CN112991666B - Fire smoke detector, smoke chamber thereof and anti-interference smoke detection method - Google Patents
Fire smoke detector, smoke chamber thereof and anti-interference smoke detection method Download PDFInfo
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- CN112991666B CN112991666B CN202110169789.3A CN202110169789A CN112991666B CN 112991666 B CN112991666 B CN 112991666B CN 202110169789 A CN202110169789 A CN 202110169789A CN 112991666 B CN112991666 B CN 112991666B
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B17/00—Fire alarms; Alarms responsive to explosion
- G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
- G08B17/103—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device
- G08B17/107—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device for detecting light-scattering due to smoke
Abstract
The invention provides a fire smoke detector, a smoke chamber and an anti-interference smoke detection method thereof, and relates to the technical field of smoke detectors. A smoke chamber of the fire smoke detector, wherein a first receiver, a first light source, a second light source and a second receiver are sequentially arranged on the circumference of the smoke chamber in a clockwise direction; a plurality of dispersing sheets are also arranged in the smoke chamber and are uniformly distributed on the circumference of the smoke chamber; the windows of the first light source and the second light source are respectively provided with a collimating sheet, and the collimating sheets are provided with a plurality of light holes. A fire smoke detector comprising a smoke chamber of the fire smoke detector. The anti-interference smoke detection method can effectively distinguish and identify the interference aerosol, can obviously reduce false alarm rate and reduce economic loss.
Description
Technical Field
The invention relates to the technical field of fire smoke detectors, in particular to a fire smoke detector, a smoke chamber thereof and an anti-interference smoke detection method.
Background
At present, a scattering type fire smoke detector is a device for detecting fire by utilizing scattering effect of fire smoke particles on light, but the existing fire smoke detector cannot accurately identify interference aerosol, so that false alarm rate is high and economic loss is large.
Disclosure of Invention
A first object of the present invention is to provide a smoke chamber for a fire smoke detector, which aims to solve the problem that the existing smoke chamber cannot accurately distinguish the interference aerosol.
A second object of the present invention is to provide a fire smoke detector, which aims to solve the problems that the existing smoke detectors cannot accurately identify the interference aerosol and have high false alarm rate.
The third purpose of the invention is to provide an anti-interference smoke detection method, which aims to solve the problems that the existing fire smoke detector cannot accurately identify interference aerosol and has high false alarm rate.
The invention is realized in the following way:
a smoke chamber of the fire smoke detector, wherein a first receiver, a first light source, a second light source and a second receiver are sequentially arranged on the circumference of the smoke chamber in a clockwise direction;
the radian between the first receiver and the first light source is 45 degrees;
the radian between the first light source and the second light source is 90 degrees;
the radian between the second light source and the second receiver is 45 degrees;
a plurality of dispersing sheets are also arranged in the smoke chamber and are uniformly distributed on the circumference of the smoke chamber;
the windows of the first light source and the second light source are respectively provided with a collimating sheet, and the collimating sheets are provided with a plurality of light holes.
Further, in a preferred embodiment of the present invention, the windows of the first receiver and the second receiver are each provided with a condensing lens.
Further, in a preferred embodiment of the present invention, a first light absorber and a second light absorber are further disposed on the circumference of the smoke chamber, the first light absorber being disposed opposite to the first light source, and the second light absorber being disposed opposite to the second light source.
Further, in a preferred embodiment of the present invention, the light passing hole is circular.
Further, in a preferred embodiment of the present invention, the light-passing hole is rectangular.
Further, in a preferred embodiment of the present invention, the dispersion sheet is of the ">" type.
A fire smoke detector comprising a smoke chamber of the fire smoke detector.
An anti-interference smoke detection method, which uses the fire smoke detector to detect, comprises the following steps:
s1, alternately emitting long-wavelength light beams and short-wavelength light beams by a first light source and a second light source; collecting and smoothing the scattered light signals received by the first receiver and the second receiver by using a scattered light signal microprocessor, outputting the scattered light signals of four detection light paths at 1s time intervals, and calculating to obtain the scattered light intensity ratio under two wavelength conditions and the relative standard deviation of the two scattered light intensity ratios;
s2, judging the relative standard deviation of the two scattering light intensity ratios, setting the preset value of the relative standard deviation to be 0.02-0.1, and returning to S1 when the relative standard deviation is larger than the preset value, and detecting the scattering light signals again; when the relative standard deviation is smaller than a preset value, entering the next step;
s3, distinguishing and identifying fire smoke and aerosol according to the ratio of the two scattered light intensities; when the aerosol is identified, the alarm threshold value is increased; when the fire smoke is identified, the alarm threshold value is reduced;
and S4, judging the intensity of the scattered light, comparing the intensity with an alarm threshold value, and giving out fire alarm when the intensity of the scattered light is higher than the alarm threshold value, otherwise, returning to S1, and continuing to detect the scattered light signal.
Further, in a preferred embodiment of the present invention, the preset value of the relative standard deviation is set to 0.05.
The fire smoke detector and the smoke chamber and the anti-interference smoke detection method thereof provided by the invention have the beneficial effects that: the method can effectively distinguish and identify the interference aerosol, can obviously reduce the false alarm rate and reduce the economic loss.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic illustration of a smoke chamber of a fire smoke detector provided in an embodiment of the invention;
FIG. 2 is a schematic view of a collimating sheet in a smoke chamber of a fire smoke detector according to an embodiment of the present invention;
fig. 3 is another schematic view of a collimating sheet in a smoke chamber of a fire smoke detector according to an embodiment of the present invention.
Icon: 111-a first light source; 112-a second light source; 121-a first receiver; 122-a second receiver; 130-dispersing flakes; 140-collimating sheets; 141-a light-passing hole; 150-a condenser lens; 161-a first light absorber; 162-a second light absorber.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.
In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Examples
As shown in fig. 1-3, the present embodiment provides a smoke chamber for a fire smoke detector.
The first receiver 121, the first light source 111, the second light source 112, and the second receiver 122 are sequentially provided on the circumference of the smoke chamber in a clockwise direction.
The arc between the first receiver 121 and the first light source 111 is 45 °; the radian between the first light source 111 and the second light source 112 is 90 °; the arc between the second light source 112 and the second receiver 122 is 45 °. That is, it can be understood that: the central axes of the first light source 111 and the second light source 112 are perpendicular to each other. The first receiver 121 and the second receiver 122 are disposed opposite to each other.
When the first light source 111 emits light, the first receiver 121 and the second receiver 122 may respectively receive two light signals emitted from the first light source 111, one being forward scattered light intensity (the scattering angle is 45 °), and the other being backward scattered light intensity (the scattering angle is 135 °). Similarly, when the second light source 112 emits light, the first receiver 121 and the second receiver 122 may also respectively receive two light signals emitted by the second light source 112.
A plurality of dispersing sheets 130 are also arranged in the smoke chamber, and the dispersing sheets 130 are uniformly distributed on the circumference of the smoke chamber. The windows of the first light source 111 and the second light source 112 are respectively provided with a collimating sheet 140, and the collimating sheet 140 is provided with a plurality of light holes 141.
When the light beams of the first light source 111 and the second light source 112 pass through the collimating sheet 140, the collimating sheet 140 disperses the light beams, and the dispersed light beams are a plurality of beamlets. The aerosol particles distributed therein will have a certain probability of being irradiated; for interfering aerosol particles, the size is larger, and the resulting scattered signal will fluctuate significantly in the dispersed light beam. The dispersion signal fluctuation is relatively small when aerosol particles are continuously irradiated with respect to the case of the light beam which is not dispersed by the collimator sheet 140. Meanwhile, for fire smoke particles, the size is smaller, and the generated scattering signal fluctuation in the scattered light beam is relatively smaller. Therefore, whether the aerosol interference exists or not can be judged according to the fluctuation of the scattered signal, namely, if the signal fluctuation is large, the aerosol interference exists, and the aerosol interference needs to be eliminated. Then distinguishing and identifying fire smoke and aerosol according to the scattering light intensity ratio; when the aerosol is identified, the alarm threshold is increased, and the possibility of alarm is reduced. When the fire smoke is identified, the alarm threshold is reduced, the sensitivity to the fire smoke is improved, and the response time is reduced.
In this embodiment, the first light source 111 and the second light source 112 may utilize the collimating plate 140 to make the scattering signal fluctuation of the "aerosol interference" more intense, and have a relatively smaller influence on the fire smoke, so as to facilitate distinguishing and identifying the "aerosol interference".
Further, the windows of the first receiver 121 and the second receiver 122 are each provided with a condenser lens 150. The first receiver 121 and the second receiver 122 can be made to collect more scattered light.
Preferably, a first light absorber 161 and a second light absorber 162 are further provided on the circumference of the smoke chamber, the first light absorber 161 being disposed opposite to the first light source 111, and the second light absorber 162 being disposed opposite to the second light source 112. At this time, stray light which may be generated by the first light source 111 and the second light source 112 can be eliminated by the first light absorber 161 and the second light absorber 162.
In the present embodiment, the dispersion sheet 130 is of a ">" type. As shown in fig. 2, in one implementation of the present embodiment, the light passing hole 141 is circular. As shown in fig. 3, in another implementation manner of this embodiment, the light-passing hole 141 is rectangular (including square). The light beam can be dispersed to a certain extent by using the circular or rectangular light passing holes 141, and the dispersing effect is better.
The embodiment also provides a fire smoke detector, comprising the smoke chamber of the fire smoke detector. The smoke detector also includes a processor and NB IOT communication module commonly used in the art. Wherein the data processing is done by the smoke detector's own processor. The NB IOT communication module is used for transmitting the working state of the smoke detector to related personnel in real time so as to know the situation or take proper countermeasures.
The embodiment also provides an anti-interference smoke detection method, which uses the fire smoke detector to detect, and comprises the following steps:
s1, the first light source 111 and the second light source 112 alternately emit long wavelength light beams and short wavelength light beams; and then the scattered light signals received by the first receiver 121 and the second receiver 122 are collected by the scattered light signal microprocessor and subjected to signal smoothing, the scattered light signals of the four detection light paths are output at 1s time intervals, and the scattered light intensity ratio under two wavelength conditions and the relative standard deviation of the two scattered light intensity ratios are calculated.
( Specifically, for example, when the first light source 111 emits light, the first receiver 121 receives an optical signal A1 emitted by the first light source 111; the second receiver 122 receives the optical signal B1 emitted by the first light source 111. When the second light source 112 emits light, the first receiver 121 receives the light signal A2 emitted by the second light source 112; the second receiver 122 receives the optical signal B2 emitted by the second light source 112. The scattered light intensity ratio is A1/A2 and B1/B2, respectively. )
S2, judging the relative standard deviation of the two scattering light intensity ratios, and setting the preset value of the relative standard deviation to be 0.02-0.1. According to the experimental detection of the inventor, when the fire smoke reaches a certain concentration, the scattered light intensity signal of the fire smoke is relatively stable, the relative standard deviation of the scattered light intensity ratio can be rapidly stabilized at a level within a preset value, and the preset value is within a range of 0.02-0.1. Further, the preset value of the relative standard deviation is set to 0.05.
When the relative standard deviation is larger than the preset value, returning to the step S1, wherein the fact that no aerosol exists in the current detection area or the fluctuation of an aerosol scattering signal is larger is indicated, if a certain scattering signal value exists, the fact that interference of a certain concentration of interference aerosol exists is generally indicated, the situation needs to be eliminated, and therefore the step S is returned to, and the scattered light signal detection is carried out again.
When the relative standard deviation is smaller than a preset value, entering the next step; indicating that a relatively stable aerosol is present in the current detection zone, it is necessary to identify whether it is smoke or an interfering aerosol in order to provide an alarm indication.
S3, distinguishing and identifying fire smoke and aerosol according to the ratio of the two scattered light intensities; when the aerosol is identified, the alarm threshold is increased, and the possibility of alarm is reduced. When the fire smoke is identified, the alarm threshold is reduced, the sensitivity to the fire smoke is improved, and the response time is reduced. It should be noted that, in this step, the corresponding relationship is established between the specific sizes of the scattering light intensity ratios A1/A2 and B1/B2 and the fire smoke and the interference aerosol to realize the differentiation. In particular, the ratio of the scattered light intensities of typical fire smoke and common interfering aerosols is known and can be obtained by standard tests.
And S4, judging the intensity of the scattered light, comparing the intensity with an alarm threshold value, and giving out fire alarm when the intensity of the scattered light is higher than the alarm threshold value, otherwise, returning to S1, and continuing to detect the scattered light signal.
By adopting the anti-interference smoke detection method, the interference aerosol can be effectively distinguished and identified, the false alarm rate can be obviously reduced, and the economic loss is reduced.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. An anti-interference smoke detection method utilizes a fire smoke detector to detect, and a first receiver, a first light source, a second light source and a second receiver are sequentially arranged on the circumference of a smoke chamber in a clockwise direction;
the radian between the first receiver and the first light source is 45 degrees;
the radian between the first light source and the second light source is 90 degrees;
the radian between the second light source and the second receiver is 45 degrees;
a plurality of dispersing sheets are also arranged in the smoke chamber, and the dispersing sheets are uniformly distributed on the circumference of the smoke chamber;
the window of first light source with the window of second light source all is equipped with the collimating sheet, be equipped with a plurality of light holes on the collimating sheet, its characterized in that includes:
s1, the first light source and the second light source alternately emit long-wavelength light beams and short-wavelength light beams; collecting the scattered light signals received by the first receiver and the second receiver by using a scattered light signal microprocessor, performing signal smoothing, outputting the scattered light signals of four detection light paths at 1s time intervals, and calculating to obtain the scattered light intensity ratio under two wavelength conditions and the relative standard deviation of the two scattered light intensity ratios;
s2, judging the relative standard deviation of the two scattering light intensity ratios, setting the preset value of the relative standard deviation to be 0.02-0.1, and returning to S1 when the relative standard deviation is larger than the preset value, and detecting the scattering light signals again; when the relative standard deviation is smaller than the preset value, entering the next step;
s3, distinguishing and identifying fire smoke and aerosol according to the ratio of the two scattered light intensities; when the aerosol is identified, the alarm threshold value is increased; when the fire smoke is identified, the alarm threshold value is reduced;
and S4, judging the intensity of the scattered light, comparing the intensity with an alarm threshold value, and giving out fire alarm when the intensity of the scattered light is higher than the alarm threshold value, otherwise, returning to S1, and continuing to detect the scattered light signal.
2. The tamper resistant smoke detection method according to claim 1, wherein said preset value of the relative standard deviation is set to 0.05.
3. The method of claim 1, wherein the windows of the first receiver and the second receiver are each provided with a condenser lens.
4. The method of claim 1 or 2, wherein a first light absorber and a second light absorber are further provided on the circumference of the smoke chamber, the first light absorber being disposed opposite to the first light source, and the second light absorber being disposed opposite to the second light source.
5. The method of claim 1, wherein the light passing holes are circular.
6. The method of claim 1, wherein the light-passing aperture is rectangular.
7. The method of claim 6, wherein the dispersion flakes are of the ">" type.
8. A fire smoke detector comprising a smoke chamber of a fire smoke detector for fire smoke detection using an anti-tamper smoke detection method according to any one of claims 1 to 7.
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