is issued in block d, Alternatively, when the corrected detection data exceeds a preset alarm level threshold, it is similarly determined that there is a fire, and a fire alarm is issued in block d.

FIG. 5 is a block diagram showing another embodiment of the present invention, and this embodiment is characterized in that the threshold value for determining fire is corrected according to the height of the ceiling surface.

In FIG. 5, an analog sensor 18-10° sampling circuit 3. A/D converter4. Ceiling height setting circuit 6. The fire judgment circuit 7 and the alarm display section 8 are the same as those in the embodiment shown in FIG. A threshold value correction circuit 9 is newly provided to perform calculations.

This correction calculation by the equivalency correction circuit 9 is performed based on the relationship between the relative output of the analog sensor () and the height of the ceiling surface shown in FIGS.
Since the relationship between "and the height of the top surface 1" is 1q, first of all, as for the threshold of the degree of danger, as shown in Figure 6, the relative output V
If the danger threshold value when = 1.0 is expressed as RO, the correction value R of the danger threshold value for the height H of the ceiling surface is as follows: R= RX 1 / y = Ro x 1 / α
It is given by e"'I-'° and -(6). Also, as shown in Fig. 7, the alarm level threshold -11- ” When the alarm level darkness value at 0 is set, the corrected alarm level threshold S is 5=Soxy=
3oxαe-p(H-”) −・−・(7) Therefore, the threshold value correction circuit 9 in FIG.
When fire judgment is made by calculating the degree of risk, the above-mentioned (
6) Correct calculation of the danger level threshold value based on the equation (7). On the other hand, when the fire judgment circuit 7 makes a fire judgment based on the comparison between the detection data and the alarm level threshold value, the correction calculation of the alarm level threshold value is performed according to the above-mentioned equation (7). Then, a fire judgment is made based on the threshold corrected in the threshold correction step M9.

That is, the operation of the embodiment shown in FIG. 5 will be explained according to the operation flow shown in FIG. Ceiling height H set for each analog sensor
-12- correction calculation of the danger threshold is performed from , and in block b, the corrected thresholds R1, R2, . . . Rn obtained for each analog sensor are set. Next, in block C, analog data is sampled and detected data D1, 02 . ...[)N is calculated using the difference method or function approximation method from multiple detection data obtained in the present and past in block d, and the risk level R is determined in block b. Compare the corrected risk threshold for each sentry with the calculated risk, and if the calculated risk is less than the corrected risk threshold, block f
Fire alarms will be issued.

Next, a correction coefficient approximately obtained from a smoke diffusion model will be described as another correction coefficient used in the correction calculation of the present invention.

FIG. 9 is an explanatory diagram of a smoke diffusion model that approximately shows the state of smoke diffusion from the fire point F, and shows the state in which smoke diffuses from the fire point F in a conical shape.

Here, in order to calculate the relative output y-, the reference height for installing the analog-13-sensor is Ho, and the analog sensor [
If the installation height of the 1g sensor is H, and the diffusion area at a height of 1-10° 1 is So, S, then the output point of the analog data is inversely proportional to the diffusion area.

Therefore, the relative output y' of the analog sensor 1 whose installation height is 1 with respect to the reference height [0] is given by y'-αSo /S (8). However, α is a coefficient for correcting variations in sensor output.

Therefore, the diffusion area So in the above equation (8).

In order to calculate S, the conical cross section of FIG. 9 is taken out, and it becomes as shown in FIG.
-1o)・tanθ0ro...(9)ro=l
-1o ・tanθ ---・(10) Howl. In addition, t
anθ is a coefficient determined by experimental values.

Substituting Equations (9) and (10) into Equation (8) above, we get y'-αSo /S=a-πro/2πr2-α(
No -tanθ) / ((1-1-l-1o)
tanθ+Ho−tanθ)2 (11) is obtained.

If C, the installation height of the analog sensor]-1 is known, the relative output y' with respect to the reference height 1-10 is determined, and the detection data or threshold value is corrected as in the previous embodiment. I can do it.

FIG. 11 is a graph showing the relationship between the Senry output and the height including other relative outputs used to execute the correction calculation of the present invention.

Figure 11 shows the experimental data of sensor output ,Also, even if the sensor is the same, it depends on the type of combustible material.
:As shown in the figure, the characteristics vary and the sensor Ill force has different values when the height l-1=Om. However, if the height coordinate axis is extended like an imaginary line and the curve is calculated mathematically, it can be seen that there is a relationship in which the sensor output J becomes infinite when shifted by a constant a.

Therefore, the characteristics of Fig. 11 can be expressed as a general formula by the answer x=A/ ((t1-1-1o) + a) ---
−(12>).

From this relational expression, the sensor output XO when the reference height is 1''0
is the blur xo = A/ (I-to +a> - (13), and the sensor output X when the height is 1'' is x = A/((
1-1-Ho)+a) ...(14) Howl.

Therefore, the relative output y is y-αX/XO = (HO+8)/((t1-)-1o)+a
...(15) -16- From this relative output relationship, it is possible to correct the detection data or the threshold value in the same manner as in the above-described embodiment.

In the embodiment shown in Fig. 1, the correction calculation of the detected data is performed on the receiver side, but a correction calculation circuit is provided for each of the analog sensors 1a to 1n, and the correction calculation is performed based on the height of the ceiling surface. Even if the corrected data is output to the receiver 2, it is not possible.

(Effects of the Invention) As explained above, according to the present invention, changes in the physical phenomenon of the circumferential concave environment caused by a fire are detected by an analog sensor,
In a fire alarm system that determines fire based on the detection data of an analog sensor, the detection data of the analog sensor or the threshold value for fire judgment is corrected depending on the height of the installation position of the analog sensor, so the analog sensor is installed. 1- Even if the height of the ceiling surface changes, the same fire judgment can be made as if the installation was always at a constant height.
7- Be able to make highly reliable fire judgments.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
Fig. 3 is a graph showing the relative change in the sensor output horn with respect to the height of the ceiling surface, Fig. 4 is an operation flow diagram of the embodiment of Fig. 1, and Fig. 5 shows another embodiment of the present invention. Block diagram, Figure 6.7 is a graph showing threshold correction calculation characteristics in the embodiment of Figure 5, Figure 8 is an operation flow diagram of the embodiment of Figure 5, Figure 9 is a graph showing other correction coefficients. Figure 10 is a cross-sectional view of the diffusion model used to calculate the diffusion area in Figure 9, and Figure 11 is used to calculate other correction coefficients. It is a graph diagram showing the relationship between sensor output and height. 1a to 1n: Analog sensor 2: Receiver 3: Sampling circuit 4: A/D converter-18- 5: Correction calculation circuit 6: Ceiling height setting circuit 7: Fire judgment circuit 8: Alarm display section 9: Threshold correction circuit Patent applicant Hochiki Co., Ltd. -F Hiromitsu Ishii Agent Patent attorney Susumu Takeuchi -19- Fig. 2 y 6 5 4 32.5 Ceiling height rn) Fig. 3 Ceiling surface /) Height m ) 9 @ Tobe) and leap straight F Hi OHO = 2.5 m A of the fire pillar fx, tH (m) procedure Neichi front entrance (spontaneous) 1. Display of the case 1982 Patent Application No. 14026 2, Name of the invention Fire alarm 4A position 3, Relationship to the case of the person who made the amendment Patent applicant address Tokyo Parts Yoku Kamiosaki 2-10-43 Name (
34,0) Bochiki Co., Ltd. 4, Agent address: 4th floor, Nishi-Shinbashi Chuo Building, 3-15-8 Nishi-Shimbashi, Minato-ku, Tokyo (1) "Inventors other than the above" section of the application form (2) In the specification [Detailed Description of the Invention] Column -1-7, Contents of the Amendment (1) Amend the furikana of ``Norio Muroi, the inventor listed in the ``Inventor other than the above'' column of the application in the attached correction application. do. (2) On page 8, lines 14 and 15 of the specification, [the shorter the time to reach the target, that is, the risk level, the more likely the fire] is corrected to ``the shorter the time to reach the target, the more likely the fire is to occur.'' (3) Specification letter page 11, line 17, 11 (H-H,) rR=RX1/y=Rox1/αe - (6) J, m-(s-Ha) rR=Ro x1/y =Ro x1/αe −= (
6) Correct with J. (4) Specification page 15, line 2 [[-α・πrO/2π
r' is corrected to [-α·πro/πr]. (5) Add the following sentence following "Can be done." on page 15, line 10 of the specification. ``Furthermore, the fiery point F, which is the apex of the cone, is an ideal point, and in reality it is not the fiery point F, but a predetermined area S', so the reference height 1
” 0 is below the floor. (6) Specification, page 16, No. 1
7th line r = (1-1o+a)/ ((H-1-1o) 10a
) J-2= is corrected as follows. -3-

Claims (1)

[Scope of Claims] A fire alarm system that detects changes in physical phenomena in the surrounding environment due to the occurrence of a fire using an analog sensor, and determines whether there is a fire based on the detection data of the analog sensor, comprising: A fire alarm device comprising an installation height setting means for setting a height, and a correction means for correcting the detection data of the analog sensor or the threshold value for fire judgment according to the setting value of the installation height setting means. .